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Influence of injection parameters and mold materials on mechanical properties of ABS in plastic injection molding
Abstract
This study optimized effect of injection parameters such as melt temperature, packing pressure, cooling time and injection pressure on the mechanical properties of Acrylonitrile–Butadiene–Styrene (ABS) moldings. Mold materials having two different thermal conductivities, 191W/mK for aluminum 2000 series and 50W/mK for AISI 1020 at 25°C were selected to use in experimental studies. Taguchi's L9(34) orthogonal array design was employed for the experimental plan. Mechanical properties of ABS specimens such as elasticity module, tensile strength and tensile strain at yield, tensile strain at break, flexural modules and izod impact strength (notched) were measured by using some test methods. Signal to noise ratio for mechanical properties of ABS using the Taguchi method was calculated and effect of the parameters on mechanical properties was determined using the analysis of variance. Linear mechanical models were also created by using regression analysis.
... Embrittlement, increase in E and decrease in εB are typically observed for ABS/aluminium composites [41,57]. In spite of the changes in injection moulding parameters due to the composites' increased viscosity, the injection pressure has minimal to low influence on the mechanical properties of injection-moulded ABS [67]. The most important parameter for E, σmax and εB was identified as melt temperature, with impact levels weighting between 43 and 87%, whilst injection pressure made up between 2 to 22% for the same properties [67]. ...
... In spite of the changes in injection moulding parameters due to the composites' increased viscosity, the injection pressure has minimal to low influence on the mechanical properties of injection-moulded ABS [67]. The most important parameter for E, σmax and εB was identified as melt temperature, with impact levels weighting between 43 and 87%, whilst injection pressure made up between 2 to 22% for the same properties [67]. Characteristics such as σ max first decreased for a 30 wt% filler content and then, with a 60 wt% metal powder, increased to ca. 90% of that of neat ABS (Figure 5), while a significant increase of σ B was observed for ABS-60%Al and ABS-60%Cu. ...
... Embrittlement, increase in E and decrease in ε B are typically observed for ABS/aluminium composites [41,57]. In spite of the changes in injection moulding parameters due to the composites' increased viscosity, the injection pressure has minimal to low influence on the mechanical properties of injection-moulded ABS [67]. The most important parameter for E, σ max and ε B was identified as melt temperature, with impact levels weighting between 43 and 87%, whilst injection pressure made up between 2 to 22% for the same properties [67]. ...
Metal-reinforced polymer composites are suitable materials for applications requiring special thermal, electrical or magnetic properties. Three-dimensional printing technologies enable these materials to be quickly shaped in any design directly and without the need for expensive moulds. However, processing data correlating specific information on how the metal particles influence the rheological behaviour of such composites is lacking, which has a direct effect on the processability of these composites through melt processing additive manufacturing. This study reports the compounding and characterisation of ABS composites filled with aluminium and copper particulates. Experimental results demonstrated that the tensile modulus increased with the incorporation of metal particles; however, there was also an intense embrittling effect. Mechanical testing and rheological analysis indicated poor affinity between the fillers and matrix, and the volume fraction proved to be a crucial factor for complex viscosity, storage modulus and thermal conductivity. However, a promising set of properties was achieved, paving the way for polymer–metal composites with optimised processability, microstructure and properties in melt processing additive manufacturing.
... Its use is not only for prototyping, but it can be used to produce finished products with full functionality. Unfortunately, during extrusion and cooling ABS has a shrinkage of 0.4-0.7%, which causes problems in the printing process [14][15][16]. Depending on the manufacturer and admixtures, ABS is printed with a nozzle at temperatures from 220 °C to 260 °C [14][15][16][17]. The material is available in different colors and with different modifiers. ...
... Unfortunately, during extrusion and cooling ABS has a shrinkage of 0.4-0.7%, which causes problems in the printing process [14][15][16]. Depending on the manufacturer and admixtures, ABS is printed with a nozzle at temperatures from 220 °C to 260 °C [14][15][16][17]. The material is available in different colors and with different modifiers. ...
... The surface treatment of the material can be carried out in acetone vapor because this solvent reacts with ABS by vulcanizing it surface. Abrasive treatment is also facilitated by a higher softening temperature [14,16,17]. ...
... For injection molding, the following need to be considered: mold base, injection method, appropriate pressure, cooling system, and the design of the final product. (3) The quality of molded products depends on several factors such as the flow rate of the injection of melted plastic, (4) the geometric calculation of injection molded parts, (5) and the mechanical properties of the material used such as shrinkage value, (6,7) the viscosity of the melted material, (8) and the removal of gas during injection molding. (9) Although these are considered important factors for injection molding, the quality is determined mainly by the appropriate design of the runner and lifter of the injection molding system. ...
... As ABS shrinks by 0.5%, the cavity size needs to be larger than the actual size of physical product because plastic has the characteristic to shrink after the injection time. (7) This mean that the cavity needs to be upsized 0.5% to produce the precise desired dimensions of the actual product. The cover of the motorcycle mirror has an insert cavity, an insert core, and a lifter. ...
... Steel mold material had four times the thermal conductivity of aluminum mold material in one study. When molding materials with different thermal conductivities were used, mechanical properties varied by 10-20% [108]. ...
... A summary of the material properties commonly used as mold base materials is listed in Table 2. It can be seen that steel and aluminum are frequently used as mold base materials as they have high thermal conductivity and hardness, meeting the requirements of mold base materials in most studies [108,113,114]. ...
Rapid tooling (RT) and additive manufacturing (AM) are currently being used in several parts of industry, particularly in the development of new products. The demand for timely deliveries of low-cost products in a variety of geometrical patterns is continuing to increase year by year. Increased demand for low-cost materials and tooling, including RT, is driving the demand for plastic and rubber products, along with engineering and product manufacturers. The development of AM and RT technologies has led to significant improvements in the technologies, especially in testing performance for newly developed products prior to the fabrication of hard tooling and low-volume production. On the other hand, the rapid heating cycle molding (RHCM) injection method can be implemented to overcome product surface defects generated by conventional injection molding (CIM), since the surface gloss of the parts is significantly improved, and surface marks such as flow marks and weld marks are eliminated. The most important RHCM technique is rapid heating and cooling of the cavity surface, which somewhat improves part quality while also maximizing production efficiencies. RT is not just about making molds quickly; it also improves molding productivity. Therefore, as RT can also be used to produce products with low-volume production, there is a good potential to explore RHCM in RT. This paper reviews the implementation of RHCM in the molding industry, which has been well established and undergone improvement on the basis of different heating technologies. Lastly, this review also introduces future research opportunities regarding the potential of RT in the RHCM technique.
... Regression analysis is a useful method to investigate the relationships between variables [22][23][24] and it was introduced to quantify the influence of gas parameters on burn marks in this study. A model was established by stepwise regression analysis in Minitab to describe the relationship between the gas parameters and burn marks. ...
... Additionally, the values of R 2 and R 2 adjust are 97.34% and 96.55%, respectively, which are close to 1. The goodness of fit for this model is much higher than the goodness of fit reported in the literature with regression analyses [16,[24][25][26]. Thus, the model accurately describes the relationship between the gas parameters and burn marks, and it is acceptable to discuss in more detail based on the result of regression analysis, as shown in Figure 8. Figure 8 shows that the gas delay time is the most important parameter of the gas parameters influencing the burn marks, followed by the gas pressure, and the gas packing time is the least important gas parameter influencing the burn marks. ...
A burn mark is a sort of serious surface defect on injection-molded parts. In some cases, it can be difficult to reduce the burn marks by traditional methods. In this study, external gas-assisted injection molding (EGAIM) was introduced to reduce the burn marks, as EGAIM has been reported to reduce the holding pressure. The parts with different severities of burn marks were produced by EGAIM and conventional injection molding (CIM) with the same molding parameters but different gas parameters. The burn marks were quantified by an image processing method and the quantitative method was introduced to discuss the influence of the gas parameters on burn marks. The results show that the burn marks can be eliminated by EGAIM without changing the structure of the part or the mold, and the severity of the burn marks changed from 4.98% with CIM to 0% with EGAIM. Additionally, the gas delay time is the most important gas parameter affecting the burn marks.
... Other relevant literature also focuses mainly on the influence of different mold materials, cooling channel design or process settings on mechanical part properties [5] or cycle time and warpage [6][7][8][9][10], without investigating if the influence of the mold material varies with different polymers. ...
... This study also showed the difficulties in the experimental determination of the molded part temperature. Other relevant literature also focuses mainly on the influence of different mold materials, cooling channel design or process settings on mechanical part properties [5] or cycle time and warpage [6][7][8][9][10], without investigating if the influence of the mold material varies with different polymers. ...
The thermal properties of the mold influence the cooling situation in the injection molding process. While there are experimental studies investigating the influence of special mold materials, they are limited to few polymers. In this work, an extensive parameter study with the simulation software Autodesk Moldflow Insight was performed to analyze the influence of the polymer itself on the impact of the mold steel on cycle time and warpage. The investigated part was a box with two thickness variations. A conventional mold steel was compared with a steel grade featuring approximately double the thermal conductivity. Simulations were performed with 18 polymers covering the most common material families. The main finding of this study was that the influence of the higher mold conductivity on cycle time ranged from an almost negligible reduction (3%) up to a strong effect (24%), depending mainly on the used polymers, but also on the part thickness. For the cycle time reduction, a correlation was found, with the melt, mold and ejection temperature being the dominant influencing factors of the polymers. With this correlation, it was possible to estimate the potential of cycle time reduction for other polymers. The simulations also showed a positive influence of the higher mold thermal conductivity on part warpage.
... In either case, these alternative materials have different mechanical strengths and thermal conductivities than conventional steel molds. Mold material strength influences its durability, while its thermal conductivity leads to different cooling rates and, consequently, affects the mechanical properties of the moldings [3][4][5]. This is more evident when using polymeric inserts. ...
... For metallic materials, some effects on molding properties can also be observed. Ozcelik et al. [3] used regression analysis as a statistical tool to investigate the relationship between the injection molding variables and mechanical properties of acrylonitrile-butadiene-styrene (ABS) injected in aluminum and AISI 1020 mold materials. The injection parameters studied were melt temperature, packing pressure, cooling time and injection pressure. ...
Prototype tooling is an option to obtain functional prototypes, or even final parts, in low-scale injection molding. In order to reduce the manufacturing time and cost of this type of tooling, alternative materials, such as zinc alloys, can be employed. However, the mold material and injection parameters can influence molding crystallinity and mechanical properties. The zinc alloy known as zamak-8 has not been explored much for this application. The objective of this work is to study the influence of this mold material on the properties of polypropylene (PP) when varying the mold (Tm) and injection (Ti) temperatures. Then, based on that, to develop some regression models to help obtain PP moldings in the zamak-8 mold with similar characteristics to those injected in a steel mold, which was used as a reference, the characterization techniques used were tensile and impact tests, and differential scanning calorimetry as well, to measure crystallinity. The results showed that zamak-8 prototype tooling only has a significant influence on the impact strength of the injected PP. The regression models showed that to obtain injected prototypes with mechanical and crystalline properties close to a production part in this specific study, Tm should be set at around 40 °C and Ti at 225 °C. In general, this indicates that zamak-8 can be used to obtain functional prototypes in PP with similar properties to the production parts.
... In [9], the acoustophoresis of microparticles in a polymer chip microchannel is detailed, highlighting the importance of resonance modes. The influence of the injection parameters on the mechanical properties of ABS moldings was investigated in [15], utilizing Taguchi's L9 (34) orthogonal array design. Moreover, the challenges of recycling non-biodegradable materials and the impact of the processing parameters on the mechanical properties of recycled plastic parts were explored in [16]. ...
Understanding the relationship between injection molding parameters and the acoustic properties of polymers is crucial for optimizing the design and performance of acoustic-based polymer devices. In this work, the impact of injection molding parameters, such as the injection velocity and packing pressure, on the acoustic parameters of polymers, namely the elastic moduli, is studied. The measurements lead to calculating material parameters, such as the Young's modulus and Poisson's ratio, that can be swiftly measured and determined thanks to this method. Polymethyl methacrylate (PMMA) was used as the molding material, and using PMMA LG IG 840, the parts were simulated and injection molded, applying a 'design of experiment' (DOE) statistical method. The results indicated a correlation between the injection molding process parameters and the acoustic characteristics, such as the elastic moduli, and a specifically decreasing trend with increase in the injection velocity. Notably, a relative decrease in the Young's modulus by 1% was observed when increasing the packing pressure from 90 MPa to 120 MPa. Similarly, a decrease in the Poisson's ratio of 2.9% was observed when the injection velocity was increased from 16 mm/s to 40 mm/s. This method can be used to fine-tune the material properties according to the needs of a given application and to facilitate the characterization of different polymer acoustic properties essential for acoustic-based polymer devices.
... When applying porous material to the production of components used in technical practice, these, like full-volume material, must meet the pre-required criteria. The resulting mechanical properties and uses of porous structures depend on many factors, with not only the material from which they are made playing an important role but also the topology of included cells and the relative volume ratio of the material in a given structure [8][9][10]. ...
This article aims to compare the behaviour of four types of lattice structures named Cartesian, Rhomboid, Octagonal, and Starlit under tensile stress loading. The structures were made of Acrylonitrile Butadiene Styrene (ABS) material using the Fused Filament Fabrication (FFF) technique with three different specific volumes (24, 42, and 60%). Five samples of each type were produced, and a total of 60 samples were tested. Experimental testing was performed according to EN ISO 527-1:2012 and EN ISO 527-2:2012. The obtained data were statistically processed, while no outliers were identified. The experimental results pointed out that the specimens’ topology, together with the specific volume, very significantly affected the resultant ABS properties of the tested samples made of the same material. The comparative study showed that in terms of ultimate strength, yield strength, and Young’s modulus, the Cartesian structure appeared to be the most suitable for tensile stress, and the least suitable structure was the Rhomboid structure. On the other hand, the Rhomboid-type of the structure showed not only the highest amount of absorbed energy but also the highest toughness among the investigated lattice structures, so in the near future, its behaviour under an impact test should be studied.
... Linear models of the mechanical properties of ABS were determined using the Taguchi method, and through analysis of variance, the effect of varying process parameters was determined. Relationships between injection parameters and mechanical properties of ABS moldings, e.g., elastic modulus, tensile strength, bending modulus, and impact strength, were determined [68]. Next, the re-injection processing capability of two types of ABS with low u high viscosity was evaluated. ...
Injection molding is a method commonly used to manufacture plastic products. This technology makes it possible to obtain products of specially designed shape and size. In addition, the developed mold allows for repeated and repeatable production of selected plastic parts. Over the years, this technology grew in importance, and nowadays, products produced by injection molding are used in almost every field of industry. This paper is a review and provides information on recent research reports in the field of modern injection molding techniques. Selected plastics most commonly processed by this technique are discussed. Next, the chosen types of this technique are presented, along with a discussion of the parameters that affect performance and process flow. Depending on the proposed method, the influence of various factors on the quality and yield of the obtained products was analyzed. Nowadays, the link between these two properties is extremely important. The work presented in the article refers to research aimed at modifying injection molding methods enabling high product quality with high productivity at the same time. An important role is also played by lowering production costs and reducing the negative impact on the environment. The review discusses modern injection molding technologies, the development of which is constantly progressing. Finally, the impact of the technology on the ecological environment is discussed and the perspectives of the process were presented.
... Pada pengujian pengaruh tekanan terhadap fill time dan cacat, melt temperature, dan mold temperature. Berdasarkan hasil pengujian sebelumnya [16], serta eksperimen data variasi data tekanan dapat terlihat pada Tabel 3. Pada penelitian di atas di dapatkan hasil cetakan yang hampir memenuhi mold, namun sebelum memenuhi mold biji plastik yang sudah masuk ke mold sudah mengering terlebih dahulu, sehingga hanya bisa mendapatkan hasil seperti di gambar nomor 1 pada Tabel 5. ...
Currently, the use of plastic products is increasing in various fields, due to their flexibility and low production costs. The injection molding process is a technique that is often used in the formation of plastic products. The focus of the problem of this study is the effect of heating temperature and hydraulic pressure on the results of box and gear molds using the injection molding process. The test method uses variations in temperature and hydraulic pressure to produce the maximum mold shape in the box and gear. From the results of the injection molding test for full yield gear products with a melt temperature of 368ºC, a mold temperature of 40ºC, and an injection pressure of 490 Psi, there was a failure in the test results due to the release of liquid which did not come out directly to fill the mold, because the pressure from the hydraulic jack must gradually.
... The materials employed in the FFF approach are separated between regularly utilized materials, such as polymers and composites (including nanocomposites), and "sustainable materials," a term coined by the authors and comprised of natural and recycled substances [10,11]. ABS is a 3D printing material for FFF (also known as FDM) technology. ...
A significant historical enabler for the improvement of industrial goods has been the characterization of novel materials. For example, a large variety of polymeric materials are readily accessible to manufacture the appropriate items depending on the production method. Due to its capacity to produce components with complicated geometries without the need for tools or a human interface, fused filament fabrication (FFF) is acquiring a unique edge in the industrial sector. By adjusting process parameters at the right values, the qualities of FFF-built items may be enhanced since they rely heavily on these factors. Increasing the service life of functioning components requires taking wear resistance into account. Because of this, the current work concentrates on a thorough investigation to comprehend the impact of 3 crucial elements, including layer thickness, printing speed, also infill density, infill density, and the sliding wear of test specimens. A mechanism of wear is explained by utilizing microphotographs.
... As injection molding is one of widely spread method for ABS applications, influence of processing conditions on properties of material has been thoroughly investigated. According to the literature, melt temperature and injection pressure are the two critical factors affecting mechanical properties significantly (Ozcelik et al., 2010). ...
Fibre reinforced composites are widely used in industry due to its light weight, corrosion resistance and high strength properties. However, large usage of composites is associated with the high amount of waste generation. European directives restrict disposal of composites to landfill. The aim of this study was to explore the use of recycled fibres in novel products. Experimental work was conducted to incorporate recycled thermoset based carbon fibres into Acrylonitrile Butadiene Styrene (ABS) to achieve functional properties in ABS filament to be used in 3D printing electronic.
Recycled carbon fibre reinforced ABS was manufactured through extrusion. Taguchi design of experiments was employed to understand effect of extrusion temperature, fibre length and concentration on mechanical and electrical properties of reinforced ABS.
This study revealed that extrusion temperature and fibre length have profound effect on formation of defects in carbon fibre reinforced ABS filaments. In the case of using lower extrusion temperatures voids were formed in the center of filaments. Longer fibres distributed more uniformly and assisted in tensile strength. However, fibres volume fraction and linking could not create conductive path to make ABS conductive, as it was below critical length. In the case of usage higher carbon concentration in reinforcement it was difficult to extrude filaments. In addition, smaller carbon fibres are supposed to be difficult to align and inclined to act as stress raiser. Thus, the recommendation is to use longer fibres with higher extrusion temperatures. This should promote better strength and could enable electrical conductivity and hence open up new applications of conductive 3D printed products.
... Standard error of estimate S measures the difference between the estimated value estimated using the regression equation and the observed value of the standard deviation. The goodness of fit for this model is much higher than the goodness of fit reported in the literature with regression analyses [36,40,41]. Thus, the model accurately describes the relationship between the parameters and replication uniformity, and it is acceptable to discuss it in more detail based on the result of regression analysis. ...
Parts with microstructure arrays have been widely used in biotechnologies and optical technologies, and their performances are affected by replication uniformity. The uniformity of the microstructure is still a challenge in micro-injection molded parts and is greatly affected by the cavity thickness and process parameters. In this study, the replication uniformity of microstructures is experimentally investigated. The relationship between the replication uniformity and cavity thickness was explored through single-factor experiments. Additionally, the impacts of the process parameters on the replication uniformity were also studied through uniform design experiments. A regression equation was established to describe the quantitative relationship between the important parameters and replication uniformity. The results showed that the replication uniformity of microstructures increases by 39.82% between the cavity with the thickness of 0.5 mm and a cavity of 0.7 mm. In addition, holding time is the most significant factor influencing the replication uniformity, followed by mold temperature, melt temperature, and injection speed. It is concluded that the thickness of cavity and the process parameters have significant influence on the replication uniformity. The experimental results provide important data on how to improve the replication uniformity of parts with microstructure arrays.
... Study by Ozcelik et al on the variation of the manufacturing parameters of injection molded samples resulted in an average tensile modulus of 2402 MPa. 25 Results, obtained in the present work, show an average tensile modulus of 2442 MPa, which coincides within the range of process-engineering deviations. ...
Additive manufacturing processes have recently been used more frequently since they offer high design
freedom and easy individualization of components. The processes have been optimized to improve mechanical
performance of the manufactured parts. Nevertheless, properties of components made by means of injection
molding could not be reached yet. In the study at hand, ultrasonic phase spectroscopy (UPS) is used to compare
the elastic properties of acrylonitrile butadiene styrene specimens manufactured by injection molding, by fused
filament fabrication, and the Arburg plastic freeforming process. UPS allows a nondestructive and prompt
determination of the elastic modulus and allows evaluation of the mechanical properties in every direction in
space. In the end, results of UPS are compared with properties derived by uniaxial tensile tests to validate UPS
as a test method for the determination of the mechanical properties of polymers. Regardless of the
manufacturing process, an approximately linear dependence of the elastic moduli on the density can be determined.
Furthermore, the quasistatic properties of the injection molded samples consistently exhibit the
mechanical properties of the other samples by at least 10%.
... Using Taguchi's technique, Erzurumlu et al. [6] employ melting temperature, mould temperature, packing pressure, rib cross section, and rib layout angle to find the optimal process combination for sink marks and warpage. Babur Ozcelik et al. use Taguchi's ap-proach for investigation the influence of input parameters on weld lines specimens [7]. With the use of simulation software, Kovács et al. discover how control parameters warpage of plastic products. ...
In the rapidly growing field of technology, there is a demand for consumer goods made of plastic. To meet needs of customer, plastic products are made in different ways. There are different plastic manufacturing process. Numerous plastic manufacturing process are thereInjection molding is involves injecting molten material into a mold and allowing it to take on the shape of the mold.There are wide ranges of products such as plastic chairs, Computer cabinet etc. are manufactured with the help of smaller and more complex profiles. Due to lack of dimensional accuracy these complex profile produces defects inside the mold. Current study provides insights into transparent thermoplastic Polypropylene products. Five plastic injection molding variable criteria are considered for reducing the depth of sink mark in injection molding for commercial grade transparent thermoplastic (Polypropylene). Melting temperature (8C), mold temperature (8C), packing time (seconds), ratio of ribs to walls (%) and rib to gate distance (mm). According to Taguchi's design L27 experiments are performed and factors are optimized using the Taguchi based utility concept for multi criteria problems. The sink mark's depth on the part's surfaceis considered as quality of product and cycle time is considered as the productivity of product. It is the one of the best techniques, which can maintain the equilibrium between two.
... Thus, all the manufacturing steps, including plastic injection molding, primer coating, laser engraving, and coating, have to be analyzed. A lot of research papers are focused on the analysis and optimization of the injection molding parameters and how these affect the properties of the injected parts [8][9][10], but a failure modes and effects analysis was not included. Thus, in [9,11] the injection parameters that can affect the characteristics of surface quality and strength, such as the injection speed, mold temperature, melt temperature, injection and holding pressures, and cooling setup and time, were analyzed. ...
Plastic parts used in automotive interior are difficult to coat, due to their low surface energies as well as their sensitivity to temperature and solvents, rendering the development of coating systems for such substrates challenging. Automotive customer requirements are explicit and clear, mainly focused on functional and surface defects. A new failure modes detection methodology of UV clear coated polymers for automotive interior, obtained by a multi-step manufacturing process, is proposed. The polymer complex parts analyzed in this paper are manufactured in various steps as follows: two components plastic injection molding, primer coating, laser engraving, and UV-cured clear coating. The failure modes detection methodology of the parts within each process step is investigated using different tests and analyses as follows: surface tension test, painting adhesion test, optical 3D measuring, energy dispersive X-ray analysis (EDX), and microscopy. A design of the experiments (DoE) based on the Taguchi technique with the aim to detect the influence of the main factors that lead to surface defects was performed. The proposed methodology is validated by a case study. The results showed that the mold temperature and the laser engraving current have a significant influence on the surface defect occurrence. Additionally, a possible contamination of the molding tool can generate the defects. A solution to reduce the occurrence of the failures was proposed, reducing the defect rate from 50% to 0.9%.
... To understand the influence of the fabrication process parameters on the mechanical properties of composites and optimize them, Athijayamani at al. used ANOVA and developed a regression equation for predicting the tensile and flexural strength of nanohybrid wood polymer composites [19]. Other authors also used statistical tools for their investigations [20][21][22][23]. ...
Polymer nanocomposites consist of a polymer matrix and reinforcing particles that have at least one dimension under 100 nm. The processing of nanocomposite polymers is the most important stage, determining the final properties of nanocomposites. Nanocomposites are now preferentially prepared by melt-mixing using conventional compounding processes such as twin-screw extrusion. Many processing parameters (polymer matrix type, content and type of nanofiller, barrel temperature, screw speed, number and shape of extruder screws, etc.) affect the properties of nanocomposites. This research work represents an investigation of the influence of processing parameters (amount of nanoclay filler, the screw rotation speed, and extruder barrel temperature) on the flexural properties of polyamide 12/nanoclay-reinforced nanocomposite. From the test results, it is apparent that an increase in nanoclay content from 1 to 8% significantly increases flexural strength. The obtained nanocomposite has a 19% higher flexural strength and a 56% higher flexural modulus than pure PA12. Mathematical models that show the dependence of flexural strength and flexural modulus on the processing parameters used were obtained as a result of this analysis.
... For impact strength test the specimens were made with the following dimensions (80x10x4) mm length, width, and thickness respectively according to (ISO 180:2019), ASTM D256 -10(2018) [25][26][27][28][29] . For surface hardness test the specimens were made with the following dimensions (65x10x2.5) ...
ABSTRACT
Background: The daily and repeated immersion of dentures in disinfectant solutions can cause changes in the properties of PMMA, but there is lack of studies evaluating the effects of hydrogen peroxide disinfectant solution on CAD/CAM based Polymethylmethacrylate (PMMA).
Aim: To investigate the effect of hydrogen peroxide solution immersion on various properties (transverse strength, impact strength and surface hardness) of CAD/CAM based polymethylmethacrylate (PMMA).
Methods: 90 samples were prepared in this study. Samples were divided into 3 groups according to the type of the test used (transverse strength, impact strength, hardness), For each test 30 samples were further subdivided into ten samples for each of the three groups according to the type of treatment, 1st group control, 2nd group immersed in 3% hydrogen peroxide solution for 10 minutes, 3rd group immersed in 3% hydrogen peroxide solution for 30 minutes. Specimens in each group were subjected to the three-point bending test for transverse strength test, impact strength test and Surface hardness using shore D hardness tester. Scanning electron microscope (SEM). Statistical analysis was performed using two-way ANOVA and the data was considered statistically significant at a level of< 0.05.
Results: Statistical analysis of transverse strength test using two-way ANOVA showed non-significant increases in the mean value of the transverse strength for both immersion times, while a non-significant decrease of impact strength was found for both immersion times. Statistical analysis of Surface hardness test showed a non-significant decrease in the Mean value of the Surface hardness for 30 minutes immersion time and a non-significant increase for the 10 minutes immersion time. Conclusions: CAD/CAM based polymethylmethacrylate (PMMA) Immersion in 3% hydrogen peroxide solution showed no significant effect and changes in the mechanical properties of the material specifically transverse strength, impact strength and surface hardness.
Keywords: CAD/CAM, disinfection, impact strength, transverse strength.
... It was observed that holding pressure and melt temperature were mainly the influential parameters on different type of defects including warpage and sink marks. Ozcelik et al. (2010) optimised different processing factors and found that mould and melt temperature are the significant factors as they are responsible for flow of plastic in the screw-barrel and the main nozzle of the machine. Similarly, Wang et al. (2014) studied that the epoxy melt temperature, mould temperature, packing time and cooling time are significant factors influencing the quality of the valve body. ...
Plastic injection moulding (PIM) represents one of the most important processes in the mass production of precise plastic parts with intricate geometries. Polypropylene (PP) is the widely used material related to plastic parts for automobile and packaging industry. It was observed that thermal shrinkage and warpage in plastic parts are the most prominent defects and affects the quality of plastic parts. In this paper, a methodology has been presented for reducing the thermal shrinkage and warpage along with the maximising the impact strength (IS) of virgin polypropylene (PP). To obtain the optimum values of injection moulding parameters, Taguchi orthogonal array (OA) was used. Overall, six parameters were chosen for the experiment. The linear graph was utilised to know the effectiveness and interactions of the parameters. Thus, with Taguchi method minimum thermal shrinkage of 4.67%, minimum warpage of 1.8 mm and maximum impact strength of 56.7 J/m were obtained in PP specimens. With this methodology, prediction equations and mathematical models for thermal shrinkage, warpage and IS of PP were developed which are useful for industrial applications. With multi objective genetic algorithm, these mathematical models were optimised.
... It was observed that holding pressure and melt temperature were mainly the influential parameters on different type of defects including warpage and sink marks. Ozcelik et al. (2010) optimised different processing factors and found that mould and melt temperature are the significant factors as they are responsible for flow of plastic in the screw-barrel and the main nozzle of the machine. Similarly, Wang et al. (2014) studied that the epoxy melt temperature, mould temperature, packing time and cooling time are significant factors influencing the quality of the valve body. ...
Plastic injection moulding (PIM) represents one of the most
important processes in the mass production of precise plastic parts with intricate geometries. Polypropylene (PP) is the widely used material related to plastic parts for automobile and packaging industry. It was observed that thermal shrinkage and warpage in plastic parts are the most prominent defects and affects the quality of plastic parts. In this paper, a methodology has been presented for reducing the thermal shrinkage and warpage along with the maximizing the impact strength (IS) of virgin polypropylene (PP). To obtain the optimum values of injection moulding parameters, Taguchi orthogonal array (OA) was used. Overall, six parameters were chosen for the experiment. The linear graph was utilised to know the effectiveness and interactions of the parameters. Thus, with Taguchi method minimum thermal shrinkage of 4.67%, minimum warpage of 1.8 mm and maximum impact strength of 56.7 J/m were obtained in PP specimens. With this methodology, prediction equations and mathematical models for thermal shrinkage, warpage and IS of PP were developed which are useful for industrial applications. With multi objective genetic algorithm, these mathematical models were optimized.
... Among the plastic injection molding parameters which evaluate the mechanical behavior, we can mention pressure, temperature, and time [1]. The link between the mechanical behavior and the injection parameters is essential as the constituents of the used material itself dependent to the microstructure [2][3][4]. Consequently, optimizing these injection molding parameters is essential to find out the preferred optimal responses. An experimental strategy is helpful to investigate the effect of the process parameters on the desired responses and with low cost and few numbers of experimental trials [5,6]. ...
The current research work presents an optimization of injection molding parameters using Taguchi technique. The design of experiment (DOE) method of Taguchi is adopted to investigate the impact of the molding process factors on the yielding strength of PC/ABS blend and to set optimal combination factors reached a significant value of the mechanical property studied. Four molding factors such as material temperature (Tma), injection pressure (Pinj), holding time (th) and mold temperature (Tmo) were selected with three levels. Signal to noise (S/N) ratios were used for defining the optimal process combination parameters providing significant yielding strength. Results showed that 260 ℃ of a material temperature, 50 bar of injection pressure, 8 s of holding time and 60 ℃ of mold temperature are the optimum combination parameters. Moreover, the main injection molding process parameters which directly effect on the mechanical property of the injected PC/ABS blend are identified as material temperature, injection pressure, mold temperature and the holding time, respectively. The most effective factor is the injection pressure followed by material temperature and mold temperature. The injection pressure is the most significant parameter on the yielding strength of the injected PC/ABS parts. These worthy findings may have potential applications in automotive part industry.
... Currently, as described by Farotti and Natalini [6] and Ardebili et al. [7], the most relevant injection parameters are the injection speed, mold temperature, melt temperature, injection and holding pressures, and cooling Sustainability 2021, 13, 12692 2 of 21 setup and time, all affecting important characteristics like the product quality, production rate, surface finishing, and strength. The literature is vast in the analysis and optimization of injection molding parameters and how these affect the injected parts' microstructure and mechanical properties [6,8,9]. Within the scope of sustainable production, different works focused on environmentally friendly materials, minimum energy consumption, raw material savings, recycling chances and cycle time reduction [10][11][12], leading to an increase of process efficiency and overall competitiveness. ...
Thermoplastic injection is currently employed in different industrial fields. This process has significantly evolved over the years, and injection machine manufacturers are continuously forced to innovate, to improve the energetic efficiency, aiming to reduce costs, improve competitiveness, and promote environmental sustainability. This work focuses on the development of a novel, profitable, and environmentally friendly plastic over-injection equipment of small metallic parts for the automotive industry, to be applied in a bowden cable production line, to cover the zamak terminations with plastic, or produce terminations entirely made of plastic. The work is based on an over-sized existing solution. The operating parameters required for the work are quantified, and all machine parts are designed separately to achieve the required functionality. Known approaches are finally used to perform the cost analysis, calculate the return on investment (ROI), and energetic efficiency, to substantiate the replacement of the current solution. The new equipment was able to increase the energetic efficiency of the current assembly line while keeping the required injection rates. An efficient and sustainable solution was presented, with a ROI of 1.2 years over the current solution. The proposed design is also applicable to different automated production lines that require this technology. Nowadays, this concept can be extended to all fields of industry that employ injection molding in their processes, enabling to integrate new manufacturing systems, and increasing energetic efficiency while reducing production costs.
... Wrong parameter selection can lead to defects such as sink marks, voids, short shots, warping, burn marks or jetting [5][6][7]. Owing to these injection issues, many studies were proposed regarding the influence of injection molding process parameters on the mechanical properties and obtained microstructure of the injected parts [3,8]. ...
The plastic injection molding process, including thermoplastic injection, is nowadays used in several industrial processes, including in the automotive industry for bowden cables. This process makes possible to produce a wide range of products with different sizes, shapes, and for varying applications. During the years, many challenges emerged, which obliged the injection machine manufacturers to adapt and continuously innovate in their equipment, and made the design process of these equipment highly complex. This work aims to design a thermoplastic micro over injection molding station adapted to the current injection rates in a real company, in order to increase efficiency, and that can be implemented in automated production lines, reducing the number of operators. The equipment should be used in the production lines of bowden cables, which are used to command different systems inside the car. These cables can have zamak terminations covered with plastic, or terminations entirely made of plastic. These plastic parts of the cables are over-injected using polyethylene, polyamide with and without the addition of glass fibers, and polyacetal. As a result of this work, the designed injection machine has an estimated production rate of 7 injected cable ends in a maximum of 39 seconds, which is equivalent to 5.57 seconds per cable end.
... However, no previous study has been found in which the mold is reinforced with long fibers in certain directions; generally, these are particulate materials or short fibers. This "effectiveness" considers reducing process times and obtaining better-quality molded parts (Ozcelik et al. 2010). In this study, it is expected to determine if molds with continuous copper fiber reinforcement have a higher process effectiveness than with copper particulate reinforcements. ...
Mold injection is an expensive manufacturing method; it involves several engineering-design hours and expensive alloys. Enabling the use of low-cost mold tooling can turn low-run productions economically and sustainably viable. There is a low-cost and more environmentally amicable alternative to injection molding for low-run productions based on epoxy resin molds. However, one drawback is the polymeric nature of the epoxy material, which possess low thermal conductivity, negatively affecting the injection process and thus quality of the molded pieces; as well as its low degradability rate. An opportunity arises for improving the performance of epoxy resin molds by studying the effect of embedding thermally conductive fibers in the matrix. The methodology used in this work consisted in the computational evaluation of a series of molds of composite material models built up from epoxy resin and copper fibers in different geometrical shapes and orientations. Injection simulations were carried out using the software Moldflow and the “effectiveness” of the injected parts was assessed (i.e., injection cycle time, percent volume shrinkage, and injected part deflection). Results suggest that embedding copper fibers within the epoxy matrix resin molds lowers the injection cycle time and reduces volumetric shrinkage while maintaining the deflection amplitude of the injected parts; optimum effectiveness results were obtained when copper is embedded as long fibers oriented along the principal heat flow direction. Moreover, epoxy resin can be replaced by up to a 70% volume of copper fibers, depending upon wall thickness and geometry complexity, thus lowering the impact this resin has on the environment.
... Uniform wall thickness reduces the risk of molded in stresses and differential shrinkage (BASF 2007) while reinforcing ribs improve rigidity and strength and eliminate heavy cross-sectional areas (Campo 2006). Material shrinkage can occur during and after the manufacturing process when plastics melt and cool, and it depends on factors such as thickness variations and temperature differences through thickness (Pomerleau and Sanschagrin 2006;Ozcelik et al. 2010). Warpage is the resulting bending that a plastic part exhibits after ejection, which is mainly caused by variations in shrinkage (Yang et al. 2002). ...
The design of a recycled-carbon fiber–reinforced plastic/metal hybrid (PMH) engine cradle is realized via combined optimization techniques. Topology optimization (TO) and free-size optimization (FSO) techniques are exploited in the design process to find the optimal rib configuration and location of metal inserts. To analyze the obtained design in terms of functionality, a material exchange technique that accounts for fiber orientation elementwise is employed. The robust design procedure is shown to be effective in developing PMH parts while considering injection molding (IM) restrictions from the early design stages. The PMH model provides a good balance between functionality and IM suitability, with a 36% weight reduction from the steel baseline model. The results contribute to the efficient multimaterial design of PMH components in the auto industry, creating light and strong structures produced by fast manufacturing processes and low-cost carbon fibers.
... The aforementioned studies revealed a great variety of research related to residual stresses generated during the injection molding process; however, these studies are limited to specific cases or applications with a particular scope. Some studies focus in processing conditions effects but variables like type of polymer and mold designs are not taken into consideration (Alkaabneh et al., 2016;Farshi et al., 2011;Kusić et al., 2013;Ozcelik et al., 2010). Other studies evaluate one specific geometry but interactions with processing conditions and different polymers are not assessed (Kansal et al., 2001;Raos and Stojsic, 2014;Wang and Young, 2005;Xu et al., 2015). ...
... The Taguchi method is widely used in moulding industries to improve the warpage on the moulded part produced. The best combination of processing parameters can be determined by using the Taguchi method [21,[30][31][32][33]. Although the Taguchi method can recommend the best combination setting of processing parameters, it is not suitable to be used in determining the optimum setting of processing parameter for continuous value. ...
Many studies have been done using recycled waste materials to minimise environmental problems. It is a great opportunity to explore mechanical recycling and the use of recycled and virgin blend as a material to produce new products with minimum defects. In this study, appropriate processing parameters were considered to mould the front panel housing part using R0% (virgin), R30% (30% virgin: 70% recycled), R40% (40% virgin: 60% recycled) and R50% (50% virgin: 50% recycled) of Polycarbonate (PC). The manufacturing ability and quality during preliminary stage can be predicted through simulation analysis using Autodesk Moldflow Insight 2012 software. The recommended processing parameters and values of warpage in x and y directions can also be obtained using this software. No value of warpage was obtained from simulation studies for x direction on the front panel housing. Therefore, this study only focused on reducing the warpage in the y direction. Response Surface Methodology (RSM) and Genetic Algorithm (GA) optimisation methods were used to find the optimal processing parameters. As the results, the optimal ratio of recycled PC material was found to be R30%, followed by R40% and R50% materials using RSM and GA methods as compared to the average value of warpage on the moulded part using R0%. The most influential processing parameter that contributed to warpage defect was packing pressure for all materials used in this study.
... However barely 5000-50,000 plastic components could be produced through such aluminium moulds. The author optimized change in mechanical properties of ABS (Acrylonitrile-Butadiene-Styrene) and the results were melt temperature and injection pressure affected the mechanical properties more for steel mould material than aluminium mould material [26]. He [27] reviewed about main failure modes of plastic mould and the reason behind the failure. ...
The high-performance plastics usage is increasing in the automobile field because of its advantages over other metals and alloys. Corrosion resistance, light weight, low cost, flexibility in design are the major advantages of plastics above the conventional metallic materials. In this paper a metal version component converted into plastic version in order to increase efficiency, reduce the overall cost of a two-wheeler and to improve the production rate of component. Different types of material such as PP + 15% TALC, PP + 30% GF, PP + 30% TALC, Nylon 6 + 15% GF, Nylon 66 UF, Nylon 6 UF, Nylon 66 + 30% GF, ASA LI941 and ASA LI913 tested for 10,000km road test, vibration test and fitment test. An injection moulding used to produce the component and ‘Mouldx3D’ software was used for mould flow analysis and other simulation. The different parts of injection moulding tool made up of C45, P20 and D2 materials. Among different materials, ASA LI913 was selected since it has better weather resistance than others and the impact strength matched to metal version component. Finally, it was found that the cost of the component made of Plastic considerably less than same component made of metal.
... Due to the inappropriate selection of these parameters, various defects like-flow line, sink marks [5], vacuum voids, weld line [6], short shot, flash, warpage [7], surface delamination, burn marks [8], jetting are caused in the product. Many studies have been done on the effect of these process parameters on mechanical properties and microstructure of the material [9][10][11]. However, no study has been done, which shows the effect of these process parameters on wear behaviour of the material. ...
Injection moulding is used significantly in modern days for manufacturing of plastic materials, mainly due to its effectiveness of mass production, modulation of complex geometry, and high precision objects. The process is influenced by various parameters like mould temperature, injection pressure, holding pressure , cooling arrangement, cooling time, injection speed and melt temperature, resulting in effective manufacturing with a quality product. The current study is focused on analysing the influence of injection pressure and holding pressure on the fabrication of Delrin specimens. Delrin is one of the most commonly used plastic for wear-related issues, mainly due to its higher wear resistance and sliding properties. In this study, the effect of injection pressure and holding pressure is analysed on the mechanical and tribo-logical properties of Delrin specimen, for which pin on disc and universal testing machine are used, respectively. Experimental results showed that the wear resistance, tensile strength and compressive strength of Delrin specimens were increased with respect to the injection pressure up to a specific limit but continuously increased with the holding pressure.
... The printing time was approximately 30 min per rotor. The mechanical properties of the 3D-printed ABS are about 27% weaker than those of the injection-molded ABS [15][16][17]. However, the rotors fabricated herein operate at low wind speeds (3 m/s), so the difference in mechanical properties due to processing is not significant. ...
Low-intensity winds can be useful power sources in the context of energy harvesting. This study aims to enhance the power generation capacity of a super micro wind turbine (SMWT) in low-intensity winds by modifying the blade geometry, which cannot be realized in conventional wind turbines owing to the stress concentration. By controlling the curved angle (θ) in the middle of the blade, the rotor performance can be improved, and the rotor diameter can be reduced to increase installation density. Experimental results indicated that the optimal θ value was 105°, at which the AC voltage was improved by 7.4% compared to that in the case of the basic model with θ = 0°. The maximum electric power output was 9.333 μW and the load resistance was 47.62 kΩ. Moreover, a computational fluid dynamics analysis was performed to clarify the pressure field and streamlines on and around the blade to demonstrate the aerodynamic performance of the SMWT. The proposed blade geometry is one of many possible designs that can enhance extremely small wind turbines for energy harvesting.
... Additionally, some researchers observed mechanical behavior of parts fabricated with different manufacturing technologies [28][29][30] and different treatments [31][32][33][34] to achieve higher resistances of mechanical properties. ...
The present study evaluates the effects of manufacturing parameters on the tensile properties of a commercial composite material based upon polylactic acid (PLA) with wood fibers known as Timberfill. The specimens are built through fused filament fabrication (FFF), and the influence of four printing parameters (layer height, fill density, printing velocity, and orientation) is considered through a L27 Taguchi orthogonal array. Tensile tests are applied to obtain the response variable used as output results to perform the ANOVA calculations. Results show that fill density is the most influential parameter on the tensile strength, followed by building orientation and layer height, whereas the printing velocity shows no significant influence. The optimal set of parameters and levels is found, being 75% fill density, 0○Z-axis orientation, 0.4 mm layer height, and 40 mm/s velocity as the best combination. Applying this combination, a 9.37-MPa maximum strength is the highest value obtained for the material. Additionally, five solid injection molded Timberfill specimens were tested as well and the results compared with the FFF samples. The values of the elastic modulus, elastic limit, and maximum strength of the injected samples were almost twofold of those were obtained for the FFF samples, but the maximum elongation of the injected specimens fell sharply.
... The tensile strength of the ASA and stamp sand composite can be compared favorably with AM ABS, which has a tensile strength of 25-40Mpa [52][53][54][55]. However, injection molded ABS has a tensile strength of about 47Mpa [56], which indicates that for conventional injection molded ABS products the composite may not be appropriate. ...
In the Upper Peninsula of Michigan, over 500 million tons of copper rich rock were removed from mines and treated in chemical baths to extract copper. Toxic substances have been seeping into the watersheds from the resultant waste stamp sands. Recent work on developing a circular economy using recycled plastic for distributed manufacturing technologies has proven promising, and this study investigates the potential to use this approach to form stamp sand and acrylonitrile styrene acrylate (ASA) composites. Specifically, this study found the maximum amount of stamp sand that was able to be added to waste ASA by mass with a single auger recyclebot system for compounding was below 40%. The mechanical properties of the composite were evaluated up to 40%, and the addition of stamp sand reduced the material's ultimate tensile strength by about half compared to the strength of raw recycled ASA, regardless of the percent stamp sand in the composite. However, this strength reduction plateaus and the tensile strength of the ASA and stamp sand composites can be compared favorably with acrylonitrile butadiene styrene (ABS) at any level. This makes waste ASA- stamp sand composites potential replacements for outdoor applications of ABS as well as some current ASA applications. These results are promising and call for future work to evaluate the technical, economic and environmental potential for waste ASA - stamp sand composites.
... Mold material selection and mold design is a very important part of any polymer processing. Mold material has an impact on polymer properties which is investigated by Ozcelick et al. [59]. The main challenge of designing mold is to design gate and runner. ...
With the expected exponential growth prospects of additive manufacturing,
petroleum-based plastic products and applications are also expected to increase. For the
last two decades, plastic pollution has become a concerning fact. About 25 million tons of
plastics find their way into the environment annually. Traditional plastics are not
biodegradable and hence they end up in landfills which is detrimental for the environment.
Hence, there exists a need for renewable alternatives to traditional petroleum-derived
plastics. Lignin, an abundant plant-derived feedstock, has been a perfect candidate for
renewable materials.
The work in this thesis focuses on investigating the effects of mixing lignin
extracted from tobacco with high-density polyethylene (HDPE) in varying concentrations.
This work is performed in three stages. The first stage is the making blends of HDPE-lignin
at varying concentrations (5, 10, 15 & 30 wt.%). Later all the materials were melt mixed
using a single screw extruder. In the later stage for mechanical testing purposes, tensile
specimens were processed via injection molding. During this process, the effect of lignin
on injection molding parameters was investigated.
In the second stage, mechanical, physical and thermal tests were conducted to
analyze the effects of blending on the overall performance of the lignin-HDPE blends.
Tensile tests were performed to determine the ultimate tensile strength (UTS), Young’s
modulus and elongation at break for each blend composition. To evaluate the physical
properties, hardness and density of the blends were measured. The miscibility of the blends
was studied using optical microscopy. TGA tests were performed to study the thermal
stability of blend materials.
In the third stage, maleic anhydride grafted polyethylene was used to compatibilize
blend materials. Compatibilized HDPE-Lignin blend materials were later subjected to
mechanical and physical tests to analyze and compare the effect of compatibilizer.
The thermoplastic injection process is an industrial technique that allows getting a high precision plastics part with high production rate. This process is considered one of the most complexes in the plastic industry due to its complexity and variability. The main problems in this technique can occur during two phases: first, during the initial setting when we try to identify the initial parameters for a new plastic part; and second, during mass production when there is a deviation in the production process. The purpose of this article is divided on three parts: first, is to make a basic review and to present overview of the main issues faced in this process, second part, is to present the contribution of the artificial intelligence methods to resolve this issues and finally to present a general guidelines for future researchers to resolve or reduce the process issues.
Purpose
Rapid tooling has numerous advantages when prototyping injection molded components, but the effects of the tooling on the resulting part properties are often overlooked. The purpose of this paper is to consider the effect of tooling on the final part properties and morphology.
Design/methodology/approach
Digital polyacrylonitrile-butadiene-styrene (ABS) tooling and aluminum tooling were used to mold test specimens from isotatic polypropylene (iPP). Tensile behavior, impact strength, shrinkage, surface roughness and porosity were evaluated for both sets of samples. Additionally, differential scanning calorimeter (DSC) and wide-angle X-ray scattering (WAXS) were used to assess the crystallinity of the samples.
Findings
Characterization of the molded parts showed that slower cooling rates in the Digital ABS inserts promoted the formation of ß-PP, while this crystal structure was not found in the parts molded using aluminum tooling. Additionally, parts molded on the digital ABS inserts exhibited higher mold shrinkage and SEM images identified microscopic shrinkage voids within the material. The change in morphology and the presence of voids significantly affected the tensile behavior with the parts molded in Digital ABS, which broke with little cold drawing and exhibited higher tensile moduli and higher yield strengths.
Practical implications
The results show that the choice of rapid tooling technique plays an important role on determining the properties of the final parts.
Originality/value
Previous studies have not characterized the effect of rapid tooling on the morphology of the molded articles fully or over a variety of processing conditions. This study builds on prior work by using both WAXS and DSC to characterize morphological changes over a wide range of processing conditions and comparing results to mechanical property and shrinkage data.
The effect of the parameters in the injection molding process conditions to the warpage inside the product and the maximum cooling time in the injection molding cycle is numerically considered in this research. A series of process conditions setting with different values of coolant temperature, packing time, and maximum packing pressure has been taken into account. The results indicate that the process conditions have a strong influence on the quality factors– the total displacement of product and the maximum cooling time. In the current model, the optimal process conditions are 50 ℃ of the coolant temperature, 14 s of the packing time, and 77% of the maximum packing pressure. With the optimal parameters, the quality of the product could be improved with low warpage and a short maximum cooling time.
Polymeric parts have been widely used for various applications and injection molding is one of the most commonly used approaches to fabricate polymeric parts. Both the mechanical properties and microstructures of fabricated parts are severely affected by the process conditions. In this article, polyamide (PA66) was selected as the exemplary polymer to make dogbone‐shaped polymeric specimens. First, the effects of key process parameters including melt temperature, mold temperature, injection pressure, and injection speed on the tensile strength and crystallinity of the specimens were systematically investigated. Then, the effects of external ultrasonic vibration field on the mechanical properties and microstructures were studied using tensile tests, X‐ray diffraction, and polarizing light microscope imaging. After that, the orthogonal experiments were designed to analyze the affecting extent of each process parameter and achieve the optimal combination of the process parameters. Finally, using the optimal process conditions, the polymeric part with the best tensile strength and crystallinity was successfully fabricated. The knowledge from this article can be expanded to the injection molding of polymeric parts from other polymers, unveiling the mechanisms during fabrication and providing guidelines for the selection of optimal process conditions in the future. This study aims to bridge the gap between microstructures and macroscale mechanical properties of PA products fabricated using different injection molding conditions, theoretically explaining the effects of the key process parameters.
As known that heat dissipation plays a very important role in the Fused Deposition Modeling (FDM) process, it can obviously affect the forming quality of filaments and the strength of parts. However, there is not much research work on it. In this paper, based on theoretical analysis of FDM process, combining with the actual machining conditions, it investigates and presents three heat dissipative factors including the ventilation rate, the layered area and the envelope temperature. Some orthogonal experiments are implemented, in which the adhesive strength between the layers and the cross-sectional shrinkage rates are measured so as to evaluate the forming quality. The results indicate that lower ventilation rate, smaller layered area and higher envelope temperature will make the adhesive strength between layers of filaments stronger. Furthermore, the influence degree of the three factors is decreased sequentially and some methods to improve the heat dissipative conditions are also proposed.
In the present work, an experimental investigation is performed to study the influence of process parameters on mechanical properties of tetra‐anti‐chiral auxetic structures manufactured by material extrusion (ME) technique of additive manufacturing (AM). Process parameters namely layer height, print speed, and print temperature are considered, while responses are compressive strength (σ), modulus (E), and specific energy absorption (SEA). Specimens of acrylonitrile‐butadiene‐styrene (ABS) polymer are fabricated and then tested under compressive loading. From the experimental results, it is observed that all process parameters significantly influence the mechanical properties of the structure. Scanning electron microscope (SEM) is used to study microstructural defects of the tested specimen. To maximize the responses, optimization of process parameter is performed using desirability function approach. Regressive models are developed to predict the mechanical properties. Influence of process parameters on mechanical properties of tetra‐anti‐chiral auxetic structures.
The present work concentrated on the determination of optimal plastic injection molding process parameters for two polymer materials, i.e. polyethylene and polypropylene, in order to achieve the highest mechanical properties and lowest volumetric shrinkage. The study used the Taguchi design of experiments with five process parameters (melt temperature, injection pressure, packing pressure, packing time, and cooling time) for the manufacture of 27 polymer sample parts via PIM. The flexural strength, flexural modulus, and yield stress were measured using a three-point bending test, whereas the volumetric shrinkage was measured according to the volume. The results were interpreted by variance analysis (ANOVA) and 3D surface plots. A predictive model was developed using stepwise regression analysis. Two multi-objective optimization methodologies were implemented to evaluate the optimal PIM process parameters for both materials: multi-criteria decision making (MCDM) and the multi-objective genetic algorithm (MOGA). The results showed that the melt temperature was the most significant parameter, followed by packing time, injection pressure, cooling time, and packing pressure. The selected model effectively predicted the responses at an error rate of less than 4% for both materials. The MCDMs found that trial Number-9 exhibited the optimal set of process parameters, and compared to the MCDMs, the MOGA results showed improvement of 7-9%. Significant contribution of the present study is to obtain the optimal manufacturing process parameters in injection molding of the polymeric materials considering two outcomes simultaneously, viz. maximize the mechanical properties and minimize the volumetric shrinkage with injection molding parameters by using multi-objective optimization methodologies with ANOVA and Regression analysis.
In this work, an experimental design was applied in the injection molding process of polycaprolactone (PCL), aiming to evaluate the mechanical properties (impact strength, tensile strength and Shore D Hardness), thermal (differential scanning calorimetry (DSC)) and thermomechanical (heat deflection temperature (HDT)), in PCL injected specimens. A type 2 ⁿ planning was applied, with n = 3 and central point, having the input factors: processing temperature profile, mold temperature and injection flow. The results showed that the DSC curves presented a complex mechanism during crystallization, suggesting that depending on the processing conditions a high degree of crystallinity can be obtained. When using a higher processing temperature and a higher injection flow, there is an increase in the mass of the PCL parts. The impact strength is more expressive when a higher injection flow and a lower processing temperature are applied, reaching values around 260 J/m. The mold temperature impairs the elongation at the break of the PCL, while the elastic modulus was governed by the degree of crystallinity. A deleterious effect on HDT was observed with increased injection flow, suggesting that this parameter negatively affects thermomechanical resistance. The use of experimental design in the processing of PCL is important, since it is possible to optimize properties with the ideal conditions of injection molding.
The development of additive technology has made it possible to produce metamaterials with a regularly recurring structure, the properties of which can be controlled, predicted, and purposefully implemented into the core of components used in various industries. Therefore, knowing the properties and behavior of these structures is a very important aspect in their application in real practice from the aspects of safety and operational reliability. This article deals with the effect of cell size and volume ratio of a body-centered cubic (BCC) lattice structure made from acrylonitrile butadiene styrene (ABS) plastic on mechanical vibration damping and compression properties. The samples were produced in three sizes of a basic cell and three volume ratios by the fused deposition modeling (FDM) technique. Vibration damping properties of the tested 3D-printed ABS samples were investigated under harmonic excitation at three employed inertial masses. The metamaterial behavior and response under compressive loading were studied under a uniaxial full range (up to failure) quasi-static compression test. Based on the experimental data, a correlation between the investigated ABS samples' stiffness evaluated through both compressive stress and mechanical vibration damping can be found.
In recent days, moulding of thermoplastic is difficult process. Injection moulding is one of the most imperative plastic processing technologies. The melted plastics were passed to the closed die unit through thrust of the screw or plunger. In this experimental work, Thermoplastic Polyurethane (TPU) was used as the processing material of injection moulding. The different input factors were applied to operate the injection moulding such as moulding temperature, cooling time and injection pressure. The response of each specimen of tensile strength was measured with respect to the change of input factors. Taguchi optimization, regression model and variance analysis have been conducted.
Demand of plastic is increasing at a rapid rate in India and across globe. Plastic is processed using plastic injection molding machine. In this article, plastic injection molding process and injection molding system is discussed in detail. Various factors which may affect the quality of product during production through plastic injection molding is also discussed. Defect in plastic injection molded product has also been discussed.
This article focuses on the estimation of dispersion effects in off‐line quality control techniques. In this context, the Taguchi design for the optimal choice of process parameters is one of the most commonly used statistical methods. Starting from Taguchi methodology, we consider that an additive or a multiplicative model defines the relationship between the deterministic component and the variability of the process. We apply a hypothesis testing in order to find the optimal factor combination that minimizes the variability indicator of product quality, using ranking and selection methods of the Bechhofer kind. Moreover, an extensive simulation study shows how the probability of finding the optimal set of factors changes according to the main sampling parameters, in order to provide guidance for practitioners.
This paper presents the experimental investigation on the implementation of Taguchi technique to optimize the drilling process parameters of nano-filled carbon fiber reinforced polymers (CFRP) to minimize the thrust force. The experiments were performed by using three drill bit types by varying point angles at three levels of drilling speeds, feed rates, percentage of CNT and point angles. The responses, namely thrust force, were measured by using Kistler multicomponent dynamometer. The drilling process parameters which directly influenced the performance characteristics were optimized using Taguchi technique. The analysis of variance (ANOVA) results clearly indicated that the feed rate was the significant factor which affected the responses. Thereafter, scanning electron microscopy (SEM) analysis was used to discuss the effect of drilling parameters on the microstructure of the investigated hybrid CFRP.
In this paper, NSGA-II algorithm is applied to look for the variety of optimum solutions in WEDM process problem. Four parameters, namely wire feed, pulse-on time and pulse-off time, and two machining criteria, i.e., kerf width and material removal rate, are, respectively, considered as input variables and responses. The obtained results showed that the proposed NSGA-II algorithm is an effective and appropriate strategy for optimizing the process of WEDM machining process parameters.
The polymer materials used in the injection molding process have a non-Newtonian characteristic. Consequently, a flow imbalance problem often occurs, even if an H-type runner system is employed. This problem can be addressed by placing a static mixer in the runner. However, the performance of the mixer is highly dependent on its design. Accordingly, the present study employs the Taguchi design methodology to optimize four geometry parameters of the passive mixer, namely the baffle lattice angle (Factor A), the baffle lattice thickness (Factor B), the mixer length (Factor C) and the baffle inset pattern angles (Factor D). For each run in the orthogonal array, the temperature distribution at the mixer outlet is evaluated by Moldex3D simulations. The parameter settings which result in the maximum temperature uniformity [i.e., the maximum signal-to-noise (S/N) ratio] are then taken as the optimal design. The validity of the optimization results is confirmed by means of ANSYS Fluent and Image J simulations. The Taguchi results show that the optimal parameter settings for the passive mixer are as follows: lattice angle = 45° (A2); lattice thickness = 0.5 mm (B1); mixer length = 30 mm (C3); and inset pattern angles = 45°–45°–90° (D2). The Moldex3D simulation results show that the optimal mixer design improves the Taguchi S/N ratio by 1.17 dB compared to the original mixer design. Furthermore, the ANSYS Fluent simulations show that the mixing index is improved from 0.5121 (original design) to 0.4213 (optimal design).
This paper estimates the volumetric shrinkage for thermoplastic Polypropylene (PP) injection molded components made using digital Acrylonitrile butadiene styrene (ABS) mold. The parameters affecting volumetric shrinkage for the digital ABS mold are mold temperature and injection temperature, cooling time, hold pressure and injecting speed. Therefore, twelve standard benchmark CAD model were selected with different geometric attributes. Subsequently, simulation analysis was performed on all CAD model using Moldflow® (MFA) simulation software. Additionally, regression analysis is applied to identify the effect of injection molding parameters on the volumetric shrinkage of part made using rapid tooling mold insert of digital ABS material. It is found that maximum volumetric shrinkage (18.75%) is observed for square pyramid frustum, conical frustum, and solid torus. On the contrary, hollow rectangular prism shows minimum shrinkage effect having 12.61% of volumetric shrinkage. This study predicted that shrinkage is the main concern for these three geometric features (i.e., square pyramid frustum, conical frustum, and solid torus) and must be looked for its minimization. The results are experimentally validated, with 3D scanner integrated with COMET plus and Inspect plus softwares. Since shrinkage estimation for digital ABS mold using Rapid Tooling technique has not been attempted before, therefore, this study provides guidance for the optimum parameter selection and assigning suitable shrinkage compensation values for digital ABS mold made using direct rapid tooling.
A literature review shows how injection molding conditions affect process capacity, energy consumption and molding structure and properties. Mechanical and thermal properties of HOPE moldings were studied in relation to mold temperature (20°C-80°C) and injection velocity (0.015-0.12 m/s). As the mold temperature was raised, the tensile strength, yield stress, tensile modulus, hardness and Vicat softening temperature were found to increase; the strain at maximum tensile stress and impact strength decreased (Figs. 1-3). At higher temperatures, the mold cavity is easier to fill. At low polymer/mold wall temperature gradients, internal stresses and molecular orientation are lesser and moldings exhibit smaller sink marks and better mechanical properties. Economically, higher temperatures, are unfavorable because then the injection molding cycle is longer. Higher injection velocities gave rise to reduced tensile strength, stress at break and hardness and to lowered softening point and to increased plastic properties (strain at break, impact strength) (Figs. 4-6). The time to fill the mold cavity is shorter and thermal losses along melt flow path are smaller. At velocities that are too high, defective moldings are likely to form containing voids and having inferior mechanical properties.
Around one third of all plastics are processed by injection molding, therefore its economy and manu-facturing technology have fundamental importance. The major issues in the development of injection molding tools include the progress in material technology and the developments in tool design method-ology, such as developing rapid tool inserts. It is essential to develop fast methods to manufacture tools for injection-molded-like prototype parts or mass-produced parts. Due to these high requirements, it is more and more significant to use simulation methods to optimize the part before manufacturing. This paper shows the advantages of tool inserts in injection molding. The main difference between the conventional injection molding tools and rapid tool insert is also described in this paper. Beyond all questions, the rapid tool inserts cause different properties such as different warpage of the polymeric part.
Calculation of fiber orientation distribution is the reference standard for determining the numerous physical and mechanical properties of injection molded short fiber reinforced thermoplastics. On the other hand, most of the properties of these composites depend on their fiber orientation pattern, which can be represented by tensorial notation, aij. This work focuses on numerical calculation of a fiber orientation tensor of an injection molded short glass fiber polystyrene (SGF-PS) composite part, shaped as a rectangular plate. In this study, the effects of some parameters of the injection molding process including injection flow rate, mold wall temprature, packing pressure and also fiber content on the changes of fiber orientations of this specimen are investigated. Our studies are concentrated on determining the changes of the first orientation tensor component in the flow direction due to different injection parameters. In addition, the changes on tensile modulus of the injected part are simulated in every condition. The simulations show how these molding parameters can influence both fiber orientation and tensile modulus of injection molded parts. At the first step, in order to be confident about the software results, they are validated by experimental data in two cases.
Adequate control of product properties in injection molded plastics requires very accurate predictions. The problem is that the mechanical properties of these plastics, such as tensile modulus, are highly non-linear with the process variables, hence they are tough to predict. Consequently, up to date, injection molding machines include only closed loop control of process variables. Control of product properties is virtually non-existent.We show here for the first time, that mechanical properties, such as tensile modulus values, can be predicted using Artificial Neural Networks quite accurately within a reasonable time. This is a major step towards an integrated self-taught control mechanism for the injection molded plastics industry.
The basic characteristics of a sandwich injection molded product depend on the properties of the respective resins that comprise the skin and core layers, and the skin/core resin volume ratio. The characteristics of the core layer resin and the skin/core ratio in particular may vary depending on the injection molding conditions. This report considers the influences that the molding conditions such as injection speed, cylinder temperature, and mold temperature confer on the mechanical properties of the sandwich moldings. The study employed, skin/core resin combinations involving similar and dissimilar materials i.e. homopolymer PP/homopolymer PP and homopolymer PP/copolymer PP, respectively. It was demonstrated that core cylinder temperature and mold temperature could be used to adjust the mechanical properties of sandwich injection moldings. In the case of single material sandwich moldings, injection speed seemed to play no significant role, even though it was clearly demonstrated that core volume increases with injection speed. However, core injection speed plays a significant role in the dual material system by lowering or increasing the mechanical strength of moldings as the case may be. Thus, the dormant or active role of injection speed depending on the material system has been highlighted.
The dependence of the mechanical properties of injection molded tensile specimens of a liquid crystal polymer (Rodrun) on the preparation method of the specimen were studied by means of the change in each of four processing parameters over the maximum range that the machine allowed, whilst holding the other parameters constant. The parameters studied were the injection rate, the melt temperature, the screw rotation rate during plasticization and the injection pressure. The common analysis of the results of this and previous works, allows us to propose parameter ranges at which the mechanical properties are independent of the preparation method.
In this paper advantages of design of experiment techniques in engineering applications were investigated by the example of the performance optimization problem of hard ceramic coatings on HSS drills. TiN and TiAlN coatings on HSS tools have shown significant improvements on tool life. To achieve the limits of the improvements, optimization of processing parameters is as important as the selection of proper coating type. Cutting speed and feeding rate have been chosen as the most important process parameter, which can be easily adjusted under industrial conditions. The work focused on the main effects of coating type, cutting speed and feeding rate on the overall performance by using design of experiment techniques. The statistical methods of signal-to-noise ratio and analysis of variance are applied for the analysis of the results and for the determination of the effects of each parameter on the drilling process. Design of the experiments is based on Taguchi L9 orthogonal array, which provides a decrease of the necessary number of experiments to 1/3 of a conventional full factorial design. As a result, the analyses show that an optimum cutting force is provided in case of TiAlN coatings, when cutting speed is 25 m/min and feeding rate is 164 mm/min. The efficiency of the optimization by Taguchi technique under industrial conditions has been proved by the decrease of the number of necessary experiments from 27 to 9.
This study analyses the tribological behaviors and mechanical properties of polycarbonate (PC) reinforced with 20% short glass fiber (SGF) and 6% polytetrafluoroethylene (PTFE), which is applied to the bottom cover of the card reader body. In order to reduce the number of experiments, the design of experiments (DOE) method based on Taguchi's orthogonal arrays were applied. The specimens were prepared under different injection molding conditions by varying four controlled factors including the filling time, the melt temperature, the mold temperature and the packing pressure with three levels for each factor. The wear mass loss, the friction coefficient, and the strain are adopted as the quality targets. In addition, an optimal parameter setting is obtained through a desirability function that balances three desired quality targets. Furthermore, analysis of variance (ANOVA) is conducted to identify the factors that have significant influence on the quality of the products. The proposed approach offered an effective and systematic way to identify an optimal setting of the injection molding process.
This study analyzes the mechanical properties and tribological behaviors of polycarbonate (PC) reinforced with 20% short glass fiber (SGF) and 6% polytetrafluoroethylene (PTFE), which is applied to the bottom cover of the card reader body. The specimens were prepared under different injection-molding conditions, by varying the filling time, the melt temperature, the mold temperature and the packing pressure. Grey relational analysis is then applied to obtain an optimal parameter setting. Plans of experiments via nine experimental runs are based on the orthogonal arrays to determine the optimum factor level condition. The mechanical properties of ultimate stress, and the tribological behaviors of surface roughness and friction coefficient variation are adopted as the quality targets. The tensile test were performed with a 25 kN computerized MTS. Simultaneously, friction and wear tests were performed with a Schwingum Reibung Verschleiss (SRV oscillation friction wear) ball-on-plane tester. Additionally, the worn surfaces were examined with scanning electron microscopy (SEM). Melt temperature was found to be the most influenced factor inultimate stress, surface roughness, and friction coefficient for the injection molding process in this study.
Injection molding is one of the most important methods for the manufacture of plastic products; however, there are several unresolved problems that confound the overall success of this technique. Sinkmarks occurring on the surface of molded parts caused by inappropriate mold design and processing conditions is one problem. In this report, an L'18 orthogonal array design based on the Taguchi method was conducted to minimize the sinkmarks of injection-molded thermoplastic parts. The polymeric materials used were general-purpose polystyrene and low-density polyethylene. A plate cavity with various ribs was used for molding. Experiments were carried out on an 80-ton reciprocating injection-molding machine. After molding, the sinkmarks on the surface of molded parts were characterized by a profile meter. For the factors selected in the main experiments, the corner geometry and the width of the rib were found to be the principal factors affecting sinkmark formation in injection-molded thermoplastics. A rib of an undercut geometry and a small width produces parts with the least sinkmark. Experimental investigation of an injection-molding problem can help illuminate the formation mechanism of sinkmarks so that steps can be taken to optimize the surface quality of molded parts. © 2001 John Wiley & Sons, Inc. Adv Polym Techn 20: 202–215, 2001
This study analyzed contour distortions, wear and tensile properties of polypropylene (PP) components applied in the interior coffer of automobiles. A hybrid method integrating a trained generalized regression neural network (GRNN) and a sequential quadratic programming (SQP) method is proposed to determine an optimal parameter setting of the injection-molding process. The specimens were prepared under different injection-molding conditions by changing melting temperatures, injection speeds, and injection pressures. Average contour distortions at six critical locations, wear and tensile properties were selected as the quality targets. Sixteen experimental runs, based on a Taguchi orthogonal array table, were utilized to train the GRNN and then the SQP method was applied to search for an optimal setting. The trained GRNN was capable of predicting average contour distortions, wear and tensile properties at various injection-molding conditions. In addition, the analysis of variance (ANOVA) was implemented to identify significant factors for the molding process and the proposed algorithm was compared with traditional schemes like the Taguchi method and the design of experiments (DOE) approach. Copyright © 2007 John Wiley & Sons, Ltd.
Plastic injection moulding is one of the most important polymer processing operations in the plastic industry today. However, lack of skill in mould making and injection moulding machine control will lead to defective plastic product. Warpage is one type of defect that usually appears in products with thickness less than 1 mm.This project is going to fabricate a mould that produced a thin plate with dimension 120 mm × 50 mm × 1 mm. The thin plate will be used for warpage testing. In mould fabrication, the mould base that purchase will be machined and assembled. After that, the mould is fixed on the injection moulding machine. The machine setting should be made to produce the product. Then, the product will be used for testing on the effective factors in warpage problem by applying the experimental design of Taguchi method.From the results, it shows that the most effective factor on the warpage is melt temperature. The filling time only slightly influenced on the warpage. The optimum parameters that can minimize the warpage defect are melt temperature (240 °C), filling time (0.5 s), packing pressure (90%) and packing time (0.6 s).
The investigation of the mechanical properties in the plastic products produced using different mold and polymer materials
- A Ozbay
A. Ozbay, The investigation of the mechanical properties in the plastic products
produced using different mold and polymer materials, MSc Thesis, Gebze Institute
of Technology, 2008 (in Turkish).
The effect of mould materials in the performance of products moulded by RIM
- M Silva
- A Mateus
- P Bartolo
- A S Pouzada
- A J Pontes
M. Silva, A. Mateus, P. Bartolo, A.S. Pouzada, A.J. Pontes, The effect of mould materials in the performance of products moulded by RIM, IV International Material Symposium, Porto, Portugal, 1–4 April 2007.
The effect of mould materials in the performance of products moulded by RIM, IV International Material Symposium
- M Silva
- A Mateus
- P Bartolo
- A S Pouzada
- A J Pontes
M. Silva, A. Mateus, P. Bartolo, A.S. Pouzada, A.J. Pontes, The effect of mould
materials in the performance of products moulded by RIM, IV International
Material Symposium, Porto, Portugal, 1-4 April 2007.
The effect of mould materials in the performance of products moulded by RIM
- Silva