Z. M. Ariff

Universiti Sains Malaysia | USM ·  School of Material and Mineral Resources Engineering

Functionally graded structures from natural rubber foams were constructed and evaluated in this study. The structures were assembled based on density gradient achieved by stacking layers of natural rubber foams with different densities. Both physical and computational structures were constructed and assembled through experimental work and computer-...

Conventional manufacturing techniques of natural rubber foam (NRF) require long processing time besides producing closed cell structure, a property that limits the application of the NRF. The NRF produced via compression moulding (CPM) and microwave-convection oven heating techniques were compared in this study. The correlation between different pr...

This study aimed to characterize cell morphology and sound absorption properties of ethylene vinyl acetate (EVA) foam produced by microwave heating. EVA was compounded with pre-determined amount of azodicarbonamide as the blowing agent, dicumyl peroxide used as the crosslinking agent and zinc oxide for the blowing agent activation. Foaming was done...

The shear flow behaviour can be controlled by adjusting the processing variable such as temperature, shear, pressure and many more. This study aims to simulate the flow of ABS inside the capillary rheometer and melt flow index (MFI) and to determine the effect of temperature on the rheology properties of the polymer. The 2D model of capillary rheom...

This paper presents a numerical analysis of different rheology models during the encapsulation of moulded underfill (MUF) for flip-chip package. Robust computational fluid dynamics of finite volume analysis software; ANSYS FLUENT Workbench 14.5 was utilised in three-dimensional. A remarkable analysis was carried out by considering three distinction...

This study describes the results of a mold filling simulation analysis of a medical syringe performed during the thermoplastic injection molding process, which was performed using a computational Fluid Dynamic Simulation (CFD) with the Volume of Fluid Method (VOF). ANSYS Fluent was used for analysis and data collection. Medical grade polypropylene...

This study used water as the physical blowing agent as well as microwave heating (MH) and convection heating (CH) to simultaneously foam and cure natural rubber foam (NRF). Various processing methods and parameters, such as single heating and sequential heating using a mix of CH and MH; were investigated. The correlation between these processing me...

There is a rising prospect for producing more efficient, widely affordable and eco-friendly microwave absorbers. Much research has demonstrated the efficacy of low-cost absorbers, particularly those made of sustainable carbonaceous and rubber-based materials structured into a hollow pyramidal shape. Natural rubber possesses outstanding resilience,...

In this work, commercial carboxylated nitrile butadiene rubber (XNBR) was ionically crosslinked with zinc thiolate forming reversible ionic salt bonding between carboxy groups (COOH) in XNBR chains and Zn²⁺ ions from zinc thiolate. The reversible nature of the ionic crosslinks allows rearrangement of rubber molecular chains under an external heat...

Melt processing is challenging for recycling of mineral-filled polypropylene (PP) composites because the melt flow system, the viscoelasticity and the appearance of the extrudate profile change due to a combination of extensive shear forces and thermal-oxidative degradation. The flow pattern and the swelling behaviour of polypropylene-co-ethylene-k...

This study mainly concerns the role of foam heating process techniques and its impact on cellular micromorphology, density and gas liberation mechanism of natural rubber foam with distilled water as blowing agent. Three different modes of heating process techniques and varying amount of distilled water have been examined on the foam density and cel...

In recent years, there has been an increasing interest in the study of lightweight syntactic foams (SFs) because of their tailorable properties, quality characteristics and suitable applications in diverse technology industry. A considerable amount of literature has been published on SFs with most of these studies focusing on particular aspect like...

Conventional mould casting technique for cell foam production demonstrated trapped air bubbles in the cell foam which are undesirable stress concentration points in the matrix. This study devise a modified process technique of fabricating syntactic foam by eliminating interstitial porosity. Varying epoxy hollow spheres and matrix stoichiometry rati...

Natural cellulose fiber extract from Pandanus tectorius (Screw pine) leaves is comprehensively investigated as viable alternative for synthetic based fibers made from petro-chemical which is non-degradable and toxic. P. tectorius leaves fiber is extracted and investigated as reinforcement in polymer composite for engineering applications. The habit...

This research work explores on Digital Image Correlation (DIC) technique as a potential tool for measuring displacement and strain in film blowing extrusion process. A feasibility study on the surface patterning technique, validation of the DIC analysis and selection of DIC parameters were investigated. Understanding on the effects of these factors...

This study gave an insight on the effect of shear modification on molecular degradation of polyamide (Nylon) 6. It also studied the feasibility of utilizing mould filling simulation package to predict shear modification and degradation in injection molded product without the need for tedious molecular weight assessment. Injection molding procedure...

Utilization of microwave in material processing has attracted significant interest due to its advantages such as rapid and volumetric heating capability. However, the use of microwave in rubbers is usually focused on vulcanization and devulcanization of rubber, but very limited on rubber foaming. Therefore in this study, attempt was made to underst...

This work focuses on studying natural rubber (NR) and epoxidized natural rubber (ENR) foams crosslinked at different absorbed doses and foamed using a chemical blowing agent. The aim is to study if the existence of epoxide groups within the natural rubber molecular structure influences the expansion capacity and the cellular structure morphology of...

This research was carried out to study the effects of kenaf loading and alkaline treatment on tensile properties, density, thermal and morphological properties of kenaf filled natural rubber latex foam (NRLF). Samples were prepared using a Dunlop method. From the results, increasing loading of kenaf reduced the tensile strength and elongation at br...

The effect of cellular microstructure and density of low-density polyethylene (LDPE) foam during the compressive deformation were evaluated. Progressive foam cell structure deformation at crosshead speed of 10 mm/min was closely monitored and captured using a portable digital microscope with the assistance of a proposed coating technique to enhance...

This paper present a numerical analysis of molded underfill (MUF) for multi flip chip package during encapsulation. Castro Macosko model is used in ANSYS fluent to describe the flow behavior of the EMC. The physical quantities such as viscosity, shear rate and velocity is plotted to analyzed the flow behavior of EMC during encapsulation. The EMC fl...

The objective of this study was to determine the effects of prevulcanization time of natural rubber latex (NRL) on properties of kenaf filled natural rubber latex foam (NRLF). The prevulcanization time of NRL was set at 24 hours. The tensile properties, compression set and morphological properties of kenaf filled NRLF after 24 hours of prevulcaniza...

The application of pour point depressant(PPD) nano-emulsion has gain extensive attention due to their cold-flow ability and improved performances compared to conventional PPD. The aim of this research was to study the impact on monomer loading in making polymethyl methacrylate PPD emulsion in order to achieve nano sized emulsion using emulsion poly...

The study was carried out to investigate the effect of amine coupling agent of graphene nanopowder (GNP) on the properties of epoxy-based electrically conductive adhesives. Amine-based coupling agent for GNP (m-GNP)/epoxy thin film nanocomposites and GNP/epoxy thin film nanocomposites were fabricated using an ultrasonication and spin-coating techni...

The influence of processing parameters onto the tensile properties, which also indicating the failure rate indirectly, of injection molded polystyrene (PS) was investigated. Dumbbell samples were being molded and tested for tensile properties by using Taguchi method as a robust design of experiment. The tensile properties of PS samples were analyze...

This paper presents the numerical simulation of epoxy molding compound (EMC) filling in multi flip-chip packages during encapsulation process. The empty and a group flip chip packages were considered in the mold cavity in order to study the flow profile of the EMC. SOLIDWORKS software was used for three-dimensional modeling and it was incorporated...

The effects of different parameters on polypropylene crystallization behavior were investigated using a constant stress capillary rheometer. Morphology changes of polypropylene spherulite were characterized using polarized light optical microscope and relationship between growth rate of spherulite, Avrami exponent with respect to the processing eff...

Compression and deformation behavior of partially open cell natural rubber (NR) foam produced from dry natural rubber (DNR), were investigated by performing compressive deformation at different strains and strain rates. Different concentrations of sodium bicarbonate as a blowing agent (BA) were utilized, from 4 to 16 phr in order to produce foams w...

Tensile and electrical properties of graphene nanopowder (GNP) and multiwalled carbon nanotubes (MWCNT) filled epoxy thin film nanocomposites were investigated. In addition, synergy effects of various mixture ratios of GNP–MWCNT hybrids on the properties of the epoxy thin film nanocomposites were evaluated. It was found that the addition of GNPs or...

Graphene nanopowder (GNP)/epoxy thin film composites were fabricated using an ultrasonication and spin-coating technique. This study aims to investigate the effect of dispersion state and filler loading (0.025–1 vol%) of GNP on the tensile, electrical and thermal properties of the GNP/epoxy composites. GNP/epoxy composites with different dispersion...

Investigation on the effect of different processing parameters onto injection moulded low density polyethylene (LDPE) had been done. The LDPE was moulded into dumbbell shape with weld line to better understand the flow front of the polymer melt and where two flow fronts meet. Three parameters were chosen to shear modify the LDPE, which were injecti...

A simple image enhancement technique was proposed to observe and analyze cell structure of polyethylene foams using optical microscopy. Two coating techniques were implemented in this study; one being a simple black soot coating and the other utilized a commercial Au/Pd coating that is commonly used for Scanning Electron Microscopy (SEM) observatio...

Laminated boards were produced by laminating banana stem fibre boards with banana leaf tapes. Various laminated boards were created by changing the number of layers of leaf tapes used. The tensile strength, elongation at break, flexural modulus and impact strength of the laminated boards increased with increasing number of layers of the leaf tapes....

This work focused on the production of natural rubber foams by cross-linking the polymer matrix using high energy electron beam at different irradiation doses (from 50 to 150 kGy) and foaming it with a chemical blowing agent. The aim was to study how the irradiation dose influenced the cellular structure morphology of the produced foams. This was a...

Corn starch has been used as hydrocolloids in kenaf filled natural rubber latex foam (NRLF). Kenaf filled NRLF was successfully prepared by using Dunlop method. This research was carried out to study the effects of hydrocolloid on compression and morphological properties of kenaf filled NRLF. From the graph of 50% compression, it was shown that ken...

Molding development and fabrication is costly and always involves part modification. The cost-effective pre-molding analysis is advantageous to engineer and designer prior to the mold design and before mass production. Computer-aided techniques are identified as virtuously cost-effective for pre-molding analysis. The numerical simulation analysis o...

Kenaf powder was incorporated with natural rubber latex (NRL) compound and foamed to make natural rubber latex foam (NRLF) by using a well known technique called the Dunlop method. Different loadings of kenaf powder were added to NRL compound and was foamed to make NRLF. The mechanical properties, density, compression, thermal, and micro-structural...

Amino-functionalization of graphene nanopowder (GNP) was carried out by grafting ethylenediamine on the surface of GNP through the acid-thionyl-chloride way. Successful grafting of ethylenediamine on GNP surface was confirmed using Fourier transform infrared spectroscopy (FTIR). Beside amino-functionalized GNP (m-GNP)/epoxy nanocomposites, GNP/epox...

A porous chitosan membrane was prepared by using an ultrasonic mixed phase inversion and solution-cast method using silica as the porogent agent and sodium hydroxide solution as the porogent remover. The porous chitosan membrane was soaked in 5.0-M ammonium acetate electrolyte for 48 hours. Several functional groups shifted, and the existence of an...

This research is carried out by incorporate kenaf powder with natural rubber latex (NRL) compound and is foamed to make natural rubber latex foam (NRLF) by using a well known technique called Dunlop method. Different loading of kenaf powder was added to NRL compound and was foamed to make NRLF. The tensile properties, and morphology of kenaf filled...

Porous chitosan–SiO2 membranes were prepared by ultrasonic mixing solution-cast and porogen removal method at different SiO2 weight ratios. To remove SiO2 from chitosan membranes, NaOH solution was used to dissolve SiO2. Porous chitosan:SiO2 membrane with the weight ratio 1:2 produced optimum average pore size (8.5 μm) with an amorphous structure a...

3-D packaging is a technology that offers high density packaging and high performance. It enables chips to be stack in a single package and widely adopted in multi-media products. Thermosetting material is used for their encapsulation, is flowed through their thin space and wide filling area during package encapsulation process has become vital con...

Deviations between data for the apparent and true viscosity measurement are commonly observed in the rheological studies of thermoplastics. To validate the significance on the usage of these data on the processing side, filling analysis for the apparent viscosity and true viscosity of polypropylene-kaolin (PP-kaolin) composites was conducted by usi...

Graphene nanoplatelets (GNP)/epoxy and multi-walled carbon nanotube (MWCNTs)/epoxy thin film composites were fabricate by ultrasonication and spin coating technique. The tensile properties of epoxy containing (0.2, 0.6 and 1 vol%) of GNP sonicated at different duration (10, 20 and 30 min) or MWCNTs sonicated at 20 min only have been studied. It was...

The influence of material data input towards the mold filling behavior of a natural rubber compound during an injection molding process was investigated. A commercial injection molding software (Cadmould) was utilized in evaluating the effect of using experimentally obtained material data on the mold filling progression in comparison to the actual...

Graphene nanopowder (GNP) and multi-walled carbon nanotube (MWCNT)-filled epoxy thin-film composites were fabricated using ultrasonication and the spin coating technique. The effect of sonication time (10, 20 and 30 min) and GNP loading (0.05–1 vol%) on the tensile and electrical properties of GNP/epoxy thin-film composites was investigated. The ad...

The possibility of using Cadmould software to simulate the filling behaviour of a natural rubber compound during an injection moulding process was investigated. For the simulation process, the determination of required material input data involving the rheological and cure kinetics data of the designed rubber compound were conducted. It was discove...

Poly(ethylene terephthalate) (PET) containing 3 wt% of organo- montmorillonite (OMMT) was prepared using twin-screw extruder followed by injection molding. Maleic anhydride-grafted styrene-ethylene/butylene-styrene (SEBS-g-MAH) and N,N-ethylenebis(stearamide) (EBS) were used as impact modifier and dispersing agent. The reprocessing ability of PET/O...

An innovative technique in producing cement syntactic foam (CSF) was proposed in this investigation. This cellular composite material basically consists of a cement matrix embedded with in-house developed cement hollow spheres (CHS). The produced foams incorporated with CHS having different wall thickness, were characterized for compressive strengt...

Additives are costly and can have negative environmental effects. Thus, searching for other alternatives to improve recycling plastics without using additives is necessary. This study aims to improve the hoop tensile strength, elongation at break, and shrinkage of the ring stopper made from an acrylonitrile butadiene styrene blend comprising 40% re...

A low frequency soundproofing cement based material has been developed in this study. This closed-cell composite material basically consists of a cement matrix embedded with in-house developed Cement Spheres (SC) and Cement Hollow Sphere (CHS) or macrospheres. The produced foams known as Cement Syntactic Foam (CSF) were characterized for its' prope...

To investigate the interlocking capability of porous epoxy microparticles (PEM) with elastomers, composites of PEM and ENR/NR were prepared on a two-roll mill. A proprietary method was used to produce the PEM, which have multiple microholes in their surfaces. By establishing an interlocking mechanism with the elastomer, the PEM have potential for u...

Vulcanization kinetics of natural rubber (NR) compounds with efficient vulcanization system was studied through phenomenological approach using the experimentally cure data obtained from a moving die rheometer. The cure kinetic parameters were defined using the proposed models by Claxton–Liska and Deng–Isayev with the support of curve fitting softw...

The crosslinking promotion effect of different peroxide decomposition temperatures in the formation of crosslinked low density polyethylene/ polyfunctional monomers (LDPE)/(PFM) foam was investigated. Two peroxides, namely Dicumyl Peroxide (DCP) and 2,5-Dimethyl-2,5-di(tert-butylperoxy) hexyne-3 (T145), were compared. This was conducted to establis...

The influence of the structure properties relationships of silicone incorporated polyimide (PI) on thermal stability was investigated by using single scan thermogravimetric analysis (TG) and differential scanning calorimetry (DSC) in nitrogen. Four systems have been synthesized based on monomer 4-(4-(1-(4-(4-aminophenoxy) phenyl)-1-methylethyl) phe...

Corak aliran leburan ABS di dalam barel rheometer kapilari tegasan-malar telah dikaji. Kesan perubahan parameter pemprosesan seperti suhu, tekanan dan sesaran penolak terhadap corak aliran diselidik. Suhu and sesaran penolak didapati mempunyai pengaruh yang ketara ke atas corak aliran. Ini diperhatikan melalui perubahan terhadap ketebalan lapisan b...

Both poly(methyl methacrylate) (PMMA) and polystyrene (PS) were synthesized through suspension polymerization, and porous epoxy microparticles (PEMP) were incorporated in-situ during polymerization. It was discovered that the hollow structure available in the PEMP was able to successfully establish an interlocking mechanism with the PMMA and PS mat...

The present study focuses on the development and characterization of epoxy syntactic foam filled with epoxy hollow spheres (ESF/EHoS). The epoxy syntactic foam (ESF) was produced by embedding epoxy hollow spheres (EHoS) into a mixture of epoxy-hardener and 3% KOH solution. An innovative approach and simple procedure was implemented in the preparati...

A study of kaolin addition in polypropylene (PP-kaolin) melt was carried out to characterize its flow behaviour and viscoelasticity at different temperatures. The compound of 20 wt% kaolin was prepared by melt mixing using two roll-mill heated at 185°C, while the compounded composites were put through a single screw extruder to evaluate its melt fl...

This paper reports the synthesis of emulsions of epoxy compounds with various ratios of epoxy, polyamide and calcium carbonate by homogenization in water at room temperature. The emulsion is cured at 80°C, and during curing the small epoxy droplets in the emulsion coalesce. The cured coalesced epoxy droplets contain holes formed due to water trappe...

Finite volume method (FVM) based simulation of encapsulation process in thin quad flat pack (TQFP) packages is presented in this paper. The 3D model of TQFP package is built and meshed with tetrahedral elements using GAMBIT, and simulated by FLUENT software. Castro-Macosko viscosity model and volume of fluid (VOF) technique are applied for flow fro...

Kaolin-filled PP composites were compounded using a heated two-roll mill prior to extrusion process in order to improve the rheological properties of the samples. The extrudate swell and flow instability (melt fracture) behavior of kaolin-filled PP composite melts were investigated using a constant rate type of capillary rheometer at high extrusion...

Acoustic absorbing foam materials are produced from dry natural rubber (NR) with the addition of sodium bicarbonate as a blowing agent. The acoustical efficiencies of NR foams were studied, and the results show a significant influence of the viscoelastic and damping properties of the base matrix. Both of these properties are governed by the average...

Melt flow and extrudate swelling behavior of polypropylene-kaolin (PP-Kaolin) composites were investigated using a single-screw extruder. Kaolin was mixed with polypropylene (PP) using a heated two-roll mill at 185°C and the filler loading were varied from 5 to 30 wt %. Subsequently, flow behavior of the compounded formulations were evaluated throu...

The influences of kaolin content, processing temperature, and shear stress on crystallization of all samples were investigated by differential scanning calorimetry (DSC). The crystallization activation energy calculated using Kissinger’s method displayed a decreasing trend with increasing kaolin content, processing temperature, and shear stress. A...

This paper presents three dimensional (3D) simulation of flow visualization in the encapsulation of stacked-chip scales packages (S-CSP), using finite volume method. The S-CSP model is constructed using GAMBIT and simulated using FLUENT CFD software. The epoxy molding compound is Hitachi CEL-9200 XU (LF) and its flow is assumed laminar and incompre...

Kaolin-filled polypropylene (PP) composites with various kaolin content, processing temperature and shear histories were compounded using a heated two roll-mill. Prior to thermal analysis, the samples were subjected to extrusion process via capillary rheometer. The influences of kaolin content, processing temperature and shear stress on crystalliza...

Polypropylene/kaolin and unplasticised poly(vinyl chloride)/kaolin composites were prepared by directly melt mixing polypropylene (PP) and unplasticised poly(vinyl chloride) (UPVC) with maleic anhydride (MAH) and low cost kaolin via in situ extrusion process. The influences of kaolin particles and MAH in PP and UPVC matrix were discussed through in...

Three-dimensional simulation and experimental investigation of polymer rheology in a miniature injection molding process is presented. The material used in the study is ABS plastic, Toyolac 250-X10 and tests are carried out at different temperatures of the molten thermoplastic which is injected into the mold cavity. FLUENT 6.3 software is used in t...