3D Printing - Science topic

Dear Zahra,

what makes you think it is not possible with SLA/PLD printers? Both tough and flex resins are readily available as commercial products, or you can design your own monomer mixture.

Our latest study, for instance, compares behavior of carbon fillers in tough (Young's modulus of 1.25 GPa without post-curing, marked as "aromatic") and flex (140 MPa, marked as "non-aromatic") resins.

The material is Graphy's Tera Harz material

Composition: Tera hard TC-80 is an LED curing polyurethane based resin suitable for 3D printing characterised by high tensile strength, high abrasion resistance and non toxicity

FDM would probably be the cheapest option. That being said if you are coming at it from a quality standpoint, You wont get better quality than resin printing. These machines do take more clean up but as something to go directly into the hands of a customer I think it would be a better bet for flexibles. Additionally, flexibles can be a bit easier and more reliable to print with resin printing machines. I'd look into DLP and SLA machines as well as FDM machines.

The maximum silicon (Si) content in aluminum-silicon (Al-Si) alloys can vary depending on the specific alloy composition and application. However, one of the commonly used Al-Si alloy series is the 3xx.x series, which typically contains silicon in the range of 1-20%. For example:

Higher silicon content can be found in specialized alloys, such as some of the 4xx.x series and 6xx.x series, which may contain silicon ranging from 4-20% or more.

Regarding the parting limit during dealloying or chemical leaching of Al-Si alloys, the extent of dealloying is influenced by various factors including the alloy composition, microstructure, processing conditions, and the specific dealloying method employed. There is no universally fixed "parting limit" as it depends on these aforementioned factors.

Dealloying involves selectively dissolving one component (often less noble) from an alloy leaving behind a porous structure enriched in the more noble component. During dealloying of Al-Si alloys, silicon is typically less noble than aluminum, so the silicon tends to dissolve more readily.

The extent of dealloying or the parting limit can vary based on the conditions of the dealloying process, the specific alloy composition, and the desired final structure. Detailed studies and experiments would be needed to determine the precise parting limit for a particular Al-Si alloy under specific dealloying conditions. It's important to consider the purpose of the dealloying and tailor the process to achieve the desired properties and structure in the remaining material after dealloying.

you could type "What material is used in dental 3D printing?" in google or google scholar for information to a wide array of materials used depending the desired result. for example teeth use different material than tissue regeneration.

Thank you very much for the response, Petr. I appreciate it.

Madison Feehan Please do recommend my message if it was helpful

Selective Laser Melting (SLM) and Selective Laser Sintering (SLS) are advanced additive manufacturing technologies used to create three-dimensional objects by selectively melting or sintering layers of material powder. These technologies have applications not only on Earth but also in space. In-space manufacturing using SLM and SLS is gaining attention due to its potential to support long-duration space missions, colonization of other planets, and sustainability in space. Here are some of the technologies being enabled for SLM/SLS manufacturing in-space:

In-space SLM/SLS manufacturing has the potential to revolutionize space exploration by reducing the need to transport all equipment and spare parts from Earth. These technologies are still in development and will continue to evolve as space exploration efforts expand.

The study of 3D printing in construction may encompasses a wide range of areas, such as:

· The development of sustainable and high-performance materials for structural purposes.

· The optimization of printing processes to enhance speed and quality.

· Experimentation with innovative design techniques and optimization methods.

· The integration of building systems such as: mechanical, electrical and plumbing.

· The use of automation and robotics to enhance productivity and safety.

· The assessment of the environmental impact of the lifecycle of structures, standardization and regulation of 3d printing.

· Analysis of the cost and economic feasibility, case studies of real-world examples, and

· Exploration of social and cultural implications such as workforce impact and ethical considerations.

Hello,

You can check the following link:

Fused Deposition Modeling (FDM) and Stereolithography (SLA) are two different 3D printing technologies, each with its own set of advantages and disadvantages. The choice between FDM and SLA depends on the specific needs and requirements of a particular project. Here are some reasons why you might choose FDM over SLA:

However, it's important to note that SLA has its own advantages, such as higher resolution and finer detail capabilities, which make it a better choice for applications like jewelry design, dental models, and intricate miniatures. Additionally, SLA can produce smoother surface finishes in some cases.

Ultimately, the choice between FDM and SLA should be based on the specific requirements of your project, including material properties, print size, cost constraints, and desired surface finish. Many 3D printing enthusiasts and professionals use both technologies in their work to take advantage of their respective strengths.

Mohsen Samimi

Thank you for the help. I have looked into the electrospray method but I thought it does not allow for exact control of bead size and therefore leads to a large difference in bead size.

Best wishes,

Abdullah

In Binder Jet 3D Printing (BJP), cobalt-based alloys are often combined with a specific type of binder material to create the printed parts. The binder serves as the adhesive that binds the metal powder particles together to form the green part, which is a fragile, porous, and non-sintered 3D printed object. After printing, the green part undergoes post-processing steps, including debinding and sintering, to achieve the final dense metal part.

For cobalt-based alloys in Binder Jet 3D Printing, the common binders used are:

The choice of binder depends on various factors, including the specific cobalt-based alloy used, the 3D printing equipment, the required part properties, and the intended post-processing methods. Different binders may have distinct effects on the green part's mechanical properties, dimensional accuracy, and ease of debinding.

After the printing process, the green part is subjected to a debinding process, where the majority of the binder is removed to create a porous structure. The final step is sintering, where the part is heated to high temperatures to fuse the metal particles together, resulting in a fully dense and functional metal component.

It's important to note that different 3D printing systems and material formulations may use variations of binders to achieve optimal results for cobalt-based alloy parts. Always follow the manufacturer's guidelines and recommended materials for your specific Binder Jet 3D Printing system and application.

Joachim Günther, for example, it could be a convencional 3D filament with shape memory alloy.

In binder jet 3D printing, the choice of binder is very crucial. It is a complex problem that depends on various factors like the powder's material, the final part's required properties, post-processing steps, and safety and environmental considerations.

For metallic powders such as copper alloys, typically, the binders used are based on acrylic or polyvinyl alcohol (PVA) materials. These are often preferred due to their good binding properties and relatively easy burnout during the post-processing phase.

Here are a few types of binders you could consider:

While these binders can provide good binding for copper alloy powders, it's important to note that the choice of binder is only one aspect of the process. The binder content, printing parameters, and post-processing steps (like debinding and sintering) all play a significant role in determining the density and mechanical properties of the final part. Therefore, optimising all these parameters for your specific application may take some trial and error.

Also, remember always to consider safety and environmental impacts when choosing a binder. Many binders can release harmful gases during burnout, so proper ventilation and safety measures are important.

Finally, it's also beneficial to consult with binder manufacturers or experts in binder jetting, as they may be able to provide more specific recommendations based on their experience and your particular needs.

yes

The swelling ratio is calculated from the water content, so it is more or less the same thing expressed in two different ways. However, remember that many biomedical applications use a physiological solution rather than pure water, so the ionic exchange can alter the swelling ratio of your hydrogel. Therefore, all stability tests shall be done in relevant conditions.

There is no absolutely identical powder before grinding, therefore there is no absolutely identical slurry after grinding. For this reason, the amount of water must always be adjusted to the specific case. The basis for adjusting the amount of water is the rheology (viscosity of the slurry). You cannot weigh the water before grinding and be sure that the rheology is correct afterwards, because many factors can play a role. Adjusting the amount of water is essential not only in the laboratory but also in industrial production.

By the way, if you grind it in a plastic container, you get a significant amount of scrap plastic in your slurry, which can massively affect rheology.

The relationship between 3D printing and quality costs is influenced by several factors. The initial investment in a 3D printer can impact quality costs, as higher-quality printers tend to offer better precision and reliability. Material costs also play a role, as higher-quality materials can lead to better prints but may be more expensive. Design optimization in 3D printing can help improve quality and reduce costs by eliminating unnecessary steps and reducing material usage. Addressing quality issues early in the design phase can reduce rework and scrap costs. Proper maintenance and calibration are crucial to achieve consistent quality and avoid additional costs. Post-processing requirements can also impact quality costs, as additional labor, equipment, and materials may be needed. The specific application, industry, and context are important considerations when analyzing the relationship between 3D printing and quality costs.

Dear all, following links for interesting literature supports. My Regards

10.1016/j.jare.2018.05.001

Nekin Joshua This is a very important question that comes to our mind whenever we start to procure the raw filament for FDM-related experiments. I was also in the same situation trying to find out, a few years before.

Answer:

Yes, the colour of the 3D printing filament does affect various material properties including mechanical strength. The common colourants used in the filaments can be pigments, dyes, masterbatches, or pearlescent powders. In FDM 3D printing, where various colours of filament are used, it is possible that some of the colouring agents present in the filaments may also act as nucleating agents, thus, influencing the crystallization rate of the material being printed. The modified crystallization rate can result in variations in stiffness, strength, and other mechanical characteristics. Therefore, the impact of colouring agents on crystallization rate and mechanical strength can vary depending on the specific material and colouring agents used. Colourant additives in FDM filaments can also play a role in the gap size or the flow characteristics of the material during the printing process, thus showing different properties for different coloured filaments. Therefore, it is important to consider the composition of the raw filaments and conduct appropriate testing and analysis to assess the effects on material properties when using colored filaments in FDM 3D printing. For better results, consider the pure form of genuine pallets (Free from colourant) and create your own filaments to be used for experiments.

One of the important literature considering PLA and its various colours impacting the material properties is :

Currenty, I am finishing a PhD on FGF, with initeresting results.

Please see our Results, all published in peer-reviewed jourals:

10.3390/polym13183160

DOI: 10.1016/j.cirpj.2022.11.020

Best regards,

AP

Dear Nekin,

Nice question, I believe that it will be difficult to find a well-supported answer!

Hereinafter there are only few considerations from my part.

a) The price of 3D printing composite filaments is determined by a multitude of factors (nature of polymer matrix, fillers, reinforcements, additives, capacity of production, and so on).

b) Traditionally, the twin-screw extruders (TSE ) can be successfully used to produce various composites by melt-compounding, of good quality and with high throughput, which can be proposed for 3D applications.

c) Unfortunately, TSE are less adapted for the direct production of 3D filaments of high quality, even that there are few suppliers that can propose this kind of equipment for one step production, designed mostly for academic research/low-capacity production (e.g., Lestritz, ThermoFischer, etc.). Maybe other RG collegues can help more with information...

d)Please take a look :

Thermo Scientific Process 11 Lab-scale 3D Filament Production System

e) For the production in big quantities of 3D filaments it’s generally agreed that the production in two steps (1. fabrication of composites with TSE; 2. the extrusion of 3D filaments, e;g., using a single screw extruder) has a large number of advantages. I will refrain from more comments...

f) Function of requirements/ your application (type of composite), I suggest you use as starting point the price of 3D filaments/composites that look similar/satisfy your needs, and which are already commercialized in the market!

Success in your R&D project and best regards,

Marius

Shohin Aheleroff Yes, 3D printing/additive manufacturing is a great technology for producing personalized products at scale. With 3D printing, it is possible to create unique and customized products without incurring significant additional costs. This technology also enables on-demand production, reducing the need for inventory and allowing for faster product delivery times.

Moreover, 3D printing can be used to produce complex shapes and structures that are difficult or impossible to manufacture using traditional manufacturing techniques. This can be especially useful for medical implants, jewelry, and other products that require a high level of customization.

However, it is important to note that 3D printing has its limitations in terms of materials, size, and production speed. It is also not suitable for mass production of certain types of products. Nonetheless, as the technology continues to improve and new materials become available, 3D printing is expected to play an increasingly important role in the production of personalized products at scale.

Thank you so much! John

For a somewhat related discussion, see: https://www.researchgate.net/post/How_can_I_avoid_the_formation_of_air_bubbles_when_hydrogels_are_made_by_gamma_irradiation_technique

3D printing with robotic arms ,and multidirectional slicing

Form labs is one company that offers a variety of SLA 3D printer

You can follow this article to get idea on various SLA 3D printer (proprietary names) and their applications in pharmaceuticals.

FDM 3D printing materials are ABS, PLA, and their various blends. More advanced FDM printers can also print with other specialized materials that offer properties like higher heat resistance, impact resistance, chemical resistance, and rigidity

Below is a table (generated by chatGPT) showing the Specific Energy Absorption, Strength, and Stiffness for each of the materials you listed.

Note: The specific energy absorption, strength, and stiffness values given above are typical values and may vary slightly depending on the manufacturing process, dimensions, and specific type of material.

try designing a gear reduction gearbox, you will need at least 2 gears to prove your point, 3 for the gears to last longer to be inspected, 4 or more for long term...I think you get it.

Hello.

There are several journals and books that may be helpful for your research on the optimization of process parameters and geometry of molds for plastic injection molding using 3D printed molds. Some journals that cover topics related to plastic injection molding and 3D printing include:

As for books, there are many books that are focused on plastic injection molding, but some that have specific information about simulation and optimization of the process include:

These resources should provide you with a good starting point for your research, but it's important to keep in mind that the field is rapidly evolving and new papers/publications on this topic can be published frequently.

Regards.

Hello Sahar Halevi ,

https://www.thermofisher.com/order/catalog/product/567-7600?cid=7010z000001DAtV

https://www.thermofisher.com/blog/materials/advanced-3d-printer-filament-strands/

Ultem is a material that can be printed by some FDM machines, however these are typically classed as high temperature FDM machines. The main differences being they have a heated chamber, heated build platform and increased nozzle temperature range.

It can be printed however not all standard FDM machines will have the capability required.

There are several biomimetic structures that are known for their energy absorbing properties and potential use in armor applications. Some structures that you may want to consider include:

To answer your question, the specific biomimetic structure that is most suitable for use in armor applications will depend on the specific requirements of the application (where and how will it be used specifically?) and the properties that are most important, such as energy absorption, toughness, and weight. I recommend conducting further research and analysis to determine which structure is the best fit for your specific needs.

Hi Kevin,

I have the same problem. Could you please let me know the concentrations that should be added for dissolving the photoinitiator?

Thank you so much in advance,

Mahmood

Hello Evgeniy Andreevich Zayats,

Selecting the right 3D printing technique for specific requirement depends on following things:

1. What size of product you want to print ?

2. What are the aesthetic & dimensional accuracy requirements ?

3. What is the product end use ?

4. How frequently you want to make product ?

SLA will give you more accurate & precise results with better finish. However, operating SLA is a tedious task as you have to handle the liquid. For which you will require Nitrile gloves, safety goggles, print washing liquid (i.e. IPA -Isopropyl alcohol) , cleaning containers, UV light source for post curing. So more money will go in the consumables. Also resin will spread some type of odour in your working area. Yes, in SLA support removal is easier but at the same time the print can break due to brittle nature of the resin.

FDM is easy to handle and more user friendly machine. You just have to buy filaments (i.e.PLA or ABS) & no other addition thing required. However, The accuracy & precision of FDM is low compared to SLA and layer lines will be visible to your product. You can make bigger product using this by cutting your protein model into pieces and print it on maximum size. After printing you can join the pieces with Cyanoacrylate adhesive & make your final big product.

If you have to make only few models then go for outsourcing services of SLS or HP multijet option (coloured object is also possible). It will give you the best output, but it will be costly.

Dear Serge V. Shil’ko

Thank you. My objective is that the monolithic composites are based on the fact, that interaction and bonding between different materials may show various properties, in this case, lower mechanical properties rather than modern technologies such as additive manufacturing.

You can use some thermoplastic elastomers e.g soft PLA and also the cellulosic materials for 3D printing

Dear Amir Hamza Khan ,

Despite all their advantages, load-bearing concrete shell structures with double curvatures are not frequently in use. The main reason is the complexity of their construction.

Regards,

Shafagat

An excellent starting point is the online database put together by W.R. Leal da Silva

Dear Sam Choppala,

Regarding your first question about methyl cellulose. This water-soluble binder works well in a basic solution at temperatures below 15°C (cold water). SiO₂ makes the solution acidic and this allows the methyl cellulose to polymerize. For acidic solutions there is another water-soluble binder - polyvinyl alcohol (PVA), which you can successfully use here.

The second question (sintering of SiO₂ ceramic) is much more complex than you think. Pure SiO₂ ceramic does not exist and cannot be produced by sintering. The problem with this is the polymorphic transformations of SiO₂, which are associated with large changes in volume (when heated, alfa quartz first transforms into beta quartz and then tridymite and cristobalite form). In order to avoid this problem with polymorphic transformations, SiO₂ (quartz) must be sintered with additions of CaO and FeO. The resulting refractory material (silica brick) is not dense technical ceramics, but porous coarse-grained refractory stone used in furnace construction.

Control the temperature.

visit this link

I sent you an email.

Keep in touch.

Dear Nekin,

You can downdoad free STL files from several websites such as Thingiverse, STLFinder, MyMiniFactory, GrabCAD and Cults.

You may find a more options at https://www.3dnatives.com/en/top-10-websites-stl-files-161120174/

I wish you good luck on this new journey.

PLA crystallizes above glass transition (ca 60°C). Crystalls have higher density and the material shrinks, causing the warping. Plus the graphene filling may cause adhesion issues because it is hydrophobic. I suggest doing the following steps (all of them):

1) decrease the bed temperature to ca 50-55C

2) increase the hot-end temparature to 200C or more

3) use some adhesive to improve the adhesion

freeze, crush and sieve

Or spot for milling of pigments.

What kind of eqipment do you have?

Hi, the quick answer would be a twin-screw extruder. Other options are mentioned in the reference kindly provided by Mohammed Hussein j. H. Al'Atia above; however, the overview there is very brief.

Maybe,

get familiar with the standard boat test?

I have not tried UVO cleaning. I found that typical microscope slides are problematic. We use Corning Incorporated micro slides (2947-75x50) at my lab. We clean the slides before hand with 2% dawn detergent (spray bottle), rinse thoroughly with tap water, then deionized water and finally with isopropanol. The slides are then dry under nitrogen and not touched with bare hands. We functionalize the PDMS and slide surfaces in a Harrick plasma generator for 30-90 seconds.

I am also trying to incorporate the laser in the ansys..but it's very difficult to find any source

Hey Ankitha,

I am following the same issue. Were you able to find any viable solution for this problem?

It’s my pleasure

Industrial 3d printers capable of producing multi-materials components by vat photopolymerization have emerged in recent years. In general, they use multiple vats, each with a different material.

The following link from a supplier has some very helpful video and images to understand the process.

Hi Ezekiel,

It's all a matter of how high you need the resolution of your DOE to be. For example, if you are having extremely high precision (low variance in replicates always) then there is barely a need to have elevated numbers of LOF/replicate points.

A more sophisticated approach is to check the Fraction of the Design Space (FDS) graph and see if the resolution for your purpose is sufficient after you have created the DOE. You can check this video from statease and make yourself familiar with FDS: https://www.youtube.com/watch?v=6CUa_n6ZEj4

Yes , read the paper (3D printing of polymer matrix composites: A review and prospective)

3D scanning, additive manufacturing, and CAD/CAM software are applied during the development process.

Ahmed Z. Naser

For FDM SimaPro modelling in gate-to-gate first you should have clear system boundaries based on the research scope. I would like to suggest the following research articles for in-depth study:

Hope them helps you

Best regards,

Shuraik

Hi Rory Gibney , thanks for the suggestion.

This was in the options I was thinking of, we actually have a Chiaro nanoindenter in the lab and would not be too difficult to move it on the microscope I need to use. We actually wrote a JoVE protocol on the Optics 11 nanoindenters: https://eprints.gla.ac.uk/261066/2/261066.pdf :)

I was thinking of something easier - not necessarily a commercial instrument - maybe something that can compress / stretch the gel perpendicularly to the direction of imaging, while recording the force.

Giuseppe

I agree with Ross James Friel. The storage modulus determines the solid character, while the loss modulus determines the liquid character of a polymer. When the storage modulus is too high, it is more difficult to break down the polymer, making it harder to run through a nozzle extruder. With a high loss modulus, the polymer is too liquid and may start to flow out of the nozzle, and not hold its shape very well. A polymer suitable for 3D printing should have a balance between these two moduli. Preference is given to polymers with a storage modulus greater than the loss modulus, as they provide a material that retains its shape while being extrudable.

Have you tried the ANSYS Additive suite? More information is available at this link::

I invite you to check our paper, in which we compared the effect of stress relief with parts attached to the building platform on, among others, residual stress in laser powder bed fused IN718 alloy.

Actually, Powder Bed Fusion (PBF) is an advanced AM technology that has matured over an extended period of research and industrial development. This technology development has enabled wide uptake of commercial applications of PBF technology, particularly for the production of high-value products that are not technically feasible with traditionally manufacturing processes.

Actually, Metal powders used in AM processes are typically microscopic in size (< 100 µm) and often pose toxicity, reactivity, combustibility and instability hazards. Dust clouds, formed for example by the accidental swirling of powders, have the potential to catch fire and explode under certain conditions.

One thing we could imagine is to use reverse FDM to make a perfect bridging machine without supports:

In reverse printing the hot filament will fall in the direction of the head. It is theoretically possible to add a cool, flat, non-adhesive substrate (yes those are harsh conditions) to maintain the filament position long enough for it to cool down and solidify. Please look at the image i included to have a better idea of what i mean.

Although the engineering side is very challenging what is your take on this idea?

You should choose a mixture whose refractive index (RI) matches the ceramic particles RI. The cured depth thickness is inversely proportional to the square of the difference between the RI of the resins and the ceramic powder.

The following paper discusses this matter and presents an extensive list of photopolymers that have successfully been used in works related to ceramic vat photopolymerization and their refractive index.

I have not heard about a photopolymer resin that is not safe to go through the heating post-processing. However, SLA uses formulations with a high amount of organic materials, and therefore, the debinding must have adequate heating rates to avoid cracks.

The following paper presents an extensive list of photopolymers that have successfully been used in works related to ceramic vat photopolymerization (SLA and DLP).

Dear Sudhakar M.P , your definition of biopolymer is not clear. Biopolymers can be divided into bio-based polymers and biodegradable polymers. Bio-based polymers are produced from biosources and can be biodegradable or not, for example, starch or bio-based PE. Similarly, biodegradable polymers can be either bio-based or fossil-based, for example, PBAT is fossil-based while PLA is bio-based.

Now, come back to your questions, I think PLA has been used extensively in 3D printing and PLA is both bio-based and biodegradable.

Best regards,

This list of scientific contributions published in the current year 2021 will be very useful:

Sonali Shankar I havent worked on DN gel. But from my experience working with hydrogel fabrication. I take 0.1 wt% of photoinitiator ( 2 mg in 2 mL Di water) and dissolve my biopolymer in that solution - 10 mg/100 μL to get 10 wt% of polymer solution and use it for hydrogel fabrications. Calculate 1mol of AMPS using its MW and then MBAA is used 4 mol% (4 equivalent) and photoinitiator 0.1 mol%(0.1 equivalent).

Hello,

"Line width defines the width of a single printed line, which should be close to the nozzle size. Based on the line width, the extrusion rate is adjusted, which means that it will automatically calculate how much material must be extruded."

From:

If you print with a 0.4 MM nozzle, you should use 0.4 MM as your line width. The documentation states "Decrease the line width slightly of the outer wall to allow sharper detail on the model." which would increase print quality.