Contrary to FDM or fused deposition modeling, which makes use of solid filament spools, resins used in 3D printing services come in the form of liquid solution. This liquid solution is often a medley of different oligomers and monomers being put together, comprising mostly carbon atoms and several functional groups. By allowing them to stand in this state, they are bound to maintain their liquid form.
There is but one goal here, and that is to create longer chains with the help of oligomers and monomers. Eventually, they will form the plastic material that is tough and hard enough for use in 3D printing. The looming question now is, how can we render these short chains come together so we can form them into longer chains?
Everything about it will be highly dependent on photopolymerization. The energy that this process can generate from a light beam produces enough power that will make the molecules found at the terminal end of oligomers and monomers to escape.
When this happens, it tends to create an imbalance charge both in the oligomers and monomers. It also creates the same impact on their terminal ends which now can freely react with each other.
If their reactive end members band together, their natural tendency is to form polymer chains that are quite long enough for it. And this may not qualify as a one-step process since they are bound to continue forming long polymer chains in the space in a fraction of a second.
One of the key advantages of having resin-based 3D printing services has something to do with the “curing” phase. It is not bound to pause or stall after all the layers have been printed. A good amount of oligomers and monomers will remain in their unreacted state, and for this reason, they will likely go and stay open or likely to bond with the next or upcoming layer.
This explains the reason why layer adhesion in 3-dimensional printing (resin-based type) is seen as less of a trouble as opposed to how it is with FDM.
Layers that were bonded together at a molecular level signify that there is practically no disparity when it comes to the tensile strength with any of the 3 dimensions. This translates the Z-axis tensile strength to be at par or equal to the X and Y axes tensile strengths.
What Makes a Resin Good for 3D Printing Jobs
When trying to look for a resin for your 3D printing concerns, the foremost important thing you need to consider is the purpose you have for the printed object or the final output. Unlike the filaments used in FDM printing, you can use them interchangeably with one another. The resins intended for 3D printing purposes are best described as more specialized products.
Quality of finish
DLP and SLA resin prints are highly reputed because they are capable of delivering a smooth finish. You are likely to achieve such a result with multiple post-processing FDM prints. But some specialty resins are making a high claim as being able to produce extraordinarily smooth prints.
If your offered 3D printing services are more after smoothness of output and high and fine quality of details, this type of resin would work best in delivering your goals.
Despite being known for their exceptional layer to layer adhesion capability of DLP and SLA prints, industry insiders are not keen on giving them high regard for being tough. 3D printed resin-based materials have earned this notoriety of being brittle. Besides, they are also known for their susceptibility to shattering and cracking.
To resolve such loopholes, the global manufacturing community came up with an innovative idea of producing “engineered resins”. They are formulated in such a way that they will mimic or simulate the inherent toughness of plastics formed by virtue of the injection-molding method.
When it comes to flexibility, there are types of resins that are known to take it a notch higher than the rest and take the prints with distinct rubber-like properties. The resulting product for this resin comes with very high elongation attributes, low tensile modulus, and lastly, extremely high impact resistance. Hence, making them ideal to use in 3D printing objects that are intended for bending and compressing.
Similar to how the translucent and transparent FDM filaments work, we have a handful of specially formulated 3D printer resins. They are made specifically for that purpose alone, creating objects that the naked eye can see through. Hence, these objects are transparent.
Objects that are made using transparent resins come with mechanical properties that are way too different from the standard resins we use. However, you can wrap up your work the moment that you are satisfied with the level of transparency that your recent printing has made. This type of resin will help you 3D print a glass-like object.
As of this writing, the use of resins in 3D printing would still command a high price compared to traditional systems we have, both in terms of the resins themselves as well as printers. But there is no denying here that high market demand for this technology only goes to show that it will continue to gain traction in various industries. With that, it is bound to still evolve and improve in the long run.