Along with thermoplastics, liquid resin is one of the most popular 3D printing materials. Its properties allow it to produce unique prints, and its resistance to melting is one such property.
3D printer resin cannot melt after it has undergone curing. Resin 3D prints can still burn, scorch, or deteriorate when exposed to high temperatures, but they will not liquefy. Thus, you cannot melt down or recycle resin 3D prints.
In 3D printing, a material’s melting tendency can be both a pro and a con. Thus, resin’s resistance to melting may affect its use. Keep reading to understand why.
Why Don’t Resin Prints Melt?
Resin printing materials harden when exposed to UV light because they change their composition and form complex, solid chemical bonds as you print with them. Because of these new bonds, resin does not melt, even under high heat.
Resin prints don’t melt because of strong chemical crosslinks. Once cured, these crosslinks are difficult to break or disturb. These crosslinks form through an irreversible photopolymerization process that makes resin prints resistant to damage, even in extreme conditions.
Photopolymerization involves using light to induce a reaction between the resin molecules, allowing them to form a strong, crosslinked network or polymer chain.
This chain results in a 3D print that will stay intact no matter how hot you get it. Therefore, resin 3D prints are ideal for applications where you plan to expose them to heat.
Do Resin Prints Soften?
Although resin prints do not melt under extreme temperatures, they are not entirely resistant to the effects of heat. They may still incur slight deformations through softening.
Resin prints soften at temperatures above 40°C (104°F). This process occurs because resin printing materials lose elasticity at such temperatures. However, the temperature at which they soften depends on the resin used and its curing conditions.
Another situation 3D printer users mistake for melting is when their resin prints leak. Leaking can be dangerous, but it doesn’t mean the model has melted.
Most likely, there was uncured resin within the model, and due to extreme pressure, the model cracked, allowing the liquid to escape. Be very careful when dealing with situations like this, and re-cure your print immediately.
What Is Resin Curling?
Resin prints don’t melt, but they can leak and soften. However, besides these two flaws, you must look for other situations affecting resin print quality, such as curling.
Resin curling in 3D printing is similar to warping in thermoplastic 3D printing. Curling can happen because of a lack of support or the existence of flat, thin structures in the model’s design. Overexposure to sunlight after curing may also cause curling.
While certain thermoplastic 3D prints melt under the heat of the sunlight, resin prints curl instead. Thus, even if resin prints do not typically melt under sunlight, you should still avoid exposing them to sunlight or heat immediately after curing.
What Are High Temp Resins?
I’ve discussed that although resin prints aren’t known to melt when exposed to heat or extreme temperatures, they are still susceptible to other irregularities. However, some resins can compensate for the inconsistencies and sensitivities of standard 3D printing resins.
High temp resins are printing materials that deflect high temperatures. This ability allows them to resist deformation, even in high heat. They form rigid prints and are thus not recommended for making flexible parts.
High temp resins are for applications involving “hot air, gas, and fluid flow.” They are also ideal for making molds.
What Are Other Resin Types?
Other resin types include standard, clear, draft, tough & durable, rigid, flexible & elastic, medical, dental, jewelry, and ceramic. These may have specific applications, such as creating dental models, jewelry, ceramic dishes, and medical tools.
Each resin type results in prints with unique properties, qualities, and appearances. For instance, if you want to make transparent 3D models, you should opt for clear resins.
You can also mix resins to take advantage of their various properties. For example, you can mix high temperature-resistant with flexible resin for a heat-resistant, soft model.
Can You Recycle Resin Prints?
You cannot recycle resin prints since resin 3D printing materials do not melt down. Since you cannot break down resin 3D prints, they are far less sustainable than filament prints. If you make a mistake with a resin print, you can only throw it away.
Some people attempt to make resin 3D printing more sustainable by grinding resin prints to reuse them for art projects. However, other than creating powders and pigments with them, there are few to no ways to reuse models made from resin.
Can You Use Leftover Resin?
Suppose you have a project with a lot of leftover resin. Is it possible to use it for other projects, or is it as good as trash?
You can use leftover resin if it hasn’t cured. You can use a filter to separate the cured resin from your leftovers. If you do not use the excess material immediately, store it in a container separate from its source.
It is crucial to ensure that your resin is not cured, even in the slightest, if you plan to reuse it. Printing with clumped-up resin often results in print failures, which would create more waste.
I also recommend storing the resin in a new and separate container to avoid contaminating the resin in the original bottle.
If you have no spare container for the leftover resin, you can leave it in the vat. However, make sure it is covered and not exposed to any light. Remember, resin polymerization occurs when light hits the material. Thus, any exposure might lead to curing, even if it is only slight.
If you leave it in the vat, use it as soon as possible. I recommend keeping it there for a few days at most.
Resins do not melt, making them more durable than thermoplastics under high temperatures. However, they are not invulnerable. Resin prints can soften and curl under heat and sunlight. Still, you can use high temp resins, which are more heat-resistant than other materials, to help resist the impact of high temperatures.
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I started 3D printing since 2013 and have learned a lot since then. Because of this I want to share my knowledge of what I have learned in the past years with the community. Currently I own 2 Bambulab X1 Carbon, Prusa SL1S and a Prusa MK3S+. Hope you learn something from my blog after my years of experience in 3D printing.