What Is Resin 3D Printing?
A Resin 3D printer is a machine that holds a vat of photosensitive liquid resin and exposes it to UV LED light beams, layer by layer to harden the resin into a plastic 3D model.
Simply put, resin 3D printing is the technology in which liquid resin is stored in a container, instead of being injected through a nozzle. It is arguably referred to as an “umbrella” term for the family of additives manufacturing technologies that are liquid photopolymers, layers-by-layers into a solid object.
As far as 3D printer is concerned, there are two common options: the filament 3D printer (FDM or FFF 3D printer) and the Resin 3D printer (otherwise known as SLA or MSLA 3D printing). As a matter of fact, close observation reveals that these two different technologies differ in quality.
Whereas resin 3D printers can print 3D models that will have super smooth surfaces with fine details; FDM 3D printers cannot print models of such high quality because of the accuracy, positioning, nozzle size, and large layer height capabilities.
For instance, an FDM 3D printer of excellent quality can usually print at a minimum of 0.05- 0.1mm (about 50-100 microns); which translates into taking printing overall. On the other hand, resin 3D printers can cure a whole layer at a time rather than having to outline the model as filament printers do.
A model printed with a resin 3D printer usually has layers that are better fused into each other in a way that brings satisfactorily high quality. They are also known to be more brittle than filament 3D prints but there are now some great highly strong and flexible resins that can be used.
Maintenance Of Resin 3D Printers
A very important characteristic of a resin 3D printer is that it has fewer moving components than a filament printer. This means that one doesn’t have to worry about dealing with so much maintenance.
Furthermore, as far as maintenance is concerned, resin 3D printers have FEP films which, although are consumable, can still be replaced if proper precautions are taken. In times past, FEP films are susceptible to punctures because of residues that are not properly cleaned out before another print. However, they were usually not expensive. Some of them cost as low as $15 for a pack of 5.
Another consumable is the LCD screen within the 3D printer. Modern monochrome screens can last up to 2000 hours and more of 3D printing, though the RGB (red, green, and blue) types of screens run out quicker and may last for up to 700-1000 hours. The LCD screens can be a bit expensive, depending on the kind of 3D printer that one has.
The larger the 3D printer, the more expensive it is. The good news, however, is that manufacturers have improved at prolonging the lifespan of these screens. Resin 3D printers particularly have improved cooling systems that help the LED lights go on for longer periods.
How Are Resin Printers Constructed?
Resin 3D printers are liquid photopolymers (resins). The resins vary by monomers, oligomers, and photo-initiators in the bleed. And as a result of this variableness, resin 3D printers differ in the following ways:
- Highest possible resolution
- Chemical and mechanical resistance
- Stiffness and strength
- Exposure time for solidification
- Wavelength required for curing
Again, resin 3D printers aren’t commonly interchangeable. For example, SLA resins won’t work on DLP printers.
A typical resin 3D printer consists of a light sourced build plate (where the object is formed), mirrors, and a resin tank. However, other features vary, depending on the kind of Resin printer.
The following are the components of a resin 3D printer
- Resin Vat
- UV LCD Screen
- UV acrylic lid to retain and block light
- FEP film
- Build plate
- USB and USB drive
- Thumbscrews to secure build plate and resin VAT
Types Of Resin 3D Printing
The major types of resin 3D printing include Stereolithography (SLA), Digital Light Processing (DLP), and Liquid Crystal Display, otherwise known as Masked Stereolithography (MSLA).
- Stereolithography (SLA)
Stereolithography resin 3D printer works with the aid of a UV laser light that is applied on the surface of a photopolymer container known as Resin VAT. During this process, the light is applied in a specific pattern so that desired shape can be formed.
SLA 3D printers include several components such as a building plate, a resin VAT, a light source, an elevator, and a pair of galvanometers (a pair of movable mirrors used to align the laser beam). The main purpose of the elevator is to increase or decrease the height of the building platform so that layers can be formed during the process.
There is a direct relationship between the resin VAT and the uncured resin because the resin VAT contains the uncured resin. Hence, the uncured resin hardens in layers due to the effect of UV light and begins to form a 3D model. Resin 3D printers keep on printing one layer after the other and this process is repeated until a complete 3D printed model of an object is formed.
- Digital Light Processing (DLP)
Digital Light Processing uses a technology that is similar to the SLA but it replaces the use of lasers with a digital projection surface as a light source. In comparison with the SLA, DLP is more advantageous — while you can only print one point at a time using the SLA technology, the DLP resin 3D printing works by printing a complete layer at a time. This explains why DLP resin 3D printing is much faster than the SLA.
In addition, the DLP technology is also popular for its reliability because it does not have moving parts and its simplicity. The major benefits of using DLP resin 3D printing are much smoother and faster prints.
It is however very essential to note that there is an inverse relationship between the print area and the quality of processing. Thus, an increase in the print area automatically decreases the quality of processing. Furthermore, one of the criteria for DLP 3D printing is that it uses an additional digital micro-mirror device to transmit light from the projector. A digital micro-mirror device (DMD) is used to control where exactly the projection will be applied in resin 3D printers.
- Masked SLA Or Liquid Crystal Display (MSLA/LCD)
In comparison with DLP 3D printers that use an additional micro-mirror device to transmit light from the projector, Masked SLA, otherwise known as Liquid Crystal Display (LCD), requires the use of UV beams or light which come directly from the LEDs that glow through the LCD screen. This technology is known as MSLA- Masked SLA.
Resin 3D printing has become more popular and accessible to the average person since the invention of MSLA/LCD technology. This results from the fact that additional components for LCD 3D printing are relatively cheap. Hence, the lifespan of an LCD 3D printer is a bit shorter than the DLP chipset and often requires more maintenance as well. In spite of this, LCD/MSLA 3D printing is more popular as it offers smoother surfaces and faster prints.
Please bear in mind that the light that is emitted from the Liquid Crystal Display screens (LCDs) is harmful to the organic compounds within. Therefore, one has to change them according to the time span and performance.
How Do You Use SLA And Resin 3D Printing?
The SLA and resin 3D printing can be used in many ways: jewelry making, dentistry, animation and props, miniatures, prototyping, and product development. These 3D printing types use VAT polymerization method for all of these functionalities.
- Jewelry Making
Resin 3D printing can produce accurate, smooth, and attractive models in a very short time. Using a castable material, these can points can be sent straight to casting services to create the final piece in a metallic form. It can also be used for making the mold itself, skipping the intermediate model.
In the 3D printing industry, resin 3D printing helps to produce both training models and end-user devices. Custom-made dental devices such as bridges, crowns, aligners night guards, surgical grill guides, splints, impression trays ad more can be printed from a bio-compatible ‘dental’ resin.
In times past, every correcting dental device must be custom-made. This takes many steps and much time to get manufactured. With CAD-compatible software and resin 3D printers, specialists usually would create easier and quicker dental devices from a CT scan, with few improvements to the 3D models.
- Animation And Props
There are many 3D printing methods for visual artists, filmmakers, and cartoonists. One of them is polymerization. In fact, polymerization is better when the props are small and detailed.
In recent times, computer-generated imagery is now commonly used in films, cartoons, and visual graphics. Nevertheless, props and real action models are being used. Animators, movie-makers, designers, and toymakers use them for better quality. They also use them for improving their digital design or straight up in making movies.
Resin printing is very common among table-top miniature makers such as gaming fans, collectors, and hobbyists of all sorts. Miniatures can be used for an array of things, especially after they are built and post-processed, or can serve as a model for creating a casting method.
- Prototyping and Product Development
As beneficial as resin 3D printing can be, it may not be the best choice for large-size objects with simple geometries because of its costs. But products with complex forms and textures would look attractive with resin printing. Prototypes and demonstration models are usually accurate, convincing, impressive, and functional. Specific resin printing technologies like Polyjet or MJM (full-color and multi-textured) objects can be created in one go.
Resin Printing Technologies
Resin 3D printing uses a number of printing technologies like SLA, DLP, DUP (LCD-BASED), CLIP, Polyjet/MJM, and MJP. Please note that DUP is different from MSLA. All these technologies have the same working principle but are different by virtue of light sources.
Advantages Of Resin 3D Printing
Resin 3D printing methods differ from each other and each technology has peculiar factors to it. It also depends on machine specs like the power of a light source, build volume, firmware, and properties of photopolymers used.
- Wide Variety Of Materials
The market range of resins covers all common applications and needs and the list is growing fast. Each photopolymer resin consists of working components that are needed for the additives and reaction such as dyes, and visual and functional supplements.
- Massive Details
Photopolymers are infused into the printer as complicated geometries than melted plastics.
- Smooth Surface
Although layer lines are competitively small and invisible on some colors of resin, they are still present on the resin surface.
- High Speed
Resin 3D printing is quicker than other prototyping methods. Modern 3D resin printers are extremely fast.
- Low Costs
Resin 3D printing is cheaper for some applications like prototyping, custom dental devices, and models for jewelry.
- Waterproof Prints
As opposed to plastics or powder materials, photopolymers come out solid and waterproof and they don’t absorb moisture from the air. As a result, they can be used for water-tight applications.
Disadvantages Of Resin 3D Printing
- Tricky Resolution
A fact about resin printing is that its resolution parameters (accuracy quality) depend on several factors including resin type, film ware, and parts’ orientation.
- Compulsory Post-Processing
An interesting fact to note about resin 3D printing is that it requires some necessary post-processing steps to prepare parts for use.
- Curing Keeps Running After The End Of Printing
Although polymerization is usually effective, it can also be tricky. After the resin is formed into an object, some reactions continue inside the part. This explains why post-curing is important. The absence of post-curing can lead to shrinkage, cracks, and deformity
- Design Limits
As efficient as resin 3D printing is, it still needs to be improved upon. It still has a lot of things that need to be included. For instance, engraved details should not be lower than 0.4mm. Also, some knowledge and experience such as mesh quality and thick part orientations are required for the resin 3D printing to be made perfectly.
Resin 3D printing is beneficial in so many ways but an inadequate knowledge about how it is used, its advantages, and its disadvantages may result in improper use (underuse or abuse) of it. This is why this article has provided a piece of detailed information about resin 3D printers, their components, how they are used, and their advantages and disadvantages. You can now have a much better experience if you have been using it before and if you just read about it, resin printers should be your go-to 3D printing option.