What is SLA 3D Printing - Everything You Need to Know

Stereolithography(SLA) is one of the 3D printing technologies for rapid prototpying, it is widely used in numerous industries. Today, in this blog, we will share everything about this technology.

What is SLA 3D printing?

SLA means Stereolithography, It is an additive manufacturing process used to create concept models, cosmetic prototypes, and complex parts. it is the first commercialized 3D printing technology in the market.

How does SLA 3D printing work?

SLA utilizes ultraviolet(UV) light to irradiate liquid photosensitive resin, causing it to solidify. During the processing, the platform gradually descends into the resin tank, which is filled with liquid resin. UV light, directed by a scanning mirror according to cross-sectional contour information, is projected onto the liquid surface. Wherever the light passes, the exposed liquid solidifies.

Main Applications of SLA 3D Printing

Creating various plastic prototypes or functional components for validating and cross-checking computer simulation results.
Used for structural verification and functional testing.
Producing intricate parts.
Low-volume Manufacturing of transparent or translucent components.
Creating master pattern for silicon mold of urethane casting process, and replicating various molds quickly.

Advantages of SLA 3D pRINTING

Good Precision

Compare with other 3D printing technologies, SLA 3D printing have a better precision. It can achieve 0.05mm to 0.1mm for the prototypes created by this technology. this accuracy can cover the most needs of the prototypes. this is one reason why SLA is popular in the market.

various Resin

There are a lot of types resin can be used for SLA 3D printing technology, such as standard resin, transparent resin, colored resin and more. manufacture can choose the proper resin base on the requirement of the products.

stable dimension

3D printing use UV light to solify the liquid resin without any heat which could potentially casue the deformation of the parts. follow the orginal 3D data and high accuracy, manufacturers use SLA 3D printing technology to produce functional parts, complex and precision models.

easy Post-Processing

Resin is easy to be post-processed such as polishing, sanding, painting. and SLA 3D printed parts have smooth surface which do not need to much further finishing, this will save your cost and time to make the prototype.

Short Time

SLA 3D printing can pint parts less than 24hours, this is becasue no need to preapre the material block and SLA printer is easy to operate. this will short the time of building a prototype.

Cost effective

Resin is cheap and SLA printer is not expensive, and just a short time needed to create the prototypes, all these factors make the SLA 3D printing is a cost effective solutions for your products.

disadvantages of SLA Technology:

SLA printing systems are precise equipment that manipulates liquids, demanding stringent environmental conditions.
SLA pinted parts are mostly resin-based, with limited strength, rigidity and heat resistance.
SLA components are typically fragile and unsuitable for functional applications.

Types of SLA Machines: Bottom-Up and Top-Down.

Bottom-up SLA printer is used in industrial SLA systems. the laser light source is positioned above the resin tank, and the model is built upwards. The build platform starts from the top of the resin tank and moves downward after each layer is formed.

Top-down SLA printer is used in desktop level. the light source is located below the resin tank, and the part is built downwards. The bottom of the tank is transparent and coated with silicone, allowing the laser to pass through. After each layer is formed, the cured resin is separated from the tank bottom as the build platform moves upward. below is picture to show a top-down desktop SLA 3D printer components.

Comparison between desktop and industrial SLA 3D printers

Desktop SLA printers are easier to manufacture and operate, but their print size is small. On the other hand, industrial printers can make large print size with good accuracy. Hers is a comparision table between these two kinds of Pinters.

	Desktop SLA pinter	Industrial SLA 3D printer
Advantages	Lower price	Can print larger models
	More widespread use	Shorter printing times
Disadvantages	Limited print size	Higher price
	Limited choice of materials	Requires more specialized operation
	More support structures, more post-processing	Material replacement can be cumbersome, requires emptying the resin tank
Print Size	Mostly below 300mm	Ranges from 300mm to 1500mm
Layer Thickness	25 to 100 micrometers	25 to 100 micrometers
Accuracy	+/- 0.1	+/- 0.05

SLA 3D Printing Workflow:

Step 1, Create a model using CAD or other 3D modeling software.
Step 2, Generate G-code by CAM software.
Step 3, Position the print platform to its initial location
Step 4, Printing: Lower the print platform layer by layer, while the laser solidify one layer of the model, Apply a new layer of resin and repeat until the model printing is complete.
Step 5, Cleaning: Remove the completed model from the printer and clean off excess resin layers using a cleaning solution.
Step 6, Post-Processing: drying, UV curing, polishing or painting the model to a final part.

SLA 3D printing Materials:

SLA technology primarily uses photosensitive resin, which is a liquid material. they are more brittle compared to FDM 3D printing or SLS 3D printing materials, which means that SLA models are generally not suitable for bearing heavy loads.here is some common used SLA 3D printing materials in the market.

3D Printing Process	Material Type	Material	Description
SLA	ABS	ABS-like White (Accura Xtreme White 200)	Durable, general-purpose resin and accommodates extra-large parts
		ABS-like Gray (Accura Xtreme Gray)	General purpose resin with highest heat deflection temperature of the ABS-like SLA resins
		ABS-like Black (Accura 7820)	Low moisture absorption, glossy cosmetic appearance
	Polycarbonate	PC-Like Advanced High Temp (Accura 5530)	best used for parts that need strength and stiffness combined with high temperature resistance.
	Polycarbonate	PC-Like Translucent/Clear (Accura 60)	PC-Like Translucent is ideal for parts with fine details that require translucence and high stiffness

Design Tips for SLA Printed Parts

Minimum detail wall thickness: 0.6mm (large thin areas should have a thickness greater than 2mm).
Minimum independent pillar diameter: 1mm.
Minimum raised (recessed) letter stroke width: 0.35.
Minimum hole diameter: 1mm.
Minimum gap: 0.4mm.

Applications of SLA 3D Printing

SLA 3D printing is widely used for building prototypes with High precision and smooth surface. Some of the most common SLA 3D Printing applications include:

Functional prototypes and assembly parts for all industries
Create Master patterns for Urethane casting
Dental models’ production
Jewelry-specific casting

Get Started with KUSLA SLA 3D Printing

KUSLA provides a comprehensive 3D printing service including SLA 3D Printing, SLS 3D Printing, FDM 3D Printing. we can manages all the requirement of your product with various post-processing capabilites. contact us today to get a instant quote.

FAQS about SLA 3D Printing

The working principle of SLA 3D printing is the layer-by-layer stacking of continuous material, much like stacking pancakes. Then, ultraviolet laser scans the resin to form individual layers. Once this process is complete, your object will exhibit a stunning three-dimensional effect.

A basic SLA printing can take from 4 to 24 hours, depending on part size and complexity.

SLA can create highly precise tooling and fixtures. It’s also an ideal choice for functional prototypes.

Resin is a type of plastic used in SLA 3D printers. It’s applied in liquid form before being cured by ultraviolet lasers, layer by layer, to create objects. There are many different types of resins with varying properties, each capable of producing different results in the final printed object. Depending on the chosen resin, you can create highly detailed models with smooth surfaces and various mechanical properties, as well as transparent or opaque objects.

Yes. Depending on the final use, you may need more or less post-processing. This can be as simple as removing any support material and washing parts in a solution to remove excess resin. However, it can also include tasks like sanding, polishing, and painting, depending on the part’s requirements.

The maximum size you can print at once depends on the size and shape of the build platform. The maximum size offered by Neo is 800 × 800 × 600 mm.

Using SLA printing typically achieves a resolution of around 20um, which is better than what FDM printers produce.