Guide to Designing Parts for SLA 3D Printing Process

Stereolithography is a 3D printing process that utilizes a laser to harden photopolymer resin layer by layer. At Creatingway, we ideally use SLA in the production of small, smooth components that have fine details hence require a high level of precision. Here is further insight into the SLA printing process, common materials used and its limitations in designing components.

 

How To Make the 3D SLA Printing Process?

At Creatingway, we have desktop SLA machines that produce a UV laser to harden a specific layer of a part using photosensitive resin from a tank. The tank’s bottom is normally transparent, and the UV laser enables us to trace a 2D contour of the components. We essentially use the laser to harden the resin resulting in a solid layer. We create an extremely thin slice of the object with each wave of the laser. The thin slice attaches to the layer before it or the build plate and the bottom of the tank. We then separate it from the bottom of the tank through either peeling, sliding or shaking the tank. Afterward, we move the build plate at a distance of 1-layer thickness away and repeat the entire process until the part is complete.

SLA prints are usually isotropic because the layers are chemically bound together during printing. It helps us produce a component that has almost the exact physical properties as the model in the x, y and z-direction. Even if we print the part parallel or perpendicular to the build plate, the final components’ properties are noticeably different.

 

What’s the SLA Printing Materials?

• Standard Resin

We normally use it for general printing purposes as it offers a high detail surface finish with resolutions lower than 25 microns. It does not offer any special material properties and is more brittle than standard FDM materials. We also use it for models that are not functional.

• Engineering Resins

SLA resin manufacturers have come up with a resin that simulates the properties of common engineering plastics like ABS or Polypropylene. This type of resins provides superior engineering properties without compromising print quality but at a higher cost or production. We ideally use it to produce components that are tough, flexible and have high-temperature applications.

• Castable Resins

We use this special type of resin in manufacturing components that require fine detail and delicate printing features. It also allows for direct investment casting. The resin captures extremely minute features with a minimum feature size of 0.2 mm. With proper hardening, the resin burns out with little to no residue.

 

How To Design for SLA 3D Printing Process?

Resolution

With SLA, one can achieve a higher level of resolution than FDM as it utilizes a laser to cure the material. SLA printing resolution in the horizontal direction is dependent on the laser point size, which ranges between 30 to 140 microns. It is not an adjustable parameter of printing. The feature’s minimum size cannot be smaller than the laser spot size. The vertical resolution ranges from 25 to 200 microns. Selecting vertical resolution is a compromise between quality and speed. Parts that have fewer curves or finer details lack any visual difference between a print at 100 microns versus a print at 25 microns.

Hollowing and Cupping

SLA machines normally print solid, dense models. However, some of our clients may require non-functional parts. We, therefore, hollow the model to reduce the time and material in use significantly. Our experts prefer that the walls of the hollow print be at least 2mm thick to minimize the risk of failure while printing.

Limitations

• Print Volume

SLA printers normally have a smaller build capacity than most FDM printers. Luckily, if the SLA print parameters exceed the printer’s volume, we usually resort to print its smaller subparts then later assembling them. We use a 5-30-minute epoxy to bind the SLA printed components together.

• Cost vs. FDM

The cost in by volume of SLA resin concerning the filament in FDM printing is generally higher. However, its benefits in the precise manufacture of finely detailed components outweigh its cost.

• Material Properties

3D printing SLA manufactured parts cannot serve as functional parts that handle loads. SLA resins normally produce brittle parts that are not as stable as other 3D printed components over extended periods. SLA printed parts need hardening in a UV chamber after printing. Post-hardening enables the parts to attain the highest possible strength and components.

 

What’s the Main Rules to Follow The SLA Printing?

Rapid prototype (SLA printing) is suitable for the production of small parts that need a smooth surface finish as well as a high level of accuracy. Support structures are often crucial to the successful printing of SLA parts. The part’s orientation should be such that it does not come into contact with the support material to ensure that you obtain an accurate finish.

The guideline to the SLA printing process, common materials used and its limitations in designing components should be the eye-opener you need to get you interested in SLA 3D printing. For any further inquiries, simply contact us now.

 

Creatingway is concentrated on CNC machining manufacturing, prototype machining, low-volume manufacturing, metal fabrication and parts finishing services, provide you the best support and services. ask us one inquire now.

 

Any questions or RFQ for metal& plastic technology and custom machining, welcome to contact us below

Call +86-0(755)-89492523 or send an inquiry to us

Welcome visit us, any metal and plastic design and machining questions, we are here to support you. Our services email address:

: sales@creatingway.com