[Basic Knowledge of 3D Printing] Application Guide for Creating Thermoforming Molds with SLA 3D Printing

High-quality thermoforming templates can be created using a variety of manufacturing methods, including 3D printing. In our previous article, we covered techniques and practical knowledge for creating thermoforming templates using SLS. In this article, we will explain the best practices and benefits of using SLA 3D printing to create thermoforming templates.

What is Resin 3D Printing?

What are the benefits of SLA?

Smooth Surface Finish
With SLA 3D printing, you can create parts with a smooth surface without the need for post-processing, leading to significant time savings! In thermoforming, a smooth surface is very useful, allowing the finished product to be more easily demolded in specific applications, reducing steps without compromising the quality of the molded part.

As seen in the image below, parts produced with resin 3D printing (SLA) have no visible layer lines, whereas the same parts made with filament 3D printing (FDM) show clear layer patterns.

Complex Pattern Creation
SLA 3D printing enables extremely detailed modeling. This is very useful in thermoforming and particularly helpful when creating templates with specific surface patterns, textures, or even lettering.

Compatible with Various Materials
SLA 3D printing is compatible with dozens of resins, each with different properties. Among these, resins like Formlabs High Temp Resin are suitable for producing thermoforming templates.

Formlabs High Temp Resin (Source: Formlabs)

Designing and Creating Thermoforming Templates
Here are key points and best practices to keep in mind when designing and creating thermoforming templates using SLA 3D printing.

Vent Hole Size
Because SLA 3D printing is so high-precision, you can create vent holes so small they are barely visible. For the Mayku Multiplier, we recommend keeping vent holes at 0.4mm or less. If the holes are too large, it may result in visible holes in the final molded product or cause the plastic sheet to burst during forming. It is also recommended to test the minimum vent hole size for your template during the prototyping phase.

Thermoforming template with vent holes

Two tips for achieving optimal vent holes:

• Create 0.4mm tapered vent holes on the template surface, widening them toward the back of the template (to about 2mm). This prevents resin from becoming trapped inside.
• Use a needle or air gun to remove any uncured resin remaining inside the vent holes before post-processing and curing the template.

Print Orientation
When slicing, ensure that the build orientation of the part is properly set to minimize visible support marks on the piece as much as possible. This not only improves the appearance of the printed template but also reduces the time spent on post-processing.

Hollow Templates
In some cases, creating a hollow template can reduce print time and material usage.

If creating a hollow template, you need to add support structures inside the object to increase strength for repeated use. You can then fill the internal structure with materials like plaster to return the part to a solid state. However, it is crucial not to block the vent holes. Also, the fill density inside the template will depend on the application and overall size.

Finally, if using the template with the Mayku Multiplier desktop pressure former, we recommend a shell thickness of at least 5mm for the hollow template.

Layer Height
Layer lines on SLA 3D prints are not as visible as in filament 3D printing (FDM). If a smooth surface is required for the template, we recommend setting a layer height of 0.05mm for the final template to make layer lines as inconspicuous as possible.

Also, if the template shape has many curved areas, layer lines may be more noticeable. In such cases, printing with a thinner layer height or changing the print orientation can help make them less visible.

Applications for SLA Thermoforming Templates
Thermoforming templates produced with SLA 3D printers play an important role in various industries and applications. Main applications include:

• Industrial Design: High detail reproduction and complex shapes are important for industrial designers. Resin 3D printing allows for the production of enclosures suitable for harsh work environments for products or other parts and tools.

• Chocolate: Beautiful surface texture and fine detail are very important in chocolate manufacturing. Resin 3D printing is a highly suitable technology for creating unique and complex designs.

• Packaging: When producing packaging prototypes, high detail reproduction and template dimensional tolerance are key. SLA 3D printing technology can fulfill these requirements.