Creating thermoforming templates with SLS 3D printing

Thermoforming is a popular manufacturing process that involves heating a plastic sheet and forming it around a mold to create a specific shape. One of the key aspects of thermoforming is creating templates that can be used to form the plastic sheet.

In a previous article, we looked at the different technologies used to fabricate thermoforming templates, as well as their main advantages and applications. In this guide, we will explore how SLS 3D printing can be used to create high-quality thermoforming templates.

Selective Laser Sintering (SLS) is a 3D printing technology that uses a high-powered laser to fuse small particles of plastic powder together. Unlike other 3D printing technologies, SLS does not require any support structures, as the powder acts as its own support.

Below are a few of SLS 3D printing’s many advantages. Those listed here are more relevant to the creation of thermoforming templates.

One of the main advantages of using SLS 3D printing for thermoforming is that the resulting parts are porous. This means that there is no need to add air holes to the template, or that the required amount may be significantly lower. This is crucial for thermoforming, as air pockets can cause the plastic sheet to bubble and deform during the forming process.

One advantage of SLS 3D printing is that it commonly uses nylon, which offers excellent mechanical properties and temperature resistance. This makes it ideal for creating thermoforming templates.

For example, the Formlabs Fuse 1 SLS 3D printer is compatible with Nylon 12, which has a Heat Deflection Temperature of 171ºC (0.45 MPa) and an Ultimate Tensile Strength of 50 MPa.

SLS 3D printing is particularly good at creating complex parts due to the laser's ability to reach every nook and cranny, resulting in a high level of detail. In addition, SLS 3D printing does not require any support material, allowing for greater design flexibility and the creation of even more intricate parts. This is because the powder itself acts as a support, eliminating the need for additional materials.

Here are some tips to remember when creating thermoforming templates using SLS 3D printing.

When designing thermoforming templates for SLS 3D printing, it is important to consider the orientation of the part on the build platform. This is because the temperature of the powder can vary depending on the location of the part, which can cause warping.

If the template you are designing is wide and relatively flat, it is recommended to 3D print it at a slight angle of 20º to minimize warping.

Although SLS 3D printing is an excellent technology for creating complex shapes and parts with no air holes, a downside is that the resulting parts often have a grainy surface finish. This is where media blasting comes in. It is highly recommended to achieve a smoother finish.

In addition, templates can be polished or coated to achieve a different finish, providing more options for customization. However, it is important to be aware that altering the surface of the template may affect its porosity, which can impact the final result of the thermoforming process.

Nylon 12 is the most popular material used for SLS 3D printing, and it is ideal for creating thermoforming templates. This is due to its excellent mechanical properties and temperature resistance. Nylon 12 has a Heat Deflection Temperature of 171ºC (0.45 MPa) and an Ultimate Tensile Strength of 50 MPa. Additionally, the resulting parts are porous, eliminating the need for air holes in the template or requiring fewer holes.

Applications for SLS thermoforming templates

SLS 3D printing offers several advantages in thermoforming scenarios due to its unique part properties:

• End-use parts: SLS templates provide excellent strength and temperature resistance, while still achieving high dimensional accuracy. As a result, they are well-suited for creating high-quality end-use parts.
• Small batch production: SLS templates typically have a longer lifespan than templates made with other 3D printing technologies, making them a great option for creating templates that will be used multiple times in small batch production.
• Complex geometries: SLS 3D printing allows for the creation of thermoforming templates with complex geometries, thanks to the laser precision and the ability to use powder as its own support material.

A quality template can mean the difference between a successful and unsuccessful thermoforming experience. This means you should go into template design and creation with the knowledge you need to adhere to the best practices of thermoforming.

You might want to get started with learning the basics of the thermoforming process. For that, you can read our guide on what is thermoforming. Or you can learn more about other template manufacturing technologies with our guide on technologies to create templates.

• Creating thermoforming templates with SLA 3D printing
• Creating thermoforming templates with FDM 3D printing
• Creating thermoforming templates with SLS 3D printing

Ready to start thermoforming? Explore Mayku's 3D formers, which are suitable for both vacuum forming and pressure forming processes.