FDM 3D Printing is just one of the many technologies that can be used to create templates. You can also laser cut or CNC machine them, but FDM 3D printing is unbeatable when it comes to ease of use and versatility.

In this guide, we’ll explore the advantages FDM 3D printers offer when creating vacuum forming templates, slicing recommendations, and recommended materials.

Why use an FDM 3D printer to create templates?

FDM 3D printers are one of the most accessible manufacturing tools. But, what makes them so popular? Here are some of the main advantages this technology offers. 

Available materials

With an FDM 3D printer, you can create objects in a wide range of materials. In this guide, we’ll explore the most common materials and which of their mechanical properties you should consider when making vacuum forming templates.

 

Fast prototyping

3D printers are known for their prototyping capabilities. They allow you to make prototypes, templates, and even final products in very little time.

At Mayku we test different template materials every week. Many of the templates are 3D printed, as it allows us to make many of the test parts within the day.

Variable print quality

Want to make a fast low-quality template to test a shape and then a detailed one with a smooth surface for the final template? With an FDM 3D printer you can make both.

3D printers allow you to create templates with different qualities, giving you the chance to save time when prototyping while also being able to create outstanding templates when you’ve got the final design.

This isn’t just about surface finish. The slicing process prepares the 3D model to be 3D printed, and it also offers settings that can improve the mechanical properties of a template, including its wall thickness or density.

No post-processing

FDM 3D printing uses filament as material, and the parts made with this technology don’t need any type of post-processing to make the parts ready to use.

Parts made with other 3D printing technologies such as SLA (resin) or SLS (powder) need to be cleaned and in some cases cured before they can be used.

Ease of use

The fact that FDM 3D printed parts don’t need post-processing makes it one of the most accessible manufacturing technologies. You can create high-quality templates with just a laptop and a 3D printer you can create.

FDM 3D printers greatly improve the vacuum forming experience with the FormBox, and they can be easily implemented in educational and creative environments.

How to 3D print vacuum forming templates

3D printing is much more than great hardware, especially if you’re making a vacuum forming template. The slicing process and the material properties play a key role as they determine the template’s quality.

Slicing process

During the slicing process, a software tool transforms your 3D model into instructions so that the 3D printer actually makes it. Advanced slicers include hundreds of settings, but here are the three most important ones that you need to know when 3D printing vacuum forming templates.

Layer height

The smaller the layer height, the smoother the surface. It’s recommended to create templates with a smooth surface finish in order to improve the de-molding experience. 

A test template can be 3D printed with a 0.3mm layer height, but the layer lines will be visible in the mold. It’s recommended to print the final template with a 0.1mm layer height to guarantee a smooth surface, especially on templates that have top curved surfaces.

 

Wall Thickness

Large and thin designs tend to deform when used as vacuum forming templates as the plastic sheets are heated before they’re pressed against the template. 

One of the ways to avoid issues like that is by increasing the Wall Thickness. The standard wall thickness when 3D printing with a 0.4mm nozzle is around 0.8mm and 1.2mm, but a 2mm wall thickness is recommended when 3D printing templates.

It’s important to mention that the Wall Thickness plays a similar role as the Infill, as both have similar effects in terms of mechanical properties.

Infill

The higher the infill density, the more resistant the part will be. 

Vacuum forming templates need to be strong to resist both the pressure and the heat. If you want to 3D print templates, you should use an Infill density of at least 30%. 

If you use a low infill density, the heated sheet may deform the top part of the 3D printed template, exposing the infill lines below. This issue is solved by increasing the Wall Thickness and the Infill density.

Material properties

Each 3D printing material has unique properties and applications. Many of them can be used to create vacuum forming templates, but you should definitely consider some of their properties if you want to 

Heat resistance

Even though PLA is the most popular 3D printing material, its heat resistance is one of the lowest. It’s recommended to use materials that offer a higher heat resistance.

Check the materials’ Technical Data Sheet to make sure you choose the right one. The Heat Deflection Temperature measures the polymer’s resistance to distortion under a specific load at elevated temperatures.

 

 

Stiffness

Vacuum forming templates need support pressure and high temperatures when forming the mold. They need to be rigid enough to avoid being deformed during that process, which can be repeated hundreds of times.

Even though there are many tests that can help identify the stiffness of a material, the Tensile Strength test stands out over the rest. The Tensile Strength measures how a material behaves under a specific load, and it helps you identify which is the best material for vacuum forming templates.

The stiffness of a template can be also improved by tuning slicing settings such as Infill density and Wall Thickness. A part made with a flexible material and a high infill density may perform better than one made with a rigid material and thin walls.

Common issues

If you choose the wrong material or slicing settings when 3D printing the template, you may experience one of the following issues.

Warping

Warping refers to the deformation caused in the corners of a 3D printed object. It’s caused by an uneven contraction of the material when printed. The material expands when heated and contracts when it cools down.

Even though this is a common problem during the 3D printing process, it can also happen after you use the template, as the hot plastic sheet transfers some heat to the template.

Using thick walls and a high infill density will help prevent warping, and adding a thick bottom base to the template may also help when the design is thin and long.

Pillowing

When the top wall of the template is too thin, the pressure caused by the vacuum forming process combined with the heat may deform the template, exposing the infill lines that support the top wall.

 

Increase the Infill density and Wall Thickness when making the templates to prevent this.

Deformation

If your template is too thin or is not rigid enough, it may deform during the vacuum forming process. In these cases it’s recommended to redesign the template so that the part is properly placed on the mesh and thicken the small components.

Best 3D printing materials

There are hundreds of FDM 3D printing materials, and many of them offer mechanical properties that make them suitable for vacuum forming applications. But, which of the most popular materials is the best one when creating vacuum-formed templates?

In the table below we compare the Heat Deflection Temperature and Tensile Strength of some of the most popular materials.

Material	Heat Deflection Temperature (0,45 MPa)	Tensile Strength (at yield, 50 mm/min)
PLA	55ºC	60 MPa
PETG	70ºC	50 MPa
ABS	81ºC (1,8 MPa)	39 MPa
HIPS	89ºC	26 MPa
ASA	96ºC	40 MPa

Source: Fillamentum material comparison

As you can see, both HIPS and ASA offer an excellent heat resistance, but their tensile strength is not that good. On the other side of the spectrum we have PLA and PETG, who offer a great tensile strength, although the heat resistance is low and that could generate some issues.

Depending on the application you’re interested in, any of these materials may work. However, you may need to increase the wall thickness and infill density of the template if you’re using PLA or PETG. This way, you’ll increase the parts’ structural strength, which will reduce the changes of warping or pillowing.

 

Main Takeaways

There are many ways in which you can create vacuum forming templates. FDM 3D printing is one of the best ways to do it, but you should consider the following tips if you want to make the best out of it.

 

• Use a small Layer Height to get a smooth surface texture, especially on templates that have top curved surfaces.
• The slicing process plays an essential role. Wall Thickness and Infill density are the most important settings in terms of mechanical properties.
• Materials with a high heat resistance such as ABS, ASA or HIPS are recommended.
• You can use materials such as PLA or PETG, but the Wall Thickness and Infill density should be increased to avoid deformation during the forming process.
• Focus on repeatability. You should be able to use a vacuum forming template dozens of times.