Thermoforming is the broader process of heating plastic sheet until it becomes flexible and forming it over or into a mould. Vacuum forming is one type of thermoforming that uses vacuum pressure to pull the heated sheet tightly against a mould. In other words, vacuum forming is a specific method within the wider thermoforming family.
What Is Thermoforming?
Thermoforming describes a group of manufacturing processes.
A plastic sheet is heated until it becomes soft enough to shape. It is then formed using a mould or tool and allowed to cool.
There are several different thermoforming techniques, depending on the desired result and equipment available.
What Is Vacuum Forming?
Vacuum forming is a specific type of thermoforming.
The heated plastic sheet is positioned over a mould, and air is removed from between the sheet and mould. Atmospheric pressure then pushes the plastic against the surface of the former.
The plastic cools while holding the mould’s shape.
This makes vacuum forming particularly useful for creating shaped plastic components from relatively simple tooling.
So What’s the Difference?
The simplest way to remember it is:
Thermoforming = the overall category.
Vacuum forming = one method within that category.
It’s similar to saying that a car is a type of vehicle. Vacuum forming is thermoforming, but not all thermoforming is vacuum forming.
When Is Vacuum Forming Useful?
Vacuum forming can be useful for a wide range of applications, particularly where you need shaped plastic parts without the complexity of some other manufacturing methods.
Potential applications include:
- Prototypes
- Model components
- Gaming accessories
- Display pieces
- Cosplay props
- Packaging
- Covers and housings
- Custom hobby parts
The suitability depends on the component’s size, shape, material and required production volume.
What Are the Advantages?
One of the attractions of vacuum forming is that tooling can be relatively straightforward for suitable designs.
This can make it useful for prototypes and smaller production runs.
It can also produce lightweight components with repeatable shapes.
What Are the Limitations?
Vacuum forming isn’t suitable for every plastic component.
Very deep shapes, sharp internal features and significant undercuts can create challenges. Material choice and thickness also need to be considered carefully.
That’s why good design is important before manufacturing begins.
Which Process Should You Choose?
The answer depends on what you’re making.
If you’re unsure whether vacuum forming is suitable for your project, start by discussing the shape, size, material and intended use of the finished component.
Jabro Games can help you explore the options and determine whether vacuum forming is a practical approach for your project.
Confused by the terminology? Just remember: vacuum forming is a type of thermoforming.