Vacuum forming is a useful process that’s used to make a variety of plastic products, including packaging trays and inserts.
How does vacuum forming work?
There are three steps in the vacuum forming process:
- A mould (tooling) is created that will produce the desired shape.
- A sheet of plastic is heated above the mould.
- A vacuum is created underneath the mould, pulling the plastic sheet tight around it. As the plastic cools, it sets into the desired shape.
- The result is then trimmed and finished.
Many different types of plastic are suitable for this, from high-impact polystyrene, PVC, acrylic and polycarbonate, to APET or RPET, which are greener alternatives.
Vacuum forming advantages
So, why is vacuum forming used? There are plenty of advantages, but in essence, it’s an effective way of making relatively complex shapes quickly and cost-effectively. You also benefit from:
- Low tooling costs.
- Fast.
- Visually appealing result.
- Ability to use transparent or opaque materials.
- Reliable and consistent.
- Excess material can be recycled.
When used for packaging, it creates trays and inserts that give a perfect fit for the product. This is ideal for saving space during transit. And they’re light too, which can help reduce your carbon footprint.
Vacuum forming vs injection moulding
Injection moulding involves forcing molten material (often plastic) into a mould. It’s a good technique for producing high volumes of finely detailed parts, where tolerances need to be high.
With vacuum forming, the material isn’t melted completely, it’s just softened to make it malleable. The mould can only be on one side of the plastic, and the shapes produced are hollow.
As the raw material is in sheet form, vacuum forming lends itself to thinner, flatter items like inserts and trays.
Generally, production of vacuum formed items is simpler, quicker and cheaper to set up.
What can vacuum forming be used for?
Vacuum forming is a really versatile process. It can be used to make almost anything that’s relatively flat or hollow.
A few examples:
- Plastic food containers
- Car dashboards, bumpers and other parts
- Packaging, often in the form of trays and inserts, like chocolate box liners
- Cases for electronic items like remote controls and mobile phones
- Prototyping
Find out more about how vacuum forming is used in the packaging industry here.