Vacuum forming is one of the most common methods of processing plastic materials to manufacture products, components and parts.
Broadly, vacuum forming involves heating a plastic sheet until soft and then draping it over a mould. A vacuum is applied sucking the sheet into the mould. The sheet is then ejected from the mould. In its advanced form, the vacuum forming process uses sophisticated pneumatic, hydraulic and heat controls thus enabling higher production speeds and more detailed, more complex vacuum formed applications.
For producers vacuum forming offers the opportunity of comparatively low cost tooling, use of inexpensive material to make the required moulds and fast fabrication speeds. Vacuum forming can be used for rapid plastic prototypes, small runs and large volume projects.
A large number of plastics can vacuum formed, helping ensure the correct materials are used for a project as well as offering cost savings by using less expensive plastic where possible
Typical materials used include
- Acrylonitrile Butadiene Styrene ABS
- Polyester Copolymer PETG
- Polystyrene PS
- Polycarbonate PC
- Polypropylene PP
- Polyethylene (sheet and foamed sheet) PE
- Polyvinyl Chloride PVC
- Acrylic PMMA
Vacuum Forming Process
Clamping – The clamp frame needs to be sufficiently powerful enough to ensure the plastic sheet is firmly held during the forming process.
Heating – the sheet is heated uniformly over its entire surface area and throughout its thickness.
Vacuum Forming – Once the material is suitably heated a vacuum can be applied to assist in forming the sheet. A vacuum pump is used to draw the air trapped between the sheet and the mould.
Cooling and release – Once formed, the plastic must be allowed to cool before being released. If released too soon then deformation of the moulding will result in a reject part.
Trimming and finishing – Once the formed part has cooled and been removed from the machine the excess material is removed. Holes, slots and cut-outs are then drilled into the part. Other post-forming processes include decoration, printing, strengthening, reinforcing and assembly.
|Vacuum forming can be used to cost-effectively manufacture a huge range of products and parts including: industrial & automotive components; enclosures and trays; POS retail display; stage and film props; signage, and product development / rapid prototyping. For a complete list check out our Plastic Forming: A-Z of Vacuum Formed Applications guide|