Vacuum forming is a well-proven and cost-effective method in thermoplastic processing where a heated plastic sheet is formed over a tool using vacuum. The technology enables the production of both functional and advanced components with relatively low tooling costs, making the process particularly suitable for medium-sized series and customized applications.
How it works
The process begins with a plastic sheet – usually made of materials such as ABS, PETG, PC or PMMA – being clamped in a frame and heated to its forming temperature, usually between 140°C and 200°C depending on the thermoplastic properties of the material.
When the plastic reaches its softening point, the tool (mold) is lowered towards the material or the frame is raised above the tool. At the same time, the air between the tool and the plastic is evacuated via negative pressure (vacuum), which causes the plastic to seal tightly against the surface of the mold. The forming accuracy depends on several factors such as the thermal mass of the tool, the location of the vent channels and the uniformity of the vacuum pressure over the surface.
After forming, the plastic is cooled rapidly, either by natural convection or by cooling systems integrated into the mold. The part is then released and moves on to post-processing such as trimming, CNC milling, drilling or assembly.
Advantages of vacuum forming
Vacuum forming is distinguished by a number of technical and economic advantages:
- Low tooling cost compared to injection molding or compression molding
- Enables large components with thin wall thickness
- Short lead time from drawing to finished part
- Suitable for optically clear materials (e.g. PMMA or PETG)
- Good repeatability in medium-sized series
- Flexible adaptation of material thickness via material selection
- Possibility of integrated details in the mold surface (e.g. radii, ribs, punch marks)
Regulations and quality requirements
In industrial vacuum forming, manufacturing must comply with relevant chemical and safety regulations. The plastic materials and any additives must meet the requirements of the REACH Regulation. For food contact, EU Regulation 10/2011 applies.
Closing reflection
Vacuum forming offers an optimal balance between economy, design freedom and technical function, especially at low to medium volumes. By mastering the physical parameters of the process and adapting the tool design to the formability of the materials, vacuum forming can deliver products with high reproducibility and long life.
Would you like to know more about how vacuum forming can be applied in your business? Visit our page for vacuum forming for more information about the technology, capacity and material selection. You are most welcome to contact us for technical advice or a quote.
