Vacuum Forming

Vacuum Forming

Vacuum forming otherwise known as thermoforming, is the process of heating plastic to a forming temperature, positioning the plastic over a mould and allowing a vacuum of air between the plastic and the mould to suck the plastic over the mould to take its shape.

With over 25 years experience in vacuum forming, we understand the process and art of thermoforming. We understand the materials best for varied jobs and how to change and evolve designs to be vacuum forming friendly.

With an in-depth knowledge on vacuum forming we are the best to come to for advice and to get the job done.

Vacumn Forming Diagram
Vacuum Forming Diagram

Vacuum Forming Stages

  1. Clamp the plastic material sheet into position.
    The heaters are turned on.
    Heaters can be programmed to heat the plastic at different temperatures and at different sections of the plastic to help the moulding. This is called Heat Zoning.
  2. Once the plastic has reached forming temperature the heaters are moved back and the tool is automatically put into place. The plastic is now pliable and will fold onto the tool.
  3. The vacuum is turned on as the heaters are moved back. This need to be a quick process so the plastic doesn’t cool and stiffen, otherwise the plastic will not flow correctly onto the tool.
    The vacuum sucks the air out from between the tool and the plastic. This process allows the plastic to take the tools shape as the plastic is pulled to the exact shape of the tool very tightly. (The air is vacuumed between the tool and the plastic through vent holes in the tool. These vent holes can leave marks on the final product and so need to be put in discreet areas. The standard size of a vent hole is half a milometer)
  4. Last stage: once the plastic has cooled, the air flow is then reversed and the air is pumped back between the plastic and the tool in order to eject it off the tool without the plastic breaking.
  5. Finally you release the clamps and take out the forming.

Problems that can be encountered in the vacuum forming process are webbing, splits in the plastic, over heating of the plastic and the plastic sticking to the tool. All these problems can be prevented with the right knowledge and tool design.

We can mould parts up to 2.2M x 1.3M by 800 mm high in materials up to 10 mm in thickness.
We have a huge amount of experience in moulding a wide range of materials including ABS, ACAP ABS, Polycarbonate, Kydex, Boltoron, HIPS, PETg, PP, HDPE, Acrylic and PVC.