Vacuum forming design guidelines

Vacuum forming design guidelines

As a business with a long history of thermoforming, we have the expertise and knowledge to help you with all your needs. We are capable of providing a diverse pool of services. With them, we can create a myriad of straightforward and complex products for you. As the foremost company specialising in vacuum forming South West has, we can ensure quality results as well.

Due to vacuum forming’s cost effective nature, it is the method manufacturers of plastic components tend to favour. Just like any procedure however, it is vital for you to follow every step accordingly. This way, your final product will have the quality you desire. When designing plastic parts, you must consider the following design issues.


You should think about merging parts with joining lines. There could be instances where you have to unite a pair of components. You will require a witness line of roughly 2mm in order to cope with the tolerance variation of the joint. The ideal approach here is to use a lap joint.

Creating holes, trims, cut-outs, and vents

Machining cut-outs, holes, trims, and vents is also important. Something you should always do is reference your trimming dimensions from the part’s moulded side. It is possible for you to machine off any excess to create a superior finish.


vacuum forming South WestAnother essential detail would be aiming for a high tolerance. A great idea would be to strive for the best level obtainable. This shall bring costs down and reduce lead time. You might be employing parts from a machined aluminium mould. If you are, go with a setting of 0.25mm for the initial 25mm. Use a tolerance of 0.25mm for each 250mm after this.

At Plastics By Design, we consistently meet the high standards customers expect from our industry. The manufacturing plant we use for our work is credited with the BS EN ISO 9001:2008 standard too. It also has the BRC/IOP Global standard.

If you need assistance from the top company for vacuum forming South West has, speak to us. We can cater for orders varying in size, so speak to us whether you need a prototype or a production run.