Avoiding Mistakes in the Vacuum Thermoforming Process

The first step to follow in the vacuum thermoforming process is to start with sketches and get your design engineer involved from the beginning. Vacuum thermoforming is a process very unlike other methods of molding plastics. Because each shape may have difficult areas to form each technician that works on the project may go about forming or attempting to form the shapes a bit differently from the next person.  This is why consistency in the process between operators within the plant is vital.

The shape you create may look nice on paper or even in CAD (Computer-Aided Design), however, it may not make a good candidate for the vacuum thermoforming process. It is always best to start with a shape that you know can be molded before you spend a lot of time and money attempting to mold a shape that is unattainable.

This process of vacuum thermoforming enjoys the following in the design of the part:

  • Plenty of Radius

  • Generous Draft Angle (no straight walls)

  • Corners that are rounded as much as possible-avoid sharps

  • Space between shapes or other molds in the event this is a family tool

  • A ratio of 1:1 or greater.  1″ tall equals 1″ wide

  • No undercuts

  • No holes before the part is formed

  • Printing of photos is always best, if not mandatory after the part is formed

  • Consider attachment of other formed, injection-molded, or machined parts to complete the product

Following these guidelines will increase the successful formation of vacuum formed parts.