Accuracy and Precision with CNC Trimming

To finish a thermoformed part, a variety of trimming processes can be used. The process selection depends on the quantity being produced, part specifications, and the tolerances needed. Options include hand trimming, die cutting, air router, and for the greatest precision, axis computer-numerical-controlled trimming, also known as CNC trimming.

When it comes to CNC trimming, the more advanced thermoformers use five-axis centers – as opposed to three-axis – to produce parts with repeatable, close tolerances. With this approach, the five axis are identified as W-Y-Z (length-width-depth), with two additional degrees of freedom sometimes referred to as C and B. It is crucial that the CNC trim fixture always duplicates the size and configuration of the part’s forming tool, meaning, that it look identical.

During the CNC trimming process, the part must be held securely and immobile, typically through the use of a vacuum system to lock the part against the trim fixture without clamps. This approach also allows for full freedom for trimming on the non-tool side of the part.

Two of the biggest advantages of CNC trimming are:

  • Part design revisions involving trimming can be easily accomplished with a CNC program change
  • Multiple part configurations can be generated from a single formed part by different trim(s)

Please contact us today at 714-894-5566 or info@Tru-FormPlastics.com to learn more about our manufacturing solutions and how they can meet your specific needs.