Thermoforming involves the heating of one or more plastic sheets to a temperature suitable for forming or stretching into or onto a mold, and then cooled before removal and trimming. Finished parts range from disposable cups to large single piece automotive body panels. Processes can be semi-continuous (fed as thin-gauge sheet from a roll) or discontinuous (large heavy-gauge single sheets).
Temperature uniformity and sufficient heat penetration across the entire sheet needs to be ensured for the sheet to be correctly formed (critical for thicker sheets). Temperature of the finished item needs to be measured to ensure it is cool enough to be removed from the tool safely.
- Measure multiple temperatures over the entire sheet corresponding to heating zones that allows cascade control for processing next sheet
- Measure temperature during the heating cycle to ensure correct heating curve and setpoint is achieved
- Measure temperature of the formed piece to allow safe removal and minimize the risk of injury