Advanced Thermoforming, 2nd Edition

Chapter 24Advanced Analysis of Thermoforming Films

Written cooperation with Manfred Reichert, Remshalden, Germany

The methods used for advanced analyses of thermoforming films are differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and torsion pendulum resistance test.¹ These methods are described here to show how the behavior of thermoforming films can be recognized and evaluated before they are processed on the thermoforming machine. For example, films made by different manufacturers that nominally seem to be the same often have significantly different behaviors on the thermoforming machine. Having reliable information will improve processing; however, it is often necessary to consult specialized institutes to obtain more exact analyses and interpretations.

24.1 PRODUCT QUALITY DEMANDS

The quality of the films to be thermoformed is extremely important. The production of cups, bowls, and so forth from a flat film constitutes a very important process step for the packaging of food.

The operating behavior of a thermoforming machine is considerably affected by the quality of the films, and ultimately the operating behavior determines the efficiency and the productivity of the production process. Film that is not machine processible or that is inferior in quality can cause serious machine malfunctions and disrupt the whole thermoforming process.

In practice, it often difficult to trace malfunctions to definite causes:

• Is the malfunction caused by the ...