ASTM D882 - Thin Plastic Film Tensile Testing Fixture

Standard Test Method for Tensile Properties of Thin Plastic Sheeting

 

Theory:

ASTM D882 tests the properties of plastic films and sheeting material. Plastic sheet is made through an extrusion process and the film is manufactured into a roll. These rolls can then be converted and combined in a roll-to-roll manufacturiing process to create new products. There are many properties that are critical for the success of roll-to-roll manufacturing including the tensile strength of the thin plastic film as well as the Co-efficient of Friction.  When films are combined to form a double, triple, or multi-ply film, the unfinished product is usually referred to as the "web" because the multiple rolls that get combined resemble a spider's web. Many consumer packaged goods companies (CPGs) like Kraft, Pepsi, and Procter & Gamble, perform this test.

 

Calculations that can be derived from this test include ultimate tensile strength, elongation, and elongation modulus. Other advanced calculations can be made as well including the yield point and young's modulus, however most manufacturers are only concerned with the basic tensile testing data. 

Solution:

Plastic film sheet under 1mm in thickness is usually tested with rubber grip face inserts and a vise grip. The sample specimen must break somewhere in the middle of the sample and not at the grip face, so care must be taken so that the two grips are aligned properly. If the elongation of the sample is quite high, an extended frame must be used so that a sample break is actually achieved. Samples for this test are generally one inch wide (25.4mm), so the standard grip face inserts of 30x30mm will be able to perform the test to the required specifications.