How to Perform ASTM D882 Thin Plastic Film Tensile Testing

Summary of Test

One of the most common specifications that our customers follow is ASTM D882, the Standard Test Method for Tensile Properties of Thin Plastic Sheeting. This test is very similar to ASTM D638 test whereby plastic material is pulled until it breaks in order to measure elongation, tensile modulus, tensile yield strength, and tensile strength at break. Unlike ASTM D638, however, D882 is designed specifically for thin sheeting and film less than 1 mm (0.04″) thick.

Two crucial aspects of ASTM D882 testing to keep in mind regarding equipment are the height of the testing machine and having grips designed to hold the thin film correctly. We recommend our eXpert 7601 single column test machine with 29″ of crosshead travel for films with less than 300% elongation and our 53″ models eXpert 7601 XLT, 7602, and 7603 for really high elongation films that elongate up to 900%. The grips we recommend are pneumatic vise grips with rubber coated inserts. The rubber coated inserts help to keep the film from prematurely breaking at the grip edge and, in combination with the constant pneumatic pressure, the film is prevented from slipping out of the grips during the test.

Our pneumatic grips feature foot pedals that allow the operator to actuate the grips with their feet. Inserting the sample into the grips usually requires both hands, and the foot pedals simplify this procedure. On a machine with 30” crosshead travel, the accessories will take up about 12”. Paired with 4” gauge length sample, this leaves 14” of testing space which is adequate for materials with less than 350% elongation. An eXpert 7601 XLT or a 7602/7603 would be much better suited for materials with higher elongation (350%-950%) If you use a 4″ gage length it will take up another 4″ of the travel. This leaves 14″ of testing travel which will be fine for materials with less than 350% elongation (14″ crosshead travel / 4″ original gage length = 3.5 * 100% = 350%) A 54″ crosshead travel machine is better suited for materials that have elongation up to 950%.

Prior to conducting ASTM D882, it is important to read the entire specification in the relevant ASTM publication.