ASTM D1004 Tear Resistance

Scope:

Tear Resistance test by ASTM D1004 is used as a quality control check for flexible plastic material comparison where tear failures are suspected in sheets and films. During this test the sample geometry produces stress levels in a small region of the sample and then the ultimate stress is recorded as tear resistance in newtons (or pounds-force), typically at the beginning of tearing. This test includes the calculation of tear resistance to very low load speeds of 51 mm (2 inches)/min of flexible plastic film and sheet.

Test Procedure:

For the ASTM D1004 test, firstly the average sample thickness is calculated. The sample must be die-cut as specified by ASTM D1004 guidelines. The samples are formed with a 90-degree notch to form a stress concentration in a specific area. The sample is then placed in the grips of the testing machine and pulled at a rate of 2 inches per minute until complete failure. 

Specimen size:

The sample is die-cut in the proper shape from a sheet. The shape of the sample is planned to create a tear when the sample is dragged in tension. Die C samples are usually used.

Data:

The resistance is calculated in Newtons.

Conclusion:

ASTM D1004 is a standard test method that determines the tear strength of flexible plastic film sheeting at very low rates of loading using a constant rate of crosshead movement type tensile testing machine.