ASTM D1004 Graves Tear Resistance of Plastic Film & Sheeting

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ASTM D1004 is a standard test method for the determination of tearing resistance of plastic film and sheeting. It gauges the force required to detach a specimen from its backing material by pulling it until it tears.

What is ASTM D1004?

ASTM D1004 test method focuses on the tear resistance of flexible plastic film and sheeting at very low speed test rates of 51 mm/min (2 in/min). The test method uses force to initiate tearing.

Why Perform Tear Tests on Plastic Film?

Plastic films are used in many applications, including packaging, consumer goods, construction, transportation, and the medical field. A raw material manufacturer can keep their materials cost low by optimizing the formula. Tear resistance is one of the properties that make a plastic film strong. It proves to be crucial for its durability if the material is subjected to tear events. When testing a film's tensile strength, tensile modulus and tear resistance are often used in conjunction to provide a comprehensive picture of its strength.

ASTM D1004 Test Method

The force to initiate tearing across a specific geometry of a film or sheeting specimen is measured using a constant rate of grip separation universal test machine, such as those listed below. The force necessary to initiate a tear is calculated from the resulting load-time or load-displacement data.

Tear resistance of plastic film or sheeting is a complex function of its ultimate resistance to rupture. The specimen geometry and speed of testing in this test method are controlled to produce tearing in a small area of stress concentration at rates far below those usually encountered in service. The test has its best utility and reliability for materials that do not have brittle failure or do not elongate greater than two hundred percent during testing.

Data from this test method are comparable only from specimens that vary no more than +/-10% from the nominal or average thickness of all specimens tested. And so the tearing resistance is expressed in maximum N (lbf) of force to tear the specimen.

What Are the ASTM D1004 Test Machine Requirements?

The test machine must be operated in a constant rate-of crosshead-movement mode that is consistent with a constant-rate-of-grip separation test mode. ASTM D1004 expects a constant uniform speed of 51 mm/min (2 in/min). Due to the low forces involved in ASTM D1004 testing, a single column test frame can be used. 

The specimen extension is measured by grip separation, which is measured by the test system as cross head movement or displacement. Maximum resistance to tearing, usually found near the onset of tearing, is recorded as tear resistance in newtons (lbf).

Our test machines meet or exceed the ASTM D1004 requirements.

What Grips Are Recommended for ASTM D1004

Our G7 self-tightening roller grips are the most popular for this application and the least expensive. They can be provided with a rubber faced surface which are the best for ASTM D1004.

Our G149 pneumatic vise style grips offer ease of use and clamping repeatability and are a good match to serve the full needs of a 1 kN capacity universal test machine.

Other ASTM D1004 Accessories

The standard calls for specimens that are die-cut. The specimen is cut with a 90° notch to create a specific stress concentration so that it will initiate a tear. Our DD1004 initial tear resistance cutting dies are specifically designed for this standard. Learn more

Software Add-On

Our TestVideo Newton software module is a great option for capturing and recording the test, with video playback synchronized with the force measurement curve, permitting a later review of the test.

Thin Film Micrometer

A digital micrometer is interfaced to our controller software and meets ASTM D5947. It reads to 0.025 mm (0.0001 in) or better.

Important Considerations When Testing According to ASTM D1004

ASTM D1004 does not apply to brittle film or sheeting material where failures occur during testing. It also is invalid where maximum extension is greater than 101.6 mm (4 in).

The specimen geometry and test speed do not simulate real world tear conditions but rather create a controlled tear to analyze force versus displacement data that is used for quality control or material comparison purposes.

Accurate Force Measurement

The ASTM D1004 standard requires accurate force measurement down to 1% (1/100th) of the test machine load cell's capacity which is achieved with our test controller. The system load cell is modular and so its full scale rating is matched to application requirements. Forces beneath the lower limits of load cells can be measured, but its accuracy cannot be guaranteed to be better than 1% accuracy. A 50 N (11 lbf) load cell is relatively inexpensive and would result in an accuracy of 0.5 N (0.11 lbf). A 5 N (1.1 lbf) cell would have an accuracy of 0.05 N (0.011 lbf).