ASTM D1922

Introducing ASTM D1922 – Industrial Physics

ASTM D1922 is a global ASTM standard test method to work out the tear resistance of plastic films and thin sheets using the pendulum method and an Elmendorf-type tearing tester. 

This ASTM method is a useful one for ranking the relative tear resistance of various types of samples at a comparable thickness. It’s widely used as an index of the tearing resistance of thin plastics used for packaging.  

ASTM D1922 provides a controlled means for tearing specimens at straining rates that are expected in the real world. This tear test alone won’t give a full picture of the other mechanical or toughness properties of your plastics, but it’s an important check.  

This ASTM testing standard is designed for plastic film testing and plastic sheet testing with a nominal thickness not greater than 0.25mm (0.010 in.). This tear resistance test works best with less extensible films and sheeting. Extensible films experience variable elongation and oblique tearing effects under test, so this precludes their use as a precise production-control tool. 

Plastic films and sheeting often show marked anisotropy in their resistance to tearing. Both can also elongate greatly during tear testing. The degree of this elongation depends on film orientation and the inherent mechanical properties of its polymer content. These factors make tear resistance of some films reproducible between sets of specimens to ±5 % of the mean value, while others show no better reproducibility than ±50 %. 

ASTM D1922 testing challenges

With ASTM D1922 we’re looking for the average force to propagate tearing through a specified length of plastic film or sheeting. The measurement begins after the tear has been started, using an Elmendorf-type tear tester and two specimens. 

ASTM D1922 testing is challenging because of difficulties in selecting uniformly identical specimens. Then there’s the varying degree of orientation across plastic films to think of.  

So, what is ASTM D1922 not a good choice for? In the main, highly extensible or highly oriented materials…or both! It can lead to headaches with the reproducibility of the test results, although provisions are made in ASTM D1922 to address any oblique directional tearing that’s common in some plastic film tests. 

ASTM D1922 testing equipment

So, how can Industrial Physics improve your ASTM D1922 testing?  

Elmendorf tear tester 83-76 

Designed and built by our popular materials inspection brand, Testing Machines Inc, this automatic, digital tear tester is just what you need for accurate Elmendorf tear testing. It’s equipped with an optical encoder that measures the angular position of the pendulum which converts to tear strength units.  

Another great feature is the large, full-color touchscreen display. It includes intuitive, easy-to-use software that provides a revolutionary new approach to tear testing and data review. 

Your global test and measurement partner for ASTM D1922