Impact Resistance of Flat, Rigid Plastic Specimen by Means of aStriker Impacted by a Falling Weight
This standard test method covers the determination of the relative ranking of materials
according to the energy required to crack or break flat, rigid plastic specimens
under various specified conditions of impact of a striker impacted by a falling
During this test a weight will fall from various heights on to a striker which is
resting on the specimen. This procedure will calculate the energy that will cause
50% of the specimens to fail referred to as Mean-Fail Energy. If, after the impact
test, a crack or split is visible on the specimen by the naked eye then this is
deemed to be a failure. Different size strikers and/or support plates can be used
in determining a pass or fail.
Because plastics are viscoelastic, meaning they are relatively gelatinous or sticky
whilst also being able to return to their original shape, it is possible for them
to be sensitive to a variation in velocity of weights falling. That being said there
might be an occasion where this test might not have enough energy to create a fail
in the specimen. There are no temperature or humidity constraints with this testing
method which represents real life environments because this is an impact only test.
The test specimen shall be at least 1” larger than the hole in the support plate
and free of major imperfections unless these are to be considered as a variable.
The test specimen shall be tested in the as-received condition. Once a random test
specimen has been measured and recorded place the item in position on top of the
support plate ensuring that the subsequent specimens are similarly positioned. With
the specimen laid flat in position raise the weight in the tube to the required
height then release to hit the striker. If there is a fail on the first attempt
then lower the height by 1 increment. The mass shall be constant and the specimen
shall be tested only once.