Design of an impact testing machine for polymer films by the free falling dart procedure

Impact forces have been used to study the behavior of materials for a long time. The aim of the impact testing is to investigate those conditions under which a material will fail in a brittle manner regarding a sudden load. There are three general methods of testing impact resistance of components: falling weight tests, pendulum tests and tumbling impact tests. In the present study, an attempt has been made to establish an impact tester used to carry out impact testing of plastic films by free falling dart method. In this, a box of wood with a hole on its upper side is used on which plastic film is held by clamps and a dart is allowed to fall onto film to note perforation. Then the impact resistance is statistically calculated. Impact resistance is determined by the energy caused by weight to fail 50 % of specimen. Practical results are found to be in good agreement with theory.