The test method ASTM D7192-08 covers the determination of puncture properties of plastic films over a range of test velocities. The materials covered by this standard are to have a thickness not greater than 0.25 mm (0.010 in) and to be non-rigid as defined by section 3.2.1 of the standard. The test outlined in the standard is designed to provide load versus deformation responses of plastic film under multi-axial deformation conditions at various impact velocities. By testing at various impact velocities a measure of the rate sensitivity of the film to impact events may be gathered. Recommended in the test standard are speeds of 2.5, 25, 125, 200 and 250 m/min. (0.137, 1.367, 6.835, 10.936 and 13.670 ft/s).
The machine used for the test shall consist of two assemblies, one fixed, the other driven by suitable method to achieve the required impact velocity, a specimen clamping assembly with an unsupported region of 76 ± 3.0 mm (2.992 ± 0.118 in.) The film shall be held taut but not stretched so tightly as to cause damage to the specimen prior to test. A minimum of five specimens shall be tested at each specified speed with a plunger assembly consisting of a 12.70 ± 0.13 mm (0.5 ± .005 in) diameter rod with a hemispherical end of the same diameter.
When asked to offer a testing solution to this standard we recommend the use of either our Mini-Tower™ Table Top Impact Test Instrument or one of our 9250 models. For those customers whose impact energy requirements fall between 0.7 – 18.0 J (0.5 – 13.2 ft-lbs) we recommend using our Mini Tower Table Top Test Instrument. For those film customers who need more impact energy one of our 9200 Series (Model 9210; Model 9250G; Model 9250HV) with energies ranging from 1.9 – 1182 ft-lb (2.6 – 1603 J) would be our recommendation. Our thin film hoops ensure that the film is pulled taut over the unsupported region prior to impact. For those films that fail in a very brittle fashion or at low loads we recommend using one of our Piezo Sensor tups. For those who have a much tougher, more ductile film we suggest using our Model 8902 Strain Gauged Tup.
The Impulse™ Data Acquisition System
provides the means for measuring and recording the load, displacement and velocity of the test event simultaneously. In addition values for energy at peak load and total energy absorbed are provided.