To determine the effect of free falling on plastic films and laminates, dart impact test is performed. In this test, a missile like dart falls freely on the test sample under controlled conditions. The test is very popular among industries where plastic pouches, laminates and other plastic packing are made. This test determines the durability and strength of the plastic films and other allied products.
Dart impact tester is used to perform the test. To perform the test, a sample is prepared as per the testing standards. This ensures uniformity and precision in the test results. Below mentioned is the standard operating procedure to perform the test.
Preparing the test sample:
The sample is prepared as per the test standards ASTM - D 1709 - 15a, ASTM - D 3029 - 82a, IS - 2508 – 1984. To prepare the sample, follow the certain steps
· In the area of the impact, the thickness of the test sample is around 0.002mm.
· It is important to take multiple thickness measurements of the sample for precise measurements.
· Find the means of all the five values and record the thickness of the sample easily.
· High level of precision can be assured with multiple thickness recordings
· There is a sample clamping ring on which the specimen should extend to atleast 25mm on all sides. The specimen is the cutout from the lot whose quality parameters are under test.
· Clamp the specimen on the ring holder
· Connect the 6 mm pneumatic pipe of vacuum pump
· Turn on the Power which activates the vacuum pump, this ensure the tight holding of the sample without any slippage of sample with the impact of dart.
Things to consider before implementation
· It is important to check whether the level of machine is adjusted with spirit level or not.
· Lock the leveling bolts in the perfect position to ensure that the apparatus does not vibrate.
· Do not forget to connect the power supply cord of the device to a 3 pin 5-ampere socket on a single phase 230V AC supply line.
· Ensure the proper earthing connection of the socket outlet.
· Ensure the location of the release mechanism of the vertical channel support.
· The dropping height of the dart of 660mmcan be attained by fixing the drop height in the middle set of holes.
· To set the height of dart at 1524mm, fix it in the upper most holes.