A plastic test is any type of test done on a sample of plastic. These tests can be used to determine the strength, flexibility, or durability of a plastic and are often used as a measure of quality control. Laboratories that offer to perform plastic tests use a variety of different machines and techniques to determine the quality of the plastic.
One common type of plastic test is a test of how the plastic holds up under different temperatures. For this type of test, a sample of the plastic is placed in a chamber where the temperature is either raised or lowered at a slow but constant rate. Engineers watch for changes in the quality of the plastic, such as expansion, breaking, melting, or contraction, depending on the specifications of the test, and note the temperature at which the change took place.
Plastics may also be tested for how durable they are under stress. One plastic test that determines durability uses a machine that bends a piece of plastic until it breaks. In another type of test, a piece of plastic may be pressed firmly between two sides of a machine until it compresses or cracks with the strain. Engineers may also use a machine that hits the sample, testing the capacity of the plastic to resist the impact and slow it down. Examining the forces used in each of these types of stress tests gives engineers information about how strong a sample of plastic is.
Some plastics that are intended for use as lenses may also undergo a plastic test that determines how the plastic interferes with light that passes through it. In one such test, a light with a specific wavelength is viewed through the sample, and the color and quality of the light is compared to the color and quality of the same wavelength of light that has not passed through a lens. Haze, or the amount of visible light that is refracted as it passes through a plastic lens, may also be tested in a similar plastic test.
For plastics that are intended for use in different types of conditions, weathering tests may also be performed. A sample can be tested to see how much water it absorbs or to see at what temperature it will catch on fire. A machine that mimics the effects of weather over a long period of time may be used in a plastic test that determines how a sample will hold up over time and exposure to the elements.