A film or sheet is formed by heating polymer to a molten state. The process is most often extruded or calendared. In the process, the molten film is pulled under tension, thus caused a stretching in machine direction. Then the film is cooled to form into a given thickness, width etc. Some undesirable stressed are locked in. When a plastic film or sheet is reheated, it can change in linear dimension. This is typically referred to as shrinkage. Shrinkage is also important because it can tell how the plastic was made. It can be used for quality control or process control.
● Mount the test specimen on the free shrink holder and place in the liquid bath when desired temperature is reached.
● When time is up, the alarm beeps.
● Remove test specimen and press Stop button to finish the test.
● Treat the specimen at ambient environment and measure the shrinkage
STANDARDS
1.P.I.D. temperature control
2.High precision timer
3.Alarming function
4.Stable heating of fluid medium
5.Standard square metal clamp and free shrink holder
STANDARDS
ASTM D2732, ISO 11501 , GB T13519
