Abstract: Shrinkage performance is an important factor affecting the use of heat shrinkable film. In this paper, the shrinkage properties such as heat shrinkage, cold shrinkage and shrinkage of POF and PVC heat shrinkable film samples were compared and tested. The test principle and parameters of the equipment FST-02 film heat shrinkage tester and its application range were introduced. The test process and other contents provide reference for the research and detection of film shrinkage performance. Key words: heat shrinkable film, shrinkage, heat shrinkage, cold shrinkage, shrinkage, film heat shrinkage tester, POF , PVC 1 , meaning There are many types of heat shrinkable film materials, such as PE , PVC , POF , PETG , BOPS, etc., which have the advantages of good fit, tight packaging and low price. They can be used for labels of food, toys, medicines, electronic components, etc. Body packaging, bundle packaging, etc. The shrinkage property of the heat shrinkable film is related to the tensile action in the high elastic state during the production process. When the formed film is heated again, there is a tendency to return to the state before stretching, and the macroscopic performance is a film. Shrinkage effect. The film material, stretching process parameters, shrinkage temperature and time will affect the shrinkage performance of the heat shrinkable film. Different products have different shrinkage properties of the heat shrinkable film used for packaging due to different objective conditions such as shape and size. Differences, therefore, studying the shrinkage properties of heat shrinkable films is instructive for their production and application. 2 , test samples In this paper , two common heat shrinkable films , POF and PVC, were used as test samples to compare their shrinkage properties. According to the stretching direction of the sample, the test direction of the POF sample is longitudinal, and the test direction of the PVC sample is transverse. 3 , the test basis This test is based on GB/T 34848-2017 "Heat Shrinkage Film Shrinkage Test Method" to test the heat shrinkage, shrinkage and shrinkage of the sample. 4 , test equipment In this paper , the sample is tested by FST-02 film heat shrinkage performance tester. The equipment is independently developed and produced by Jinan Languang Electromechanical Technology Co., Ltd. Figure 1 FST-02 film heat shrinkage performance tester 4.1 Test principle By adjusting the shrinkage temperature, the heat shrinkage force of the sample appeared within 15-30 s after the start of the test, and the heat shrinkage, cold shrinkage and shrinkage of the sample at this temperature were tested. In order to realize the test of each parameter, the displacement sensor and the force value sensor are respectively arranged on the fixture of the device. When the temperature in the heating cover reaches the set value, the fixture containing the sample is automatically pushed into the heating cover, and the force value sensor records During the heating process, the force value of the sample changes, and the 蕞 蕞 value is reported as the heat shrinking force; after the cabin condition is reached, the clamp drives the sample away from the heating hood and enters the environment for cooling, and the force value sensor records the force value during the cooling process. And the 蕞 蕞 value is reported as the cold shrinking force; the displacement sensor monitors the change of the sample displacement during the whole test to obtain the shrinkage value. 4.2 Equipment parameters 4.3 Scope of application (1) It can be used to test the heat shrinkage force, cold shrinkage force and shrinkage rate of the heat shrinkable film material under certain test conditions. (2) Applicable to GB/T 34848 , ISO 14616 , DIN 53369 and other domestic and international standards. 5 , the test process 5.1 POF shrink film test (1) the POF sample thickness, then cut out to a width in the longitudinal direction 15.0 mm, 12 cm long sample 20, the sample was perforated with a special specimen preparation. (2) two samples taken in a set of clamps are attached to the apparatus, wherein a sample for testing contractility, the other specimens for testing shrinkage. Set the sample name, test temperature, test end temperature and other parameter information, click the test option, the test starts. When the temperature inside the heating hood reaches the test temperature, the fixture automatically enters the cabin, and the heat shrink - out cabin - cooling process is automatically completed in accordance with the set parameters . (3) Constantly adjust the test temperature parameters according to the time when the heat shrinkage occurs, and install the sample for testing until the heat shrinkage force occurs between 15 and 30 s . At the test temperature, 5 sets of samples were repeatedly tested , and the average of the test results was taken as the shrinkage performance of the POF sample. 5.2 Testing of PVC heat shrinkable film samples The sample is cut along the transverse direction of the sample. For the rest of the operation, see section 5.1 . 6 , test results The test temperature the test sample POF shrink film occurs between 15 ~ 30s shrink force corresponding to 140 ℃, shrink force of 0.46 N, a shrink force of 0.21 N, a shrinkage of 51%; PVC The heat shrinkage film sample exhibited a heat shrinkage force of 15 to 30 s corresponding to a test temperature of 80 ° C , a heat shrinkage force of 2.12 N , a shrinkage force of 2.37 N and a shrinkage of 34% . 7 , conclusion The shrinkage properties of different films are different. When using heat shrinkable film packaging, the shrinkage performance test should be carried out in time to screen out suitable packaging materials. In this paper , the shrinkage properties such as heat shrinkage, cold shrinkage and shrinkage of POF and PVC heat shrinkable film samples were tested by FST-02 film heat shrinkage tester . The test results show that compared with the POF sample, the PVC sample has higher heat shrinkage and cold shrinkage, but the shrinkage rate is lower. The test process of the device is simple and the automation of the device is high. Jinan Languang Electromechanical Technology Co., Ltd. is a high-tech enterprise specializing in R&D, production and packaging inspection services for packaging inspection equipment. The existing equipment can also test the thickness, tensile strength, tensile properties, heat sealing performance of heat shrinkable film. Physical and mechanical performance indicators such as puncture resistance, tear performance, friction coefficient, impact strength, light transmittance and haze . The more you understand, the more you trust! Labthink is looking forward to enhancing technical communication and cooperation with enterprises and institutions in the industry. Ningbo Siny Medical Technology Co., Ltd , https://www.sinymedical.com