Methods for testing physical properties of pallet shrink wrap
1, shortening function test will pallet shrink wrap supplier slowly close to the flame, different varieties of pallet shrink wrap supplier showed sharp shortening and not sharp shortening two conditions.Shrink the lack of stretch film polyester, cellulose acetate stretch film, rigid polyvinyl chloride (no shrinkage agent), polycarbonate stretch film, sharp shortening stretch film stretch polyvinyl chloride (hot shortening polyvinyl chloride), stretch polypropylene, polyvinylidene chloride, polyethylene and other thin films.In addition, when the stretch film is put into hot water, the stretch film is easily shortened: polyvinyl chloride (hot shortening), polystyrene, polyvinylidene chloride, hydrochloric acid rubber stretch film.There is little change in the stretched film of peng polyester, polycarbonate, nylon, etc.
2, extensibility test cut off a running time of 10 ~ 15 cm, 1 cm wide strip of the stretch film, hold the two end stretching, gradually adopt the test way can be found: polyethylene, elongation of tensile membrane have not been stretching polypropylene, soft PVC, polyvinyl alcohol, hydrochloric acid rubber, not stretch nylon stretch film, elongation of small stretch film has a general cellophane paper, polyester, cellulose acetate, rigid polyvinyl chloride (PVC) and polyvinylidene chloride such as stretch film, polycarbonate, tensile elongation of nylon between the above two.
3. Tear strength test cut the stretch film into one centimeter long with scissors at one end of the stretch film, and then tear it by hand to investigate the resistance to tear and crack of the stretch film.Simple tear of the film is polystyrene, cellophane, cellulose acetate stretch film.The tearing strength of polyethylene, polyester, nylon and polypropylene tensile films is large, but varies slightly according to the processing conditions and plasticizer content.For example, the stretch film of PVC with high plasticizer content is slightly stronger than the stretch film of PVC without plasticizer.Bidirectional stretch membranes generally have a horizontal and vertical balance of strength, but in fact they sometimes exhibit a number of differences.The unidirectional tensile film is lengthwise stretched, so the longitudinal tear strength is greater than the transverse one.
Through the physical properties of the test stretch film varieties are more complex, general requirements and other classification method induction, so we are in the distinction of time, must adopt the corresponding method, learn to change the method according to different circumstances, not the original, to learn to be flexible.