Views: 0 Author: Site Editor Publish Time: 2021-04-07 Origin: Site
First of all, combining the performance characteristics of PE film for aluminium and the requirements of the composite purpose can be roughly distinguished. If judged by transparency, aluminum foil, aluminized film, etc. are generally opaque composite films; with high barrier function, they are generally composite. Skills to judge the quality of PE film for aluminium. From the appearance and mechanical properties of the PE film for aluminium, the base film material can be roughly judged, such as high-strength PET, puncture-resistant PA, easy-to-tear PP, etc.; PET and PA are generally combined with PE or CPP to solve heat sealing problem.
① PE film for aluminium generally has natural curling phenomenon, which is more obvious if it is placed in hot water.
② If the material of the innermost layer and outermost layer of PE film for aluminium is different, the touch of the two sides of the aluminized film is different, which can be distinguished by careful touch.
③ Cut a small cut on the PE film for aluminium, and then slowly tear it diagonally. It is easy to separate the layers of the composite aluminized film composed of substrates with different tearability.
④ If it is a printed PE film for aluminium, if the printed layer cannot be rubbed off, it means that the printed layer is sandwiched between two layers of film, and it is a composite film.
The more reliable method is the physical property measurement method, that is, the thermogram is obtained by thermal analysis, and the judgment is made according to the characteristic temperature in the graph. If it is a composite film such as PP/PE, PET/PE, PA/PE, the corresponding spectrum will appear The melting temperature peak of each component.
The microscope method can also identify PE film for aluminium. This is because the refractive index of various plastics is different, and the birefringence value after stretching is different. When observed under a phase contrast or polarized light microscope, the composite layers will show different colors, thus Can distinguish Skills to judge the quality of PE film for aluminium. After it is determined as a composite Skills to judge the quality of PE film for aluminium, its various components should be separated and identified.
① Stripping method. For composite Skills to judge the quality of PE film for aluminium made by extrusion compounding or dry compounding, after pulling or kneading, peeling occurs due to inconsistent deformation; certain heating treatment is carried out to soften the adhesive layer. The aluminized film that is bonded together is peeled off; it can also be separated according to the melting point of the crystalline polymer.
② Dissolution method or solvent method. Different resins have different dissolution or swelling properties, or change the interfacial tension after the solvent penetrates into the interface, to separate the composite Skills to judge the quality of PE film for aluminium.
After separating the base material of the composite Skills to judge the quality of PE film for aluminium, it is necessary to find out which base material is compounded, and the base material of the peeled Skills to judge the quality of PE film for aluminium can be analyzed OK, but pay attention to the interference of the adhesive at this time.