How to do to get the composite film bag will know its structure?

When you get a flexible packaging bags, is how to quickly identify the single-layer bags or composite bags? And what is its structural properties? Single-layer film and composite film how the difference? As a flexible packaging industry, these problems are all we need to develop. Here to help you recommend some of the ways to identify composite membrane and its structure. First, through the appearance to judge composite membrane type plastic composite packaging film is made from various types of monolayer film composite, its identification methods are different from single layer film. First of all, combined with the purpose of the performance characteristics of single layer film and composite requirements, can be roughly. Such as judging according to transparency, such as aluminum foil, aluminum plating film is not transparent composite film; Has high barrier function, general for the composite membrane. From the film appearance and mechanical properties can be roughly judge the membrane material. Second, the rapid identification of composite film of four small tip 1, composite film, generally has a natural wave phenomenon, such as put it in hot water. 2, composite membrane, such as the inner and outer material is not at the same time, the two sides of the film feel is different, the careful touch can be distinguished. 3, make a small cut on film, and then slowly inclined to tear, the tear of different base material of composite film is easily separated layers. 4, if printed film, if printing layer friction not to drop, then printing layer sandwiched between two layers of film, composite membrane. These are relatively simple identification composite membrane. More reliable is a physical property measurement, which USES thermal analysis method for thermal spectrum diagram, and according to the figure will appear in the corresponding components of molten wen. Microscopy, moreover, can also identify composite film, this is because all kinds of plastic refractive index is different, after stretching birefringence values is different, the difference and polarization microscope observation, the composite layers will show different color, to distinguish between a single membrane and composite membrane. Three, identification of various components of composite membrane methods for composite membrane after to its various components of the separation and identification. 1, dissolved method or solvent method using different resin dissolved or swelling performance, or solvent after infiltration interface change interfacial tension, to separate composite membrane layers. To the base material of composite membrane separation, is to figure out what kinds of substrate composition, to peel open the base material of composite membrane were analyzed to determine, but attention should be paid to the interference of adhesive at this time. 2, stripping method for composite extrusion or dry type composite made of composite membrane, after pulling or rub, because of the inconsistent deformation and peel; Certain heating processing, to soften the adhesive layer and make together film stripping; Can also be based on crystalline polymer melting point is different, separate from them.