Technical Q&A on Flexible Plastic Packaging
DATE：2021/8/19 8:25:54 / READ： / SOURCE：This station
Technical Q&A on Flexible Plastic Packaging
1. PVC shrink film is easy to break during printing. Is the quality of PVC shrink film bad?
It is not the poor quality of PVC shrink film, but the problem of the special PVC printing ink used. In this special PVC printing ink, there is a solvent that can dissolve the PVC film, and this solvent has low volatility. Therefore, if the solvent content of the solvent dissolving PVC in the special PVC ink is too much, it will be used in the printing process. The PVC shrink film dissolves and is torn off. However, if the PVC special printing ink is not used, the printing fastness is not satisfactory. That is to say, if the content of this solvent dissolving PVC in the special ink is too small, the printing fastness will be reduced.
2. How to crush and re-granulate waste PE and PP films? What are the current and future prospects of waste PE and PP pellets?
PE and PP film is a kind of material with strong impact resistance, which is not easy to be crushed by ordinary plastic crusher. Ordinary material shredders, one uses the hammering method, which can make PVC pipes, plates, stone powder-filled PE, PP plate pipes with small hardness and toughness to be crushed by hammer impact; the other is cutter cutting, one row A fixed knife and a set of rotating knives form a cutting tool. It is obviously inappropriate to use the former method for pure PE and PP films, and the latter, because PE and PP films are soft and not easy to shred, not to mention the high temperature of the tool at high speeds, which will cause the LDPE to melt and adhere to the cutting edge. superior. Therefore, PE and PP film granulation, after washing and drying, are directly put into the feeding port of the extruder, and the PE and PP film are dragged into the barrel by the shear force of the screw to be heated, melted, and extruded for granulation. It must also be pointed out that even if you use a chaff-breaking machine (beating straw and dried grass into fine powder for feeding animals) to break PE and PP films into small films, you cannot use the self-weight feeding method to add materials, because these films The film is too light to float on the surface and must use a screw forced feeding device to enter the barrel. Therefore, the very complicated PE and PP recycled primary materials can still be blown film, used for non-food and pharmaceutical packaging, and widely used in Oxford In the production of leather and waterproof cloth, the future is very good.
Author：admin