The physical and chemical properties of cellophane

A regenerated cellulose film with high transparency and gloss. There are flat paper and roll paper. The quantitative is 30～60g/㎡. It is colorless and can also be dyed into various colors. The paper is soft, transparent and smooth, without holes, slightly breathable, impermeable to oil and water. There is a moderate stiffness. Has good tensile strength, gloss and printability. The production method is different from that of papermaking and similar to the rayon process. Using refined chemical wood pulp or cotton linters dissolving pulp with high content of α-cellulose as raw materials, alkali cellulose is obtained through processes such as alkalization (18% sodium hydroxide), pressing and crushing. After aging, carbon disulfide is added to make alkali cellulose. It is yellowed into cellulose xanthate, dissolved in sodium hydroxide solution to make orange-yellow cellulose viscose. The viscose is matured at a temperature of 20～30℃, and filtered to remove impurities and bubbles, and then extruded from a narrow gap in the stretch film machine, and flows into the coagulation bath of the mixed solution of sulfuric acid and sodium sulfate , To form a film (regenerated cellulose film), and then processed by water washing, desulfurization, bleaching, desalination and plasticization (glycerin and ethylene glycol, etc.), and finally made by drying. It is used for packaging medicines, food, cigarettes, textiles, cosmetics, precision instruments and other commodities.