As the existing production process of the composite membrane is more or less accompanied by the generation of waste, it is necessary to make some changes in the production process to meet the needs of environmental protection.
First, in the dry compounding process, the solvent used is ethyl acetate. Although the "Emission Standards for Integrated Air Pollutants Emission" (G816297-1996) does not specify the emission of ethyl acetate gas, the gas has harmful effects on the human respiratory tract and should be used as little as possible. Ethanol-soluble adhesives have been developed that can replace polyurethane adhesives with ethyl acetate as a solvent. The adhesive is alcohol-based, non-polluting, and not costly. It will be widely used.
Second, raw materials and material structure. The materials needed for the production of composite membranes are mainly polypropylene, polyethylene, polyester, polyester aluminum, aluminum foil, etc. These materials are still the main raw materials for composite membrane production in the future. It will continue to be used for a long time. Since composite films and bags made of these raw materials are secondary consumer products, they can rarely be recycled and reused, so people try to replace them with degradable plastic films having the same performance.
Third, in the process of plastic gravure printing, benzene-free ink is used instead of current benzene-based inks. At present, although many domestic manufacturers have introduced benzene-free inks, their performance has not yet fully satisfied the need for plastic printing, and they are expensive. The unit price is 2-4 times that of ordinary inks, which is not conducive to reducing printing costs. Therefore, benzene-free ink will replace ordinary ink. Companies should install exhaust gas treatment devices to reduce the emission of organics (especially benzene) during the printing process.