Professional Polymer Technology
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Solvent free adhesive is environmentally friendly adhes […]
Solvent free adhesive is environmentally friendly adhesives, which have been popular in recent years. Solvent-free polyurethane adhesives are one of them.
Polyurethane is a rapid development of polymer materials, due to the diversification of raw materials and molecular structure of the soft and hard section can be adjusted, can be made of foam, adhesives, but the solvent in the production process will not only pollute the air, Directly harm the health of workers, and eventually there will be a small part of the solvent can not be excluded, residual food packaging in the harm to the health of consumers, which is more dangerous than the food itself, the hidden dangers.
At home and abroad are very important to the problem of environmental pollution, composite film using solvent-free polyurethane adhesive can completely solve the problem caused by solvent pollution. 1974 Germany first with solvent-free polyurethane adhesive made of composite packaging materials. China's current solvent-free coating machine equipment has not yet universal, so the application is less, with the economic development and equipment promotion, solvent-free polyurethane adhesive will be widely developed.
Solvent-free polyurethane adhesives are two-component and one-component. Two-component type of the main agent and curing agent at room temperature viscosity is high, but still has mobility, is semi-solid material. When the compound is to be compounded, the main agent and the curing agent are mixed in proportion and placed in a rubber tray having a heating and holding function, the temperature is raised to 50 to 60C, the viscosity is reduced to 1 Pa.s or less, and then, Insulation function of the intaglio roll applied to the substrate. After the glue does not have to bake drying and drying, because it does not have any solvent, can be directly with another substrate compound.
The use of solvent free adhesives does not present the problem of exhaust emissions, does not require a large and complex heating blast and exhaust gas treatment device, simple equipment, raw material savings, reduced energy consumption, low maintenance costs, production speed, so the benefits are very significant. At present, most of the ordinary composite film packaging materials can be used solvent-free adhesive production, and even resistant to 121 ℃ high temperature cooking high-grade composite film packaging materials can also be used to manufacture this method.