Extrusion composite membrane bond fastness is not good reason and the corresponding solutions

Extrusion composite membrane, the extrusion of the bonding layer, printing ink and printing the expansion coefficient of the substrate, the cooling process, the cause of the stress and displacement between layer and layer, easy cause compound not firm. So, what causes these problems, how should solve? Bond fastness of composite extrusion ( Peel strength) Bad the cause and the solution 1, melt extrusion viscoelasticity. Melt index of the resin is too small, should choose the proper density and melt index of resin. Thermal oxidation of 2, melt inadequate, low polarity, poor bondability. Extruder temperature is low, the production line speed is too fast, the density of the resin is too high, the low melt index can make the melt oxidation ability, therefore, to properly raise the temperature of extrusion body, reduce the traction winding speed, with high melt index, low density resin. 3, base material factors. Base material surface treatment is not enough, low surface tension, base material of the additives in the heat transfer to the surface and form a thin layer. For paper, moisture absorption and cause the loss of bond; For aluminum foil, should pay attention to its surface cleanliness, production should test wettability on the surface of the base material, pay attention to keep the material. 4, the adaptability of ink is bad. Basically has the following several aspects: the ink does not match with AC agent, agent of AC coating quantity is less, AC agent was ink absorption of, small adhesion between substrate and ink, ink resin low softening point, ink additives with high temperature and precipitation. Therefore, choosing the right ink with suitable for complex process is very important. 5, the influence factors of AC agent. AC agent bad wettability of base material, AC agent off, dry, AC agent AC agent selection is not suitable for base material, coating AC agent quantity is not enough, AC agent thermalization reaction was not enough. Is to take the corresponding measures can solve the above factors caused by AC agent bad bonding. 6, composite temperature when the pressure is low. Should improve the resin temperature, increase liquidity in the resin melt, extrusion melt curtain should be slightly to the rubber roller, not touching the cooling roll first, prevent melt shade and the base material is cooled before laminating, but also to the substrate preheating. 7, composite pressure is insufficient. Can increase the pressure of the pressure roller, generally lower, plastic membrane paper pressure high. The pressure roller pressure should be uniform.