PUR hot melt glue laminating machine compound pressure is too large or the pressure at both ends of the compound roller is uneven, will cause the compound film surface folds, after the compound folds form an empty tunnel, affecting the bonding fastness of the finished product.
The effective way to solve this problem is to increase the amount of glue coating, appropriate drying temperature, appropriate increase of compound pressure.
(1) Increase the amount of glue. Glue amount is too little or part of the substrate surface is not coated with adhesive, will lead to the composite of the two substrate is difficult to fit. We can choose the roller with deeper net hole, or by increasing the pressure of rubber roller and reducing the contact pressure of scraper and roller to increase the amount of glue coating on the surface of the substrate. For some plastic film substrates, corona treatment can be carried out before coating, so that the surface of the fuzz, so as to improve the substrate adsorption adhesive ability, so that the surface of the amount of glue.
(2) To select appropriate drying temperature. Too high or too low temperature will affect the bonding fastness of the composite film. Coating substrate drying heating temperature is too high or after high temperature cooking, will make the surface of the adhesive is carbonized, thus destroying the adhesive bonding ability. Drying temperature is too low, the adhesive curing is not complete, the adhesive viscosity is poor, the composite is not strong and after a period of time, the composite film is easy to form bubbles, destroy the composite quality of the product. Of course, we can choose adhesives with good high temperature resistance and cooking resistance to adapt to higher temperature drying, such as polyurethane adhesives.
(3) Appropriately increase the compound pressure, the machine compound pressure is too large or both ends of the compound roller pressure is uneven, will cause the surface of the compound film fold, after the compound fold at the formation of an empty tunnel, affecting the bonding fastness of the finished product. Proper increase of compound pressure is beneficial to improve the bonding force of compound.
Post time: Jul-19-2022