Dry composite thin film

summary

Dry lamination is the process of applying adhesive solutions to the surface of a plastic substrate using various coating methods and then passing them into a drying channel to evaporate the solvent of the adhesive, forming a uniform adhesive layer (approximately 1.5-5um thick) without solvent on the surface of the film. The adhesive is then compounded with a second substrate using a lamination device. To cure the adhesive, the product film needs to be rolled at a certain temperature and cured for a certain time to obtain appropriate adhesive strength.

The biggest feature of dry lamination is the ability to freely choose various coating methods, which can select the best coating method based on different film characteristics, coating amount, adhesive properties, film properties, etc.

The characteristics of dry compounding are as follows:

1) The substrate available for selection is quite wide, which can be plastic/plastic, plastic/metal foil, plastic fabric, non-woven fabric, paper, etc. It is particularly suitable for the production of a wide variety of small amounts of composite films.

2) The composite strength is high, and the composite strength of plastic/plastic can reach 1N/15mm, which can adapt to high-end soft packaging materials such as steaming bags for goods with extremely harsh production and usage conditions.

3) Fast recombination speed; Generally, it can reach 100min, and the maximum can reach 250m/min

4) Dry products can be surface printed (surface printed) or reverse printed (inner printed). When printing inside, the ink is sandwiched between two layers of thin film, which will not discolor, has good hygiene, and the gloss of the ink after printing is good

5) The adhesive used for dry lamination contains residual unreacted monomers and solvents, but selecting the adhesive and controlling the process conditions can meet hygiene standards.

6) The cost of producing composite films is relatively high, especially when using high-temperature inks and adhesives, so they are generally used for high-end packaging.

7) There is environmental pollution caused by solvent evaporation, and there are issues with safe operation and industrial production hygiene conditions. Therefore, the equipment used must be equipped with strict operating conditions and necessary preventive measures must be taken.

In addition, dry composite films generally have good stiffness, and films used for cooking are mostly produced using this method.

In addition to solvent based adhesives, water soluble adhesives and solvent-free adhesives have also been developed for dry bonding. Therefore, similar bonding processes include solvent-free dry bonding, wax bonding and Hot-melt adhesive bonding.