Thin film composite technology
Multi-layer composite film or film and aluminum foil, paper multi-layer composite material, in terms of air barrier properties, heat sealability, printability, peel strength, hygiene and economic rationality, there is a significant improvement over single-layer packaging, so more and more More and more used in the packaging field to replace traditional metal, glass, wood and paper. The composite methods are roughly as follows:
(1) Hot-melt composite EVA-based hot melt adhesive or microcrystalline wax is used as a binder. When used, it is heated and melted into a fluid by a constant temperature bath, quantitatively applied to paper, compounded with aluminum foil, etc., and is usually used as beer. Trademarks, etc.
(2) Wet compounding is commonly used in the composite of aluminum foil and paper. The binder also contains a solvent at the completion of the compounding, and the substrate is loosely flanked by one side of the substrate, has gas permeability, and completely volatilizes the solvent in the drying chamber, so the substrate used in the method is selective. The wet composite adhesive is represented by vinyl acetate latex, and the adhesion fastness is proportional to the amount of the adhesive coating and the solid content. Wet composite materials are currently mainly used for the packaging of cigarette boxes, labels and dried fruits.
(3) dry compounding
(4) extrusion coating
(5) co-extrusion compounding