ã€Chinese Packaging Network News】 After decades of elimination, screening, the current dry composite adhesives are basically using solvent-based two-component polyurethane adhesive. What are the characteristics of this polyurethane two-component adhesive used in composite flexible packaging?
Polyurethane two-component adhesives are used on flexible packaging
1, in appearance: light color, good transparency, suitable for packaging.
2, good adhesion: Composite flexible packaging using a wide range of substrates, different properties of the material, the state varies, requiring adhesives have a strong adaptability, all kinds of materials must be good adhesion, and polyurethane adhesives on Paper, plastic film, aluminum foil, and fabric all have good adhesion.
3, good flexibility: suitable for flexible packaging of various substrates, anti-folding, good elasticity.
4, good processability: After continuous improvement, composite polyurethane adhesive in the composite production can be a good initial adhesion, fluidity, good infiltration, and composite ink has a strong adhesion.
5, good heat resistance: This is a very important requirement for composite flexible packaging processing. On the one hand, the packaged products are required to be pasteurized at 85°C, boiled and sterilized at 100°C, cooked at 121°C, and cooked at 135°C. On the other hand, the composite film processing process needs to pass through a drying tunnel and composite roll at 60-90°C, and a hot knife with a resistance of 160-220°C must be formed in the bag.
6, cold resistance: at low temperatures will not be hardened, brittle, layered, many foods need to be frozen, refrigerated, stored, the north can be used in winter with low temperatures
7, anti-media: polyurethane adhesive curing cross-linked, can resist most of the acid, spicy, fragrant, salt and other chemical media.
8, good health: no odor, safety. At present, the FDA recognizes that aromatic polyurethane adhesives are only used for boiling in the following packaging at 100°C. Only high-temperature cooking can use aliphatic polyurethane adhesives.