Dry composite process
DATE：2019/5/28 8:22:04 / READ： / SOURCE：This station
Dry composite process
Dry compounding is carried out by applying an adhesive to a substrate, drying it, volatilizing the solvent, improving the initial tack and adhesion of the adhesive, and then pressing and laminating with another substrate. In the case of wet compounding, the glue is applied to the composite, and then dried and cured. Obviously, wet compounding is not suitable for the compounding of plastic films. Because a large amount of adhesive solvent is pressed and laminated on the composite film after the adhesive is pressed, the plastic film cannot volatilize these solvents during drying and solidification, and cannot be absorbed by the plastic film, so the wet composite is not suitable for plastics. Lamination and bonding between films. Wet compounding is only suitable for the lamination of porous materials such as paper, wood, plywood, etc. or lamination of porous foam. Because these materials are loose in material and have a large number of pores, the solvent in the adhesive can pass through the heat curing process.
The pores are emitted or absorbed.
The glue for wet compounding is generally acrylic latex, EVA latex, phenolic resin glue and other organic solvent glue. The substrate is paper, woven fabric, non-woven fabric, cellophane, aluminum foil, or the like. A starch gel can also be used for the wet composite adhesive. The wet composite process of aluminum foil and paper is as follows: aluminum foil unwinding → coating adhesive → pressing with the same paper → another surface of the aluminum foil coated with a slip agent or a polishing agent → drying and curing of the drying tunnel → winding. The composite material of the method can be used for packaging of cigarettes, chocolates, etc., and can also be used for packaging of confectionery, pharmaceuticals, and baked confectionery, but the water resistance, heat resistance, chemical resistance and the like of the interlayer adhesion are poor. Under high temperature and high humidity, these hydrophilic adhesives may cause delamination and corrosion of the aluminum foil.
Compared with other composite processes, the dry composite method has the following advantages: (1) The surface of the substrate to be selected is wide, and it can be plastic with plastic, plastic with paper, plastic with metal and fabric, non-woven fabric, etc. Composite, even without plastic, the paper can be composited with metal; (2) The composite has high fastness, and the peeling force between layers can reach 100025m or more, which can produce high-grade packaging products, such as high-temperature cooking bags; (3) The thickness of the layer can be freely selected and precisely controlled; (4) can be surface printed
Brush, can also be printed on the reverse side; (5) production speed is fast, the general operating speed is 150 ~ 180m / min, the fastest can reach more than 200m / min. The disadvantages of dry compounding are: (1) the adhesive needs to be used in the compound, and there is a toxicity problem of the residual solvent. Therefore, the dry composite packaging material, especially the dry packaging material cured by using the two-component polyurethane rubber cannot be used in North America. And in the European market, but only in Southeast Asia, Africa and other places.
Dry compounding is carried out by applying an adhesive to a substrate, drying it, volatilizing the solvent, improving the initial tack and adhesion of the adhesive, and then pressing and laminating with another substrate. In the case of wet compounding, the glue is applied to the composite, and then dried and cured. Obviously, wet compounding is not suitable for the compounding of plastic films. Because a large amount of adhesive solvent is pressed and laminated on the composite film after the adhesive is pressed, the plastic film cannot volatilize these solvents during drying and solidification, and cannot be absorbed by the plastic film, so the wet composite is not suitable for plastics. Lamination and bonding between films. Wet compounding is only suitable for the lamination of porous materials such as paper, wood, plywood, etc. or lamination of porous foam. Because these materials are loose in material and have a large number of pores, the solvent in the adhesive can pass through the heat curing process.
The pores are emitted or absorbed.
The glue for wet compounding is generally acrylic latex, EVA latex, phenolic resin glue and other organic solvent glue. The substrate is paper, woven fabric, non-woven fabric, cellophane, aluminum foil, or the like. A starch gel can also be used for the wet composite adhesive. The wet composite process of aluminum foil and paper is as follows: aluminum foil unwinding → coating adhesive → pressing with the same paper → another surface of the aluminum foil coated with a slip agent or a polishing agent → drying and curing of the drying tunnel → winding. The composite material of the method can be used for packaging of cigarettes, chocolates, etc., and can also be used for packaging of confectionery, pharmaceuticals, and baked confectionery, but the water resistance, heat resistance, chemical resistance and the like of the interlayer adhesion are poor. Under high temperature and high humidity, these hydrophilic adhesives may cause delamination and corrosion of the aluminum foil.
Compared with other composite processes, the dry composite method has the following advantages: (1) The surface of the substrate to be selected is wide, and it can be plastic with plastic, plastic with paper, plastic with metal and fabric, non-woven fabric, etc. Composite, even without plastic, the paper can be composited with metal; (2) The composite has high fastness, and the peeling force between layers can reach 100025m or more, which can produce high-grade packaging products, such as high-temperature cooking bags; (3) The thickness of the layer can be freely selected and precisely controlled; (4) can be surface printed
Brush, can also be printed on the reverse side; (5) production speed is fast, the general operating speed is 150 ~ 180m / min, the fastest can reach more than 200m / min. The disadvantages of dry compounding are: (1) the adhesive needs to be used in the compound, and there is a toxicity problem of the residual solvent. Therefore, the dry composite packaging material, especially the dry packaging material cured by using the two-component polyurethane rubber cannot be used in North America. And in the European market, but only in Southeast Asia, Africa and other places.
Author：admin