4. Why nylon film composite CPP, the finished product has sporadic foaming phenomenon?
This situation is mostly caused by glue bubble too high or nylon film damp, and the residual solvent in the composite layer is too much. In the humid climate of the south, this is a common problem in cooking and packaging. At this time, it is necessary to increase the circulation of glue in the glue tank to prevent the occurrence of bubbles, or to increase the drying temperature of printing and laminating machine, or to add no more than 5% curing agent in the glue. Moreover, when the weather is good (humidity is less than 70%), the printed nylon film should be compounded immediately or wrapped with aluminum foil, Do not use for too long (within 5min), in order to avoid the nylon membrane water absorption and moisture, and produce bubbles.
5. The reason why the nylon film is easy to peel off when it is used as the surface layer of composite water boiling?
Due to the water absorption of nylon, there are more problems in surface printing, composite boiling or cooking of nylon film, which seriously affects the peel strength. Therefore, the general water boiling adhesive dare not use the adhesive with resistance below 121 ℃. In the structure of BOPA / PE (115 ℃) and BOPA / CPP (21 ℃), only 135 ℃ cooking adhesive can be used, that is, the temperature resistance of the adhesive can be increased by one grade and the glue amount can be properly increased. It is better to use a waterproof coating to prevent moisture from entering the nylon membrane. Nylon film after cooking a small amount of yellowing phenomenon, will make the packaging bag color difference, should pay special attention to.
6. What are the reasons for the bubble formation after a period of time in combination with BOPA film but not in BOPP?
BOPA is a good barrier material, but in the process of printing and lamination, the residual solvent is too much, which can not be volatilized through the film after aging, but still remains in the film interlayer. This is due to the reaction of residual water with isocyanate group of curing agent in adhesive, resulting in the gas residue dominated by carbon dioxide. However, the barrier property of BOPP is weak, and some residual solvents in the film interlayer evaporate from the surface layer of BOPP by aging. Therefore, there are less bubbles in general BOPP film after compound aging.
7. The aluminum foil of OPA / Al / rcpp material combination cracks or even breaks at the sealing position?
Both BOPA film and aluminum foil are materials with certain ductility, but the phenomenon of cracking occurs at the moment of heat sealing when it is processed into packaging bag. Generally, the elongation of the package material imposed by the heat sealing knife has exceeded the acceptable level of the material, so the thermal seal layer is crushed. If it is automatic packaging double roller heat sealing, it should also consider whether the concave convex shape of the double roller is too sharp and piercing extrusion makes the aluminum foil layer break into black line cracking.
8. When BOPA / Al / PE (15.07.60um) composite is used, the edge of bag making heat sealing is easy to delamination?
Due to the high heat sealing temperature of bag making, the heating temperature of heat sealing position is generally increased by two-stage heat sealing. And in the heat sealing position is in the blank transparent state. Low molecular substances (such as smooth agent) in the film will permeate and float up to the surface at high temperature, which will degrade the adhesive and cause delamination. On the other hand, the oil contamination in the production process of Al is not completely removed, and a large heat separation distance occurs during heat sealing.
9. Why is there a nylon film combination, the printing ink containing jam bag is easy to fade?
Material combination b0pa / Al / LDPE or PA / CPE. In fact, no matter what kind of film combination, there are some phenomena. Discoloration caused mainly by contents. Pickle is a kind of food which contains various condiments, and its chemical composition is very complex, and many of them are chemical substances with high permeability. Therefore, LDPE or CPE should not be used in the inner layer. CCPP (salivating copolypropylene) with good cold resistance should be used, which can withstand 10 degrees below zero without embrittlement, so as to penetrate into the ink layer and have a smaller probability of chemical change.
Dongguan Beite packaging materials Co., Ltd. - located in Dongguan City, the world's manufacturing city, is a subsidiary of Beite packaging (China) Co., Ltd., with a plant area of 6000 square meters. It is a flexible packaging enterprise integrating R & D, production and sales. It has a complete set of domestic advanced production equipment, a scientific and humanized management system and a group of experienced technical personnel For backing, to provide customers with quality products and first-class service. The company produces composite bags, roll film, fruit bags, aluminum foil bags, suction mouth bags, self-supporting bags, zipper bags, anti-static bags, special-shaped bags, etc., which are suitable for the internal and external packaging of food, daily chemicals, electronics, toys, medicine, cosmetics, industrial products and other industries. We uphold the integrity of cooperation, good quality, good service business philosophy, won the industry's approval, products sold to all over the world; welcome friends from all walks of life to inquire, visit our factory to investigate guidance and business negotiations.