Key points of solventless composite control for cooking resistance
① Environmental control
Solvent free compounding has high requirements on the production environment. The production workshop must be clean and tidy, free of dust, mosquitoes, etc. at the same time, the production workshop is not affected by printing and dry compound solvent. Before production, make sure that all cots, steel bars and other parts of the machine are clean and free of stains.
The environmental humidity should be controlled within a reasonable range, generally 30% - 70% of the relative humidity (or according to the technical instructions of various adhesive manufacturers). Poor environmental humidity control has a fatal impact on the cooking solvent-free composite (many cooking materials use nylon materials, and nylon is easy to absorb moisture), and has an impact on the appearance, peel strength and even the final cooking resistance of the composite products Will have a negative impact.
② Small test before production
Before the formal production of solvent-free composite, the matching of ink, composite substrate and solvent-free adhesive must be tested by small test. The use of composite materials, but also closely related to the performance of the adhesive. Especially for the composite of cooking materials, it is very important to confirm the small-scale test.
The solvent-free composite workshop should be separated from the dry lamination Workshop and printing workshop to avoid the influence of solvent, dust, mosquitoes, etc. on solvent-free lamination; at the same time, air conditioning should be installed to control the temperature and humidity. Only in this way can the conditions of trial production be consistent with those of formal production. The small-scale test products can not only be finished by filling water at 121 ℃ or vacuumizing, but also be filled with the contents that need to be packed for steaming and sterilization test, because different packaging contents have different effects on the permeability of film materials and adhesive adhesion properties; there is no problem in boiling at 128 ℃ in water, which does not mean that sterilization at 121 ℃ is certainly not a problem after packaging contents are packed; only the contents are packed in After the packaging contents are sterilized according to the actual sterilization temperature and there is no problem, the formal production can be carried out. In view of this, flexible packaging enterprises should pay more attention to it.
③ Control of glue quantity
The amount of glue applied should be adjusted according to the thickness of printing ink, the requirements of package contents, the type of substrate film and the composite appearance on site; if the glue amount is not controlled well, it will not only affect the appearance of the product, but also affect its ultimate peel strength and cooking resistance. The amount of glue applied in solvent-free cooking is generally controlled at 1.8g/m2 ~ 2.2g/m2, which can be less for materials with small printing ink area; when the printing ink area is large or the content is spicy, spicy and greasy, the glue amount should be appropriately increased. In the small-scale test, two or three different amount of glue can be tested to select the optimal process.
④ Control of ripening conditions
Curing should be carried out within the range of curing temperature and time provided by the adhesive manufacturer; insufficient curing temperature and time will seriously affect the final cooking resistance of the product. In the process of ripening, it is usually required to complete one-time aging, so as to avoid testing and testing without complete ripening. If it is found that there is no complete ripening, it will be put back to ripen again for secondary aging, which will affect the final performance of the product. Generally, the curing condition is controlled at 45 ℃ ~ 50 ℃ for 48h ~ 72h, which should be controlled according to the technical instruction of adhesive manufacturer.
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.
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