After the film is thinned, the company will reduce the cost and improve the quality.

At present, the "thinning" of plastic film has become the development direction and research hotspot of the production and use of flexible packaging plastic film. Among them, BOPA film thinning has been paid more and more attention in the process of production and use. Some flexible packaging companies have replaced 15μm with a thickness of 12μm when using BOPA film, and their thickness is reduced by 20%. This contribution contributes a lot to film reduction. However, some problems have arisen in the use after thinning. The following precautions, please bear in mind, pay attention to control in printing production.

Tension adjustment

Due to the thin thickness of the ultra-thin BOPA film, during the printing and compounding process, the tension of the nylon film is appropriately adjusted to balance it and meet the production requirements, so as to prevent deformation and wrinkling after the material is thinned, especially in comparison with When the aluminum foil is compounded, it is necessary to pay attention to the adjustment of the tension. Since the aluminum foil is a non-stretchable material, if the tension of the 12 μm nylon is too large, the rebound will cause wrinkle deformation after stretching. In addition, some BOPA/BOPA, the basic characteristics of the two materials of this structure are consistent, and it is more difficult to adjust the tension and the amount of compounding. It is necessary to obtain experience after many times to get better results , just like Same as PET/PET.

Ink selection

Since the ultra-thin BOPA film has a high moisture absorption property, the use of a solvent and an ink containing water and an alcohol is minimized. However, if it is not necessary, it should be dried as much as possible to eliminate residual solvent.

At present, the use of water-based adhesives, solvent-free composites and inks is being developed and promoted in China, and the nylon membrane should be controlled and ensured within a certain water content range (the smaller the water content, the better) . Secondly, when using water (alcohol)-based inks, the color density and vividness of the ink are very important. Generally, the amount of ink is small and the ink layer is thin, the hiding power is good, and no solvent remains . When using the water gel process in the compounding, a high concentration blending method should be used, which not only ensures the amount of glue and the composite fastness, but also reduces the amount of residual solvent. When using, it is best to dry in the mature room of 45~50°C for 1~2h. When producing in wet weather or low temperature, the preheating system of the equipment should be opened to eliminate the adhesion of small water droplets on the surface of BOPA film.

Requirements for plates and composite applicators

When printing ultra-thin BOPA film, it is required that the mesh on the printing plate used should be appropriately shallower, so as to prevent the ink layer from being too thick during printing, and drying and drying is not complete and solvent residue is likely to occur. In the compounding process, it is better to use high concentration (35%~40%) and high solid content adhesive. The composite coated wire roller can be controlled between 140 lines and 160 lines/inch. Adhesive, appropriate increase in the amount of glue. If water-based adhesives are used, 200 line/inch coated web rolls can be used to minimize the residual solvent and ensure the quality of the product.

Requirements for interlayer film

If the nylon membrane is sandwiched between the intermediate layers, a double-sided corona-treated film must be used to ensure that the composite fastness after compounding meets the requirements.

The double-sided corona nylon film should have a corona difference of more than 4 dynes on both sides, so as to avoid the adhesive film from sticking and falling off . Secondly, when PE film is used as the heat sealing layer of the pasteurized pouch, the PE film with little or no additive or the MPE film should be selected to prevent the additive from floating when the boiling temperature rises. Delamination. Check if the surface wetting tension is up to standard before use, otherwise it cannot be used. If you use a semi-high temperature cooking bag, please do all the testing and testing before you get the experience.

With the increasing voice of environmental protection, “reduction of packaging materials ” is one of the important ways to achieve green packaging. How to minimize the production of plastic waste under the premise of satisfying the packaging function has become an important issue facing the plastic flexible packaging industry. . Therefore, the development of packaging films in the direction of weight reduction, thinning, and ultra-thinning is an inevitable trend. Film-making and printing companies can establish strategic alliances for material use, make full use of material modification technology to obtain new packaging materials, fundamentally improve the barrier properties of plastics, improve their mechanical properties, and produce more functional plastic films. Soft packaging materials are ultra-thin, lightweight, high-performance, and multi-functional green.

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