The advantages of precoating film over film covering

The use of precoated film for laminating can effectively prevent bubbles or demoulding of the coated product.

That is, the common point of blistering and film stripping of the film-coated products processed by the gluing wet composite process is that the film breaks away from the substrate of paper and printing, and damages the compactness and smoothness of the paper/plastic composite.

Only in different forms. Blistering is the local void of needle tip, rice grain, stripe, crack and other shapes. Demembrane is the separation of paper and plastic in large area or as a whole.

Careful analysis of accident cases in various forms shows that"film lengthening"and"glue sticking"are basic laws. The reason for the change of"film lengthening"and"glue tackiness"is that there are a large amount of organic solvents in the adhesive used in the coating wet composite process.

These organic solvents cannot be fully used in the production process, and remain in the adhesive layer, which is compounded by film and paper printing.

The residual organic solvent in the adhesive layer moves continuously in the paper/plastic composite. In order to escape from the colloidal matrix and volatilize to the atmosphere, the movement of organic solvent molecules is carried out simultaneously in different directions.

A part moves in the middle of the adhesive layer, making the adhesive soft and sticky;The other part penetrates through the adhesive layer and moves towards the paper, forming diffusion in the ink printing layer and damaging the adhesion and penetration of the ink to the paper;

Another part passes through the adhesive layer and moves towards the film. After being blocked, it will gather on the inner surface of the film, which will swell the film and make it longer, and locally bulge into bubbles.

The softening and tackiness of the adhesive reduces the thermosetting adhesion of the polymer material;The diffusion and dispersion of ink will cause damage to the adhesion with paper;The swelling of the film becomes longer, and it must extend outward to separate from the paper substrate.

The application of instant adhesive wet composite technology, sooner or later, or light or heavy, will inevitably lead to blistering or peeling.

There is no solvent in the hot melt adhesive used for precoating. There is no softening of adhesive by organic solvent, diffusion of ink, swelling of film, etc. The thermoplastic adhesive force of polymer material is generated after it is separated from heat source, and it is firm and durable. Therefore, it can effectively prevent the occurrence of quality accidents such as blistering and film stripping of the coated products.

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