The quality control of film-covered products

The laminating process is often used in the manufacture of labels and packaging. However, in actual production, due to improper operation of the operator or other reasons, it often causes wrinkling, foaming, curling, and other quality problems after the product is covered with a film. The phenomenon of blistering is usually generated after a period of storage, which affects the quality of the product and even causes it to be scrapped in severe cases. Therefore, the operator is required to operate correctly in production, grasp all aspects, and make the product meet quality requirements. The following talks about the quality control of film-covered products.

Control of product to be constructed

1. The product to be constructed must be straight. Non-flat paper with "foliate" and "tight edges" should be handled. "Ruffled" paper can be baked, and the "fast edge" paper can be hung.

2. Be sure to wait for the blot to dry before coating, otherwise it will cause blistering or pulling phenomenon.

3. Spray as little as possible when printing, otherwise it will cause empty foam at the heap. Before the film is coated, the powder should be removed. The number of prints can be hung to dry, and the number of prints can be manually wiped.

4. The direction of the paper web should also be taken into account when applying the film, especially thick paper, to reduce the curling phenomenon caused by the paper being stretched and rolled.

Operational control

1. The thickness of the glue should be appropriate. Too thick and easy to produce curl, and affect the gloss; too thin, not enough viscosity, and even blistering. Should be adjusted according to the product, the general control of coated paper is slightly thinner, and the thickness of the offset paper is appropriately controlled.

2. The pressure should be adjusted according to the product condition. In general, the pressure of coated paper should be smaller than that of offset paper. Thin paper is smaller than thick paper.

3. The general temperature control is 40 ~ 60 °C. Too high a temperature will deform the paper and film, causing the product to curl, but it should not be too low, otherwise it will cause insufficient viscosity. Coated paper temperature should be slightly lower than offset paper.

4. The film tension should be appropriate. It is generally advisable to be able to maintain normal work without lagging behind. Too tight and easy to curl the product, too loose will wrinkle.

Workshop temperature and humidity control

1. In order to ensure product quality, the temperature of the film coating shop should generally be compatible with the printing shop, and should not be too high or too low.

2. The humidity is generally slightly smaller than the printing shop. If the humidity is too high, the product may be deformed or even wrinkled, and curling may occur after the product is processed. If the humidity is too low, static electricity may be generated during the lamination process, which may affect the subsequent process.

Raw material control

According to the nature of the product, the thickness of the paper, quality requirements and other correct choice of raw materials. In general, thin films should also be thin to avoid curling. Products with high requirements should choose a better gloss film. The glue should be transparent and non-precipitating. Promote the use of pre-coated films to reduce damage to human health.

Source: Coinprint