Cover a layer of polypropylene plastic film on the cover for book printing, so that it has the functions of moisture resistance, stain resistance and folding resistance. After lamination, the books appear gorgeous and luxurious, and the grade value is greatly improved.

However, due to the use of operation and other reasons, laminating machine after the commodity often presents not bright or blistering, wrinkle and other appearances. Now talk about the handling of common questions in operation.

1. Temperature control

In rainy days or plum rain season, if the temperature conditioning is not appropriate, plastic coated goods will not be bright. There is significant water vapor on the silica gel roller, which is caused by the paper absorbing a lot of water. At this time, the temperature of hot pressing drum can be adjusted to 40 ℃. If the temperature is too high, it will blister. Some hydrosol laminating machine does not have heating equipment, need to add drying lamp before pressing, so that the rubber layer is dry and reduce foaming.

2. Pressure control

When laminating, the pressure should be adjusted according to the thickness of the paper, usually in 5pa. If the pressure is too large, film wrinkle and paper deformation.

3. Gluing control

The amount of glue is controlled by the gap between the glue roller and the glue roller, and the scraping film is added. The pressure of the squeegee is light, the glue is large, the pressure is heavy, and the glue quantity is small. The amount of glue should be well controlled, which can cover evenly without crystal point. If the amount of glue is too large, it will make the goods have no luster. Attention should be paid to avoid the retention of fine particles and impurities in the glue plate after gelatinization. If stuck in scraping film, there will be a white moulage, resulting in linear blistering. Before starting the machine, clean the cots and buckets with alcohol solvent. If the cots are not clean, it will cause blistering.

4. Drum cleaning

When the paper offset, the glue will be directly rolled on the silicone roller, accumulation, easy to make the commodity wrinkle, or affect the brightness of the commodity, should always clean the drum, adhere to cleaning. The drum itself will wrinkle and need to be replaced.

5. Control of temperature and humidity

The environment temperature and humidity change greatly, the paper moisture absorption occurs "lotus leaf edge", the paper is easy to wrinkle when covered with film, should adhere to the balance of temperature and humidity. Heating drum temperature is too high, paper tight edge will wrinkle, need to control the temperature according to demand.

6. Paper feeding control

Feeding paper tilt will make the paper wrinkle, operation should be careful, so that the paper is flat, pressure on both ends. In the paper feeding, each paper is stacked for 3mm, and the amount of glue is controlled to avoid the appearance of overflow. This can reduce the mutual adhesion after the commercial film covering. If the joint wrinkle or bubble, should adhere to the temperature and humidity balance conditions, appropriate pressure, so that the adhesion is smooth, reduce foaming.

7. Roll control

Avoid wrinkling due to different tightness at both ends of the film roll. First of all, we need to choose two pairs of thin film, then adjust the tension of the two ends to balance it and avoid wrinkling. In the film covering, try to use the film with the width of the size of the rough book plus the width of the material. For example, for the large 16 format, 440mm wide film should be used instead of 460mm wide film, which can save 4% of the cost. When using 780mm wide film in 16 format, trim the edge as much as possible, reduce the amount of glue and save glue.

8. Do not use additives in printing and control the amount of powder spray

Try not to use additives in the printing process, because it is not easy to be dry and easy to blister after film covering. But also need to control the use of powder. Before covering the film, special personnel should be organized to wipe off the dusting on the cover, and reduce the appearance of plastic film blooming or foaming, so as to make the goods bright.

9. Speed control

In the process of laminating, do not change the speed of the host machine at will. If the speed is too fast, the glue cannot meet the demand. When the speed is slightly added, the glue amount is too large. If the speed is adjusted too low, the amount of glue cut, easy to bubble. In order to ensure the same amount of glue, the speed of laminating machine can be limited by 60% of the highest speed, so that each shift can operate at regular speed, and implement data processing to reduce unnecessary loss.