Products that are coated on the surface of printed covers such as book covers often show no light or blistering or wrinkling. Now talk about the handling of common problems in the operation.
1. Temperature control
In the rainy or plum rain season, if the temperature adjustment is not suitable, the film product will be no light. There is significant water vapor on the silicone drum, which is caused by the paper absorbing a lot of water. At this time, the temperature of the hot press roller can be adjusted to 40 degrees Celsius. If the temperature is too high, it will foam. Some hydrosol laminators do not have a heating device, and it is necessary to add a baking lamp before pressing to make the rubber layer dry and reduce foaming.
2. Pressure control
The pressure should be adjusted according to the thickness of the paper during lamination, generally at 5 Pa. If the pressure is too high, wrinkles and paper deformation will occur.
3. Glue control
The glue quantity control is controlled by the gap size of the glue roller and the glue roller, and the scraping film is added. Scratch film pressure is light and the amount of glue is small. The amount of glue should be mastered, and it can be evenly covered without generating crystal points. If the amount of glue is too large, the product will be dull. Pay attention to the gluing process, and be sure to prevent the tiny particles and impurities after the coagulation from remaining in the rubber pan. If the card is stuck on the film, a white offset will be produced, causing a linear blister. The glue roller and the rubber bucket should be cleaned with an alcohol solvent before starting the machine. If the rubber roller is not cleaned, it will cause pinholes. For the rubber containing impurities, it can be diluted with water. After the impurities are precipitated, when the diluent is used, the waste of the glue is reduced.
4. Drum cleaning
When the paper is separated, the glue will directly roll on the silicone roller to cause accumulation, which will easily wrinkle the product or affect the brightness of the product. The roller should be cleaned frequently and kept clean. The drum itself will wrinkle when it is not flat and needs to be replaced.
5. Temperature and humidity control
The temperature and humidity of the environment change greatly, and the paper absorbs moisture to produce “floating edge”. When the film is coated, the paper is easy to wrinkle, and the temperature and humidity should be balanced. The temperature of the heating roller is too high, and the tight side of the paper will also wrinkle, and the temperature needs to be controlled as required.
6. Paper feeding control
Paper skew will cause the paper to wrinkle, and the operation should be taken seriously, so that the paper is fed flat and the pressure is consistent on both sides. When feeding paper, strive to stack 3mm of each paper, and control the amount of glue to prevent the phenomenon of overflow. This will reduce the adhesion of the product after lamination. If the joint is wrinkled or voided, the pressure should be increased appropriately to maintain the temperature and humidity balance, so that the adhesive is flat and the foaming is reduced.
7. Film roll control
Prevents wrinkles from being inconsistent on both sides of the film roll. First, select the film that is elastic on both sides, and then adjust the tension on both sides of the film to balance and prevent wrinkles. When using the film, try to use a film with a wide size and a wide opening size. For example, if you use a large 16-inch film, use a 44-mm wide film instead of a 460-mm wide film, which can save 4%. When using a 780mm wide film, try to trim the edges as much as possible to reduce the amount of glue and save the glue.
8. Control the powder sprayed.
Do not use additives as much as possible during the printing process because it is not easy to dry and easy to foam after lamination. And also need to control the amount of dust used. Before the film is covered, a special person should be arranged to wipe off the dust on the cover to reduce the phenomenon of blooming or foaming of the film, so that the product is bright.
9. Machine speed control
During the laminating process, do not arbitrarily change the speed of the main machine. The speed is too fast, the sizing does not meet the requirements. When the speed is slightly increased, the amount of glue is too large. If the speed is adjusted too low, the amount of glue is reduced and it is easy to foam. In order to ensure that the amount of glue is basically the same, the speed limit of the laminating machine can be 60% of the speed of the speed, so that each class runs at the specified speed, and data management is implemented to reduce unnecessary losses.