Common Problems And Solutions Of Lamination

Common problems and solutions of lamination - taking digital printing products as an example. Some people think that lamination is very simple, but it is not. After lamination, we will find that various problems emerge in an endless stream, and sometimes they are not all product quality problems, because there are many factors that affect the quality of lamination.

This article takes the lamination of digital printing products as an example to analyze in detail the causes of common problems in the lamination process and the corresponding solutions.

-Bubbles Appear After Lamination

-Wrinkles Appear On The Product After Lamination

-Curling Of Products After Lamination

BUBBLES APPEAR AFTER LAMINATION

The so-called bubbles refer to the fact that the two layers of film are not completely bonded, and there is a gap and gas between the film and the printed matter. Bubbles are not necessarily bulging, but also exist in other forms. As long as the two layers of film are not completely bonded, there will be a difference in transparency, and bubbles will appear. Bubbles will affect the appearance and durability, and may cause the film to tear. Avoiding bubbles in products after lamination is an issue that should be paid attention to during the lamination process.

Causes & solutions:

1. Bubbles caused by printed products. Insufficient drying of the ink solvent on the surface of the printed matter will produce bubbles, which is caused by the residual solvent of the printed film. Generally, it appears in the part with high ink overprinting rate, and there are few bubbles in the part with low overprinting rate. It should be ensured that it is completely dry before lamination. It can also be solved by processing the printed film or reducing the lamination speed.

2. Bubbles caused by the film. Poor film material and dust impurities on the film surface will cause bubbles. In the selection of film materials, suitable high-quality laminating films should be selected to avoid the appearance of bubbles as much as possible. In addition, before laminating, attention should be paid to the cleanliness of the film surface to prevent bubbles caused by dust impurities.

3. Bubbles caused by laminating process. Refers to the control of some parameters, mainly including laminating pressure, temperature and speed. The main reasons for the appearance of bubbles in laminating products due to the production process are that the laminating pressure is too small or the temperature is too low. In this case, it can be solved by increasing the pressure of the silicon roller or increasing the laminating temperature.

4. Bubbles caused by equipment process reasons, such as damage or foreign matter on the silicon roller, the silicon roller should be replaced and the foreign matter should be removed immediately.

WRINKLES APPEAR ON THE PRODUCT AFTER LAMINATION

The manifestation of wrinkles is that the film cannot smoothly cover the surface of the printed product. Wrinkles will affect the aesthetics and flatness, and will also affect the service life of the film.

Causes & solutions:

1. Silicon roller and silicon roller parameter setting problems. Wrinkles can be caused by excessive roller pressure, damaged roller surface, or unbalanced pressure between the roller and the heating roller. If the pressure between the roller and the heating roller is unbalanced, uneven pressure will occur during the lamination process. The wrinkles caused by this situation are generally large and can be easily seen by the naked eye. The pressure at both ends of the roller can be balanced by adjusting the springs at both ends of the roller.

2. The film itself is defective. Some film materials have defects when they leave the factory, and there are wrinkles on them, which are often not easy to find with the naked eye. Therefore, before laminating, we must carefully check whether the film is damaged to avoid wrinkles after laminating.

3. Laminating machine parameter setting problem. Laminating temperature, laminating speed and laminating pressure are also important factors affecting wrinkles during laminating.
If the laminating machine temperature is too high or too low, wrinkles will appear after laminating. Excessive temperature will cause the laminating film to dry quickly, resulting in wrinkles. If your laminating needs do not include heating, it is recommended to choose a low-heating cold laminating machine, MEFU low-heating 40℃ laminator for efficient lamination to avoid wrinkles.

CURLING OF PRODUCTS AFTER LAMINATION

The main manifestation is that the finished product after lamination curls in the direction of the film and cannot maintain a flat state. In severe cases, it automatically curls into a cylindrical shape.

Causes & Solutions:

1. Curling is caused by insufficient preparation before lamination. The humidity of the laminating site environment is too high, and the printed product is not dry, resulting in moisture between the printed product and the film after lamination. After the laminated product with high moisture content is fully dried, the paper will dehydrate and deform, causing the paper product to bend to one side of the paper. The curling caused by this reason is more serious. Before lamination, the printed product should be completely dry, and the humidity should be controlled at the laminating site.

2. Curling is caused by unreasonable parameter settings during lamination. The tension of the film is constantly changing during lamination. Generally speaking, the tension of the film is relatively small when it is just unrolled, and the closer it is to the core of the roll, the greater the tension of the film. Therefore, the tension of the film needs to be adjusted during the lamination process. The tension of the film should be increased when it is just unrolled, and the tension of the film should be reduced when the lamination is about to be completed.

3. Curling is caused by uneven tension after lamination. Too much tension during winding will cause the film and printed matter to deform together, but the deformation is different. After the external force is removed, the film will bend toward the printed matter. The solution is to strictly control the tension during winding.

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