Film adhesive characteristics and printing process (2)

In the previous issue, the article mainly introduced the types, characteristics and surface treatment methods of commonly used film adhesive materials. The printing process of film self-adhesive materials will be analyzed below.

Printing ink selection and application

1. Select special ink for film printing, varnish and matching additives

There are many types of inks. Some inks are specially designed for film adhesive materials, even for certain film adhesive materials, so the ink must be used exclusively, and the matching varnish and additives should be used, otherwise it will appear. The printing quality problem that the ink does not match the printing material causes the ink layer to fall off.

2. Select the ink matching the film material coating to increase the firmness of the ink layer.

For film materials with a surface coating, it is necessary to select the properties and matching inks, otherwise there will be problems with ink loss. If the ink is properly selected, the resin in the ink is firmly bonded to the resin in the coating, and the ink layer does not fall off even if the ink is not completely dried. For example, when a label printing company uses Hanghua 161 ink in the production of a certain job, the effect is not good, and the same brand of VP ink is used, the effect is improved, and the ink loss problem is solved.

3. Control the thickness of the ink layer, if necessary, can use the printing method of overprinting

Some prints require a certain thickness of the ink layer. In the case of a thick ink layer, the problem of ink loss may occur if the ink is not dried thoroughly. The best solution is to use screen printing and gravure printing. For unconditional printers, you can consider the same color ink printing twice. The usual method is to first print a very thin layer of ink, and then print it again on the surface after it is completely dried, so that after two printings, the thickness of the ink layer can be improved, and the problem of the firmness of the ink is solved, and the process is achieved. Claim.

4. Control the drying speed of the ink

Pay attention to the expiration date of the ink, and add a small amount of desiccant when the ink is dry slowly to increase the drying speed.

5. Ensure the drying or curing energy of the ink

Regular cleaning of the ink curing unit and periodic replacement of the UV lamp are key to ensuring complete curing of the UV ink. The efficiency and state of the UV curing device are periodically checked with an instrument or test paper, and the thickness of the ink layer and the printing speed are adjusted based on the data to achieve an optimum printing effect.

6. Multi-color printing controls the printing speed to ensure that the ink layer is completely dry

For multi-color printing labels, high-speed printing is not recommended. It is recommended that the printing speed be controlled at 30 to 50 m/min to ensure that the printing ink layer is completely dry and waste is reduced.