Flexo plate material characteristics and process two

3. Printing has very special requirements for sticky printing:

(1) The printing plate must be firmly adhered to ensure that it does not fall off during the printing process and does not run.

(2) The printing plate must be able to be easily and conveniently removed from the cylinder so that the printing plate can be stored.

(3) The printing plate is stuck on the roller in the case of inaccurate registration or gauge, and the printing is started.

(4) Good temperature resistance and weather resistance. Sticking at a temperature of 40°C or less, the printing process does not run.

(5) Do not fly or run at speeds up to 10,000 rpm.

(6) It can adapt to the adhesion of various printing plates to various types of rollers.

(7) Adhesive requirements are non-toxic, there must not be stupid, stupid and other toxic solutions, and toxic cleaning agents cannot be used.

(8) Sticking costs are as low as possible.

The performance of the flexo adhesive should meet the above requirements in order to ensure the quality of the paste. However, there are many types of specifications for double-sided pressure-sensitive adhesives. There are a number of factories in the country, and foreign ones are also imported. Which one is better, should be based on the above eight requirements, and reasonable choices, in order to obtain satisfactory results.

In addition to the main double-sided pressure-sensitive adhesives, the sticker materials include solvents commonly used in the pasting process (such as stupid, stupid, naphtha, gasoline, alcohol, etc.) and polyethylene films for wrapping. , pad version, etc.

4. Special requirements for printing double-sided tape

(1). Good conformability: Adhesiveness of the tape is manifested in its ability to adhere to the printing plate and the roller. If the tape is too hard, not only can it not be applied to the roller but also can generate air bubbles. On the other hand, it is too soft and it is difficult to use and is accompanied by wrinkles and air bubbles.

(2) Appropriate suitability: The stickiness of the tape depends not only on the choice of the adhesive system but also on the following factors.

1.) Use of adhesive tape: Firstly, it is necessary to ensure that the rollers and printing plates are dry, free from contamination, and no chips are generated. Second, the tape must be properly applied to the rollers and the plate to avoid wrinkles and air bubbles; Appropriate pressure is applied to the tape so that the pressure-sensitive adhesive is adequately adhered to the surface to achieve a proper adhesive effect. The wrong method of operation may cause the sticker to fail.

2.) The nature of the plate: Different media should use different tackiness. Such as: natural rubber and synthetic rubber plate on the requirements of the viscosity is not the same. Because their material is different.

3.) Processing effect of the plate surface: The effect of the plate surface treatment changes its viscosity level. The grinded rubber plate has a higher viscosity than the unpolished plate, and a rubber plate coated with a half liquid mixture of wood paint and ether will replace the uncoated adhesive.

4..) Intermediate Substrate: The type of substrate will affect the print quality. Such as: vinyl based hard substrate because of its uniform thickness and good suitability, has been used for some printing so far, but some types of printing must use flexible tape. Scotch tape can improve the printing effect, but not all elastic tapes are suitable for different printing types. Understanding the difference in the sounds of them can be targeted. Here, it is necessary to make a statement on the indicators of elastic tape.

5.) Density: It can be regarded as an index of a harder or softer elastic tape. It is not a print quality indicator. It can be said that different elastic tapes are used. Different tapes will produce different printing effects. The operator must follow the process. Ask for the right choice.

5. The choice of double-sided adhesive

(1) The type of double-sided tape (take 3M, tape as an example)

Tapes often found in flexible sheets can be divided into four types depending on the type of substrate

1.) Low density; 2.) Medium density; 3.) High density; 4. Hard.

(2) The scope of application of double-sided adhesive

Low density: for high quality primary color printing and line printing;

Medium Density: primary colors, lines, full version printing;

High density: lines and full print;

Hard: lines and full print. (to be continued)