UV glazing materials and process indicators (3)

Fifth, we currently have the following four common ways of uv glazing:

Three-roll coating principle

The uv gloss oil flows into the acetic acid tank formed by the rollers m and r, and is uniformly extruded by the m-r, the varnish adheres to r, and the r and m extrusions apply the oil on the r to the paper. The scraper scrapes the excess lacquer on the embossing roller m into the lower sump and is used again. The amount of coating is determined by the pressure between m and r.

This machine is characterized by fast glazing speed, simple machine structure, low price, and low operating technology. The disadvantage is that it is not suitable for thin paper because the thin paper tends to stick to the roll r and roll back. There are also designs where the air knife can peel off the paper from the roller r, so that the thin paper is not taken away by the roller r, but it is not ideal for use. Then, the coating amount is not easy to control, the coating is too thick, the coating amount of varnish is not easy to adjust, and the coating thickness can only be controlled by heating oil or adding thinner.

The principle of fang-type polishing mechanism.

The principle of the dental glazing mechanism is shown in the figure. The ink stick m brings the oil from the oil sump to the embossing roll r, r presses against the crepe paper imprinting cylinder l, and the varnish is transferred to the paper for coating. Advantages: Thick and thick paper are suitable, generally 80g/m2 single-sided copper paper to 450g/m2 whiteboard paper can be. Simple operation, simple structure and easy maintenance. Since the pressure between the rollers r and l is large, the ink distribution effect is better than the three roller type. Disadvantages: slow speed, generally 2500 / hour; operators, at least 4 people; coating amount is not easy to control.

Four-roll anilox roller coater structure.

The structure of the four-roll anilox roller coater is shown in the figure. Comparison of three-roll coater, four-roller an anilox roller (metering roller), corresponding to a more scraper. The purpose of adding an anilox roller is to quantitatively control the amount of coating and to ensure the consistency of the thickness of the film on the product.

General long version packaging with this type of machine, such as cigarettes, wine, soap, Toothpaste, film and other product boxes need to quantitatively control the quality of products to ensure the consistency of product quality. Another example is a brand of soap box produced at different times, but placed in the same counter, if the use of three-roller polishing machine will appear different brightness of the surface of the box, and with anilox roller coating machine coating, it is not clear which Batch production of products.

Polished with an offset press.

The method of using the offset printing machine and its features are as follows:

1 Varnish is placed in a sink and coated with a water roller.

2 Remove the water fleece sleeve of the water roller and spread the oil with the rubber roller so as to reduce the oil transfer amount.

3 Adjust the amount of water on the roller, that is, adjust the amount of oil.

4 Widen the sink so that all ink rollers are above the sink. Because of the low viscosity of the varnish, the oil on the water roller drops downward on the underlying paper.

5 The cutting blanket is the same or slightly smaller than the width of the print.

6 can be coated with uv oil, water-based gloss oil, but can not be coated with solvent-based thermal drying Varnish, or sticky roll.

7 Use ordinary PS version, ordinary blanket can be.

8 The thickness of the coating oil layer should not be too large, otherwise there will be pitting. (To be continued)