Gravure ink mixing category and purchase points

In the gravure printing production, because of the volatilization of the solvent in the ink tank, the uniformity of the ink is reduced, and the surface is easily formed into ink skins and ink sticks. After the printing roller is brought on, the scraping knife is not easy to scrape clean, so that the printing product produces paste plates, knife lines, etc. Defect D to solve this problem, as long as the ink "flow" up, constantly mixing, you can naturally avoid this situation.

There are two means to move the ink: one is to use an ink circulating pump to let the ink circulate; the other is to place an ink stick in the ink tank to allow the ink to flow in the ink tank. The former is the external circulation of the ink, the cost is high, and the factors that cause failures are increased. Generally, the addition of the solvent and the automatic viscosity control system are not included in this article. From the point of view of uniform ink, the latter is the most economical and effective measure.

Agitating rods are generally rods made of aluminum alloys, with spiral-shaped continuous protrusions on the surface, so-called "ripples" or unwinding lines, with magnetic material at both ends, which can be adsorbed on a plate roller. During the printing, the agitating rod floats on the surface of the ink, and when the printing roller rotates, it rotates in the reverse direction by the adsorption effect. When rotating, the corrugation drives the surface layer of the ink to allow the ink on the surface to move, thereby evening the ink and avoiding the corresponding quality problems of the printed product.

The following are the two main factors that determine the quality of agitating sticks:

1, effect

The ink mixing of the agitating stick mainly depends on the unwinding line, which is called ripple, and the size, angle, structure, and rotational speed of the agitating rod determine the agitating effect. In general, the faster the agitating rod rotates, the better the agitating effect. The bigger the development line is, the larger the angle is and the better the ink mixing effect is. However, if the developing line is too large, the magnet part is far from the platen roller, the magnetic force is weakened, and the magnetic force is not easy to be absorbed. The rotation speed of the ink stirring rod is reduced (discarded), but the effect is poor.

2, life

The agitating rod needs to float on the surface of the ink and is generally hollow. If the seal leaks, the solvent enters the interior of the agitating rod and will sink and lose the stirring effect. Therefore, the seal at both ends should be resistant to corrosion. In addition, the surface wear resistance is better.

At present, the commercial agitating stick generally has the following kinds:

1, plastic stirring rod

Commonly used in imported products, the surface is made of abrasion-resistant plastic sheeting. The inner core is used. The quality is quite good, and the price is relatively high. Generally, it is about 1,000 yuan per meter. It is said that at present some people in China have already imitated it, but because there is no better friction-resistant plastic material, the life expectancy is relatively poor. In addition, the effect of ink mixing is also not very good.

2, around the rope stir stick

Generally made of general aluminum tube, the surface of a wire wound around the line to do the expansion line, this product has two defects: 1 because the winding wire, the angle of the expansion line is relatively small, 2 wire will be saturated with ink, when changing the ink color Not easy to clean.

3, single-line aluminum alloy corrugated ink stick

The structure is similar to the roving agitator, except that the string is changed to an aluminum alloy spiral protrusion because only one deployment line has a small angle and the ink mixing effect is relatively poor.

4, eight-wire aluminum alloy corrugated ink stick

Aluminium alloy rotary extrusion profiles have 8 lines of development on the surface and have a large angle, which is the best product for current ink mixing. In addition, this type of product is not only more resistant to corrosion at both ends of the seal, and wear resistance is also relatively good, if the timely removal of iron powder and other impurities absorbed by the ink stick, the life is generally 2-3 years, it really saves the manufacturers of uniform Ink costs. This is also the product that most color printing plants currently choose. At present, Beijing RAND Meike's LB-03 eight-wire ink stick, Guangxi's eight-wire ink stick is such a product.

There is a problem of the ink reflow direction of the eight-line corrugated ink stick, which is actually whether the corrugation has an interface problem. If the left and right spirals meet in the middle, the ink will flow from the middle to the ends of the ink tank or the two ends will flow in the middle (need to reverse the orientation); if the ink stick is a grain (that is, there is no interface, no matter whether it is left-handed or right-handed) When working, the ink will flow from one end of the ink tank to the other. However, these two ink-return methods basically have no effect on the uniformity of the ink.