Self-adhesive trademark printing and process points

Self-adhesive labels are mainly used to meet the needs of the easy-to-use brand labels. On the back of the paper, a layer of self-adhesive layer is evenly applied and adhered to a layer of easily peelable wax-coated paper. And leaflet type two. Self-adhesive labels are commonly printed by cutting with a knife line, die-cutting, stripping excess parts, and leaving a certain shape of printed matter on waxed paper. When used, simply peel the finished product and paste it directly on the product or package, which is very convenient and quick. In addition to coated paper and other paper, self-adhesive labels include aluminum foil, gold cards, silver cards, and color polyester films for printing substrates.

First, the characteristics of stickers printing

Our factory often uses four-opening and eight-opening offset printing machines to print self-adhesive labels, packaging and decorating products, and the difference between self-adhesive printing and other printing methods:

1, sticker paper is relatively thick, there are generally two 150g/m2 coated paper thickness. It is made up of two layers of coated paper, aluminum foil, color polyester film printing layer and wax paper layer.

2. Self-adhesive printing paper is generally high-grade coated paper, gold card, silver cardboard, and colored polyester film. The surface of the paper is smooth and clean.

3, self-adhesive paper absorption is small.

4, printing a large version of the full version of the image on the ground, prone to back stained.

Second, the adhesive printing should pay attention to several points

1, adjust the printing pressure. In the offset printing process, each adjacent two of the three cylinders of the printing plate, the rubber, and the embossing press contact with each other to form a transfer. In order to get the normal ink transfer on the printing paper, the continuous text, lines, images, halftone dots of the graphic part are faithfully reproduced. In addition to the contact between the two rollers, the marks must be additionally provided with the necessary printing pressure. effect. The severity of the printing pressure, and whether or not the degree of adjustment is accurate, will directly determine the extent to which the image transfer printing and printing dots reproduce the size of the ink and the depth and depth of the ink. It is necessary to adjust the center distance between the impression cylinder and the blanket cylinder during sticker printing, and the center distance of the cylinder can be increased by about 0.2-0.4 mm. If the paper is thick and thin, the thickness that should be reduced is that the thickness of the liner drawn from the plate liner is added to the blanket cylinder; if the printed paper is thin to thick, it is subtracted from the blanket cylinder liner. To a certain thickness, and the corresponding thickness is added to the pad of the plate cylinder.

When the plate is loaded, it should be compacted and compacted to prevent the relative slippage during printing. In the actual production, the ideal printing pressure is generally controlled to be about 0.15-0.25mm. It is necessary to emphasize the ideal printing pressure, that is, compression at a certain printing surface. Under deformation, the imprint of the graphic part of the printing plate is sufficiently strong on the paper, and the minimum pressure is used on the basis of the clear and complete dot.

2. Pay attention to the adjustment of the paper feeding part when printing stickers. The air volume of the paper suction nozzle and paper blowing nozzle of the paper feeding section must be adjusted accordingly.

3, the paper suction nozzle, feeding nozzle to replace the larger diameter and greater thickness of the rubber apron, in order to achieve a smooth paper feeding, feed roller does not swing the purpose.

4, stickers because it is two thickness of coated paper, paper thickness should pay attention to the gap between the two-sheet controller should also be increased accordingly, side gauge and front gauge paper tongue and the distance between the cardboard should be increased Bigger.

5. The distance between the transfer tooth pad and the impression cylinder surface, and between the transfer tooth pad and the feeding plate must be increased, and the distance should be approximately equal to the thickness of the paper plus 0.3 mm.

Third, stickers printed color arrangement

1, sticker printing products are full version of the field, there are text, lines, patterns. Such as: wine boxes, pharmaceutical trademarks and other printed products, printing the color sequence is best to first print text, lines, patterns, and then put the full version on the ground in the last machine printing, so you can avoid due to the adhesive paper thickness, the blot is not When dry, the papers collide with each other, and the back surface becomes dirty.

2, the dark color on the front of the India, lighter colors on the back of the printing, due to the deeper color of the ink hiding power, strong adhesion, printing on the front, easy to overprint accurate, light color of the hiding power Weakness, it's not easy to observe the rules when it is superimposed on the back side. In other words, the effect of overprinting is also good.

3, often in a printed product, there are halftone four-color electric points of the network, there are continuous adjustment patterns, text, lines, at this time, the electricity is divided into four color dots should be printed, is conducive to overprint accuracy, reduce the paper's expansion Influences, and then print continuous text, lines, patterns, in order to identify the primary and secondary times in the printing sequence arrangement, the first difficult to be more appropriate.

4, the summer weather changes, and rainy season, to control the temperature and humidity of the environment, before and after printing must be cut out of the paper basket, semi-finished products wrapped in plastic tight.

Fourth, how to prevent the sticker printing stained

1, stickers in the full version of the ground when the back of the stain is easy, due to adhesive surface coated paper poor ink absorption, printing as much as possible with the original barrel ink, without adding 6 # ink, appropriate to add some to stick Agent, anti-adhesive agent, do not add dry oil when the weather is hot. The full-fill version of the field is often susceptible to dirt on the back side, which is usually solved by dusting. Although the printed anti-adhesive dirty dusting agent contains pure plant material, the dispersion and fluidity are good, but the use of dusting agents will directly affect the printing product. The surface gloss makes the ink color not bright, and pollutes the environment, and it also affects the accuracy of the offset press.

2, pay attention to offset ink balance, control the size of the printing plate surface moisture. Use the minimum amount of layout water on the premise of not printing plates, and the stickers are smooth and smooth. When the full-print version is on the ground, it must be printed with dark colors first, and the amount of ink should be printed in full. Thinly overprinting the background color will make this print product smoother.

3, to overcome the drawbacks of large ink in offset printing, ink can not be adjusted too thin, too thin is easy to stain on the back, if too thin can add some new ink to enhance the ink viscosity.

Fifth, stickers printed sticky

Since the adhesive is evenly coated with a layer of adhesive on the back of the paper, it adheres to a layer of easily peelable wax paper. When the weather is hot in summer, the temperature is high, and the adhesive is under the roller between the rollers. The glue liquid will emerge from the gaps in the paper, and the adhesive glue will flow out under the pressure of the high temperature and the mechanical roller. The stickiness and the hair will directly affect the accurate overprinting of normal paper feeding. The paper glue on the edge of the paper will Paste on the rubber roller, it is easy to stick on the roller, ink roller and the impression roller, commonly known as "gum." This is one of the biggest drawbacks of stickers in printing. In the practical work of offset printing, the solution to this kind of situation is: Before offset printing, after self-adhesive cutting, apply talcum powder and vegetable starch on the sides and all around the notch. Anti-adhesive dusting) to wipe off and apply the non-adhesive solution, so as to avoid the disadvantages of the adhesive flow caused by the roller pressure and the weather, and the effect is very good.

Self-adhesive printing due to the thick paper, more than a piece of self-adhesive jam into the imprinting and rubber roller to easily lead to "stingy car", so before opening the printing must be carefully and carefully double control, skew control and other electrical device adjustment Suitably, the distance between the double-sheet control roller and the paper-feeding roller during double-sheet control shall not be less than two paper thicknesses, but it may not be greater than three paper thicknesses, otherwise the arched paper will stop when passing the controller; or Zhang has already passed the controller and the two contacts of the controller power supply have not yet come into contact with each other, which does not serve the purpose of controlling double sheets. When working, clean up the surface of the double-sheet control roller and the feed roller, or the dust, dirt, or insulation on the two contact surfaces of the power supply control unit to prevent the failure of the double-sheet control system and avoid the “stuffed car”. , Jamming blanket cylinder and impression cylinder.

Reprinted from: Shenzhen self-adhesive web