Self-adhesive label die-cutting machine with flat press down high precision die-cutting, dragging and slicing, controlled by computer, printing label on both sides and longitudinal by three photoelectric eyes accurate tracking and positioning, die-cutting, laminating, waste collection, slicing or automatic labeling machine with a roll to complete. It is very suitable for die-cutting of paper self-adhesive trademarks, polyester film trademarks and laser anti-counterfeiting trademarks. This machine is the best supporting equipment for flexographic printing machine, continuous screen printing machine, gravure printing machine and anti-counterfeiting trademark molding machine, and is the most ideal choice for trademark printing factories. The main parameters are: model, die cutting speed, unwinding maximum diameter, web maximum width, die cutting maximum width, die cutting maximum length, positioning accuracy, total power, power supply voltage, overall size, machine weight 11 items.

First, focus on several factors

(1) The binding force of the coated surface and the adhesive: for the self-adhesive label with the film as the surface material, the low binding force of the coated surface and the adhesive is an important factor causing residual glue and overflow. In order to increase this bonding force, it is necessary to treat the coated surface of the film before gluing, one method is coating treatment, the other method is corona treatment. Corona treatment method is used more by enterprises because of its comparative advantage in cost, but the control of Dyne value of coating surface before and after corona treatment is very important.

The water content and solidified content of the adhesive are also important factors affecting the binding force, so they also need to be strictly controlled. The cohesiveness of the adhesive is another factor that needs attention, the lower the cohesiveness of the adhesive, the higher the possibility of overflow.

(2) the fluidity of the adhesive and the amount of coating: the stronger the fluidity of the adhesive, the more likely it is to overflow. When the temperature is higher, the fluidity of the adhesive is good, and the initial viscosity is stronger at this time. The high temperature and high humidity environment will greatly increase the fluidity of adhesives, so summer and rainy season are frequent seasons of overflow problems. Based on this, it is necessary to attach great importance to the temperature and humidity control of the inventory environment of self-adhesive materials, the processing environment of self-adhesive labels and the storage environment of finished labels.

It should be noted that the adhesive material that is not resistant to high temperature adhesives should not be placed in an inappropriate high temperature printing processing environment, such as the hot melt adhesive material used for HPWS2000 digital printing machine is required to withstand temperature above 150 ° C, but the AW5209 self-adhesive material can only withstand temperature below 70 ° C. This means that AW5209 is not suitable for processing on HPWS2000 digital presses; The printing and scraping coating needs to use the screen printing process to print the scraping silver ink, but the silver ink layer of the screen printing is relatively thick, the infrared drying time and temperature are relatively high, and the high temperature resistant self-adhesive material needs to be selected at this time.

The overflow problem is also closely related to the amount of adhesive coating. For example, the amount of adhesive applied to tire labels is relatively large, so it is also more prone to overflow (although the choke agent has been added to the adhesive). The coating amount of winter and summer adhesives should be different, which is more sensitive to self-adhesive materials with thin films. Since there is a difference between winter self-adhesive and summer self-adhesive in the formula, it should not be used in the wrong season, and should not stock self-adhesive materials and labels for a long time, the inventory should be reduced as much as possible, and the use of self-adhesive materials according to the principle of "first-in-first-out".

(3) Control of the depth of die cutting: improper control of the depth of die cutting will destroy the silicone oil layer and cause overflow, so that the automatic labeling machine is not normal or not labeled, or frequently broken tape (the bottom paper break is commonly known as "broken tape"). If the broken tape occurs frequently during the labeling process, it will be found that a certain part of the broken line is consistent with the die cutting part when checking the broken tape, as shown in Figure 5.

If the adhesive layer is not cut off during die cutting, it will be the same as the backflow of the cut adhesive layer, and the adhesive under the waste edge and the label will be gradually stretched into silk before breaking. These floating broken wires constantly fall on the edge of the forward label, forming a unilateral (label side in the direction of the die cutting paper) overflow phenomenon.

(4) Roll tension control: When the self-adhesive label is printed (including online circular pressing and die cutting), the roll tension is too large, which will lead to excessive extrusion of the face paper or the base paper on the adhesive layer. When the label becomes an "island" after die cutting, the adhesive will slowly leak out around the label and produce glue overflow.

When the small roll is cut into the customer's use, the tension is too large to make the small roll very tight. After the small roll is die-cut and discharged, because a single label has been formed on the surface of the bottom paper, the extrusion pressure generated by the tension is changed from the original spread on the entire surface of the paper roll (including the waste edge) to the single label (the waste edge has been removed). Therefore, after the waste is discharged, the label is directly subjected to extrusion pressure.

If the area of the waste side is the same as the area of the label, then the extrusion pressure of the label after the waste is discharged should be twice that of the original. For example, as shown in Figure 6, the original force of 3 kg (about 29.4N) is now subjected to 6 kg (about 58.8N). When the 3-piece volume is divided into 3 small volumes, the original extrusion pressure evenly spread on the 3 labels is all concentrated on one label, so the extrusion pressure on a single small volume is 3 times that of the waste volume, and it is 6 times that of the printed volume. Through calculation, we can realize the influence of tension, so the winding tension of small rolls should be set smaller.

Second, some experiences

(1) Label shape design: special-shaped labels are more likely to overflow glue than square or rectangular labels.

(2) Several basic judgment criteria for pre-printing overflow: When the reel self-adhesive material is rolled on the printing press, if there is no wire drawing or slight wire drawing between the upper and lower layers, then the material can be judged to be qualified. Of course, you should also know about the temperature and humidity of the site. When sheet self-adhesive material is fed on the feed table of the offset press, if there is wire drawing or adhesion between the upper and lower layers, the material can be judged to be unqualified. Because the phenomenon of wire drawing between the upper and lower layers occurs when the paper is fed on the paper conveyor, the self-adhesive material will run off and cause the overprinting to be inaccurate.

(3) Glue overflow after printing die cutting: if the white material end face adhesion is serious, there is an obvious wire-drawing phenomenon when printing and rolling, then it is likely to occur around the label after die cutting. It should be pointed out that the overflow is also related to the displacement and contraction of the label on the backing paper. During the die cutting process or when winding after die cutting, label movement will cause glue overflow on one side of the label, and label shrinkage will cause glue overflow around the label.

(4) Control of winding tension: due to the different processing materials, production processes, and printing presses used, it is unrealistic to give a "correct" tension data. The result of tension control is ultimately reflected in the tightness of the coil, and it should be the best practice to keep the coil as loose as possible, subject to the customer's acceptance. When printing (including die-cutting), on the basis of not affecting the accuracy of overprinting and the following process, the smaller the control of the winding tension, the better. No matter which process, the winding tension should be smaller than the winding tension, and the tension ratio should not be large difference. When picking up the small roll after die-cutting with both hands, at least the thumb can push the end face up and down at will. If the small roll cut after die cutting is like a "discus", then the winding tension is definitely too large.

 来源：珠海腾佳印务