Eight problems of color box die-cutting

Die-cutting is a key step in the processing of color boxes, how to ensure the quality of die-cutting is a very important issue for printing houses. Now the main problems faced by the color box printing plant is a long time to change the version of time, print to cut the accuracy of poor, poor quality die cutting, paper hair, articulation point is too much too big, trace line irregularity, slow production speed, scrap rate of senior. Here are several more common quality problems and their solutions, I hope to be able to assist colleagues.

1, die cutting precision is not high

Problem causes: die-cutting accuracy is not high because of the die-cutting version of their own problems, there are also problems with the print. Craftsman-made die-cutting version of the larger error; die-cutting indentation and printing process of the operating environment will constitute a different paper deformation, resulting in die-cutting indentation orientation is prohibited, especially through the varnish, lamination, paper deformation is more serious, affecting the die-cutting accuracy.

Solution: Select advanced die-cutting plate making process to improve the accuracy of die-cutting plate. Try to ensure that the die-cutting indentation and printing process in the same operating environment, or to ensure the homogeneity of the operating environment (i.e., the same temperature, relative humidity, etc.); varnishing and laminating the paper should be die-cutting pre-disposal, try to cut down on the deformation of the paper on the precision of die-cutting impact.

2, die-cutting indentation seizure “burst line” and “dark line”

Problem causes: “burst line” refers to the die-cutting indentation pressure is too large, over the paper fiber acceptance limit, so that the paper fiber cracking or part of the crack; “dark line” refers to the indentation line should not be there, generally because of the die-cutting version of the indentation and steel line selection is not suitable, Die-cutting pressure adjustment is not appropriate, poor paper quality, paper fiber direction and die-cutting version of the knife direction is not common, low water content of paper leads to a decline in flexibility and other reasons.

Solution: select the appropriate die-cutting version; appropriate adjustment of die-cutting pressure; die-cutting before the first to be die-cutting prints in the workshop for a period of time; progress in the relative humidity of the workshop environment.

In addition there is a special case, is in the die-cutting hard box cigarette packet small box, because many of the indentation between the distance between the line is very close, assuming that according to the normal situation of the equipment indentation height of the steel wire, die pressure on the paper tension is too large, will also constitute a “burst line”. Therefore, we should try to minimize the tension on the paper, there are two ways: one is to reduce the height of the creasing line; the second is to reduce the thickness of the creasing base mold strip, but the two can not be used at the same time, otherwise it will not play a good creasing effect. The better way is to reduce the height of the creasing steel line, the height of the decline of 0.1 ~ 0.2mm, according to the paper ration determination, ration in 350g/m2 above the height of the paper need to drop the creasing steel line of 0.2mm, ration in 350g/m2 below the paper should be reduced by 0.1mm.

3、Indentation line running, not full

Cause of the problem: the creasing steel line is twisted under the effect of die-cutting pressure, which causes the creasing line to run; the lack of die-cutting pressure will cause the creasing line not to be full.

Solution: Replace the die-cutting plate and increase the die-cutting pressure to improve the problem.

4、Die cutting hair, dust

Cause of the problem: In the die-cutting, often present die-cutting products cutting edge is not bright, hairy phenomenon, especially from the indentation line closer to some of the cutting edge at the situation is more serious. This is because in the die cutting pressure, die-cutting version of the adhesive strip, indentation steel line on the paper onset of tension, paper in the not completely cut through when the onset of tension pull off, presenting the burrs.

Solution: First of all, according to the paper selection of different types of die cutting knife. Die cutting knife contains straight knife and cross grain knife, the two texture of the knife blade and high and low points, the knife blade constitutes the texture and high and low different, directly related to the quality of die-cutting and die-cutting knife life. In the avoidance of die-cutting hairy, straight knife than cross-grain knife good; in terms of service life, short blade knife than high blade knife good. In die-cutting laminated cardboard, should choose straight high-front knife, and the requirements of the blade is ground, it is best not to choose to press the convex one-time molding process, otherwise the pressure will be too big on the die-cutting a great impact; and in the processing of general cardboard is recommended to use a short-front knife, and according to the quality of the paper fiber to determine the texture of the knife blade. Poor fiber or thicker paper should be used straight knife, fiber quality of the paper can be used across the knife, in order to improve the use of die-cutting knife life.

Secondly, can also be closer to the indentation of the steel line of the die-cutting knife at the paste 60 ° of the arch of the rubber strip, reduce the die cut pressure when the indentation of the steel line here on the paper onset of tension. Such as die-cutting ration of 300g/m2 of paper when the shallow selection of 0.4mm × 1.3mm, 23.4mm high creasing steel wire, such as this problem can be changed to 0.4mm × 1.2mm, 23.3mm high pointed creasing steel wire, in this way, reducing the die cutting pressure on the paper when the tensile force of the die-cutting hairy problem can be solved at the bottom.

5, die-cutting “paste plate”

Problem causes: die-cutting “paste version” refers to the paper adhesion in the die-cutting version, the onset of this problem is due to the following reasons. Die-cutting knife posted around the sponge rubber strip density is too small or too small hardness, lack of resilience; die-cutting knife edge is not sharp, the paper is too thick, resulting in clamping knife or die-cutting sticky knife.

Solution: according to the distribution of the die-cutting knife, reasonable choice of different hardness of the sponge strip or replace the die-cutting knife.

6, die-cutting “scattered version”

Problem causes: die-cutting “loose version” is mainly related to the die-cutting version of the plate making process and sponge tape. Assuming that the shape of the live piece is messy or arrangement of live pieces of many, while the die-cutting version of the connecting point is both small and less, it is very simple to constitute a loose version of the die-cutting.

Solution: properly increase the number of connecting points on the die-cutting version, manufacturing die-cutting version of the length of the printed materials as far as possible in the direction of the direction of paper transport to maintain a common.

7、Too many articulation points

The end user of the color box always requires the articulation point is smaller and less, at the same time the producer always let the machine speed work faster, which increases the difficulty of the operator. In order to reduce the difficulty, the articulation point should be in the stress point, with the grinder to play, in the need to play the articulation point of the knife side of the use of hard tape or cork to avoid cracking the articulation point, so that the point of articulation to be able to smaller and fewer.

8、Trace line irregularity

Thinking about the needs of folding paste boxes, color boxes must have a good indentation line. More importantly, when these boxes run on the active packaging machine, the force of the flip must be stable and common. In this way, picking the right type of crease line for die cutting is the bottom element. By picking the height and width of the crease line according to the thickness of the paper, and by bonding the appropriate crease line to the die-cutting backing, the creasing can reach a higher quality and make the box easy to fold.