Three aspects of cardboard box die cutting technology

Fourth, the indentation line is not clear, there is a poor deflection

The indentation line is not clear due to unstable or too small die-cutting pressure. Due to the wear or looseness of the machine components, the stroke of the press roller or the platen is not uniform each time, there is a light weight phenomenon, and when the pressure is light, the indentation line of the product is not clear, and the equipment should be properly handled. Overhaul to ensure uniform die-cutting pressure.

Indentation sipe width does not cause the indentation line is not clear or the crease line is inaccurate. If the width of the indentation sipe is too large, the indentation line is likely to be unclear, and the product tends to be deflected after folding. Therefore, the width of the sipe can only be matched with the thickness of the steel knife to ensure the clearness of the indentation and the accuracy of the crease line.

Indentation steel knife thickness does not cause the cartons semi-finished products to appear skewed phenomenon. When die-cutting corrugated cardboard, if the thickness of the indentation steel knife is too thin, the depression (shrinkage) of the paper surface at the crease line portion of the printed product is not enough, and at the time of folding, the paper surface of the crease is liable to bulge due to “paper accumulation”. , resulting in skewed products after folding. Therefore, when the thickness of the die-cut product is large, the thickness of the steel wire cutter must be correspondingly larger, so that the indentation is “crushed”, so that the edge of the crease is less likely to generate a “stacking” phenomenon, which can prevent the folded product from appearing. Skew phenomenon.

The rubber strips are too dense and too thick to make the indentation lines unclear. When the aging precision of the machine is poor, if the rubber strips are over-tightened or over-thickened, the resistance due to the pressure will be large, which will inevitably affect the uniformity and stability of the pressure, and will also cause the indentation lines to be unclear. Therefore, the density and thickness of the rubber strip should be appropriate to make the pressure of the die-cut indentation uniform.

When the folder is folded, for example, the outside of the cardboard indentation line is cracked. The reason is that the indentation line is too deep or the width of the indentation mold is not enough; if the inside of the cardboard is cracked, the pressure of the die-cut indentation is too large and the paper fiber is broken. Properly reduce the pressure on the die press and use a slightly lower indentation line. Or widen the indentation line according to the board thickness. Die-cutting pressure is unstable, scrap cannot be cut off

In the process of die-cutting and indentation, if the scrap can be cut off and cannot be completely cut off, this phenomenon is also common in production. The main reasons for this are: the equipment precision is not high, and the pressurizing mechanism strokes each time Inconsistent, there are differences in the pressure; the die-cutting layout is large, the pressure of the steel knife and steel wire layout is difficult to fully take into account, so that the pressure is uneven and unstable, the pressure is likely to fluctuate when die-cutting; the rubber strip is over-tightened, over Thickness, and the elasticity of the material is unstable, so that the working pressure of the pressure-compressing mechanism is large and the pressure is unstable; the four sides of the die-cutting plate are not square, and there is a hypotenuse. After the plate is fastened, the bowing phenomenon is likely to occur, and the pressure is increased. During the process, the local layout of the steel knife changes.

Fifth, uneven die-cutting pressure

The pressure in the die-cutting indentation is uneven. There are generally two situations: if the pressure is slightly uneven, it may be due to the uneven distribution of die cutters, wires (steel cutters, steel wires), which causes the moving platform to die-cut. Due to the force deflection, a balanced knife line should be added to the die-cutting plate so that the platform can be evenly distributed. If the front and back of the platform are severely uneven in pressure at the four corners, it is mainly supported by the four connecting plates. Inconsistent height of rod and lever, the shield of the die-cut base should be opened at this time to check whether the pendulum rod is worn. If the abrasion is serious, it needs to be replaced. Otherwise, four pressure adjustment inclined irons need to be adjusted until the pressure is consistent.

Six, die cutting accuracy is not high

The precision of die-cutting is one of the most important standards for measuring the quality of die-cutting and is an important guarantee for the production of qualified products. In the actual production process, die-cutting precision often fails to meet the design requirements. There are many factors that affect die-cutting precision, mainly in the following aspects: The main drive chain wears and stretches, will directly affect the positioning accuracy before die-cutting, at this time can only replace the chain; intermittent mechanism wear, resulting in the tooth row in the stop or start process Jitter occurs, affecting die-cutting accuracy. In this case, generally only the positioning accuracy is affected. At this time, the intermittent mechanism should be repaired; the front and rear positioning, the positioning distance of the swing frame is too small. Because there is a certain error in the length of the chain itself, if the positioning distance is too small, the chain error cannot be eliminated in the front and rear positioning. To die-cutting accuracy, the cam position of the adjusting screw of the front positioning swing frame or the rear positioning swing frame should be adjusted at this time, so that the distance between the front and rear positioning frame can pull the teeth row 2-3 mm; the upper die cutting plate or the lower die cutting plate Inaccurate positioning, long-term use of the machine will result in the wear of the positioning block on the die-cut frame or die-cut base plate, so that the fit clearance is too large and the precision of die-cutting is reduced. At this time, the positioning block should be replaced; the side positioning plate is worn out An important factor for the inaccurate positioning of the side is that the positioning amount of toggle is not sufficient to make up for the amount of wear. Therefore, the positioning accuracy of the side is deteriorated. In this case, the side positioning plate should be replaced; the pressure of the gripper is too small or uneven. If the elasticity of the movable teeth of the gripper becomes smaller due to long-term use, it will cause the paper to slip or fall off during the transfer, which will directly affect the precision of die cutting, and uneven pressure between the grippers may cause the paper to die-cut. Skew in the process, this time should replace the movable teeth. In addition, the height of the fixed teeth on the level should also be the same, otherwise there may be paper collision or crease after crepe paper, affecting the cutting accuracy; cardboard deformation or extension during operation, resulting in "overprint" is not allowed, In order to influence the precision of die-cutting, appropriate paper should be used to reduce the influence of the defect of the material itself on die-cutting accuracy; operator's operation error leads to insufficient precision, or the die-cutting precision can not meet the requirement due to the low accuracy of the die-cutting version. At this time, professional training for operators should be conducted to increase production management requirements, or to remake the die-cut version.

Rubber over-filled around the edge of the knife caused insufficient resilience, or rubber hard, medium, soft performance is not suitable; steel knife edge is not sharp, paper thickness is too large, causing the clamp or die cutting pressure is too large. According to the distribution of the template steel knife, reasonable selection of rubber with different hardness, attention to sticking when the density distribution should be appropriate; appropriate adjustment of die-cutting pressure, if necessary, replace the steel knife.

The so-called scattered edition refers to the phenomena that the waste paper and the cardboard are scattered when die-cutting, which results in the paper slippage. When the loose version is severe, the normal production will be affected. The main reason for the dispersal is the mistakes in the die-cutting plate-making process and the improper selection of elastic rubber strips (or sponges); at the same time, there are many other factors that may also cause dispersal.

In the production of die-cutting plates, if the shape of the work is complex or the number of jobs is too large, and the die-cutting joints are small and few, it is very easy to cause die-cutting, and the joints should be properly increased. Quantity, where possible, should align the length of the job with the paper transport direction.

If the elastic strip (or sponge) on the die-cut version is too soft and can not bounce the paper smoothly, it will also cause loose printing. At this time, a high-quality elastic tape (or sponge) with high hardness and good elasticity should be used.

The premature start of pressure stripping is also an important cause of the scattered version. After die cutting, when the moving platform descends, although the paper has been ejected from the knife line by the elastic rubber strip (sponge), the elastic rubber strip (sponge) is generally 2-3 mm higher than the cutting line. When it starts to move, the elastic strip (sponge) will still press the paper on the die-cutting bottom plate to easily tear the paper and cause the loose printing. At this time, the coupling mechanism of the intermittent mechanism and the main chain wheel axle should be released to adjust, so that the movable platform From the top dead center drop of 7-8 mm (when corrugated paper should be about 10 to 15 mm), the pressure row starts to move.

The quality of the die-cut print is also one of the reasons for the dispersal. If the printed material is too bad and the fibers are too short, it may be scattered during the die-cutting process. In this case, the cutting speed can be reduced and the number of connection points can be appropriately increased.

The reason for the indentation line irregularity is mainly that the indentation groove on the steel wire pad paper is too wide, the position of the paperboard is indefinite when the mark is indented, and the appropriate indentation die groove width should be selected; the thickness of the steel wire pad paper is insufficient, and the groove shape Angle is not standardized, extra fillets appear; row knife, solid knife tightness is not suitable, steel is too tight, the bottom can not achieve ideal contact with the platen plane, twisting occurs easily when the indentation, replace the knife plate, use a qualified mold Cut indentation plate steel money is too loose, easy to move around indentation. The exclusion method is to replace the steel wire pad paper, the width of the creasing groove is appropriate; increase the thickness of the steel wire pad paper, trim the groove angle; the tightness of the row knife solid knife should be appropriate.

There are several reasons for the occurrence of paper and dust: Due to the poor quality of the die-cutting steel knife and the unreasonable choice, the die-cutting edge is not sharp, and different quality die-cutting tools should be selected according to the different materials of the die-cutting paperboard. , To improve its die-cutting adaptability; should always check the cutting edge of the steel knife and wear, wear and replace the die-cutting steel knife after the wear, severe wear of the die-cutting steel knife edge will cause the generation of paper ash; die-cutting steel knife and sponge rubber Bar selection or installation is not standardized, because the sponge strip should have enough hardness to compress the paper, so that the die cutter can cut the paper smoothly. Different paper should use different hardness of the sponge strip, sponge strip installation The position should be at least 1mm from both sides of the die-cutting blade. If the distance is large, the sponge strips on both sides of the die-cutting blade can only expand away from the die-cutting blade after being pressed. At this time, the cardboard is not yet completely die-cut. The knife is cut, but it has been broken by sponge rubber strips, which will result in fluffing and paper dust; in addition, the amount, hardness, and height of the sponge glue should be evenly distributed in all positions on the entire template. Both sides of the knife should also be properly disposed foam tape.

Seven, die cutting edge is not smooth

The quality of the steel knife is not good, the cutting edge is not sharp, and the die cutting adaptability is poor; the cutting edge of the steel knife is severely worn and has not been replaced in time; the pressure of the machine is not enough; when the cutting pressure is adjusted, the steel sheet is improperly handled, and the pressure is not suitable when the cutting is performed. According to the different performances of die-cut cardboard, steel knives with different quality characteristics are selected to improve the die-cutting adaptability; the cutting edge and wear of the steel blade are frequently inspected, and new steel knives are replaced in time; the die-cutting pressure of the die-cutting machine is appropriately increased; Adjust the blade pressure and replace the pad.

The issues discussed above are just some of the common problems in production. We also need to pay attention to the emergence of other die-cutting issues, such as long changeover times, low accuracy of printing and cutting, slow production speeds, and high scrap rates. We can Specific analysis of the situation, to identify possible causes, and take appropriate measures to resolve. Only in the actual production and operation of continuous summary, master all kinds of skills, familiar with the performance of production equipment, proficiency in the production process requirements, in order to promptly and correctly eliminate the various problems occurred in the production, for the smooth production of high quality The die-cut indentation products create favorable conditions.