Broken line rupture is a quality problem often encountered in die-cutting production, and the difficulty of solving it is relatively large. In general, we pay more attention to the results of cutting, often overlooking the details of the pressure line. The die-cutting line is related to whether the product can be formed smoothly, whether the precision after forming can meet the requirements, and the broken line will affect the strength of the product, thereby weakening the protection function of the package.
The die line always bursts when die cutting, and 3 methods can be solved.
The problem of proper crimping depth but not breaking is the key to improving the quality of the cutting. We can analyze the operation of equipment, cardboard and operators to find out the cause of the broken line and then prescribe the right medicine.
Unreasonable equipment design will cause the pressure line to rupture
1. The height of the cutter and the height of the crimping knife are unreasonable.
When the cardboard passes through the die-cutting part in the production process, the main reason for pushing the paperboard forward is the pressing line. If the crimping knife is too low, the pressing line will not only affect the forming of the pressing line, but also cause the die-cutting escape due to insufficient transmission force. However, if the crimping knife is too high, although the crimping line is deep, the cardboard is broken due to excessive force. Therefore, the choice of tool height is very important, and should be determined according to the situation of single and double watts, pressure line depth requirements, and paper quality.
2. Adding pressure line strips on both sides of the crimping knife can effectively reduce the breakdown of the pressure line.
After the crimping strip is installed, the crimping strip can pressurize the paper, corrugated and core paper on both sides of the cardboard pressing line and softly deform it while the cutting line is being pressed during the die cutting. Effectively reduce pressure concentration to reduce or eliminate crushing. In general, the height of the crimping strip is about 0.9 mm lower than that of the crimping knife, and the shape of the crimping strip can be selected according to the effect of use.
3. The surface of the felt pad is not flat
Nowadays, the circular die-cutting method adopts the soft die-cutting method. The cutter on the die is continuously cut on the polyurethane anvil pad to form a lot of grooves to make the surface uneven, and the cardboard takes up various points in the die-cutting process. The reaction force will also be different, so it is necessary to check the surface of the felt pad frequently. If there are deep grooves or notches, it should be repaired in time.
Note: In addition to the above three aspects, there is also a large force during the working of the die-cutting part. The large transmission gap during operation and the large radial runout of the die-cutting wheel and the anvil wheel will be detrimental to the die-cutting quality. In particular, the phenomenon of broken lines of the pressure line will occur, and more attention should be paid.