Next we look at the effect of the printing plate on the overall compression of the carton.
Watermarks are generally printed on flexographic plates. For different printing plates, we should use plates of different hardness in order to achieve the printing effect and control the compressive strength. In this case, no matter what type of layout is adopted, the low profile is used to save costs. The high hardness of the plate, the result and the wear of the paper feed roller together with the cardboard during the entire printing process is severely damaged. After printing, the hand-made compressive strength test for the 3250N, 3010N, 3420N, than the unpressed carton compressive strength is reduced 2900N, it can be seen that the irrational printing process has an impact on pressure of 50%.
Similarly, we used hand-made comparisons to test the impact and die-cutting processes. Here, I would like to mention the issue of pressure line production. There are often two misunderstandings in our consciousness: First, it is believed that the wider the width of the pressure line, the better the compressive strength of the carton; Second, it is considered that die-cutting a round or flat die. The misalignment of the pressure lines in the platemaking process helps to increase the overall pressure resistance of the carton. For the above problems, I have done special experiments, the test results for each increase in the width of the line lmm, the compressive strength will be reduced by about 100N, while the deformation of the compressive test increases, the effective value decreases; dislocation of the pressure line It will reduce the compressive strength of the carton by 10-20%. The pressure of the die-cut production process mainly comes from the pressure of the poplar paper rollers. In order to eliminate the impact of the paper-transport roller against compressive strength, we still use this process to compare the two types of carton before and after production. The printing has seriously damaged the corrugated medium. Destruction can increase this damage during die-cutting. In this case, the misalignment of the paperboard process pressure line, together with the pressure of the paper feeding roller during the production process, caused a 30% compressive strength loss of the carton.
Finally, the carton bonding process, the most common combination of stickies and nail boxes.
The lap joint of the nail box is prone to separation of joints during the testing process, forming the weakest part of the compression test process, and losing about 10% of the compressive strength; while the adhesive box process is just the opposite, with the joint part. As a whole, the pressure resistance of the carton will be greatly improved. In this case, the nail box was used, so that the pressure resistance of the carton formed a part of the impact.
Due to the various degrees of influence of the various processes on the formation of the compressive strength of the carton, the carton was eventually damaged by about 70% compressive strength.
Through the analysis of various cases, it is found that there are many factors that affect the compressive strength of corrugated boxes. We adopt different methods to solve the different influencing factors, so that the physical index of the base paper can be maximized in the production process of the carton. Transformation, so that the carton compressive quality to do better.
In the face of different kinds of pressure resistance, it is necessary to make efforts to find the root cause of carton pressure resistance. Sometimes it is inevitable to experience some bumps and setbacks. We need to have a scientific spirit of exploration, including the application of some theories. It also requires us to carry out scientific verification before we can finally make this theory serve the guidance of a company's production operations correctly.
Corrugated cardboard box pressure failure analysis:
Situation: The final force value is small and the deformation is also small. Cause:
1. The ring paper strength of the base paper, especially the crepe paper, was not enough. The test showed a low ring pressure index and the paper was soft.
2. Corrugated clay was crushed during the production process.
3. It is unreasonable to match the box shape with the box type, and the perimeter of the carton is large and small.
Situation: The final force value is high and the final deformation is large, but the effective force value is low and the buffering during the test is slow.
Cause:
1. Base paper, especially crepe paper, uses low-grade, high-weight base paper.
2. Poor paperboard adhesion.
3. Corrugated paper pulp is uneven.
4. It is unreasonable to match the box shape with the box type. The carton is small and large.
5. The line is too wide.
Situation: Force value and deformation Quantum stable increase, the relative change is not obvious, the test process does not change the peak, the final deformation of the carton is like an accordion.
Cause:
1. The base paper, especially the crepe paper, is too brittle, and the test shows that the breakage length is not enough, and the fibers of the pulp are short and have no toughness.
2. The carton is damp.
Happening:
During the test, the side pressure strength is high and the compressive strength is low.
Cause:
1. The carton was partially damaged unreasonably, which caused the carton to be unbalanced when it was under pressure. For example, the corrugated around the four corners was damaged, the ventilation holes were not designed properly, and so on.
Happening:
During the testing process, there was a large deviation between the tested individuals and the overall pressure resistance was unstable.
Cause:
1. The thickness of the cardboard is not uniform.
2. The moisture content of the carton is inconsistent and the water resistance of the paper is poor.
(Baoding Yuejin Carton Co., Ltd. Anti Yingjie)
China Packaging News
