How to Solve the Problems of Printing Grooves and Pressing Lines after Printing (Part One)

With the development of the packaging industry in China and the needs of the market, the printing slotting die-cutting process and the post-press line process in paper products have become the common production of the carton industry due to its high production efficiency, simple and convenient operation, and good carton forming. Process. Its integrated production equipment is commonly used by cartons, and its production process is increasingly valued by people. This production process is unmatched by general printing slot machines. This production process enables printing, slotting and die cutting to be completed on one device at a time. It can also be used for hand-holding, helium venting, and the like.

However, if the good production equipment is not properly controlled, there will be different degrees of quality problems. The author here only analyzes the problems such as inaccurate dimensions, broken vertical lines, lack of slots, burrs, broken lines, broken lines, and inconsistent line widths during the production process.

Inaccurate dimensions cause and solution

1. The tightness of the original paper is not good, that is to say, the base paper is relatively loose, and the heat shrinkage is severe, resulting in warp and deformation of the cardboard, which is one of the reasons for the dimensional inaccuracy. Excessive moisture or warpage of raw materials and corrugated board is also a cause for inaccurate dimensions. Under normal circumstances, the water content of the corrugated board is basically about 10% to 14%, but if the moisture of the lower thread is between 14% and 18% or higher, it is more humid. If the cardboard is printed directly after the thread is cut, the size is more accurate. However, for a period of time, when the water content is less than 10% after the water is dispersed, the cardboard will retract, the overall paperboard size will become smaller, and the size of each part will be different. The 1m long paperboard will shrink about 4mm to 6mm. Therefore, it is very important to grasp the moisture of paper and board. Each batch of cardboard must be measured with a quick moisture meter moisture content, depending on the size of the water to arrange the printing slot cutting time. If the moisture is too large, it must be placed in the cardboard for 4 hours after the line is dried and then the next process of production, the general factory delivery of water in the 10% ± 2. This is also the reason why the size of an ordinary carton enterprise when it is produced is accurate, but the reason why the size becomes smaller after putting it under a natural condition for a certain period of time.

2. The size of the carton is not allowed to be adjusted when the production size is down or the adjustment is wrong. This is mainly caused by the operator's inaccuracy. This problem will be avoided if a serious review is performed during normal production.

The vertical line breaks the problem reason and the solution

1. Vertical line pressure is too high. When the board enters the pinch roller operation, the pinch rolls smash the board, causing the board's inner or front paper to break in the corrugated direction. To solve this problem, it is necessary for the operator to adjust the pressure of the vertical line pressure roller according to the thickness of the paperboard. Under normal circumstances, the depth of the three-layer cardboard roll line is preferably 2 mm-3mm pressed into the paperboard by the pressure roller. However, during normal production, the operator should adjust the pressure according to the quality of the base paper, so as not to crush and fold as the standard.

2. Crimping wheel is unreasonable. The most commonly used in cardboard press lines is convex to concave. Because of the different paper quality, production environment factors, and the thickness of the paperboard, the structure of the pressure roller used is also different. The main parameter is that the width of the upper and lower pressure roller should be appropriate, and the step transition arc of the pressure roller should be adjusted according to the depth of the pressure line and the applicable cardboard. In general, the thicker the cardboard, the corresponding larger width of the pressure line, for the three-layer paperboard can also use the arc surface of the pressure line wheel. There is no uniform structure for the pinch roller, which requires the operator to find a suitable pinch wheel structure according to the actual situation.

Solution

1. Improved on the crimper structure. The adjustment of the structure of the pinch roller can increase the radius of the step transition arc of the pinch roller appropriately.

2. The pre-compression method is used to pre-press before the pressure is applied. The disadvantage is the formation of more obvious lines of pressure.