Corrugated board process control

The quality problem of corrugated cardboard has always been a common problem for carton manufacturers. Whether it is domestic, foreign, or wide-size corrugated cardboard production lines, cardboard problems will occur to varying degrees, but they all have common features. To solve these problems, in addition to equipment and objective reasons, mainly lies in the operator's operation and adjustment. The main quality problems in the process of corrugated board production lines are analyzed and solutions are provided. Corrugated Cardboard Production Line Process 1. Preparation 1-1 Adhesive Preparation 1-2 Raw Materials Input ↓ 2. Single Sided Unit 2-2 A Single Sided 2-2 A Single Sided ↓ 3. Double Sided Unit 3-1 Double Sided Machine 3-2 Drying Cooling ↓ 4. Slitting Line 4-1 Longitudinal Cutting 4-2 Vertical Pressure Line ↓ 5. Lateral Cutting 5-1 Upper Cutting 5-2 Lower Cutting ↓ 6. Stacking Code 垛 6-1 Stacking Machine 6-2 side conveyor ↓ 7. Semi-finished transfer 7-1 Sales of paperboard 7-2 Specifications Cardboard corrugated board production line process is roughly divided into the above seven processes. Enterprises should formulate process flow and process regulations according to the actual conditions of the equipment so as to guide and restrain the operators and prevent and avoid the occurrence of cardboard problems.

The quality of corrugated board basically includes the following four aspects:

Bonding problems, warpage problems, warpage problems, and dimensional issues. Adhesion problems include poor paperboard bonding, degumming, blistering, pleating, and the like. Analysis of the reasons: There are many reasons for the above problems. Adhesion problems may occur due to adhesive problems, various aspects of tension, and improper adjustment of the gap between rollers.

Solution: Adhesive problems occur on all parts of the board. The first thing to consider is whether the adhesive has problems. Because the production of adhesives is the first step of the entire production line, it is also a major quality control point across the board. Therefore, adhesives should be made according to a fixed process recipe to ensure the viscosity and temperature of single and double-sided machine adhesives. After the adhesive is manufactured, use a 4# cup to measure the viscosity. The viscosity should be determined according to the device performance.

In addition, the adjustment of the clearance between the rollers of the single and double-side units is also very important. For example, the single-side unit mainly adjusts the pressure roller and the lower corrugating roller, the paste roller and the lower corrugating roller, the thickness setting roller and the paste roller 3 The gap between the two must be appropriate. The gap should be determined according to the thickness of the raw material used. The gap should be approximately 0.2mm to 0.3mm. Special attention should be paid to the fact that the rollers must be kept parallel to each other. The width of the paste line is controlled at 1mm. If the width is too large, the phenomenon of un-gelatinization, bending, or unsatisfactory adhesion strength may occur. Width is small, easy to produce false bonding or degumming, blistering phenomenon. The double-sided unit mainly adjusts the gap between the floating roller and the paste roller, paste roller, and set thickness roller. The gap between the floating roller and the coating roller is equal to the height of the single-faced corrugation plus the thickness of the tissue, and the paste roller should have a fixed gap. At lower times, the thickness of the corrugation is reduced, the corrugation is damaged, and the flat compressive strength of the cardboard is reduced. Higher consumption of paste. Rollers that do not produce squeezing, good quality, economy, and high speed. The gap between the coating roller and the setting roller is about 0.25mm. Base paper bracket brake system should be based on the diameter of the base paper, the size of the weight of the base paper to properly control the tension. Deformation includes: 楞 tilt, skew, height, shape, etc. Analysis of causes: The above problems are mainly manifested in the fact that there is no correct corrugation height, there is a very small height difference in the corrugation height, and the corrugation is tilted to one side or the left and right thicknesses are not uniform. The reason is that due to the wear of the corrugating roll and the deformation of the crucible, it is mainly due to the unevenness of the moisture of the base paper, the insufficient temperature of the heat roller, and the improper adjustment of the tension force. Solution: Defects generally refer to the phenomenon of badly formed single-sided corrugations, which are often distinguished from the deformations caused by subsequent processes. The deformations that occur in the cardboard line are collectively referred to as defects.

In addition to the deformation of the corrugated rollers, the following problems must be solved: The moisture content of the base paper must be controlled within the range of 8-10%. When the moisture content is too low, the heater must be adjusted. When the moisture content is too high, adjust the moisture content. Preheat area. Corrugated roll, preheat roll and hot plate steam pressure and surface temperature adjustment, the general steam pressure to 11MPa or more, the surface temperature is basically 160 degrees -170 degrees. If it is lower than the above value, we must reduce the speed. When using the paper guide device, check the position of the guide plate to prevent the deformation of the file due to the wear of the guide plate or improper position adjustment. In addition, the pressure of the hot plate weight roller must not be too large, and no foreign matter or processing marks are allowed on the conveyor belt. Also pay attention to the adjustment of the single-sided corrugated board brake device on the double-layer conveyor and the gap between the double-sided floating roller and the paste roller. Cardboard warpage includes: vertical upturned, vertical downturned, upturned horizontally, laterally upturned, and S-shaped warped cardboard deformation. Analysis of causes: The main reason for warpage is that the water in the paperboard, the surface materials and the base paper are inconsistently severe, and the temperature, air pressure, and vehicle speed become low. Regular parking will cause warpage. Solution: Cardboard warpage is a common problem for all carton manufacturers. This problem directly plagues the production and efficiency of the company. It concentrates on the unevenness of the cardboard surface and the phenomenon of bending, which affects the cardboard of the container used to collectively distort the cardboard.


To solve the warpage problem, there are mainly the following points: First, strict control over the moisture content of raw paper and the poor grammage of surface paper and surface paper. They are the main factors that affect the lateral warpage of the cardboard. The moisture content of the raw paper into the factory must be tested and must be kept within the limits set by the national standards. Basically, it can be controlled at 8%2. If the water content is too low, spray or water spray measures must be taken. If the moisture content is too high, the warm-up area must be increased to ensure that the paper moisture content is within 3%. The difference in paper weight is controlled within 30-50g. The second is to adjust the speed at any time according to changes in steam pressure and surface temperature. To prevent the vehicle from flickering or stopping, the time it takes for cardboard to stay in the hot plate determines the degree and form of warping. The third is that the single-faced corrugation on the double-layer conveyor and the strength of the face-paper tension also directly affect the longitudinal warp of the cardboard. It is necessary to appropriately increase or decrease various kinds of tension control according to different situations of warp of the board. Size is not allowed to include: slitting, pressure lines, horizontal and other dimensions.

Analysis of the reasons: due to deviations in production size adjustments that have not been issued in accordance with production instructions, or inaccurate longitudinal dimensions due to the lack of fixation of the slitting pressure reel. And because of the speed of the vehicle and the conveyor belt, the transverse cutoff is inaccurate. Solution: The board size includes the length, width, and manufacturing dimensions of the pressboard. First, it should be produced according to the production size given by the production order or the process drawing. It is not allowed to make mistakes due to human factors. It is necessary to adjust the upper and lower knives and the lower line of the press line to the exact position. After the first inspection, it can be officially produced. In addition, the slitting of the upper and lower knives is strictly for the thickness of half a cardboard, and the artificial bolts must be tightened in order to prevent “runners”. The centerline of the next wheel on the pressure line should be aligned, the depth of the pressure line should be 3/4th of the board thickness, and the bolt should be tightened to prevent “runaway”.

The control of single-sided corrugated and tissue paper tension also has a direct impact on the size of the transverse cut. The slippage of the conveyor belt or unstable vehicle speed has an effect on the dimensions. If there is no problem with the above, it is necessary to check whether there is a problem with the cutting machine itself or the computer input program. Corrugated paperboards have many quality problems in the production process and are not listed one by one. In short, as long as the products are carefully manipulated and adjusted in production, and correct measures are taken for different quality problems, some problems are easily eliminated and resolved.

Source: Feilang Carton Technology Media