Quality Control in Corrugated Box Production

With the increasingly fierce competition in the paper packaging industry, customers have become more and more critical of the quality of corrugated boxes. This requires corrugated box manufacturers to continuously improve the quality of corrugated boxes.
Put an end to various quality problems. At the same time, improve service quality, strengthen communication and exchanges with customers, listen to the opinions of customers, and make friends with customers. Only in this way can we take the initiative in market competition to reduce customer complaints about corrugated boxes and win the trust of customers.
satisfy customer needs.

According to the customer's complaints about the quality of corrugated boxes for many years, corrugated boxes are mainly prone to the following quality problems. Only by avoiding these quality problems, can the quality of corrugated boxes withstand the test of customers.

Print layout is fuzzy, dirty, leaking.

The phenomenon of vague printing, dirty, and missing white on the layout is relatively common, which directly affects the appearance of corrugated boxes. Customers are very picky about this. Corrugated boxes with severe print quality issues can only be scrapped.
Lighter can be repaired manually. Layout blur is mainly caused by excessive printing pressure.
Dirty layout mainly has excess print marks, which need to be controlled in the printing process.
Strengthen technical training for printing operators, improve the operational skills of equipment, analyze the causes of quality problems, and eliminate and correct them in a timely manner. The operation of the printing press is the team's performance. Everyone should understand their own work and responsibilities, and have the tacit cooperation in order to maximize the processing quality and efficiency of the equipment.

Corrugated box size is inaccurate
The design and manufacture of corrugated boxes is indispensable to the size, the wrong size, and the manufacture of corrugated cartons has become a waste product. Corrugated carton size is divided into inner diameter size, outer diameter size and processing size. Customers generally have strict requirements on the inner size of corrugated carton. The inside diameter of the carton must be such that the contents can be packed, generally equal to the maximum outside diameter of the contents plus parameter 3—
7mm. The outer diameter size is the size used in circulation. For the export corrugated box, the outer diameter size is very strict, otherwise it will affect the container shipment due to the size. This requires that in the production process, not only should the size of the board of the production line and the size of the printing slot press line be strictly controlled, but also the size control of the process of the nail box and the adhesive box should be grasped.

Layout printing error
The layout of corrugated cartons is often printed in text, which is extremely prone to errors. Once problems with the design layout have not been corrected, the consequences will be unthinkable. Under normal circumstances, the layout errors of corrugated boxes are easily neglected, often with one word or less, or the wrong word. Proofreading must be carried out one by one during the proofreading process, and strict checks must be made. Otherwise, the whole mistake will be caused by small mistakes. The corrugated cartons were scrapped. Businesses must pay attention to the proofreading of corrugated boxes and must not relax.

The paperboard has too shallow indentation in the horizontal direction, and the horizontal indentation line is not straight when the flap is collapsed to go single line or folded; the paperboard is indented too deep in the longitudinal direction and cracks occur inside the paperboard.

Cardboard indentation is one of the necessary processes for corrugated cardboard box processing. The quality of indentation plays an important role in the use of cardboard in folding or boxing. The depth of the indentation and the deviation of the position accuracy often lead to deviations in the size of the carton.

Cardboard transverse indentation is typically achieved on cardboard production lines using double-flanged indentations. Longitudinal indentations are generally done on a printing slotter using a single flange indentation. Generally, the width of single indentation is 6-12mm, and the width of double indentation is about 10-16mm.

The principle of indentation is to adjust the pressure of the indentation so as to achieve easy folding, marked indentation, and non-breakage of the paper.

For horizontal indentation, the center position of the upper and lower wheels should be aligned, and the indentation should be pressed through, ie, there should be no gaps. Generally, the thickness of the five-layer cardboard indentation is about 2mm. For longitudinal indentation,
The gap between the upper and lower wheels of the trace should not be adjusted too small. At the same time, the moisture content of the cardboard should not be too low to prevent the paperboard from breaking during processing.

Cardboard flap breaks
Rolling cover folding resistance is one of the important indicators of corrugated board quality. According to the national standard GB6543-86, the corrugated box flaps must be opened and rotated 180 degrees for more than 5 times. Types 1 and 2 should have no cracks in the surface layer and the inner layer, and there should be no cracks in the outer layer of the type 3 boxboard. The total length of cracks must not exceed 70mm. However, in use, the customer's requirements are much stricter. They require the flaps to be folded 180 degrees outwards and downwards. There must be no cracks in the outside of the paper. This requires controlling the quality of the raw materials and avoiding the use of rough, low-grade corrugated paper. The corrugated base paper may burst the face paper when the flap is folded.

Too dry paper and paperboard is also an important reason for the breakage of the flap crease line. During the production process,
Be sure to control the moisture content of paper and board.

The indentation of the flap fold line must be controlled so that the indentation is moderate. If the flap is found to be broken during production, immediately after the cardboard leaves the machine, the inside of the paper flap is sprayed, and the flap is folded back to the two sides to the end. , can greatly improve the folding cover folding degree.

Cardboard blister
Solve the cardboard bubble glue to do a good job of adhesive control and adhesion control in order to achieve the best adhesive effect.

Adhesive quality is the basic factor that affects the adhesion of paperboard. In the preparation process, the concentration of various ingredients, technical indicators, formulation ratios, oxidation, pasting time and temperature must be strictly controlled.
Every time the adhesive is prepared, it must be tested to stabilize the quality of the adhesive.

We must effectively improve the quality of good raw materials, especially the tightness and moisture content of the base paper, and at the same time strengthen the technical training of operators to improve the ability to use and maintain the equipment. According to the drying speed, the paper quality, the temperature of the drying path, the glue quantity can be flexibly adjusted and the equipment can be operated to the best condition. All kinds of unfavorable factors should be eliminated, so that the correct analysis and reasonable adjustment can be achieved. The problem of foaming glue can be solved easily. .

Cardboard soft
The low raw material strength index is the main reason causing the cardboard to be soft. The quality of corrugated base paper directly influences the compressive strength of corrugated boxes. Choosing high-strength corrugated base paper can produce strong and flexible corrugated cartons. In addition, cardboard dumping can also cause cardboard to be soft, and the emphasis should be placed on the adjustment of printing pressure in the production line process and printing process.

Excessive moisture content of raw materials and excessive sizing are important reasons for the softness of the cardboard box.
Due to the large amount of glue applied, the moisture in the glue penetrates into the corrugated board and causes the corrugated sheet to become soft. After entering the drying system, the paper board becomes soft due to the lack of sufficient moisture in the cardboard.

The printing color is not uniform or the color of corrugated cardboard is not uniform
Print color samples are different in different batches of supplies, or color samples that do not meet customer requirements.
It may be returned. This requires that, while strictly controlling the hue of the ink, the best method is to archive the print color sample when printing the first batch of products so that the same product can be checked for later printing.

Due to the different face paper manufacturers of corrugated board, there are differences in the color of the face paper. Even if the liner board of the same manufacturer is different, there are color differences in different batches. This requires strict controls on the inspection of incoming raw materials and archiving of the samples. At the very least, the color of the container board of the same manufacturer should be unified. At the time of production, the same corrugated box is made of the cardboard paper produced by the same company, maintaining the same color of the face paper.

Corrugated cardboard creased
Corrugated paperboard creases are mainly caused by the storage and transportation process. This flow link often fails to attract the attention of the company and lacks quality control. In addition, during the production process of the carton, the strength of the tissue paper is not enough, the height in the pressure roller is not enough, and the uneven moisture content of the tissue paper also causes the crease of the tissue paper.