1

At present, people not only have higher and higher requirements for the inherent quality of goods, but also pay more attention to the packaging of goods. This requires that the packaging color boxes not only have bright colors and generous designs, but also have beautiful shapes and squares. The automatic folder gluer is more and more widely used due to its high production efficiency and good molding quality. However, in the actual production process, there are often some thorny problems, and it is difficult to give full play to its advantages. Here, I would like to express my personal views on my actual work experience, and also take this opportunity to discuss with you the problems of carton forming. There are various factors that affect the quality of carton forming, and there are two main aspects.

(1) Material factors, including the use of roll paper, the moisture content of the paper, the fiber direction of the paper, the rational selection of adhesives, etc.

(2) Process factors, such as surface finishing of printed matter, production of die-cutting plate, setting of process parameters, etc.

If these two problems can be solved well, then the problem of carton forming can be solved accordingly. The influence of material factors:

1. The effect of paper deformation on carton forming

The paper itself is not flat and curled. After printing, die-cutting and gluing, the appearance of the box will be affected. The deformation of paper is mainly reflected in the following aspects.

(1) Deformation caused by curling of the web itself. Most of the color boxes are now printed on roll paper, and some also use imported roll paper. Due to the limitation of site and transportation conditions, the imported paper rolls must be cut domestically. The storage time of the paper after cutting is generally short. In addition, some manufacturers have difficulty in capital turnover. Most of the paper is not completely flat before printing. The situation is much better if the slitted sheets are purchased directly.

(2) Deformation caused by changes in paper moisture content. The moisture content of each sheet must be evenly distributed and must be balanced with the surrounding humidity, otherwise, over time, the phenomenon of "lotus leaf edge" and "tight edge" will appear, which will affect the aesthetics of the final box shape. For the cut cardboard, the stacking time should not be too long.

(3) Deformation caused by inappropriate imposition method. The decisive factor is the direction of the paper fibers.

Once the opening direction of the carton is parallel to the fiber direction of the paper, the phenomenon of bulging of the opening is very obvious, because the paper absorbs moisture during the printing process, and then undergoes surface processing such as UV coating, calendering, and lamination. More or less deformation will occur in the middle of the paper, and the tension between the surface and the bottom of the deformed paper is inconsistent. Since the two sides of the carton have been glued and fixed during the forming, they can only be opened outwards, resulting in the opening of the carton is too large after forming. The phenomenon.

In this regard, it is necessary to find a solution from the way of imposition. Nowadays, the fiber direction of paper on the market is basically fixed, and most of them take the longitudinal direction as the fiber direction, while the printing of the color box is printed on a folio or four-fold paper in a certain number, which generally does not affect the quality of the product. Under the premise, the more pieces of paper, the better, because in this way, the waste of materials and costs can be reduced, and the price calculated in this way can be accepted by customers. The formed carton also fails to meet the customer's requirements. In general, it is ideal that the fiber direction of the paper is perpendicular to the direction of the opening.

At the same time, special attention should be paid to avoid sticking the box tongue at the mouth to the left side of the socket, otherwise when the flip cover is inserted into the socket side, the flap will easily be held up by the box tongue at the sticky mouth. When the box is small and the quantity is large, the paper will be fed The use of the box is very inconvenient.

2. The effect of paper type on the fastness of pasting box

Different types of paper have different effects on the glue fastness. White cardboard, white cardboard with grey background, gold/silver cardboard and some other special papers are mainly used for printing wine boxes and medicine boxes.

White cardboard has high quantitative, good surface smoothness, high flatness, high tightness, and poor permeability of adhesives. Therefore, in the process of gluing, if the surface characteristics are not considered, it may lead to poor adhesion. In this regard, edging treatment is generally adopted to increase the friction coefficient of the sticky edge and the permeability of the adhesive, and improve the adhesion fastness.

The bottom layer of the gray-backed whiteboard paper is rough, the water absorption is strong, and the permeability to the adhesive is better, so the adhesion fastness is better than that of the white cardboard. The surface smoothness and flatness of gold/silver cardboard are higher, but it is generally treated by lamination. At this time, the use of film/paper adhesive is beneficial to improve the bonding fastness.

3. The effect of adhesive on the fastness of pasting box

Adhesive is one of the most important factors affecting the fastness of the glue box. The choice of adhesive is generally selected according to paper/paper, plastic/paper. The paper/paper adhesive used by our company is 313 water-based adhesive, which has good consistency, high stability, good leveling, and is suitable for fast bonding. The plastic/paper type adhesive adopts 815 machine sticky plastic/paper sealing adhesive, which has high solid content, fast drying speed, good adhesion performance, good high and low temperature resistance, moderate hardness, good brushability, and cold resistance. Good heat resistance, fast initial bonding speed, and high-speed bonding can be achieved.

The influence of process factors

1. The effect of surface finishing on the quality of the glue box

The influence of surface finishing is mainly manifested in the products that are fully varnished and laminated after printing. For such semi-finished products, since it is difficult for the adhesive to penetrate through the varnish layer and the plastic film layer to reach the paper, the bonding fastness will not be very high. In this regard, some folder gluers are equipped with edge grinding devices to grind the surface layer of the bonding place, but this is somewhat difficult in terms of technology. Therefore, many manufacturers try to avoid the bonding area when glazing and laminating, and only glazing or laminating on the part of the carton product.

2. Influence of die-cutting process on box shape

The production process of the die-cut version also has a great influence on the box shape. The hand-made die-cutting plate is relatively poor, and the specifications, cutting and machete are not well grasped. At present, hand-made plate-making is basically eliminated and the die-cutting plate made by laser knife die is used. But sometimes whether the size of the anti-lock button and the high and low lines are set according to the quantitative of the paper, whether the specifications of the cutting line are suitable for all paper thicknesses, and the height of the die-cutting line also affect the effect of carton pasting. Among them, during the indentation, the fibers of the paper will be deformed due to the pressure. If the indentation line is too shallow, the fibers of the paper may not be completely pressed through. Due to the elasticity of the paper itself, when the two sides of the carton are formed and folded back, the incision on the side of the opening will expand outwards, forming the phenomenon of opening the opening.

3. The effect of process parameters on the quality of the glue box

In actual production, in order to avoid the occurrence of faults such as inaccurate adhesion, weak adhesion, degumming, overflowing glue, sticking flowers, etc., the process parameters should be set reasonably. Factors to be considered generally include the characteristics of the paper material, the size of the opening, and the surface finish. The pressure after pasting the box is based on the box being firmly pasted and without indentation (especially to prevent scratches in the forming process of special paper, such as gold/silver cardboard, pay attention to the reasonable adjustment of the pressure), and the amount of glue is determined by It is mainly determined by the width of the sticky edge of the box. The larger the number of sheets of paper, the thicker the thickness, the higher the flatness, the more complicated the process and the lower the working speed. The specific parameter setting needs to be determined according to the actual situation. (from the Internet)