Boutique white cardboard gift boxes blistering? I didn't think there was a problem here!

1. Pay attention to the blistering defect of white cardboard gift boxes together----Blistering:

The production process of white cardboard gift boxes is a multi-process and multi-step process. Due to the long production process of white cardboard gift boxes, the control of each step is related to the quality of each product. However, there will still be some problems in the actual production of white cardboard gift boxes, which will affect the smooth progress of production.

Through 5 issues, the author analyzes the common problems in the process of white cardboard gift boxes - high and low angles, acne, dew, blistering, and embossing. In this issue, let's pay attention to the blistering defect of white cardboard gift boxes----Blistering, during the pasting process of white cardboard gift boxes, irregular blisters of different sizes and shapes often appear at the corners of white cardboard gift boxes. , the bubble is hollow and cannot be recovered by pressing.

2. The reasons for the blistering of white cardboard gift boxes are mainly caused by the following factors:

After analyzing and observing the blistering position of white cardboard gift boxes, and doing various experiments at the same time, it is found that the reasons for blistering of white cardboard gift boxes are mainly caused by the following factors.

First, the basic structure of the whiteboard card will be described. As shown in Figure 1, the thickness of the whiteboard card is 1.50mm, of which the thickness of the paper base is about 1.44mm, and the thickness of the paint layer is about 0.06mm.

Figure 1 The basic structure of the whiteboard card. In theory, the slotting of the white cardboard gift boxes is a smooth operation process. The depth, angle and slot width of the V-slot will not change, but in fact, the knife runs on the cardboard. It is not a perfect straight line. There is a height difference between the knife and the knife. Generally, the knife is a little deeper, and the knife is a little shallower when it is dropped. The difference between the front and rear is about 0.015mm. This difference is mainly limited by the accuracy of the equipment itself, resulting in The V-groove cannot achieve the same depth and width. At the same time, when the machine is running, there will be a slight hesitation and shaking. Although it is not obvious visually, the stepped ripples can be found under a 10x magnifying glass. In addition, the thickness of the whiteboard card is also different. A whiteboard card is measured at different positions with a micrometer. It will be found that the thinnest part is only 1.40mm, the thickest part is 1.52mm, and the difference is 0.12mm. Different thicknesses can also cause the V groove to remain. The bottom is inconsistent, which is one of the reasons for the slotting error of white cardboard gift boxes. Assuming that the data of the slot of the whiteboard card is 9.00mm wide, about 0.03mm bottom, and 138 degrees, such a setting seems to be fine on the surface, but after careful consideration, it will be found that there is a certain risk (as shown in Figure 2). Show).

Figure 2 The paint layer is broken. It can be seen from the picture that the paint layer on the top of the V groove of the white cardboard gift boxes has been broken by the groove knife. The thickness that can connect the two sides of the slot together is only about 0.03mm, so that its ability to resist tension will be reduced. Originally, the function of the coating layer of white cardboard gift boxes is to improve the smoothness, strength, gloss and stiffness of the paper surface, and its waterproof ability is limited. In this state, the coating layer will bear the excessive tensile force. When the jelly glue is applied, the drying conditions will be changed, and the water molecules have a strong penetration force. The top of the white cardboard gift boxes is the weakest part. After the jelly glue is applied, the water molecules will immerse in from here (as shown in Figure 3). ).

Figure 3 Immersion of water molecules

The water molecules in the jelly glue partially wet the top of the tank, and then penetrate between the paper base layer and the paint layer of the white cardboard gift boxes, and the paint layer and the paper base layer lose their bonding ability. Attached together, the two are interdependent. When the coating layer loses the support and protection of the paper base, the coating layer will lose its resistance. As long as there is an external force, the separation of the layer is inevitable. In the same way, the white cardboard gift boxes leather shell material will also change when it encounters water, and the weight and thickness of the leather shell material are larger than the paint layer. A slight change can pull up the paint layer. The closer to the top of the V groove, the pull-up layer The more obvious the area is (as shown in Figure 4), the action of water molecules destroys the bonding ability between the coating layer and the paper base layer.

Figure 4 Changes of leather shell material in contact with water

The same whiteboard card and the same outer material, why some white cardboard gift boxes bubble and some don't? This boils down to the stability of the slotting of the white cardboard gift boxes. As mentioned earlier, the depth of the slot is affected by the operation and equipment accuracy. It is impossible to always guarantee the same effect, and the operator's inspection frequency is not enough to find the problem in time, which is also one of the reasons for the problem of white cardboard gift boxes.

The cause and effect are clear, and the solution is simple. That is, the thickness of the bottom of the white cardboard gift boxes should not be too thin, and a reasonable thickness of the bottom should be formulated according to the structural characteristics of the white cardboard gift boxes.

The correct operation requirement of white cardboard gift boxes is that the paint layer and the paper base layer should not be out of proportion (as shown in Figure 5), and should account for about 50% each when the process requirements are met, that is, the paint layer is 0.06mm, and the paper base layer is 0.06mm. mm, it is reasonable to keep the bottom layer at about 0.12mm, and the coating amount of glue should be controlled at about 28g/m² to reduce the coating amount of glue, which will correspondingly reduce the amount of water molecules on the surface of the white cardboard gift boxes paper. reserve.

Figure 5 The ratio of paint layer to paper base layer

In theory, the minimum coating amount should be selected for white cardboard gift boxes to achieve the best bonding effect. This is a common understanding of the pasting process of white cardboard gift boxes.

3. Notice for the next issue of white cardboard gift boxes:

The imprinting of white cardboard gift boxes means that after the white cardboard gift boxes are pasted, irregular, irregular and unequal-sized marks appear on the surface of the white cardboard gift boxes, most of which appear as a concave straight line, shallow pit or radial shape. Lines, these depressions of various shapes are embedded on the surface of white cardboard gift boxes, which seriously affects the overall effect of the product, especially on the surface of the white cardboard gift boxes with dark or all black design. The white cardboard gift boxes are reported to be scrapped, causing huge waste to the enterprise.