Reasons for excessive opening of color box after molding mailer shipping box
The packaging color box of the product should not only have bright colors and generous design paper box, but also require the paper box to be beautifully shaped, square and upright, with clear and smooth indentation lines, and without exploding lines. However, some thorny issues often arise during the production process, such as the excessive opening of some packaging cartons after molding, which directly affects consumers’ trust in the product.
The packaging color box of the product should not only have bright colors and generous design, but also require the paper box to be beautifully shaped, square and upright, with clear and smooth indentation lines, and without exploding lines. However, some thorny problems often arise in the production process, such as the phenomenon that the opening part of some packaging cartons is excessively opened after molding. This is especially true of pharmaceutical packaging cartons, which face thousands of patients. The poor quality of packaging cartons directly affects consumers’ trust in the product. At the same time, the large quantity and small specifications of pharmaceutical packaging cartons make it more difficult to solve the corresponding problems. Based on my practical work experience, I am now discussing with my colleagues the problem of excessive opening of pharmaceutical packaging boxes after molding.
There are various reasons for the excessive opening of the paper box after molding, and the decisive factors are mainly in two aspects: first, the reasons for the paper, including the use of web paper, the water content of the paper, and the fiber direction of the paper. 2、 Technological reasons include surface treatment, template production, depth of indentation lines, and stencil format. If these two major problems can be well solved, the problem of carton molding will also be solved accordingly.
1、 Paper is the main factor affecting the formation of paper boxes.
As you know, most of them now use roller paper, and some still use imported roller paper. Due to site and transportation issues, domestic slitting is required, and the storage time of the slitted paper is short. In addition, some manufacturers have difficulty in capital turnover, and they sell and buy as they go. Therefore, most of the slitted paper is not completely flat, and there is still a tendency to curl. If you directly purchase sliced flat paper, the situation is much better, at least it has a certain storage process after cutting. In addition, the water content of the paper must be evenly distributed, and must be balanced with the surrounding temperature and humidity, otherwise, over time, deformation will occur. If the cut paper is stacked for too long and not used in a timely manner, and the water content on the four sides is greater than or less than the water content in the middle, the paper will bend. Therefore, in the process of using paper jams, it is advisable to use the paper that has been cut on the same day and not stack it for too long to avoid causing deformation of the paper. There are also factors such as excessive opening of the paper box after molding, as well as the fiber direction of the paper. The deformation of the paper fiber arrangement in the transverse direction is small, while the deformation in the vertical direction is large. Once the opening direction of the paper box is parallel to the fiber direction of the paper, this phenomenon of opening bulge is very obvious. Due to the fact that the paper absorbs moisture during the printing process, and undergoes surface treatments such as UV varnish, polishing, and film covering, the paper will more or less deform during the production process. The tension between the deformed paper surface and the bottom surface is inconsistent. Once the paper deforms, as the two sides of the paper box have been glued and fixed during molding, only opening outward can lead to excessive opening after molding.
2、 The process operation is also a factor that cannot be ignored due to the excessive opening of the color box molding opening.
1. The surface treatment of pharmaceutical packaging usually adopts UV polishing, film covering, polishing, and other processes. Among them, polishing, film covering, and polishing make the paper undergo high temperature dehydration, significantly reducing its water content, and then through stretching, some of the paper fibers become brittle and deformed. Especially for water-based machine coated paperboard with a weight of more than 300g, the stretching of the paper is more obvious, and the coated product has an inward bending phenomenon, which generally requires manual correction. The temperature of the polished product should not be too high, generally controlled below 80 ℃. After polishing, it usually needs to be left for about 24 hours, and the next process can only be started after the product is fully cooled, otherwise there may be a line explosion.paper-gift-packaging
2. The production technology of die cutting plates also affects the molding of paper boxes. The production of manual plates is relatively poor, and the specifications, cutting, and machetes are not well understood. Generally, manufacturers generally eliminate manual plates and choose beer plates produced by laser knife mold companies. However, issues such as whether the size of the anti lock and high/low line is set according to the weight of the paper, whether the specification of the knife line is suitable for all paper thicknesses, and whether the depth of the die line is appropriate affect the molding effect of the paper box. The die line is a mark pressed on the surface of the paper by the pressure between the template and the machine. If the die line is too deep, the fibers of the paper will deform due to pressure; If the die line is too shallow, the paper fibers are not fully pressed through. Due to the elasticity of the paper itself, when both sides of the paper box are formed and folded back, the cutout on the opening edge will expand outward, forming a phenomenon of excessive opening.
3. In order to ensure a good indentation effect, in addition to selecting appropriate indentation lines and high-quality steel knives, attention should also be paid to the adjustment of machine pressure, selection of adhesive strips, and standardized installation. Generally, printing companies use the form of cardboard to adjust the depth of the indentation line. We know that paperboard generally has a loose texture and insufficient hardness, which results in a less full and durable indentation line. If imported bottom mold materials can be used, the indentation line will become fuller.
4. The main way to solve the fiber orientation of paper is to find a way to solve the problem from the composition format. Nowadays, the fiber orientation of paper on the market is basically fixed, mostly in the longitudinal direction, while the printing of color boxes is carried out on a certain amount of split, triplet, or quadruple paper. Generally, without affecting product quality, the more pieces of paper are spliced, the better, as this can reduce material waste and thereby reduce costs. However, blindly considering material costs without considering fiber orientation, The molded carton cannot meet the customer’s requirements. In general, it is ideal for the fiber direction of the paper to be perpendicular to the direction of the opening.
To sum up, as long as we pay attention to this aspect during the production process and avoid it as much as possible from the aspects of paper and technology, the problem of excessive opening of paper boxes after molding can be easily solved.
Post time: Apr-04-2023
