There are many reasons that cause the opening of the carton to be too wide after molding. The decisive factors are mainly in two aspects: First, the reasons on the paper, including the use of roll paper, the moisture content of the paper, and the fiber direction of the paper. Second, the technical reasons, including surface treatment, template production, the depth of the indentation line and imposition format. If these two big problems can be solved well, then the problem of carton molding will be solved accordingly.
1. Paper ringing is the main factor for forming the shadow box
As we all know, most of the paper is now roll paper, and some are still imported roll paper. Due to site and transportation problems, it is required to be cut in the country, and the paper storage time after cutting is short, plus some manufacturers have difficult capital turnover, they are all sold now, so the paper after cutting is large. None of the parts are completely flat, and there is still a tendency to curl. If you directly buy the cut sheet paper, the situation is much better, at least it has a certain storage process after slitting. In addition, the moisture content of the paper must be evenly distributed, and at the same time must be balanced with the surrounding temperature and humidity, otherwise, after a long time, it will also deform. If the cut paper is stacked for a long time and is not used in time, the moisture content of the four sides is greater than or less than that of the middle, and the paper will bend. Therefore, in the process of using jammed paper, the cut on the same day of use should not be stacked for too long to avoid paper deformation. After the carton is formed, the opening is too large and the fiber direction of the paper is also a factor. The deformation of the paper fiber arrangement in the horizontal grain direction is small, and the vertical grain direction deformation is large. Once the opening direction of the paper box is parallel to the paper fiber direction, the phenomenon of this opening bulging is very obvious. Because the paper absorbs water during printing, after UV varnish, polishing, coating and other surface treatments, the paper is more or less deformed during the production process. The tension of the deformed paper surface and the bottom surface is inconsistent. Deformation occurs, because the two sides of the carton have been glued and fixed when it is molded, and the opening is too large after molding only when it is opened outward.
Second, the process operation is also a factor that cannot be ignored when the color box molding opening is too large
1. The surface treatment of pharmaceutical packaging usually adopts UV glazing, coating, polishing and other processes. Among them, glazing, coating, polishing, etc. cause the paper to undergo high-temperature dehydration, and the water content is significantly reduced. The brittle fibers will deform. Especially for paperboards over 300g coated with a water-based machine, the stretching of the paper is more obvious. The products from the film are bent inwards, and they must be corrected manually. The temperature of the polished product should not be too high. It is generally controlled below 80 ℃. After polishing, it is usually placed for about 24 hours. The product can be processed in the next process after the product is sufficiently cooled, otherwise there will be a line explosion.
2. The production technology of the die-cut version also affects the forming of the carton. The production of the manual version is relatively inferior, and the specifications, cutting, and machete of each place are not well grasped. Generally, manufacturers generally eliminate the manual version and choose the laser knife mold company. Crafted beer board. However, whether the size of the anti-lock and the high and low lines are set according to the weight of the paper, whether the specifications of the knife line are suitable for all paper thicknesses, and whether the depth of the die cutting line is appropriate, etc. affect the carton molding effect. The die cutting line is the trace that is pressed on the surface of the paper by the pressure between the stencil and the machine. If the die cutting line is too deep, the paper fibers will be deformed by compression; if the die cutting line is too shallow, the paper fibers will not be fully penetrated. Due to the elasticity of the paper, when the two sides of the carton are formed and folded back, the cut at the edge of the opening will expand outward, resulting in the phenomenon that the opening is too wide.
3. In order to ensure a good indentation effect, in addition to the selection of suitable indentation lines and high-quality steel knives, attention should also be paid to the adjustment of machine pressure, the selection of rubber strips and standard installation. Generally, printing manufacturers use the form of sticker board to adjust the depth of the indentation line. We know that the cardboard is generally loose in texture and insufficient in hardness. The effect is that the indentation line is not full and durable. If the imported bottom mold material can be used, the indentation line will be more full.
4. To find a way from the imposition format is the main way to solve the paper fiber direction. The fiber direction of paper on the market today is basically fixed, most of which take the longitudinal direction as the fiber direction, and the color box printing is printed on a folio, triple or quadruple paper by a certain amount. The general situation is On the premise of not affecting the quality of the product, the more a piece of paper, the better, because it can reduce the waste of materials and thus reduce the cost. Unable to meet customer requirements. In general, the fiber direction of the paper is perpendicular to the direction of the opening.
In summary, as for the phenomenon that the opening of the carton is too large after molding, as long as we pay attention to this aspect in the production process, try to avoid it from the paper and process aspects, the problem is also easy to solve.
