Nowadays, packaging and printing factories have found the following five methods on how to increase the pressure of corrugated paper packaging boxes. Now, we will describe in detail the five methods of enhancing the pressure of corrugated paper packaging boxes. The production experts of Changsha carton packaging factory know that the cardboard line to make cartons is formed by gluing, heating, instant bonding, and drying; the laminated color box color box cardboard is not heated and dried, and the water in the glue penetrates Into the paper, coupled with the barrier of the varnish on the colored surface and the plastic film, the moisture in the blank box will not be distributed for a long time, and it will naturally soften and reduce the strength. Now we are looking for ways to enhance the corrugated color box color box from the following factors:
1. Production environment
The production environment temperature should not exceed 33°C, and the air humidity should not exceed 45%, otherwise the cardboard will easily absorb moisture, and its own moisture will not be volatilized, which naturally reduces the bearing pressure of the carton. In addition, it is best to rotate the small box blank for 4 hours before forming. Due to the urgent needs of customers, a blower can be used to force the air to accelerate the adhesion of the cardboard and drive out the excess water.
2. Paper matching
Some companies have such a misunderstanding: the larger the weight of the paper inside, the more it can increase the bearing pressure and compressive strength of the carton, but this is not the case. To increase the pressure and compressive strength of the color box, the pressure-bearing capacity of the core paper must be enhanced. As long as the surface paper does not show corrugated traces after the glue is mounted, low-weight paper should be used as much as possible; the core paper and corrugated paper are best to be used. Straw pulp or wood pulp paper with good strength and high ring compressive strength. Do not use medium-strength or normal-strength tile paper, because it is mostly a mixture of raw pulp and recycled pulp, which has fast water absorption, low ring pressure strength, and good toughness but low stiffness. According to the test, the water absorption rate of medium-strength corrugated paper is 15%-30% higher than that of scoring paper by the Kobo method; the lining paper can be appropriately increased in weight. Practice has proved that reducing the weight of paper inside and increasing the weight of corrugated paper and core paper have a competitive advantage in terms of quality and price.
Third, the quality of single-sided cardboard
The quality of single-sided corrugated board is determined by the quality of the base paper, the type of corrugation, the working temperature of the corrugator, the quality of the adhesive, the speed of the machine, and the technical level of the operator.
When the base paper is reasonably matched and the quality can meet the production requirements, it is necessary to check whether the corrugated roll peak of the single-facer is severely worn. The normal corrugated type should be UV type. After a long time of use, the corrugated peak of the corrugated roller becomes semi-circular due to factors such as sand in the paper or the hardness of the corrugated roller. The single-sided cardboard produced by the equipment is resistant to such conditions. The compressive strength is greatly reduced. In addition, if the pressure roller is too high, the temperature of the corrugator is too high, and the single-sided cardboard is likely to be broken. Similar single-faced corrugated cardboard will eat more glue when bonding and laminating, and its physical properties have changed, making it difficult to guarantee the compressive strength.
When the raw material equipment is normal, it is necessary to increase the preheating area of the preheater according to the moisture content of the paper, control the single-sided temperature at about 200℃, and adjust the pressure to about 0.3-0.4kPa (as long as the corrugated paper is not broken) No cracks, the Riva paper fits well).
The vehicle speed is controlled at the medium speed of the equipment design speed, and the viscosity of the adhesive is adjusted to 30-35S. If the adhesive deposits and yellows water with peculiar smell, it should be updated immediately. The operator must be skilled and have a high sense of responsibility. And good professional ethics, can flexibly adjust the pressure and speed of each roller according to the actual production situation, so that the quality of single-sided corrugated cardboard can be guaranteed.
Fourth, the quality of glue
Most carton production now uses self-made or purchased corn starch glue. High-quality corn gum not only has good bonding strength, but also can enhance the pressure and stiffness of the cardboard, and the box is not easy to deform. The pros and cons of corn starch glue are closely related to the production process, environment, quality of raw and auxiliary materials, and mixing time. The quality requirements of corn starch are 98-100 mesh, ash content no more than 0.1%; water content 14.0%; acidity 20CC/100g; sulfur dioxide 0.004%; smell is normal; color is white or slightly yellow.
If the quality of gum starch does not meet this standard, the water ratio may be appropriately reduced depending on the situation. As the temperature rises, the water ratio should be reduced accordingly, borax and caustic soda should be increased as appropriate, and the amount of hydrogen peroxide should be reduced. The cooked glue should not be put for a long time after it is made, especially in summer. It is best to use it in summer. Adding 3%-4% formaldehyde, 0.1% glycerin and boric acid to the glue can increase the water blocking capacity of the paper, accelerate the bonding speed, and strengthen the cardboard. hardness.
In addition, environmentally-friendly chemical glue, namely PVA adhesive, can also be used when mounting the sticker board. Its characteristics are that the laminated corrugated board is flat, straight, good adhesion, and not deformed for a long time. Its production method is (taking 100kg adhesive as an example): the ratio of materials: polyvinyl alcohol 13.7kg, acetic acid polyvinyl alcohol emulsion 2.74kg, 1.37kg of oxalic acid, 82kg of water, water ratio 1:6). First, heat the water to 90°C, add polyglycol and stir evenly, continue to heat until the water boils, keep it for 3 hours, add oxalic acid and stir, and finally add the acetic acid polyvinyl alcohol emulsion and stir evenly.
Five, the amount of glue
Whether it is manual or automatic mechanical mounting and pasting of colored surfaces, the amount of glue should not be too large. In actual production, some employees artificially increase the amount of glue applied in order to avoid degumming, which is not desirable and must be strictly controlled. The amount of glue applied should be 80-110g/m2. However, depending on the size of the corrugation, it is better to control the amount of glue to coat the corrugated peak evenly. As long as the amount of glue is not degummed, the smaller the amount of glue, the better.
