Crack the problem of color box bearing pressure

Paper collocation

Some companies use the material, the surface is 300g coated paper, which is 170g American red, core paper (paper) is 170g medium strong wavy paper. With such paper collocation, I thought it was wrong. To increase the bearing pressure of the carton, that is, the compressive strength, it is necessary to enhance the pressure resistance of the core paper. The author suggests that: as long as no noticeable signs of corrugating after the face paper is applied, low-gram weight paper should be used; core paper (paper) can be used Good strength and high embossing strength of straw pulp paper instead of medium strong wavy paper. (Middle strong kraft paper is mostly mixed paper with recycled pulp and raw slurry. It has fast water absorption, low ring pressure strength and good toughness, but its stiffness is low. The test has determined that the medium-strong tiles can absorb about 15-30% more water than the straw-pulp paper; the frozen product boxes should also use low-absorption paper. Paper can be properly increased weight. The paper with the surface can choose 220-230g coated paper, tile paper can choose 180g straw paste, 200g or 220g American red for the paper, so whether it is quality, or price more competitive advantage.

The quality of the glue

Color box veneer to the second couple, mostly self-made or purchased corn starch glue. Advantages and disadvantages of corn starch glue and production process environment, raw material quality, mixing time, etc. are closely related, as we all know, there is no need to gossip.

The author only refers to the quality requirements of cornstarch, which is one of the main raw materials for making rubber, and the ratio of starch to starch, and the addition of additives. References: The quality requirements of corn starch, fineness of 98-100 mesh, ash content not exceeding 0.1%, water content 14.0%, acidity 20cc/100g; sulfur dioxide 0.004%, odor normal, color white or slightly yellowish. When starch quality is not met in this standard, the water ratio may be appropriately reduced depending on the quality. As the temperature rises, the water ratio should be reduced accordingly, and borax and protopine should be increased as appropriate, and H2O2 should be appropriately reduced. After the cooked rubber is prepared, it should not be put for a long time, especially in the summer, it is best to use with formaldehyde. 3-5% formaldehyde, 0.1% glycerin, and 0.1% boric acid can improve the water resistance of the paper and speed up the bonding speed. Cardboard hardness. (Refer to the frozen product box for reference)

In addition, environmentally friendly chemical adhesives, ie PCA adhesives, can also be used when applying panels. It is characterized by a smooth, straight, well-bonded, durable, and non-deformable stenciled corrugated paperboard. Its production method is (100 kg of adhesive as an example):

The ratio of materials used was: polyvinyl alcohol 13.7kg, acetic acid polyvinyl alcohol emulsion 2.74kg, oxalic acid 1.37kg, water 82kg (water ratio 1:6).

First, heat the water to 90°C, add polyvinyl alcohol, stir well, continue heating until the water boils, keep warm for 3 hours, add oxalic acid, stir, and finally add acetic acid and polyvinyl alcohol emulsion to mix well and serve.

Coating amount

Manual veneer, the amount of glue should not be too large, some employees in the actual production in order to avoid degumming, artificial increase in the amount of glue, which is undesirable, must be added to control. The amount of glue should be 80-110g/m2. However, depending on the size of the corrugator, it is better to control the amount of glue and evenly coat the peak. As long as it is not degummed, the smaller the amount of glue, the better.

Single board quality

The quality of single-sided corrugated board is determined by the quality of the base paper, corrugated type, temperature of the corrugating machine, adhesive quality, machine running speed, and operator skill level.

When the base paper with a reasonable and quality can meet the production needs, it is necessary to check whether the single-sided machine corrugated roller peak wear. The normal enamel type is UV type. After a long period of use, the peak of the corrugating roll becomes a semicircular type due to factors such as the sand content of the paper or the hardness of the corrugating roll itself. The equipment is in such a condition that the single-sided board produced is resistant to pressure. The intensity is greatly reduced. Also, if the pressure roller is excessively pressurized, the temperature of the roller is too high, and the cardboard corrugated on one side may be easily disintegrated. When similar single-sided corrugated cardboard is glued to tannin, it is difficult to ensure the compressive strength.

Under the normal condition of raw materials and equipment, the preheater preheating area should be appropriately adjusted depending on the moisture content of the paper. The single machine temperature should be controlled at about 200°C, and the pressure roller pressure should be adjusted to about 0.3-0.4 kpa (as long as the paper is not cracked). Not broken, good Riva paper fit). The speed of the vehicle is controlled at the medium speed of the equipment design speed is low, and the viscosity of the adhesive is adjusted to 30S-35S. If the adhesive is precipitated with yellowish water and there is odor, it should be updated immediately. The operator must be skilled, have a high sense of responsibility and good professional ethics, and can flexibly adjust the pressure and speed of each roller according to the actual production conditions, so that the quality of single-sided corrugated cardboard can be guaranteed.

Production Environment

The temperature of the production environment should not exceed 33°C, and the humidity of the air should not exceed 45%. Otherwise, the cardboard can easily absorb moisture, and its moisture is not volatilized, which naturally reduces the bearing pressure of the carton. In addition, it is better to place the box blank for 4 hours before molding. Indeed, customers are in urgent need of a blower to force the air blow in the direction of the blanks of the blanks, so as to promote their adhesion and remove excess moisture. To sum up, to increase the pressure on the color box must be considered comprehensively and comprehensively, and efforts should be made to reduce various unfavorable factors.

Reprinted from: Huaxi Packaging Network