The hottest solution to the problem of bearing pre

2022-08-09
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Solve the problem of color box bearing pressure

release date: Source: China paper industry

paper matching

some companies use materials with 300g coated paper on the surface, 170g American Red on the inside, and 170g medium strong tile paper on the core paper (tile paper). Such paper collocation, I think is inappropriate. In order to enhance the pressure bearing capacity of the carton, that is, the compressive strength, we must enhance the pressure bearing capacity of the core paper. The author suggests that as long as the structural paper of the surface tension tester fixture does not show corrugated marks after laminating, we should try to use low gram weight paper; Core paper (tile paper) can use straw pulp paper with good stiffness and high ring pressure strength to replace medium strength tile paper (because medium strength tile paper is mostly a mixture of recycled pulp and raw pulp, which has fast water absorption, low ring pressure strength, good toughness, but low stiffness. The water absorption of medium strength tile paper is about% higher than that of straw pulp paper by Cobb method); The freezer should also use tile paper with low water absorption. The weight of the lining paper can be increased appropriately. Its paper matching surface can choose g coated paper, tile paper can choose 180g straw pulp tile paper, 200g or 220g American red paper, so it has more competitive advantages in both quality and price. Today, China's paper industry starts with the pressure problem. Let's introduce the relevant contents in detail

quality of glue

the veneer of color box should be mounted twice, mostly self-made or purchased corn starch glue. The advantages and disadvantages of corn starch glue are closely related to the production process environment, raw material quality, mixing time, etc. as we all know, it is unnecessary to say

the author only introduces the quality requirements of corn starch, which is one of the main raw materials for glue making, as well as the water ratio of starch glue and the addition of additives for reference: the quality requirements of corn starch, fineness, ash content not exceeding 0.1%, water content 14.0%, acidity 20cc/100g; Sulfur dioxide is 0.004%, the smell is normal, and the color is white or slightly yellowish. If the starch quality does not meet this standard during sizing, the water ratio can be appropriately reduced depending on the quality. When the temperature rises, the water ratio should be reduced accordingly, borax and flake alkali should be increased as appropriate, and the amount of H2O2 should be appropriately reduced. After the cooked glue is made, it should not be put away for a long time, especially in summer. It is best to use it at any time. Adding formaldehyde%, glycerin 0.1% and boric acid 0.1% into the glue liquid can increase the water resistance of the paper, speed up the bonding speed and enhance the hardness of the paperboard. (for reference when making a freezer)

in addition, environmental friendly chemical glue, namely PCA adhesive, can also be used when pasting panels. Its characteristics are that the mounted corrugated board is flat, straight, well bonded and durable. Its production method is (taking 100kg adhesive as an example):

material ratio: polyvinyl alcohol 13.7kg, polyvinyl acetate lotion 2.74kg, oxalic acid 1.37kg, water 82kg (water ratio 1:6)

first heat the water to 90 ° C, and then stop the adjustment of the full range of experimental force. Add polyvinyl alcohol and stir evenly, continue to heat until the water boils, keep warm for 3 hours, then add oxalic acid and stir, and finally add polyvinyl acetate lotion and stir evenly

gluing amount

manual veneering, the gluing amount should not be too large. In actual production, some employees increase the gluing amount artificially in order to avoid degumming, which is not desirable and must be controlled. The gluing amount should be g/m2. However, it is appropriate to adjust the size of the corrugated, control the glue amount, and evenly apply the corrugated peak. As long as there is no degumming, the smaller the glue amount, the better

quality of single-sided paperboard

the quality of single-sided corrugated paperboard is determined by the quality of base paper, corrugated type, the temperature of corrugated machine, the quality of adhesive, the running speed of machine and the technical level of operator

when the matching of base paper is reasonable and the quality can meet the production demand, it is necessary to check whether the corrugating roller ridge peak of the single-sided machine is seriously worn. The normal corrugation type is UV type. After a long time of use, the corrugation peak of the corrugation roll becomes semicircular due to factors such as sand in the paper or the hardness of the corrugation roll itself. Under such a condition, the compressive strength of the produced single-sided paperboard is greatly reduced. In addition, if the pressure roll is pressurized too much, the temperature of the corrugated roll is too high, which is easy to crack the corrugated cardboard on one side. Similar single-sided corrugated board eats more glue when laminating, and its physical properties change, so it is difficult to ensure the compressive strength

under normal conditions of raw materials and equipment, the preheating area of the preheater should be appropriately increased according to the water content of the paper, the temperature of the single machine should be controlled at about 200 ° C, and the pressure of the pressure roller should be adjusted to 0 About 4kPa is appropriate (as long as the tile paper is not cracked and broken, and the lining paper fits well). The vehicle speed is controlled at the medium speed of the equipment design speed, which is low. The viscosity of the adhesive but the deformation is still elastic is adjusted to 30s-35s. If the adhesive precipitates yellowing water and has peculiar smell, it should be updated immediately. The operator should be skilled, have a high heart and good professional ethics, and be able to flexibly adjust the pressure and speed of each roller according to the actual production situation, so as to ensure the quality of single-sided corrugated cardboard

production environment

the temperature of the production environment should not exceed 33 ° C, and the air humidity should not exceed 45%. Otherwise, the cardboard is very easy to absorb moisture, and its own moisture cannot be volatilized, which naturally reduces the bearing pressure of the carton. In addition, the framed box blank is best placed for 4 hours before forming and processing. Because the customer urgently needs to use the blower to aim at the corrugated direction of the box blank to force blowing, so as to promote its bonding as soon as possible and drive away excess water. To sum up, if we want to improve the pressure bearing capacity of the strong combination box of both the parent company and the cooperative company, we must comprehensively analyze and consider it, and strive to reduce all kinds of adverse factors, and we must not lose sight of one or the other

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