Production quality problems and corresponding coun

Low weight corrugated box production quality problems and corresponding countermeasures

low weight corrugated box refers to the corrugated box with the surface and lining paper of the corrugated box below 150g/m2 and the corrugated paper below 127g/m2. Some manufacturers in the more developed areas of China's carton industry have gradually used low weight, high strength base paper to produce low weight corrugated boxes. However, it should be pointed out that there are many factors in the current low quantity corrugated box production for supervision and audit; Such as the problem of uneven quality when the total dosage exceeds 50000 kg

corrugated box has become a world recognized green environmental protection packaging product, and its market demand is increasing. However, due to the lack of forest resources in the world and the protection of 2:4 of the earth's water and soil resources, the cutting of wood required for the production of paper for packaging cartons has been restricted in many countries, and the wood fiber resources have been seriously affected. Although the development direction of papermaking is to replace wood with grass and use renewable resources, there is a big difference between paper and original fiber paper in terms of performance and quality. In the future, resources, whether native or regenerated, will be gradually reduced. Therefore, the use of low weight base paper has gradually become the development direction of the full launch of corrugated boxes and the implementation of aeroengine and gas turbine projects. Due to the rapid development of the paper packaging industry, market competition and other factors, many manufacturers blindly pursue the cost and reduce the quantity of the base paper when using the corrugated box (i.e. the low quantity corrugated box) produced by the low quantity base paper, ignoring the physical performance requirements of the base paper itself and the production technology problems, so that the quality of the existing low quantity corrugated box is uneven and very unstable, especially in the comprehensive strength of the box. Although some enterprises have also taken certain measures to control it, the effect can not meet the requirements of customers. Cause complaints and returns, but bring great losses to the enterprise. In view of this, I will discuss the issues related to low weight corrugated boxes with you

I. main current situation of low weight corrugated boxes

at present, some manufacturers in Guangdong, Fujian, Jiangsu, Zhejiang and Shanghai are gradually using base paper with low weight and high strength to produce low weight corrugated boxes. The so-called low weight corrugated box refers to the corrugated box with the surface and lining paper of the corrugated box below 150g/m2 and the corrugated paper below 127g/m2 (whether this definition is accurate remains to be discussed). At present, some manufacturers in Guangdong and Fujian have reduced the surface and lining paper to below 127g/m2, the lowest is about 0g/M ', and the use of corrugated paper has been reduced to about 90g/m2

however, the low weight corrugated boxes produced by some of its existing manufacturers have relatively common quality defects: generally, the strength of cartons is low. Whether it is the bursting strength, edge compression strength of paperboard, or the compressive strength test of the whole empty carton, its detection value is low. In particular, the use of C-grade corrugated base paper or unglued corrugated base paper is even worse. If it is a three-layer paperboard, it can only be made into an inner box, but cannot meet the requirements of an outer packing carton. The paperboard of some cartons has the phenomenon that the face paper is through the ridge, or shows ribs marks, creases, pockmarks on the inner paper, etc., and the surface flatness is poor. The printing effect, especially the dot or large layout printing, is exposed, dot spread, the layout is blurred, and the level is not clear. In addition, the paperboard is easy to deform and warp, which not only affects the printing effect, but also reduces the compressive strength of the formed carton

second, the reasons for the unstable quality of low weight corrugated boxes and technological measures

the main reason for the problems I mentioned above is that the strength of the cardboard is low, and it fails to meet the due requirements of low weight and high strength. Therefore, I believe that carton manufacturers should scientifically and reasonably design their paper materials according to the performance, weight and stacking requirements of customers' products, rather than blindly and casually using low quantitative base paper for production. In order to produce low weight corrugated boxes, the transformation of the coal-fired furnace of the plastic granulator system should be controlled from the performance and quality requirements of the base paper itself, and research and improvement should be carried out in the production equipment and process technology, so as to ensure the quality of low weight corrugated boxes

(I) factors and technical requirements of the base paper itself

the physical performance of the base paper is the key factor to produce high-quality and low weight corrugated board. To use low weight base paper instead of high weight base paper, we should first consider the bursting index and ring pressure index of the base paper itself, and then consider the quantitative stability, moisture and tensile strength of the base paper. Therefore, the supplier should put forward higher requirements for the physical properties of the base paper and strictly test it. When the paper mill produces low weight base paper, it should also be technically controlled: ensure the accuracy of the equipment and set up the automatic control or computer control system of pulp volume to ensure the stability of the base paper quantity

in addition, the fiber quality of the base paper should be guaranteed to make the paper have high physical properties. Low weight base paper should use better fibers. If it is recycled fiber raw materials, they should be classified and used. Although the cost will be higher, the price of low weight base paper will also be relatively higher. In this way, the basic physical properties and quality of the base paper can be guaranteed, especially the ring compression strength and burst resistance

when it comes to controlling the tightness and sizing of the base paper, of course, the paper mill needs to adjust and improve the equipment, such as the automatic pressure adjustment of the press roll. Due to the low tightness of the base paper, it will affect the physical properties of the paper, such as burst resistance; If the tightness is too high, the paper will become too thin, which is not conducive to the compression resistance of the carton. If the sizing degree is too high, it will affect the bonding strength of the paperboard and make the paper brittle. If it is too low, it will make the paper easy to absorb moisture and become soft, which will affect the strength of the carton, including vertical pressing and flat pressing

(to be continued)