With the acceleration of industrialization, more and more commodities need to be effectively protected. Compared with other packaging materials, corrugated boxes have their own advantages: low cost, easy to recycle, small size before forming, and high strength, which are deeply loved by customers.
Effective protection of the contents is the significance of corrugated boxes, and it is particularly important to increase the degree of attention to the reliability of the boxes. In other words, it is whether the box can well complete the functions of stacking, warehousing, circulation and other links during its entire life. Whether a box can be given these excellent reliability, and the structure design and cost are reasonable is affected by many factors.
Next, I will talk about some of the more important influencing factors I think.
The influence of base paper on the reliability of corrugated boxes
Starting from the base paper manufacturer, it has already had an impact on the compressive performance of the carton. Corrugated base paper is the basic material for carton production, and the quality of the base paper is directly related to the quality of the final box. To produce cartons with qualified compressive strength and effectively ensure the reliability of cartons, we must first control the quality of the original paper.
Ring crush strength is an important index to measure the performance of base paper. Cut it into a 152.4mmX12.7mm sample along the transverse direction of the base paper, and perform a pressure test on a press. The maximum force that the base paper bears within the deformation range is the ring compression strength.
Generally speaking, paper with good ring compressive strength has good paper fiber toughness and high strength, and the compressive performance of the made carton is relatively good; on the contrary, the ring compressive strength of the paper is too low, and the compressive strength of the carton varies with The deterioration.
The influence of moisture content on the reliability of cartons
Moisture content is also an important indicator that affects the performance of cardboard. If the paper fiber used is loose and porous, it can easily absorb the moisture in the air, and the increase of the moisture content will greatly reduce the compressive strength of the carton, produce deformation, and cause collapse during transportation and stacking. Choosing high-quality fiber and tightly arranged base paper can effectively solve the problem of paper water absorption. At the same time, the waterproof work of the carton should also be done well. A good waterproof treatment is very necessary for the storage and transportation of high-humidity goods in a high-humidity environment.
The new version of the national standard “Corrugated Board” GB/T6544-2008 stipulates that the moisture content of the cardboard should not be greater than 14%, which is an upper limit of the moisture content of the cardboard. Too much water in the cardboard will affect its normal use. But it is worth mentioning that the national standard here does not give a specific lower limit value. In fact, the moisture content of the cardboard is too low and does not conform to the actual production situation. In daily work, it is found that the moisture content of the cardboard is generally above 7%, which is more suitable for processing and production. It can be seen that too high or too low moisture content of paperboard is undesirable, and it is very necessary to keep it at an appropriate level.
The Influence of Corrugated Board Glue Amount and Its Proportion on the Reliability of Carton
Corrugated cardboard manufacturers, in the corrugated cardboard processing process, sizing is a relatively important link. The control of the amount of glue directly affects the quality of corrugated board. Excessive amount of glue will cause the corrugated cardboard to appear perforated, wrinkled, and excessive moisture content, which will affect the physical properties of the cardboard, and will cause many problems in the processing process, which will bury hidden dangers to the quality of the final box; If the amount is too small, the corrugated cardboard layer will not be firmly bonded to each other, and the glue will break, which will also have a great impact on processing and box formation.
An important index to measure the compression resistance of cardboard is: edge compression strength.
The measurement of edge compression strength is to cut the corrugated cardboard according to the sample (sample size: 100mmX25mm) as shown in the figure, and press it with a press. When crushing, the instrument reads the maximum pressure value of the cardboard, which is the edge compression strength. . If you encounter the above-mentioned cardboard opening and other conditions, the corrugated paper will separate, and the compression resistance of the cardboard will be weakened, which will eventually be less than the expected compression effect. Therefore, the adhesive strength of corrugated cardboard must be strictly checked.
In addition, the ratio of cardboard is also a key factor. The use of corrugated cardboard with qualified strength in the production of corrugated boxes, and reasonable matching is the basic condition to ensure the compressive strength of the cardboard boxes. Nowadays, the production situation of cardboard is developing in the direction of high strength and low weight. It is necessary to reduce the production cost of the base paper, but also to improve its own performance. Through the adjustment of market supply and demand, the types of cardboard and corrugated base paper in quantitative terms should be enriched. Base papers with similar strength and weight should be used as much as possible to match, so that the role of each layer of paper can be fully utilized. At the same time, the stability of corrugated cardboard is enhanced. [next]
The influence of design on carton reliability
While paying attention to the physical properties of raw materials, it is often easy to overlook the impact of carton design on its reliability. First of all, the designer should have a certain understanding of the contents, such as: dimensions, geometric center, vulnerable parts, etc., and then deploy a reasonable box shape to establish a good stacking arrangement; secondly, the contents of the package Carry out preliminary packaging design, evaluate the design through actual assessment or simulation test; finally complete a packaging design task.
Here we focus on the impact of printing and opening on the box. Of course, it is better to make the box simpler and more practical. However, in most cases, it is difficult to avoid these processing techniques.
1. The influence of printing design on the cabinet
As the surface of the transport packaging box, the larger the printing area, the greater the decrease in strength, and the influence of the end face is greater than that of the side face.
Let’s take a look at the change in the strength of the box after printing.
(1) As shown in Figure 3, when the box surface is fully printed, the compression resistance of the empty box will drop by about 40%.
(2) Printing in the middle of the box as shown in Figure 4, the compression resistance will drop by about 37%.
(3) As shown in Fig. 5 and Fig. 6, the compressive strength will drop by about 5% and 30% when printing in the conditions shown.
Therefore, it is recommended: If it is used as a promotion, it is better to print the promotion function on a relatively independent small package. The smaller the printing area and the simpler the pattern, the better. If necessary, there should be an obvious logo.
2. The influence of slotting design on the box
Since the opening can be regarded as a damage to the carton, for this reason: the larger the opening, the lower the strength; the closer to the corners, the lower the strength; the closer to the centerline, the smaller the strength drop; the closer to the center point, the lower the strength The smaller the drop; the less the cut corrugation, the smaller the strength drop; the scattered openings are used as much as possible, which will be better than the concentrated openings.
Following this principle will help improve the compressive performance of the carton. At the same time, some methods can be used to compensate, such as: reasonable design of the size, shape and position of the opening; sticking reinforcing ribs at or near the opening; adding partitions and gaskets inside the box.
Finally, the overall performance of the box can be assessed through the empty box compression test. The test method is shown in Figure 7: Put the folded empty box (sealed with tape at the lap of the box cover) on the press for a pressure test. When it is crushed within a certain deformation range, the instrument reads that the box can withstand The maximum pressure value is the pressure resistance value of the empty box under no-load static pressure. If the performance of the corrugated board is poor due to improper links in some links, it is more likely that the box shape variable will continue to increase during the compression test, resulting in the final effective force value being too low, and the box body will be crushed and deformed after the test. Use performance.
It should be pointed out here that the above-mentioned test is carried out under static conditions and is not applicable to the actual situation of the package in the circulation process.
In order to meet the transportation needs, the compressive value of the empty box measured under static load conditions is often multiplied by a value, which is the safety factor K (K>1). The calculation of the K value should be through the evaluation of the temperature and humidity environment, stacking time, stacking method, loading and unloading circulation method, etc. or the printing process, carton length, width and height dimensions and ratio, carton opening method and position, die cutting process, etc. Calculated from the evaluation.
The selection of the safety factor is mainly affected by three aspects: one is the storage and transportation conditions, corresponding to different safety factors for roads, railways, mountain roads, waterways, etc.; the second is the structure of the packaging box, such as whether there are linings or hard pads in the carton Blocks, etc.; the third is the preciousness of the packaged objects. Considering all factors, select the most suitable safety factor.
When buying a carton, you should choose a packing box with appropriate strength for the product to be packaged. If the selected strength is too strong, it will increase the customer’s packaging cost and cause unnecessary expenses; if the strength is too low, it will not provide corresponding protection for the packaged product.
Ensuring the reliability of the carton means ensuring that it completes the task in its own life. Through effective control of the above factors and regular inspections, the reliability of cartons can be ensured, the storage and transportation of goods will be safer, the loss will be reduced, and the value of the boxes will be improved.