Analysis of influencing factors on the pressure re

2022-08-02
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Analysis on the influencing factors of the pressure resistance of corrugated box (II)

▲ 3. the influence of the type of corrugated board

is the same as the influence of the corrugated type of corrugated board. It is also a matter of the number of bearing materials and the thickness of corrugated board. Under the same other conditions, the order of the pressure resistance of the carton is of course: three corrugated> double corrugated> single corrugated

▲ 4. influence of water content of corrugated paperboard

Figure 3 shows the relationship between the pressure resistance of corrugated boxes and their water content found through experiments

Figure 3 moisture content of carton and anti pressure of carton

the relationship between anti pressure of corrugated carton and its moisture content can be expressed by the following formula:

where: P - anti pressure of corrugated carton, N

a - pressure resistance when water content is 0, N

x - moisture content of corrugated box,%

as long as we know the anti pressure of corrugated boxes at a certain moisture content, we can use this relationship to calculate the anti pressure at any moisture content

for example, the anti pressure of a corrugated box is measured to be 2400N. At this time, the moisture content of the corrugated box is 13%. When the moisture content of the corrugated box is 10%, what is the anti pressure

solution: first, calculate the pressure resistance a when the moisture content is 0 according to the known conditions (of course, this is only theoretical data, which can not be achieved in practice): because,

so

a=2400/0.913=2400/0.254=9449 (n)

the compressive force when the moisture content of the corrugated box is 10%:

9449 × 0.910=9449 × 0.349=3298 (n)

from the above calculation, it can be seen that when the moisture content of the corrugated box is reduced from 13% to 10%, its anti pressure can be increased by about 40%. The difference is considerable. This relationship can also be seen from Figure 3. Therefore, when comparing the pressure resistance of corrugated boxes, the moisture content of the boxes must be consistent

II. The influence of corrugated box design on the pressure resistance of corrugated box

▲ 1. the relationship between the box type of corrugated box and the pressure resistance of corrugated box

Figure 4 shows the distribution of compressive stress when the corrugated box is under pressure. When the carton is under stacking pressure, most of the stress is concentrated in the four corners, while the compression stress in the central part of the four sides is much smaller than that in the four corners. Click "read data". It can be inferred that:

① square cartons are more ideal than rectangular cartons. As the side length of the carton increases, its resistance to pressure cannot increase proportionally. The increase in the side length only increases the boundary with less pressure, but this is slightly different from the actual test results (see Figure 6)

② the more carton corners, the greater the pressure resistance. Ordinary slotted cartons are not the most ideal from the stacking point of view. Because they are easy to deform, the most ideal cartons for stacking should be cylindrical cartons. Because it has no creases, and its periphery can bear the same compressive force. But it should not be called a carton, but a paper tube

in addition, even if the paper, corrugated type and carton size of corrugated board are the same, and the carton type is different, the pressure resistance of the carton will be different. The following are the actual tests on the pressure resistance of different box types

① A-line single corrugated board of the same material

② test box type (developed according to FEFCO's gradual elimination of varieties with high quality and safety risks/assco, and ICCA's approval of the international standard for box type used internationally): 0201, 0205, 0512, 0510, 0301 and 0320. Each kind of box has increased 10 safety types in the process of product use; ③ External dimension of test chamber: 335mm × 365mm × 245mm;

④ test conditions: measure after 24h adjustment in the temperature of 20 ℃ and humidity of 65%rh (the following tests are all such test conditions)

⑤ test results: when the anti pressure of the most commonly used type 0201 is 100, the anti pressure of the six box types is shown in Table 6

only the different box types have such a great impact on the pressure resistance of cartons. Therefore, special attention must be paid to the selection of box types of cartons. Of course, when selecting the box type, we should not only consider the pressure resistance, but also consider the characteristics of the contents, the consumption of materials, the convenience of use and other factors. For example, the pressure resistance of 0320 corrugated box is more than twice that of 0201 corrugated box. This is because the former is a nested carton, with a layer of corrugated cardboard on its side and end face. Obviously, its material consumption is much more than the latter

however, it has also accelerated the ongoing integration process of domestic rare earth enterprises. The most commonly used box type is 0201, and the anti pressure discussed or calculated below is based on 0201

(to be continued)

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