Corrugated carton compressive strength of the paper configuration method article two

Third, the safety factor design method

In addition to the weight of the stacking, the impact of the carton in the circulation process is also affected by factors such as stacking time, temperature and humidity, moisture and vibration of the contents, and impact on the impact of these factors. These factors can cause the compressive strength of the carton to decrease. Therefore, a safety factor must be set to ensure that the carton, under the influence of various factors, still has enough capacity to withstand the weight of the carton stacked on it after the compressive strength is reduced.

In general, the contents can withstand a certain degree of pressure resistance, and the internal safety factor is set to about 3 to 5 when the content is a domestic product with a relatively short transit flow. If the contents themselves emit water, or if the contents are fragile items, the safety factor is set to 5 to 8 when the stacking time is long, circulation is large, or the storage conditions are in poor circulation.

The safety factor can be calculated according to a certain method on the premise that various factors leading to the reduction of the compressive strength are determined.

Comprehensive example

There is a carton. The total weight of the carton is 18kg. The maximum stacking layer of the carton is 5 layers. The carton is printed in a single color. There is a handle on both sides. It is shipped to the United States through the containership. The pit type is BC. The pit is 415cm x 124cm x 230cm in size. Please design it in paper configuration.

answer:

The first step: set the safety factor

Because it is through the container exit, the set temperature and humidity changes cause the carton pressure reduction rate to be 60%, the reduction rate caused by the set piling time is 30%, and the reduction rate caused by the stacking method is 20%; the loading and unloading conditions are not specified , Set the reduction rate caused by the loading and unloading process to 20%.

The safety factor

Step 2: Calculate compressive strength

According to the compression design formula P = G x (n - 1) x K

The compressive value of the carton should be P=18 x (5-1) x 5.6

=403kg (3955N)

The third step: correcting the compressive strength according to the printing process

Because the cartons are printed in monochrome, and each side of the cartons is used as a pull-in handle, the calculated compressive strength needs to be corrected in advance to compensate for the damage caused by the pressure-reducing process. according to

3955 X (1 10 26%) = 4983N

Step 4: Push back the cardboard side pressure strength according to the formula for calculating the compressive strength

According to the size, the circumference is 1.078m. According to the pit type, the thickness of the board is 0.0065m. It is known that the pressure resistance of the carton is 3559N.

It is then substituted into the carton pressure-reduction formula:

The paperboard configuration must reach 10,135 N/m edge pressure to meet the requirements of the carton.

Step 5: Finalize a Reasonable Paper Configuration

According to the side pressure strength formula, the cardboard type, and the lateral ring pressure strength parameters of the factory base paper determine the most reasonable paper configuration, which is not listed here.