Calculation method for compressive strength of corrugated boxes

Two carton compression method

Finding out the corrugated paper box structural process and the law of the compressive strength of the carton has always been one of the important topics that the majority of colleagues in the corrugated industry are striving to study. Corrugated packaging has a long history in Europe and the United States, and foreign counterparts have made achievements in the study of compressive strength, and summarized some empirical formulas for calculating compressive strength. Among the more popular ones are:

â–  Calculate the KOK ellicutt of the carton compressive strength based on the ring pressure strength of the corrugated paperboard base paper,

â–  The Maltenfoit formula for calculating the compressive strength based on the transverse Corcan's flat compressive strength of the inner and outer sheets of corrugated cardboard:

â–  The Wolff formula (Wolf) for calculating the compressive strength of corrugated boxes by taking the side pressure strength and thickness of corrugated cardboard as the parameters of corrugated cardboard, and taking the box perimeter, aspect ratio and height as the factors of the sign structure:

â–  Make the side pressure strength and stiffness of the cardboard as the main factors influencing the strength of the corrugated box, and consider the pressure resistance of the carton as the square root of the circumference of the carton. Ma Ke formula: (Makee).

Among them, the Kerry Carter formula is most respected by domestic counterparts, and most articles published in domestic professional magazines on carton pressure resistance use it as an inferential formula. However, it has been proved through practice that the accuracy of the carton compressive strength calculated by the Carey Carter formula is low, and the calculation method is relatively complex and difficult to grasp.

Through a large amount of data analysis, the author summarized a set of methods to accurately calculate the compressive strength. The accuracy of the practice test can reach more than 90%. The method mainly calculates the initial value of the carton compressive strength based on the compressive formula, and combines the carton structural process to correct the formula and calculate the final result.

1. Carton compressive strength calculation process

To accurately calculate the compressive strength of a carton, first the circumference of the carton, the thickness of the carton, and the edge pressure of the carton must be measured, and the estimated value should be corrected in conjunction with the carton structure process. The side pressure strength can be calculated based on the lateral ring pressure strength of the base paper of each layer of corrugated cardboard and the paperboard pit type. For factories without test equipment, as long as you know the ring paper strength or the ring pressure index of the base paper, you can calculate the compressive strength of the carton. It must be pointed out that the ring pressure value of the base paper must be objective and true, and the ring pressure strength of the base paper should be a test value under a temperature and humidity environment of 23°C±1°C, 52% 2%RH.

Carton compressive strength calculation process shown in Figure 6.

2. Formula for calculating the compressive strength of carton

Through a large number of test data verifications, we find that the following formulas are inferred to be closer to the actual values, and the calculations are simple and easy to master. Recommend to everyone here:

For example:

One size is 360mm X 32 5mm X195mm ordinary slotted carton, the pit shape is C pit, the cardboard thickness is 3.6mm, the side pressure strength is 4270N/m, try to calculate the pressure value of the whole box.

answer:

It can be seen that the carton perimeter is 1.37m, the cardboard thickness knife is 3.6mm, and the side pressure strength is 4270 N/m.

According to the formula:



(to be continued)