1. Edge pressure strength: along the corrugated direction, the maximum force that the corrugated cardboard can withstand per unit length before pressure feeding. Unit: N/m.
Edge compressive strength = surface base paper comprehensive ring compressive strength + comprehensive corrugated paper ring compressive strength * shrinkage rate
The general edge pressure calculation is based on the lowest ring pressure strength of the base paper (safe and reliable), and the actual test value will be appropriately greater than the theoretical calculation value.
2. Bursting strength: the maximum external force that can withstand a uniform increase in a unit area of corrugated cardboard before rupture. Unit: Kg/cm2.
paperboard breaking strength = surface paper breaking strength + medium grid paper breaking strength + bottom paper breaking strength
*Due to a certain strength loss during the manufacturing process, the actual rupture strength tested will be less than the calculated value by about 1 Kg/cm2.
3. Piercing strength: The new national standard GB6544-1999 has cancelled the requirement for cardboard piercing strength. (The original standard GB6544-1986)
Strength requirements for corrugated boxes:
1. Side pressure, burst resistance and piercing are the same as cardboard. The carton edge compressive strength will be lower than the cardboard edge compressive strength (due to the corrugation loss during the manufacturing process).
2. Carton compressive strength: (ordinary box type, corresponding to international box type code: 0201)
Compressive strength = Edge compressive strength (N/cm)*Kerry Carter constant F
F value depends on the carton’s peripheral length, 2*(length + width) cm. and corrugated type. After the two items are determined, the F value can be checked in the table. The actual compressive strength test value is related to the ratio of carton length, width, and height. Carton boxes with the same length and same material: the higher the height, the smaller the compression resistance; the larger the length * width of the bottom area, the greater the compression resistance.
3. Compressive strength of the machine package box = Compressive strength of the corresponding ordinary box type * 0.6 * 1.62 * swing cover width / carton width.
4. Adhesive strength of carton and cardboard (the peel strength of corrugated molding instead of the adhesive strength of the box glued to the tongue). The force required to separate the cardboard and corrugated paper per unit length. Unit: N/m flute. The industry standard uniformly stipulates that it is greater than 588 N/m.
5. Stacking strength and compressive strength.
The required compressive strength of the carton = [carton gross weight * (stacking layer number -1)] * safety factor K. The front part is the static stacking strength of the cartons. The K value depends on the number of printing plates, the degree of opening, the nature of the inner packaging, the degree of preciousness, storage and transportation time, conditions, etc. The K value is generally 2-5.