Edge crush resistance

The edge crush resistance ( ECT value - Edge Crush Test ) provides information about the maximum force with which a corrugated cardboard sample with a defined length and height (100 mm × 25 mm) was stressed. The edge crush resistance , expressed in kilonewtons per meter (kN / m), is calculated by the equation:, where the mean value is the maximum force and is given in newtons. DIN EN ISO 3037, Feb 1996 regulates more precisely. ${\displaystyle R}$ ${\displaystyle R}$ ${\displaystyle R=0{,}01\cdot {\overline {F}}_{\mathrm {max} }}$ ${\displaystyle {\overline {F}}_{\mathrm {max} }}$

The ECT value can be used to approximate the stacking compressibility of a cardboard box ( BCT value ). The McKee formula is the simplest for calculating the BCT value, but it is also the least precise. The height to girth ratio must be greater than 1: 7; even then, there are still many reservations.

McKee formula: BCT = 5.876 × ECT (kN / m) × root of [box circumference (mm) × corrugated cardboard thickness (mm)]

${\displaystyle {\color {Blue}BCT}=5{,}876\cdot {\color {Red}ECT}\cdot {\sqrt {U\cdot d}}}$

If you use the circumference in cm instead of mm , the shape is the result ${\displaystyle 5{,}876\cdot {\sqrt {0{,}1}}=1{,}86}$

BCT = 1.86 × ECT × root of [box circumference (cm) × corrugated cardboard thickness (mm)].

${\displaystyle {\color {Blue}BCT}=1{,}86\cdot {\color {Red}ECT}\cdot {\sqrt {U\cdot d}}}$