Packages rarely stand alone. They are most often bundled together into palletized unit loads, which means the packages will be stacked atop and alongside each other. Friction testing determines the rate at which the packaging materials (most often corrugated board making up boxes) will slide against each other – either causing movement and slippage within the unit load or damaging the packaging material or even possibly causing damage to the products themselves.
Friction testing, also called a coefficient-of-friction (COF) testing, takes any sheet-like substrate (paper, corrugated, plastic film, paperboard, etc…) and determines the angle of inclination at which one sheet affixed to a sled will begin to slide/slip against the surface of another sheet of a similar material.
This package test basically determines how the packaging material will perform in various critical applications – such as measuring slippage amounts in unit loads which would compromise unit load stability.
Package testing and packaging materials testing are important parts of the research and development process. Package evaluation through packaging tests help to ensure that all corrugated board products and new package designs are created specifically to handle real-world situations.
This method determines the coefficient of static friction of most packaging materials by measuring the angle at which one test surface begins to slide against another inclined surface as the incline is increased at a constant and prescribed rate. The test is frequently referred to as slide angle. The coefficient of friction is numerically equivalent to the tangent of that angle.