Crease and stiffness testers are useful to test carton board, paper, printing and packaging materials. These are important measures to have correct and uniform quality. The board stiffness and crease recovery is critical in the performance of cartons. Especially on high speed packaging machines. And when manually folding. The value of crease stiffness is technically important in the folding of carton blanks. Most importantly during their release and closure.
The crease recovery (spring back) can result in forces, which distort the erected carton or cause stresses to closures. Thereby, reduce their effectiveness.
Crease recovery is the decrease in resistance by creased board after it is folded 90°. This is at the crease measuring the recovery force after 15 secs. Bending a 50mm length of board through a 15° angle determines board Stifness
The Crease and Stiffness testers optionally can test round corner creases. This is using easily changeable Round Corner Jaw.