IMPORTANT PARAMETERS FOR PAPER & PAPERBOARD
- Bursting Strength - the maximum hydrostatic pressure required to ruptre the sample by constantly increasing the pressure applied through a rubber diaphragm on 1.20 inch diameter sample.
- Ply Bond - the interlayer strength of the paperboard, measured on Scott Bond Tester, expressed in J/m2.
- Tensile Strength - the tensile force required to produce a rupture in a strip of paperboard, measured in MD & CD, expressed in kN/m.
- Elongation - the tensile strain developed in a test sample at maximum tensile strength before rupture, measured as the % increase in the length of the sample to the original length.
- Tearing Resistance - the force required to tear a paperboard, measured in both MD & CD, expressed in mN (millinewtons).
- Surface Strength (Wax Pick) - a measure of the surface strength of the sample or surface resistance to picking. Pick occurs due to blisters or coating substance adhering to graded wax sticks. This test is valid only for uncoated board or paper. For coated stock IGT pick test is applicable.
- Roughness (PPS) - this is a measure of surface roughness (hills and valleys) expressed in microns. This is an important measure of coated board surface evenness/smoothness. Lower the value in microns better the coated surface smoothness.
- Smoothness (BENDSTEN) - this is a measure of ml of air escaping per minute through the hills and valleys of the surface of paperboard. Higher the value, rougher the surface. This is normally done for all uncoated paper and boards. This is considered a better measure to predict flexographic printability.
- Print Quality - the degree to which the appearance and other properties of a print approach a desired result. Many paper and board parameters like caliper, roughness, gloss, ink absorption, whiteness and brightness affect this.