Virgin SBS against White Lined Chipboard for Retail Facings
Virgin SBS provides superior print brightness, stiffness consistency, and crack-free scoring, whereas recycled board lowers initial cost but adds waste.
Scott Bond Impact Test
Dynamic Delamination
The energy required to split a paperboard specimen internally under a rapid, dynamic shearing force measures the strength of the fiber-to-fiber bonds within the sheet. The procedure known as the scott bond impact test uses a swinging pendulum to strike a specimen held between double-sided adhesive tape and a metal angle. It measures the energy absorbed during the split in joules per square metre.
This method does not evaluate static tensile forces or surface pick resistance, which are measured by different tests. Instead, it simulates the fast, mechanical stresses of modern converters.
Impact Resistance
High-speed offset presses and folding machines apply sudden forces to the board. If the internal bond is too low, the sheet will delaminate during printing or folding, causing process halts. Performing a scott bond impact test allows mills to verify that the internal plies are well bonded.
This is especially important for multi-ply board grades.
Strength Balance
Internal starch addition and refining can raise the bond strength. Mills use the results of the scott bond impact test to adjust the chemical doses on the paper machine. They must balance this bond strength with the bulk of the board, because high bonding often reduces thickness.
This balance is critical for folding carton performance.