Analytical Dockside Laboratory Verification Protocols for Paper Substrate Modifications
Dockside testing screens moisture, barrier integrity, and mechanical strength to verify paper substrate modifications before cargo clears port custody.
Scott Plybond Delamination
Internal Strength
Dynamic energy measurement quantifies the resistance of a paper or board to internal splitting between its constituent fibres. This test is widely known as scott plybond delamination and uses a swinging pendulum to strike a metal angle glued to the sample. It measures the energy lost as the paper is torn apart in the thickness direction.
The results are expressed in joules per square metre.
Mechanical Impact
High values indicate that the fibres are well bonded and will resist the stresses of high-speed printing or folding. During the offset printing process, the tack of the ink can pull the surface of the paper away if the internal strength is too low. This type of failure leads to machine downtime and wasted material.
The test is particularly important for multi-ply boards where the layers might not be perfectly joined at the wet end of the paper machine.
Structural Limit
Preparation of the sample involves using a specific double-sided tape and a standardized amount of pressure to ensure the bond to the metal is stronger than the paper itself. Any variation in the tape or the pressing time can cause inconsistent results. The test stops being useful if the adhesive on the tape fails before the paper does.
Regular calibration of the pendulum ensures that the energy reading remains accurate over time.