Paper Grades and Board Types a Buyer Chooses Between
Matching substrate furnish and bulk to press stress secures structural integrity, optimizes print quality, and minimizes total landed packaging cost.
Mullen Burst Strength
Hydraulic Resistance
Hydrostatic test pressure defines mullen burst strength through the measurement of hydraulic force applied against a clamped circular diaphragm until the test piece ruptures. Paper mills and converter plants monitor this hydraulic threshold to verify that corrugated container board withstands stacking loads and internal shipping pressures during transit. Maximum pressure resistance ceases to govern once the packaging substrate suffers moisture ingress or mechanical scoring along conversion lines.
Resistance Standard
Diaphragm clamping pressure dictates the recorded peak because slippage falsifies the final breaking point during laboratory evaluations. Container board manufacturers rely on hydraulic rupture values to separate low grade recycled content from virgin kraft liners before corrugated assembly begins. Testing machines apply fluid continuously underneath a rubber membrane until sample failure occurs under uniform stress.
Converting facilities adjust refining parameters during pulp preparation when preliminary trials show falling resistance numbers across successive production batches.
Rupture Tolerance
Packaging converters demand strict repeatability from base stock because sudden drops in strength cause box failure on high speed automated filling lines. Print runs involving heavy solid bleached board require consistent internal bonding to prevent delamination during rotary die cutting operations. Fibre orientation determines lateral tear resistance differently from uniform multi directional pressure applied by fluid expansion.
Mill verification procedures guarantee that finished corrugated packaging meets structural integrity limits specified by shipping regulations without adding unnecessary basis weight.