Why 300mm/min Matters for Heat Seals (ChP 4008)
Why random test speeds invalidate your seal strength data. A deep dive into ChP 4008 and ASTM F88 speed requirements.
The Speed Variable
In peel testing, speed changes the result. A seal tested at 100mm/min yields different force values than one tested at 500mm/min.
• The Standard: ChP 2025 General Chapter 4008 explicitly mandates a test speed of 300mm/min ± 30mm/min for heat seal strength.
• The Mistake: Many labs use the default 100mm/min setting of their old testers. This generates "False Passes" or "False Failures" because the viscoelastic behavior of the polymer changes with strain rate.
The KHT Advantage
The KHT XLW Series comes pre-programmed with the "ChP 4008 Standard Mode".
• One-Click Setup: Select "Heat Seal" from the menu, and the machine automatically locks the speed to 300mm/min.
• Result Calculation: It automatically calculates the mean force in N/15mm, saving your technicians from manual conversions and calculation errors.
