Why can the same packaging film seal differently on different machines?

• Different heat-seal temperature, pressure and dwell time settings directly change seal strength.
• Heat-seal jaw material and coating alter heat transfer rate and sticking tendency.
• Film tension and pull speed differ, affecting stretch and cooling in the seal zone.
• Cooling roller or air-cooling efficiency changes seal crystallization and peel strength.
• Run a heat-seal curve test on each machine to lock optimal temperature, pressure and time.