(1) Define the Seal Window
Set the sealing range where peel stays smooth and hermetic integrity is maintained. Typical starting points:
· PET-based lidding: 110–130 °C (flat-jaw), pressure 0.2–0.4 MPa, dwell 0.4–0.8 s
· PP-compatible: 120–140 °C, adjust dwell slightly higher
Record the lowest temp that seals hermetically (Tmin) and the highest that still peels cleanly (Tmax). Your seal window = Tmin~Tmax.
(2) Choose Target Tear Force
Expressed as N/15 mm. Practical bands:
· Dairy/RTD: 4–6 N/15 mm (gentle, consumer friendly)
· Snacks/Bakery: 6–9 N/15 mm (balance integrity/peel)
· Industrial/food service: 8–12 N/15 mm (robust seal)
Measure with a tensile tester; test after aging (24–48 h) and across storage temps.
(3) Control the Variables
· Tray rim flatness & film tension (avoid micro-channels)
· Surface energy/treatment level for print/lamination
· Jaw type (flat vs serrated) & coating cleanliness
· Environment: oil, condensing moisture, or powder contamination
(4) Validate on Line
Run a short matrix trial: temps × dwell times × pressures. Capture peel curves and failure modes (adhesive/cohesive).
(5) When to Use Add-Ons
· Anti-fog for chilled displays
· Tamper evidence (patterned peel)
· Print-ready primers for brand work
