Precision Sealing: Resolving Leakage Issues in Liquid Packaging

Leakage is the most common complaint on liquid packaging lines — and almost always preventable. At Link Machinery, precision sealing starts with understanding the three variables that control every seal: temperature, pressure and dwell time. On any liquid packing machine, sealing consistency determines product quality.

Why Liquid Pouches Leak

Liquid products put stress on seals from the inside: product splashes the seal area during filling, and internal pressure builds during handling. Common causes of leakage include contaminated seal zones, low sealing temperature, misaligned jaws, and film with poor sealant layers.

Link's Precision Sealing System

• Accurate temperature control: servo-stabilized heating keeps jaw temperature within a narrow band, avoiding weak or burnt seals
• Balanced jaw pressure: pneumatic pressure set per film grade, applied evenly across the full seal width
• Dwell time control: sealing time synchronized with line speed for consistent seal strength
• Anti-drip dosing: clean nozzle cut-off keeps the seal zone free of liquid residue
• Sanitary jaw design: easy-cleaning jaws with non-stick coating reduce contamination build-up

Practical Fixes for Leaking Seals

1. Raise temperature step by step. Increase by 5–10°C and run a leak test; stop at the lowest setting that seals reliably.

2. Check jaw alignment daily. Misaligned jaws cause weak or partial seals — inspect and adjust before every shift.

3. Verify film quality. The sealant layer must match your product and machine settings; test new film lots before production.

4. Keep the seal zone dry. Install anti-drip nozzles and check the dosing cut-off regularly.

Proven Results

On honey, sauce and juice pouch lines, Link machines hold seal integrity through pressure tests and long-distance shipping, with leakage rates reduced to near zero when the above parameters are applied.

Contact the Link Machinery team for a sealing parameter sheet matched to your film and product.