Troubleshooting Heat Seal Issues on Shrink Wrappers
Effective sealing is vital for package integrity. Common sealing faults are:
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Weak Seals (Opening Easily): Caused by insufficient seal temperature, too short sealing time, inadequate sealing pressure, worn/damaged/dirty seal bars (especially silicone strips), faulty/damaged heating elements, or poor film quality. Solution: Increase temperature, extend sealing time, check/adjust sealing cylinder pressure, clean/repair/replace silicone strips, test/replace heating elements, use quality film.
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Burned/Perforated Seals: Results from excessive temperature, overly long sealing time, localized overheating (due to poor element contact or failure), or film with low heat tolerance. Solution: Reduce temperature, shorten sealing time, inspect/replace faulty heating elements, use higher heat-resistant film.
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Misaligned Seals: Caused by product mispositioning before sealing, incorrect pusher stroke, misaligned lower film conveyor, or inaccurate film clamping mechanism position. Solution: Adjust infeed conveyor/product alignment, correct pusher stroke/position, realign lower conveyor, inspect/adjust film clamp position.
Critical Check: Always inspect the condition of the seal bars (silicone strips) and heating elements. Contamination or wear is a frequent cause of seal failure. Ensure consistent pressure across the seal bar.
