Problem 1: Wrinkled or Poked appearance
Root cause:
- Uneven heat or adequate heat.
- Uneven material shrinkage due to type of plastic, decorative inks, coating, embossing or finishes on shrink labels.
Solutions:
- Increase the tunnel temperature or airflow to increase the degree of shrink.
- More complex issues require a custom designed solution to optimized the application of heat to the part.
Problem 2: Rising
Root cause:
- Tapered bottle design.
- Too much heat at the top of the bottle.
Solutions:
- Tack label at the lock point of the bottle before entering the shrink tunnel.
- Adjust the heat flow from top area.
Problem 3: Uneven shrinking
Root cause:
- Uneven or inefficient application of heat.
- Uneven material shrinkage due to type of plastic, decorative ink, coating and complex bottle shape.
Solutions:
- Adjust the heat flow up or down to get a more uniform application of heat.
- Adjust the tunnel temperature according to type of shrink.
Problem 4: Over shrinking (cow feet shape or tear the material)
Root cause:
- Give the heat for long time.
- emperature is more according to material.
- More complex shape bottle design.
Problem 5: Splitting seals
Root cause:
- Bad seals are probably common in shrink wrap.
- Sometimes it is less sealed or open.
Solutions:
- Use proper glue to seal the shrink sleeve according to material.
- Sometimes it is unevenness of shrink material.
- Sometimes it is without perforation or pin holes.
Problem 6: Hair type
Root cause:
- It is due to uneven cutting of shrink sleeve.
Solutions:
- Make sure cutter is ok or cutting speed is uneven.
- Film is not uneven in thickness.
Problem 7: Ballooning type
Root cause:
- Shrink film exposed to hot air after sealing.
- Complex shape of container.
Solutions:
- Pin hole is used or perforation is used
Problem 8: Picasso effect type
Root cause:
- Unevenness of shrinking
- More distortion of film.
Solutions:
- Check distortion of design first and conveyor speed also.
- Check shelf life of shrink film, each shrink film has its own life for use.
- Check if chain temperature is too high.