Common Shrink Label Problems and Solutions

The hallmarks of a bad shrinking job are easy to spot: wrinkling, rising, dimpling, tearing and uneven shrinking. These problems drive packagers nuts and can put off potential customers. Read on to discover possible causes and solutions to the most common problems facing packagers working with shrink labels. 

Problem

Wrinkled or Pocked Appearance

Possible Cause

• Uneven or inadequate heat application
• Uneven material shrinking due to type of plastic
• Uneven shrinking due to decorative inks, coatings, embossing, or finishes on shrink labels

Possible Solution

• Increase the tunnel temperature or airflow to increase the degree of shrink
• More complex issues require a custom designed solution to optimize the application of heat to the part

Rising

• Tapered bottle design
• Too much heat at the top of the bottle

• Tack label at a lock-point on bottle before entering shrink tunnel

Uneven Shrinking

• Uneven or inefficient application of heat
• Uneven material shrinking due to type of plastic
• Decorative inks, coatings, embossing, or finishes on shrink labels
• Complex bottle shape

• Adjust airflow up or down to get a more uniform application of heat
• Adjust the tunnel temperature up or down to optimize the shrink
• More complex issues require a custom designed solution to optimize the application of heat to the part

Tearing or Over-Shrinking

• Extreme cross-sectional changes in bottle shape
• Temperature too high
• Exposed to heat for too long

• Lower temperature
• Shorten time spent in shrink tunnel
• Customize the heat profile so that edges or corners of the container are exposed to less heat

Still having problems? Give us a call. We’re experts at building heat shrink systems and finding solutions to difficult applications.

Recommended Further Reading:

• Heat Shrink Tunnels Explained:
  • Part One: Types of Heat Tunnels
  • Part Two: Advantages and Disadvantages
  • Part Three: Technical Complications of Heat Shrinking
• The Effect of Bottle Shape on Shrink Quality
• ​Temperature and Time: Your Formula for Perfect Shrink Labels

​Originally published: 03/17/2014