A Tech Bite from Greener Technical Service Specialist Jeff Fouche
Problems with the forming process on flow wrappers have a big impact on package appearance and seal quality. This Greener Tech Bite explains how to adjust the tension on your flexible packaging material as it moves through the forming process to produce tightly wrapped, well sealed packages that are free from stretch marks and wrinkles.
Adjusting Flexible Packaging Material Tension
This tension can be adjusted by changing the position of the final, “dance” roller, which controls the angle at which the material enters the forming box. The rollers that come before the dance roller are also important and should not be bypassed—they help prevent the tension from fluctuating during production.
A lower angle creates less tension on the material and tightens the wrap. Higher angles create more tension and loosen the wrap.
Inspect the quality of your packages to determine if you have too much or not enough tension.
Not Enough Tension
Problems with tracking, uneven fin seals, and end seal wrinkles occur when there is not enough tension on the packaging material as it moves through the forming process,
Raise the dance roller to increase the angle of entry and the tension on the packaging material until these symptoms dissipate.
Too Much Tension
Too much tension causes loosely wrapped packages, stretch marks or wrinkles in the fin seal, and narrow, undersized fin seals that pull out of the fin wheels and require downtime for the material to be rethreaded.
When these symptoms occur, lower the dance roller to decrease the angle of entry and the tension.
Optimal Tension Level
The optimal tension level on the material as it moves through the forming process depends on your product, forming box design, and the structure of your flexible packaging material.
A new material may have a different thickness, stiffness, or other characteristics that alter its performance.
Structures with more stretch require the angle of entry to be reduced, to decrease tension.
Materials with less stretch often need a higher angle that increases tension.
When conditions change, evaluate trial packages and adjust the dance roller as needed.
If you’d like recommendations for improving the package formation process on your flow wrappers, send us sample packages or photos.
Greener Corporation provides integrated parts and technical service solutions worldwide.
