Complex shaped packaging
How to properly apply a shrink sleeve
Right from the start, it is important to keep in mind that the shrink sleeve packaging is 3D and not a flat label. Be careful to design in three-dimensions or the graphics will not overlap once the shrink sleeve is applied and be even more careful if you are sleevering a complexly shaped bottle.
Before starting with any project you need to define:
the kind of application: full body sleeve or partial sleeve?
the material of the container: glass? metal? HDPE? PET?
the state of the container: full or empty?
the colors of the graphics: keep in mind that dark colors absorb more heat and make the film shrink differently
It is safer to place barcodes in low shrink areas and better if vertically oriented; the horizontal shrinkage ratio is the higher and barcodes could be affected by distortion.
The application of the shrink sleeve must be consistent or the products will be a different one to another, showing a displacement of the front/back sides of the sleeve on the container.
For achieving the best results is important to choose a film with sufficient shrink capability or it won’t fit perfectly in the high shrink areas. Films with high shrinkage ratio are best for complexly shaped containers because they fit in the right way, adhering to the curves and the changes of width.
Let’s see some examples:
PDC International achieved to sleeve a very difficult shaped container and explains how they get this result:
“PDC turned this “difficult” shrink into a true (POM) wonderful solution by solving two major issues. To expel trapped air in the bottle’s midsection, vents were made by a PDC R-300 Shrink labeler, allowing air to escape and producing a tight, wrinkle-free shrink. The neck and crown of POM’s bottle is tiny in comparison to its body, and the smaller section required more heat to shrink than the larger portion. So, PDC used two identical adjustable steam tunnels, Model KST 80-712, and three temperature controllers.
Two controllers were place in manual (fixed percentage) mode; the third was set in automatic mode, and automatically adjusts, in real time, to the thermal load of the incoming product.”