fly-off during waste stripping and rewinding.

Die cutting is an essential step in self-adhesive label production — and one that label printers' technical teams most often overlook. Die-cutting quality directly affects the customer experience, and label fly-off during die cutting is a perennial headache for label printing companies. So what exactly causes it?

08 Rebound sponge used incorrectly

Mounting rebound sponge on the die plate at the label positions presses labels down as the blade retracts, preventing pre-release; leave the waste-margin areas without sponge, so the matrix pre-releases and strips off the liner more easily. Used correctly, rebound sponge smooths die-cutting and stripping and greatly cuts the odds of small-labelfly-off. Flatbed die plates should be fitted with medium-hardness rebound sponge.

09 Ambient temperature too low

Low ambient temperature can also causefly-off: cold stiffens the adhesive and hardens film materials so they resist bending. Once the adhesive hardens, its bond to the liner weakens and release force drops. This type of fly-off mostly occurs at die-cut rewinding, slitting into small rolls, and automatic labeling.

10 Lamination tension too high

If a laminated label's film was applied under excessive tension, the stretched film curls the laminate toward the facestock; after die-cutting and stripping, individual labels — no longer restrained by the surrounding material — spring up, causingfly-off, mostly during rewinding or automatic labeling. To avoid this, do not test lamination tension by peeling die-cut, stripped labels straight off the liner. Instead, mimic an applicator's dispensing action: curl the liner to push the label off, letting it fall adhesive-side down onto a flat sheet of silicone-coated liner prepared in advance. A label with proper lamination tension lies flat on the silicone surface; one applied under excess tension curls up at both ends toward the facestock.

01 Insufficient die-cut depth

If the die blade fails to cut cleanly through the facestock, the waste matrix easily carries labels away —fly-off. Likewise, if the adhesive layer is not fully severed, stripping pulls labels up intermittently, because the adhesive under the matrix stays connected to the adhesive under the label, with visible stringing.

02 Adhesive reflow after die-cutting

At higher ambient temperatures the adhesive flows more readily; if the die-cutting and stripping stations sit far apart, the severed adhesive can easily reflow and re-bond. The matrix then lifts labels at random positions and in varying numbers, and separating label from matrix shows obvious stringing — much like an uncut adhesive layer. The two can be told apart by dye testing: with adhesive reflow the cut is deep and blade marks show on the liner's silicone surface; with an under-cut adhesive layer the cut is shallow and the blade marks are faint or absent. Either way, the matrix lifts labels irregularly. Shortening the distance between die-cutting and stripping stations greatly reduces the chance of reflow, and increasing the stripping angle reduces stringing. A small stripping roller and a large stripping angle both peel the matrix away quickly, easing its grip on the label adhesive and helping labels separate cleanly.03 Defective die blade