Soft PSAs and some hot melts keep moving over time even without heat. Cold flow shows as adhesive oozing from roll edges and die-cut parts, and as stacked rolls or label sheets sticking to each other. It is the flip side of good tack: a softer adhesive grabs faster but flows more. Crosslinking the adhesive or choosing a firmer grade limits it.
Rolls sat stacked on their sides for a month and cold flow glued the whole pallet together at the edges.
Do not mix it up with
- Creep: Creep is a loaded joint slowly giving way; cold flow is the adhesive mass itself spreading under its own weight or light pressure.
Related terms
Creep
Slow, continuing deformation of an adhesive under a constant load, which can end in failure over time.
Edge ooze
Adhesive squeezing out from the sides of a tape roll or die-cut part, making edges sticky and dirty.
Static shear
A tape test that hangs a weight from a bonded strip and records how long it holds before sliding off.
PSA
Pressure-sensitive adhesive, the always-tacky layer on tapes and labels that bonds under finger pressure with no cure step.