A pressure sensitive adhesive (PSA) bonds with pressure only. No water, solvent or heat is needed. It must flow onto the surface at contact, then resist peel and creep like a solid.
Tack, peel and shear pull against each other. A softer PSA wets faster but creeps more. A firmer PSA holds more load but wets less. Most fixes move one of these and cost some of another, so test on your real part.
Always report the test method, dwell, substrate and failure mode with any peel, tack or shear number. A result on steel is not a result on your bottle or box. For grade selection, see how to choose a pressure sensitive adhesive by end use.
What's in this guide
- Why won't my label or tape stick to the part?
- Why are my labels lifting at the edges on curved containers?
- Why does my tape slide or creep under load?
- Why does my PSA leave residue when I remove it?
- Why does the adhesive transfer to the liner or to the back of the tape?
- Why does adhesive ooze from the edges of my rolls or labels?
- Why is my liner release too tight or too easy?
- Why does my PSA bond fail in the cold or in the heat?
- Why does my water-based PSA coat show fisheyes, craters or foam?
- Why do my packing slip pouches or security bag seals open in transit?
- Why does my hot melt PSA string or char in the coater?
Why won't my label or tape stick to the part?
Symptom: The label or tape does not grab, or it lifts right after it goes on.
Likely cause: The surface is low surface energy, cold, dusty or oily. Application pressure is too low. The coat weight may also be low.
Fix: Clean the surface and let it dry. Bring parts to room temperature. Roll the label or tape down with firm pressure. Check the surface with dyne pens. See how to bond low surface energy substrates.
Why are my labels lifting at the edges on curved containers?
Symptom: Label edges lift or flag on round or small-diameter containers.
Likely cause: The face stock is too stiff for the curve. The PSA did not have time or pressure to wet out. Cold containers make it worse.
Fix: Roll or brush the label down after you apply it. Label containers at room temperature. Give the bond time before handling. Ask about a thinner face stock or a PSA with more tack. For wet-glue labelers, see how to solve container labeling problems.
Why does my tape slide or creep under load?
Symptom: The tape or label slowly moves, or a hung part drops over time.
Likely cause: The PSA does not have enough shear for the load or the temperature. A coat that is too heavy can also creep.
Fix: Test shear at your real use temperature and load. Lower the coat weight in small steps. Ask our lab for a grade with more shear. Do not use a softening point as a heat resistance number.
Why does my PSA leave residue when I remove it?
Symptom: Adhesive stays on the part after you peel the label or tape.
Likely cause: The PSA splits instead of releasing. Heat, light or age can firm it up or break it down. A permanent grade used where you need a removable grade also leaves residue.
Fix: Confirm if the job needs permanent or removable. Test removal after aging at your real heat and light. Ask our lab for a removable grade if you need clean removal.
Why does the adhesive transfer to the liner or to the back of the tape?
Symptom: The adhesive pulls off the face stock and stays on the liner or the next wrap.
Likely cause: The PSA does not anchor well to the face stock. The face may need a primer or a surface treatment. The release coating may also not match the PSA.
Fix: Check the face stock surface with dyne pens. Treat or prime the face. Match the liner or release coat to the PSA. Send face stock and liner to our lab.
Why does adhesive ooze from the edges of my rolls or labels?
Symptom: Roll edges get sticky. Labels stick together after slitting or die cutting.
Likely cause: The PSA is soft, the coat is heavy, or the rewind tension is high. Warm storage makes it worse.
Fix: Lower the coat weight in small steps. Lower the rewind tension. Store rolls cool and flat. Ask about a firmer grade for your converting.
Why is my liner release too tight or too easy?
Symptom: Labels do not dispense, the liner tears, or labels fall off the liner.
Likely cause: The release coat and the PSA do not match. Release force can change with age and heat.
Fix: Match the liner to the PSA. Test release when fresh and after aging. Send the liner and face stock to our lab.
Why does my PSA bond fail in the cold or in the heat?
Symptom: The bond holds at room temperature but fails in a freezer, a truck or a hot warehouse.
Likely cause: Each PSA has a working temperature window. Below it, the PSA gets hard and does not wet. Above it, it gets soft and creeps.
Fix: Tell us the lowest application temperature and the full service range. Test at those temperatures. Ask our lab for a grade made for that window.
Why does my water-based PSA coat show fisheyes, craters or foam?
Symptom: The dry coat has fisheyes, craters, pinholes or bare spots.
Likely cause: Contamination such as silicone or oil, foam from pumping, or a surface the PSA cannot wet.
Fix: Clean the coater and pans. Use low-shear pumps. Use only the defoamer we specify. Check the web surface with dyne pens. See why should you control viscosity.
Why do my packing slip pouches or security bag seals open in transit?
Symptom: Pouches or seals lift during shipping.
Likely cause: The PSA did not wet the coated board or paper. Dust, cold boxes and low pressure at application cause this.
Fix: Apply firm pressure across the full seal. Keep boxes at room temperature where you apply. Test on your real board. Stock hot melt PSA 9810 is listed for packing slips and security bags.
Why does my hot melt PSA string or char in the coater?
Symptom: The hot melt PSA strings, smokes or darkens in the tank.
Likely cause: The temperature is too low (stringing) or too high (char). The tank may be low or the lid open.
Fix: Keep the temperature within the TDS range. Keep the tank full and the lid closed. See how to solve hot melt application problems.
Stock grades
Stock PSA grades from our pressure sensitive adhesive page. Get the TDS for viscosity and use temperature.
| Product number | Use |
|---|---|
| 8241 | Water-based acrylic PSA. High tack. Tapes, labels, films. |
| 8250 | Water-based acrylic PSA. Masking tapes. |
| 8299 | Water-based PSA. Foams, films, foils, coated board. |
| 9195A | Hot melt PSA. High heat. Automotive interior assembly. |
| 9810 | Hot melt PSA. Packing slips and security bags. About 5,000 cps. |
What to send before you call
Tell us the face stock, the liner, the surface it goes on, the application temperature and the service temperature. Send failed labels or tape still on the part.
Related: pressure sensitive adhesive, tapes and films, how to choose a label adhesive, how to bond plastics, chart showing surface tension of various plastics.
Still stuck on the line?
Call 800-249-0337 or contact us. Ask for a sample, an SDS, or a TDS. Our lab can test your substrate and your failed parts.
Call 800-249-0337 Request a sample Request an SDS
General plant guidance only — not a substitute for your process, SDS/TDS, or line trials. Call 800-249-0337 to match a grade.