Sustainability
Wash-off labels for PET bottle recycling: what actually gets validated
15 July 2026 · 6 min read · AllinLabel technical team
A wash-off label must release completely in the recycler's caustic bath — typically 1–2% sodium hydroxide at 80 °C for 15 minutes — leaving no adhesive residue on the flake and no ink bleed into the wash water. That is a whole-construction property: facestock, adhesive and ink all have to pass together.
What the recycler tests
Design-for-recycling protocols check three things: the label detaches within the wash cycle, the adhesive stays with the label rather than the flake, and neither ink nor facestock discolours the wash bath or the recovered pellet.
- Complete detachment within the stated time and temperature.
- No adhesive residue on PET flake after rinse.
- No colour transfer into the wash water.
- Label material floats or sinks predictably for separation.
Specify the wash condition first
Wash conditions vary by region and plant. An adhesive tuned for 80 °C caustic may not release at 65 °C, and a hot-caustic grade can pre-release during hot-fill or pasteurisation. Send us the target plant's protocol before we quote.
| Layer | Specification | Why |
|---|---|---|
| Facestock | rPET or wet-strength paper | Survives the bottle's use phase, separates in wash |
| Adhesive | Alkaline-releasable wash-off | Deactivates in caustic, holds at ambient |
| Liner | Glassine 60–65 gsm or PET 30 µm | Dispensing speed and die-cut precision |
| Ink | Wash-resistant, non-bleeding | Prevents colouring the wash bath |
Common failure modes
Labels that release perfectly in the lab and fail in production usually met one of three things: a hot-fill or pasteurisation step that pre-softened the adhesive, condensation during storage, or an overlaminate that sealed the label edges and stopped caustic reaching the adhesive.
Frequently asked questions
- Does a wash-off adhesive stay on during normal use?
- Yes. It behaves as a permanent adhesive at ambient conditions and only releases under alkaline wash at elevated temperature.
- Can I use wash-off labels on returnable glass?
- Yes — returnable glass bottle washers use similar caustic conditions, though usually with longer soak times. Tell us the washer settings.
Request a quote or a free sample
Send us your facestock, adhesive, liner and roll specification. Low MOQ, OEM/ODM, export to 60+ countries.