What is a wash-off adhesive?

Wash-off adhesive is a specialized, water-sensitive industrial adhesive used for labeling reusable containers. It securely bonds labels to substrates like glass or plastic during transport and consumer handling. However, it completely detaches and dissolves during industrial washing cycles with hot, alkaline water (typically a caustic soda solution around 65°C to 80°C) without leaving sticky residue. 

Wash-off adhesives are especially helpful in the recycling process of glass or PET bottles.

During storage, transport, and consumer handling, the wash-off adhesive behaves like a standard, permanent pressure-sensitive adhesive. It is engineered to be moisture resistant, meaning it will not slip or peel off when exposed to condensation, cold environments, or water immersion at room temperature.

When the empty container enters an industrial recycling plant or washing facility, it is exposed to specific environmental triggers:

• High temperature: Typically heated water between 65°C and 80°C

• Alkaline chemistry: A mild caustic soda solution (usually 1% to 2% concentration)

Once the trigger conditions are met, the adhesive properties change based on the label material used. Film labels (PP, PET) are designed to mechanically shrink or curl when exposed to the hot wash bath. This curling action creates a physical pulling force that exposes the adhesive layer directly to the caustic water. With paper labels, hot water penetrates directly through the porous paper fibers to reach the adhesive backing instantly.

During the release process, the adhesive loses its structural cohesion, allowing the face material to separate cleanly. Industrial bottle washers use high-pressure water jets and friction which help slide or lift the deactivated label away from the container.

Unlike water-soluble labels that completely dissolve and turn the washing water into a sticky sludge, wash-off adhesives are designed to lose cohesion but remain bound to the label face. The chemical composition undergoes a phase change where it loses all tackiness, preventing it from re-adhering to the container or clogging the industrial machinery. 

Wash-off adhesives are particularly helpful because they guarantee a clean recycling process. If, for example, plastic contains label residue from a previous label, the melting process used to recycle plastic will result in low grade plastic instead of clear, high-quality plastic.

No. The function performed by wash-off adhesives (allowing label removal without leaving residue behind) is usually reserved for the recycling phase.

Labels applied with wash-off adhesives are as resistant and sticky as labels applied with other adhesive types. They can be exposed to water, cold or other conditions without losing their stickiness. The bonding itself only disappears when the label is exposed to high temperatures.

Weber Marking Systems not only provides labeling systems: it also manufactures all sorts of labels. If you are looking for labels that can be easily removed in the recycling process, make sure to get in touch with us!