# Polyurethane (PU) Solvent-based Adhesives

> From: LOCTITE®X Digital Manual for Bonding (https://www.loctitex.com/en/manuals/bonding/id-APqVCtK7/)

###### Polyurethane (PU) Solvent-based Adhesives

Solvent-borne contact adhesives based on PU (or PUR) are characterised by resistance to plasticisers and good adhesion to a vast array of different materials (except bare metal). For example, they are used for bonding soft PVC parts to each other and to many other materials. Similar to CR adhesives, they can also be reactivated by heat (e.g. in vacuum deep-drawing methods for laminating formed parts with flexible top layers).

To achieve good heat and plasticiser resistances, the adhesive is usually mixed with a 3-7% crosslinking agent before processing. The immediate strength is built up by physical hardening while the final strength is achieved by chemical crosslinking (final strength after approx. 3-5 days).