Coming unstuck

Gluing materials together may be a reliable way of joining them, but it's also a one-way process - if you need to separate the pieces, it's generally better to use a mechanical method.

But that could well change, thanks to a joint project between the Fraunhofer Institute for Manufacturing Engineering and Applied Materials Research in Bremen and German adhesives manufacturer Degussa.

They have designed a reversible adhesive system, so that plastic parts which have been glued together can be quickly and easily disassembled. What's more, the system gets around some of the inherent difficulties of gluing plastics.

Most adhesives are hardened by heat, which is a distinct problem with plastics. Many polymers have low melting points or degrade with heat, so if an adhesive has to be warmed to set, it can be completely incompatible or extremely difficult to use. Two-part epoxy adhesives will set hard without extra heat, but the curing is rather gradual, making the bonding a time-consuming process.