To fix flaps, satellite dishes or heavy load carriers, chemical sealing is now an essential solution. The principle: a threaded rod is maintained by the crosslinking (chemical melting) of a resin and a hardener, possibly injected into a sieve installed in the hole to be equipped.
Appeared in the late 1970s, the system is inspired by a discovery patented in Germany in 1934 by Paul Schlack, an engineer of IG Farben: the crosslinking of polymers, in other words the possibility of obtaining a very strong glue by combining an adhesive and a hardener.
The use of the crosslinking principle for seals starts with polyester resins, then vinyl resins better adapted to wet environments (developed in 1989), and finally the epoxy withdrawal almost nil. Today, hybrid resins even associate with the chemical compounds of cement and water, making them even more resistant over time.
The market is largely occupied by companies specializing in fastening systems: Würth, Hilti or Fischer as well as brands specializing in fastener research, such as Scell-it or Spit. Progress is therefore steadily continuing, both in product performance and packaging.