Thread pre-coating
BSH Sealing-T
Our coatings ensure a permanent grip in the thread
Closing the open space between the internal and external threads can also seal against a medium. One option is the use of reactive thread pre-coatings. Here, a liquid, in which micro-encapsulated components are embedded, is applied to the external thread. This leaves a dry-to-touch coating that allows automated handling and is storable for a certain time.
When screwed into the female thread, these microencapsulations are opened and the released active agents react with one another. At the end of the chemical reaction – at the earliest after a 24-hour curing period – a polymerisation layer is created that fills and seals the thread backlash. This layer prevents the screw connection from coming loose and, therefore, ensures that the connection in the thread is tight.
Threads can also be sealed inside using non-curing systems. They consist either of viscous-elastic, liquid-based substances without micro-encapsulated components or of harder, melted plastics. These systems do not require curing times and can be loaded immediately after installation.
The various thread pre-coating methods are usually applied in conical threads where there is no space for a screw head.