Hot caulking
Hot caulking, also known as hot riveting or hot forming, is a form-fitting, non-detachable joining process. For this purpose, a thermoplastic part is given domes,
which protrude through holes in the part to be joined. These domes are heated with a hot riveting punch until the plastic becomes soft and can be formed.
The hollow shape of the hot riveting punch forms the cylindrical mandrel and like a rivet. After shaping, the punch is lifted off and the moulded head cools
freely to ambient temperature level. To keep the material recovery of the formed head low, the riveting temperature should be set very precisely.
It is below the glass transition temperature for amorphous thermoplastics and between the melting and glass transition temperature for semi-crystalline plastics.
Often hot caulking is much easier to realise than, for example, bolting.
In contrast to ultrasonic riveting, thermal riveting can be used without any problems for sheet metal/plastic joints, as no vibrating tools touch the sheets and thus endanger the joint.
contact with the sheet metal and thus endanger the joint. Particularly with welding-critical plastics such as POM or PAGF, which tend to become brittle with ultrasonic riveting, thermal riveting achieves the best results.
brittle during ultrasonic riveting, thermal riveting achieves a very high joining quality.
Application examples
Hot caulking
for fixing printed circuit boards
Hot caulking
of plastic lenses