Plastics welding – joining
performed by qualified and certified plastics fitters
Rauch GmbH uses the following plastics welding methods:
- hot gas welding with and without welding rod
- extrusion welding of sheets for electroplating tanks
- heated tool welding to join components or surfaces with a heated tool at the right temperature and pressure
- welding of connecting sleeves
- resistance welding of pipes
- rotary friction welding of round parts or pipes
- gluing with physical or chemical adhesives
Welding examination pursuant to DVS 2212 and DVS 2221:
Our staff have all passed the latest welding examinations by TÜV, rbv and DVGW covering plastics and joining methods and are regularly updating their qualifications by way of repeat examinations. As a result, all plastics welding works are performed to the most recent technological and quality standards.
Hot gas welding is one of the most prevalent and traditional welding methods for thermoplastics and is typically used to join PE, PP, PVC and PVDF. It is not advisable to join different thermoplastics through hot gas welding. The materials are bonded by the addition of a filler added in a continuous flow. Hot air heats up the material at its edges and the filler until they melt and the filler becomes attached through the applied pressure. Hot gas welding is used to join sections of containers, boxes, ducts and plastic pipes.
Extrusion welding is usually performed by hand, using a continuously fed filler. Components of up to 30 mm in thickness can be joined in a single pass. The method is typically used for the construction of devices, containers, tanks and pipelines. Hot-gas extrusion welding is characterised by the following features:
- The filler is of an equal mass.
- The filler is homogeneous and fully plasticised.
- The edges to be joined are heated with hot air to the welding temperature.
- The bonding material is distributed and added with a hand-held extruder.
- Compared to hot gas welding, the method achieves greater strength at an excellent weld quality and low internal stress.
Butt-welding: The welding tool, heated to the welding temperature, is placed between the sections to be bonded and their planed surfaces are pressed against the tool at the requisite pressure. Once heated, the surfaces can be detached from the tool clean and undamaged. The surfaces to be welded are bonded at a constantly increasing pressure which needs to be maintained until they are cooled.
Welding of connecting sleeves: Pipe sections are overlap-welded. Using a sleeve-shaped tool, the two weld ends are heated to the proper temperature and bonded. The pipe end, tool and sleeve are dimensioned so that they generate a joining pressure when joined. When the pipe diameter exceeds 63 mm PE-HD and PP and 50 mm PVDF, a suitable welding device needs to be used.
Gluing: The cold or solvent welding process involves temporarily dissolving the cleaned surfaces and joining them with a suitable glue. Gluing occurs when the edges are in a plastic state, mingling and becoming entangled with the chains of the other edge to form a homogeneous joint.