In the 1980’s BWE pioneered the development of cladding and sheathing using the Conform continuous rotary extrusion (CRE) method. This work led to the introduction of Conklad, which has become the industry standard for many applications.

Conklad ™ Extrusion Technology

The geometry of the Conklad process is arranged so that a central core can be introduced inside the extrusion. Twin or Single feedstock rods are used to produce two flows of metal on either side of the chamber so that the pressure around the central core is balanced.

The Conklad process has two formats – direct cladding on hard cores and indirect sheathing of soft cores.

The greatest advance in Conform technology has been achieved by BWE in the application of the process for the sheathing or cladding of temperature sensitive (soft) or hard cores as they pass through the extrusion tooling.

There are three basic variants of the Conklad ™ Process:

• High Pressure Direct Cladding – where the core material is directly exposed to the extrusion pressure. This method is used where a measurable bond (diffusion bond) is required between the core and the cladding material. Usually the core material is heated in an inert atmosphere immediately before it enters the Conklad machine. An example of High Pressure Direct Cladding is A.S. Wire.

• Low Pressure Direct Cladding – where the core material comes into contact with the cladding material but is protected from the full extrusion pressure. This method is used where the core material is not strong enough to withstand the extrusion pressure, e.g. cladding copper wire with aluminium.

• Indirect Cladding or Sheathing – where the core material is temperature sensitive or it is not desirable that it comes into contact with the cladding material. In this case the tube is extruded oversize and subsequently drawn down in line to be a close or loose fit on the core as required.