Joining components of thermoplastic resin by fusion

摘要

A method of joining the two thermoplastic parts (20,30) which may be a casing (41, 42) for electronics as example, uses an electric heating element wire (20) which is seated in channels (44) of the bottom casing (41). The casing cover (42) has a rim which presses the wire (20) into the channel (44) when the parts are assembled. Electric current is applied to the ends (21) of the element wire (20) using electrodes (10) which are pressed into contact with each end (21) of the wire (20) to heat the wire and fuse the plastic parts together at the joint after which the electrodes are withdrawn. The electrode (10) has a central axial bore through which cooling gas may flow fed from a supply via pipe (34). The cooling gas prevents the ends (21) of the wire (20) from heating up to melt or spoil the support base (45) or adjacent parts and to prevent the electrodes sinking into the base 45.