Steam tight joints between plastic coated aluminium strips - where plastic is locally removed for spot welding the aluminium

摘要

Steam-tight joints are made between aluminium strips, coated on both sides with plastic, by welding and bonding. The novelty is that at the ends of the strips, small congruent regions are freed from the plastic on both sides and, after placing one strip over the other, the bare regions are spot welded together. The ends of the strips are pref. placed in a slot in a diamond-shaped jig provided with windows, and wire brushes applied through the windows on both sides of the strip t remove the plastic coating in the congruent regions. The welded strip is used as a sheath on data transmission cables. The sheath is applied using an extruder, and the process permits the tail end of one strip to be joined to the leading end of the next strip during the spiral winding of the strip to form a tubular sheath on the cable.