Water cooled electrode for inductive weld- - ing of plastic lined metal tubes

摘要

Compressible tubular containers, e.g. for toothpaste with an outer metal layer and an inner plastic layer have their ends inductively welded together by high frequency energy produced by a generator and supplied to a water-cooled electrode. A magnetic core e.g. ferrite, is positioned in the electrode while a relatively thin water-cooled metal shield for damping the eddy current stray field is made from non-ferromagnetic material and is located parallel to the electrode. Water flows between shield and electrode through an insulating tube made from plastic e.g. PVC.