| 摘要 |
The invention relates to a sealing jaw for sealing thermoplastic materials o r paper or cardboard coated with thermoplastic material, preferably packaging material. The sealing jaw is constructed from two ceram ic materials, of which one is electrically insulating and the other electrically conductive. The electrically conductive ceramic material (3) forms a continuous strand embedded in the insulating material (21) and is, at or in the proximity of its end points, metallized s o as to make good connection with an electric current source. The electrically conductive ceramic material may be of optional extent and desig n over the upper surface of the electrically insulating ceramic material (2), and both of the ceramic materials are treated with high pressu re and heat so that they together form a pore-free, hard and abrasion-resistant body which can be applied to a steel rail (1). |
