| 摘要 |
<p>PURPOSE: To enable high frequency welding of high density and proper thickness using polyurethane as a matrix by providing lower and upper electrodes provided with projections to a welding region and attaching an insert element comprising heat-resistant plastic to the upper electrode and preventing the effusion of one of two layers comprising a plastic material. CONSTITUTION: A mold 1 has at least one projection element 15 in its welding region and has a lower electrode 5 and an upper electrode 4. An insert element 17 is attached to the upper electrode 4 and comprises heat-resistant plastic and a means for preventing the effusion on one of two layers comprising a plastic material is provided. Herein, two layers, that is, a first layer 2 and a second layer 3 comprise a thermoplastic material with electric strength of 40-50 kV/mm, electric resistance of about 10<12>Ω/cm and a dielectric strength of 4.6-4.9. The upper and lower electrodes 4, 5 are superposed one upon another by pressure.</p> |
