摘要 |
Apparatus for continuously welding polymeric sheets comprises a pair of opposed rollers 15 and 22 across which a radio frequency, high frequency or dielectric field is applied to heat weld the material by generator 36 as it is fed between the rollers. The gap between the rollers may be adjustable by turning knobs 26. The sheets may be fed through the gap via slots 20 and 21. The radio frequency signals may be generated using a matching circuit (figure 3) with means to adjust the voltage. The device may have a second pair of unheated rollers 16 and 24 driven at the same rate to help cool the weld. |