Method for high frequency welding flangeless thermoplastic shells
AssigneeS. C. Johnson & Son, Inc.
InventorGeorg Nemeskeri
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Abstract
A method for dielectric welding together of two substantially rigid thermoplastic flanged parts (or "subshells") to form a flangeless, typically thin-walled, thermoplastic shell. The method may be praticed using a pair of relatively movable, clamping electrodes, which define a shell-receiving hollowed space bounded by flange-engaging areas, operate together to create a flangeless weld. The characteristics of the dielectric field application, that is, making the dielectric field most concentrated along the line forming the proximal edge of the flanges, the clamping action, and the timing of various operations are all important features of the invention. One of the preferred embodiments utilizes a double-beveled cutting electrode.
Claims6
A method for welding together two substantially rigid thermoplastic subshells of the type having flanges with congruent proximal edges to form a flangeless thermoplastic shell, comprising:
- applying clamping pressure to clamp the subshell flanges together between a pair of facing electrodes, the proximal edges of such flanges being aligned;
- while continuing such clamping pressure, applying a dielectric field to the flanges, said field being most concentrated at the proximal edges, to soften and fuse said flanges together at or near the proximal edges, said continued clamping pressure producing further clamping movement whereby some softened flange material is displaced to form a bead inside the proximal edge location;
- terminating application of the dielectric field;
- and
- thereafter continuing such clamping movement of said electrodes to substantially sever the flanges from the flangeless shell at said proximal edges.
Dependencies are inferred from the claim text.