Back to results
US 4,090,897 AGranted
Ultrasonic welding of thermoplastic fabrics
AssigneeThe Sinclair Company
InventorDavid G. Minick
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeThe Sinclair Company
InventorDavid G. Minick
Estimating the term…
Method and apparatus for patching or seaming thermoplastic mesh fabrics, such as used in the papermaking industry by means of an ultrasonic welding tool. The tool is provided with one or more tips having raised surface portions or projections adapted for contacting the plastic mesh at a plurality of spaced points whereby ultrasonic welding is accomplished without substantial disruption or dimunition of the generally uniform porosity inherent to the mesh fabric. The method modifications involve the use of templates for guiding the positioning and movement of the ultrasonic welding tips for both butt seaming and overlap seaming of the opposed edges of thermoplastic mesh fabric. In the butt seaming technique, the outermost weft filaments of the opposed edges of the plastic fabric are replaced by one heat stabilized filament and the picket ends of the fabric are interdigitated about this stable filament preparatory to the welding step.
Method of bonding together mesh fabric composed of thermoplastic filaments comprising the step of juxtapositioning in overlapping relation free edge portions of said fabric with the filaments constituting one edge being superimposed with the filaments constituting the other edge, selectively compressing said superimposed filaments between a metallic anvil and the tip of an ultrasonic welding tool, said anvil being in the form of a metal plate with a transparent template carried thereby, said template being provided with a plurality of spaced apertures extending thereacross in an undulating pattern, and applying ultrasonic energy to said superimposed filaments at spaced points defined by the apertures in said template, the tip of said tool having a relief surface for engagement with said filaments.
A method of bonding together mesh fabric composed of thermoplastic warp and weft filaments comprising the steps of removing the outermost weft filament from the free edge portions of said fabric, substituting a preshrunk thermoplastic filament for one of the web filaments which was removed, juxtapositioning the free edge portions of said fabric by interdigitating the outer ends of said warp filaments of said fabric in embracing relation about the upper and lower surfaces of said preshrunk filament, selectively compressing said juxtapositioned edges between a metallic anvil and the tip of an ultrasonic welding tool by clamping together said juxtapositioned edges and applying ultrasonic vibratory energy using said welding tip to the interdigitated filaments for softening and fusing together the interdigitated ends of said warp filaments and said preshrunk weft filament, the tip of said tool having a relief surface for engagement with said filaments.
Method of bonding together mesh fabric composed of thermoplastic warp and weft filaments comprising the steps of juxtapositioning a thermoplastic patch formed of warp and weft thermoplastic filaments over a hole in the thermoplastic mesh fabric, the warp and weft filaments of the patch being disposed at an oblique angle to the warp and weft filaments of the mesh fabric, welding the edges of said patch to said mesh fabric by the use of an ultrasonic tool having a relief tip with a plurality of spaced nodes engaged with the filaments about the marginal edge of said patch, compressing the marginal edges of said patch and said underlying portions of the mesh fabric between said spaced nodes and a metallic anvil disposed under said mesh fabric, the spacing of the nodes being approximately the same as the filaments of said patch, said tool being actuated by a pressure switch to emit vibratory energy.
Method of bonding together mesh fabric composed of thermoplastic filaments comprising the step of juxtapositioning free edge portions of said fabric with the filaments constituting one edge being superimposed with the filaments constituting the other edge, selectively compressing said superimposed filaments between a metallic anvil and the tip of an ultrasonic welding tool having a relief surface for engagement with said filaments and applying ultrasonic vibratory energy at spaced points of said superimposed filaments to soften and fuse said thermoplastic filaments without substantial penetration by said tip of the thermoplastic filaments.
Dependencies are inferred from the claim text.