| 摘要 |
A simple and inexpensive method and apparatus for molding a peripheral frame around a sheet or grid of thermoplastic material to produce a framed panel. A peripheral frame, preferably of structural foam or the like, is injection molded about a thermoplastic sheet or grid of panel-forming material which has been previously drawn or stretched at a temperature which orients the molecules of the polymer, i.e., below the glass transition temperature of the polymer, Tg. Either during the frame molding process, or subsequent thereto, the panel-forming material is heated sufficiently to cause the material to shrink or revert toward its prestretched condition so as to tension the panel-forming material within the frame. Elastomeric sealing means are disclosed for sealing the mold during injection of the frame-forming material and locator fingers are provided to position a grid-like panel-forming material prior to initiation of the molding process. By the utilization of structural foam molding techniques, a panel of thermoplastic material may be integrally-molded and tensioned within a rigid frame to produce a framed panel of any size for use as a barrier, a fence, a guard, a closure, a seat or bedding support, a filter member or other such applications.
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