| 摘要 |
A method of making a plastic article having an internal conduit for electrical wires including the steps of forming a mold cavity in the shape of the plastic article having a surface area segment defining a passage in the mold cavity, injecting hot liquid plastic into the mold cavity which is quenched by the surface area segment of the mold cavity to form a solidified tubular wall in the passage having liquid plastic therein, injecting gas at the first site in the mold cavity into the liquid plastic in the tubular wall to expel liquid plastic from within the tubular wall so that an elongated gas-filled void is formed within the tubular wall, sustaining the elongated gas-filled void until all of the liquid plastic in the mold cavity solidifies, removing the plastic article from the mold cavity, and opening the elongated voids at opposite ends by drilling or otherwise machining the plastic article to convert the elongated void into an internal conduit for the electrical wires.
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