| 摘要 |
<p>A valve controlled multiple port nozzle device is provided for co-injection molding to sequentially and simultaneously feed a plurality of plastics material melts into a mold. The nozzle device is especially adapted for initially feeding a skin melt followed by a simultaneous feeding of the skin melt and core or foamed melt and then followed by a final skin melt feed into a mold for producing a molded article with a core surrounded by a complete skin. The nozzle device has a single needle or pin valve controlling flow through the nozzle orifice and sequentially opening the orifice to flow from two inlet ports. The needle or pin has a blind bore selectively communicating with one of the ports as it is retracted from the nozzle orifice and spacers are provided to vary the gap between the needle valve tip and the orifice relative to the opening of the blind bore to its port. - i</p> |
