| 摘要 |
<p>A check valve (16) is provided that is especially useful in gas-assisted injection molding wherein pressurized gas is injected into molten plastic material. A tapered or cone-shaped valve member (34) which seats into a correspondingly tapered or cone-shaped valve member (32) provides the means by which the valve seats against reverse flow. Any plastic material entering the gas passageway (24) would contact the base end (46) of the tapered or cone-shaped valve member (34) and not any sealing surfaces (40,42). By minimizing contact with the sealing surfaces, the useful lifetime of the check valve is significantly increased. <IMAGE> <IMAGE></p> |
