| 摘要 |
Improved injection molding apparatus for the manufacture of an article formed of a thermoplastics material having a melt index selected from the range 50 DEG C - 350 DEG C, comprising an article-shaping mold in communication with a melted feed means for intermittently feeding said thermoplastics material under pressure and at a temperature above said melt index in a first mold-filling and article-shaping amount to said mold; said mold having (i) cooling means within said mold for cooling said melted thermoplastics material below said melt index to form a cooled, said article; (ii) means for opening said mold to allow removal of said cooled article; (iii) means for sealably closing said mold for said mold to operably receive, intermittently, a second and subsequent mold filling amount of said melted thermoplastics material; (iv) an extrudate receiving aperture; (v) an inner surface defining an article-shaped inner cavity; the improvement wherein said melted feed means comprises (a) a converging die having a converging passage of which the cross-sectional area diminishes in the forward direction of plastic flow and produce an extrudate for said mold, and (b) means to control the temperature of said method thermoplastics material or close to said melt index in said converging die. The articles are formed of oriented thermoplastics materials which may further comprise an oriented particulate material and may be hollow, foamed or unfoamed. The articles have strength, modulus and density values comparable to typical hardwoods or softwoods. |
