Patent ID: 6500380
Filing Date: 2002-12-31
Classification: B29B,B29C,B29L,B65D

Abstract:
In the process of forming a one-piece self-draining plastic container comprising the steps of:(a) providing a cavity in an injection mold defining (i) a spout forming portion, (ii) a cylindrical wall forming portion having an outer surface and an inner surface including a thread forming projection extending around the inner surface of said cylindrical wall forming portion for at least two complete turns, (iii) a web forming portion interconnecting the spout forming portion and cylindrical wall forming portion, each of said portions opening to the exterior of said mold; (b) imparting relative movement between an extrusion die head, operable for extruding heated and plasticized plastic material, and said injection mold to thereby engage said injection mold and said die head to close said cavity; (c) injecting plastic material from said die head into said cavity to fill said cavity to form a pouring spout, cylindrical wall and integral web interconnecting said spout and said cylindrical wall with a thread integral with and extending around on the inner surface of said cylindrical wall; (d) imparting relative movement between said die head and said injection mold while extruding plastic material in the form of tubing from said die head, said tubing having a diameter nearly equal to the diameter of said cylindrical wall; (e) closing mold halves about the extruded tubing; (f) expanding the tubing to form a self draining plastic container having a closed bottom and said integral pouring spout, web and cylindrical wall; (g) opening said mold halves and moving said pouring spout, cylindrical wall and integral web axially relative to said spout forming portion and said cylindrical wall forming portion to strip said pouring spout, cylindrical wall and web from said cavity and said thread from said thread forming projection; the improvement in combination with the foregoing process comprising the further steps of:(h) constructing and arranging in step (a) the web forming portion of the injection mold cavity to mold form a generally frustoconical upper surface on the web, and (i) constructing and arranging in step (b) the end surface of said die head that closes said cavity so as to mold form a generally frustoconical lower surface on the web.