Patent ID: 6379600
Filing Date: 2002-04-30
Classification: B29C

Abstract:
A method of manufacturing a continuous length trough, having integrally molded raised ribs, comprising the steps of:(a) providing male and female molds arranged to form a mold cavity therebetween when in mating engagement and enable release of a molded trough formed in said cavity when disengaged, said cavity being shaped to form an elongate section of trough having raised ribs, and being open at a first end and closed at an opposite end when in mating engagement, said opposite end of said cavity being configured to form a plurality of spaced extensions arranged along the corresponding opposite end of a trough section molded therein; (b) providing means for cooling a molten thermoplastic resin comprised in said injection mold cavity; (c) matingly engaging said male and female molds and injecting a molten thermoplastic resin, at an elevated temperature, into said mold cavity; (d) cooling the injected molten thermoplastic resin to a pre-determined resin setting temperature; (e) disengaging said male and female molds and releasing a molded resin set trough section therefrom having a plurality of spaced extensions formed along its opposite end; (f) inserting the end of said resin set molded trough section comprising the spaced extensions, into the open end of the mold cavity, arranged so as to close the open end of said mold cavity when said male and female molds are engaged; (g) matingly engaging said male and female molds and injecting molten thermoplastic resin into the mold cavity, at an elevated temperature sufficient to melt said resin set spaced extensions of the molded trough section of (f) and form a molded trough section in homogeneous continuum with said molded trough section of (f), having a plurality of spaced extensions formed at the corresponding end; (h) cooling the injected molten thermoplastic resin of (g) to a pre-established setting temperature; (j) disengaging said male and female molds and releasing said continuum molded resin set trough section therefrom having a plurality of spaced extensions formed at the corresponding end; and repeating steps (f) through (j) in successive order until a trough of a desired length is formed.