Vent tube system

Abstract

A vent tube assembly is disclosed for use in a vent hole commonly found in metal molds which are used to produce, by rotational molding processes, a wide variety of plastic goods. The main body of the vent tube assembly is produced from a heat resistant, thermoplastic composition. Preferably, the composition will be polyetheretherketone (PEEK). The vent tube assembly resembles a probe-like rod comprising: a large diameter annular top section; an annular mid-section that is substantially smaller in diameter than the annular top section; and an annular bottom section that is slightly smaller in diameter than the annular mid-section and that terminates in with a rounded innermost tip. An elongated central bore is provided through the vent tube assembly. The central bore, along with a counterbore located near the top of the annular top section, provides an air escape passageway. The passageway fluidly communicates with the interior of the mold via a plurality of pore-like holes situated near the innermost tip. To help prevent loss of plastic raw material through the vent tube as the mold rotates, a plurality of beads is included within the length of the passageway that extends through the annular bottom section. The beads are kept in the tube by a perforated top disk and a retaining clip. A principal advantage provided by the vent tube system over conventional systems is elimination of the need to service the vent tube by cleaning and repacking it after every curing cycle.

Dependencies are inferred from the claim text.