METHOD AND APPARATUS FOR HOLLOW CORE EXTRUSION OF HIGH VISCOSITY MATERIALS

• Main Authors: TREVATHAN; LARRY C, SMITH; JAMES C, HOOVER; SCOTT C
• Format: Patent
• Language: English
• Published: 18.02.1992
• Subjects: ADHESIVES; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; APPARATUS FOR APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TOSURFACES, IN GENERAL; APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL; CHEMISTRY; COMPOSITIONS BASED THEREON; DYES; GENERAL PROCESSES OF COMPOUNDING; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; MAKING GRANULES OR PREFORMS; MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FORELSEWHERE; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; ORGANIC MACROMOLECULAR COMPOUNDS; PAINTS; PERFORMING OPERATIONS; POLISHES; PREPARATION OR PRETREATMENT OF THE MATERIAL TO BESHAPED; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIALCONTAINING PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; SPRAYING OR ATOMISING IN GENERAL; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ARTCOLLECTIONS [XRACs] AND DIGESTS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; WORKING-UP

A method and apparatus for dispensing a foamable, pressurized solution of a gas and a high viscosity polymeric material in a manner which produces a foamed bead (100) having a hollow core. Initial foaming (57) occurs in a nozzle (12) through which the solution is dispensed to atmosphere, at the core of the bead. Subsequent foaming of of the bead exteriorly of the core occurs outside the nozzle, and results in an extruded, foamed bead (60) of high viscosity polymeric material having a tubular shape and particularly suitable for form-in-place gasket applications.