Compound extrusion die for producing an internally lined extrudate
AssigneeThermoplastice Processes Inc.
InventorHerbert C. Hessenthaler
Life of this patent
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Abstract
An extrusion die is disclosed for producing a compound extrusion in the form of a lined tubing where the materials forming the main tubing wall and the lining are difficult to bond. The die includes a plenum chamber in which there is spider-mounted a torpedo section passed which the main extrudate flows. The torpedo section is equipped with the circumferential orifice for orthogonally injecting the secondary extrudate as an internal lining. The combined extrudate is then caused to flow through a conical passageway which increasingly confines the combined extrudate and enhances the bonding therebetween. Thereafter, the combined extrudate passes through a passgeway having a constant clearance dimension wherein the bonded materials are stablized before they are permitted to exit the die.
Claims8
An extrusion die for producing a bonded extrudate of two thermoplastic materials comprising a main extrusion passageway having an annular cross-section for transporting a first extrudate stream and an increasingly constricted conical passageway joining said main passageway, a radial orifice intermediate and orthogonal to said main and said conical passageway for injecting a secondary extrudate onto the inside of said first extrudate stream, said radial orifice being positioned adjacent the upstream end of said conical passageway and an afterthroat passageway of substantially constant cross-sectional throat size downstream of said conical passageway.
An extrusion die for simultaneous extrusion of two thermoplastic resins comprising a die body having a plenum chamber therein for receiving a first thermoplastic resin stream,
- a torpedo section having one end thereof disposed within said plenum chamber,
- an elongated tapering tailpiece coupled to the end of said torpedo section remote from said plenum chamber,
- circumferential orifice means disposed about said torpedo section at the junction with said tailpiece section, said orifice means being adapted to dispense a second thermoplastic resin,
- an entry port in said torpedo section for introducing said second thermoplastic resin,
- reservoir means communicating with said circumferential orifice means and said entry port and eccentrically positioned with respect to said orifice means to compensate for differential pressure drop of said second resin in following from said entry port to said orifice means, and
- a tapering throat section disposed aft of said circumferential orifice means and conformably containing said tailpiece and provided a channel for the passage of said first and second resins.
An extrusion die for producing a bonded extrudate of two thermoplastic materials comprising a main extrusion passageway having an annular cross-section for transporting a first extrudate and an increasingly constricted conical passageway joining said main passageway, a radial orifice intermediate and orthogonal to said main and said conical passageway for injecting a secondary extrudate into the stream of said first extrudate, a semi-annular reservoir communicating with said radial orifice for receiving said secondary extrudate, said semiannular reservoir being offset with respect to the longitudinal axis of said main passageway, and an afterthroat passageway of constant size downstream of said conical passageway.
Dependencies are inferred from the claim text.