Multi-component coextrusion

• US 20040142157A1
• Filed: 10/30/2003
• Published: 07/22/2004
• Est. Priority Date: 11/13/2000
• Status: Abandoned Application

• Current Assignee: George Melkonian
• Original Assignee: George Melkonian
• Inventors: Melkonian, George
• Application Number:
  US10/699,253
• Publication Number:
  US 20040142157A1
• Time in Patent Office: Days
• US Class Current: 428/292.1
• CPC Class Codes: B29C 48/06 Rod-shaped
• CPC Class Codes: B29C 48/12 Articles with an irregular circumference when viewed in cross-section, e.g. window profiles
• CPC Class Codes: B29C 48/154 Coating solid articles, i.e. non-hollow articles
• CPC Class Codes: B29C 48/304 specially adapted for bringing together components, e.g. melts within the die
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 37/00 Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
• CPC Class Codes: B32B 5/18 characterised by features of a layer of foamed material
• CPC Class Codes: Y10T 428/24496 Foamed or cellular component
• CPC Class Codes: Y10T 428/249924 Noninterengaged fiber-containing paper-free web or sheet which is not of specified porosity

Abstract

A multi-component composite extrusion includes various combinations of a hollow, high density profile filled in with a foamed, thermoplastic core. A further low density foamed profile can alternately surround the high density, hollow component. A capstock can be provided on either embodiment of the multi-component extrusion. All of the components are preferably substantially simultaneously extruded in a single multi-plate extrusion die, so that the various components are substantially laterally coextensive with one another and molecularly bonded to the adjacent component. The thin wall, high density component and the adjacent low density foamed thermoplastic component may optionally be provided with substantial wood fiber content to alter the macroscopic properties of the resulting multi-component extrusion. The extrusion has utility in the fenestration, decking, and remodeling industries. The method disclosed for making the extrusion permits the extrusion designer to vary the type of thermoplastic material used with respect to each component and the presence or absence of wood fiber in the components to vary the macroscopic properties of the entire composite extrusion, surface characteristics of the extrusion, and weatherability of the extrusion.

Claims

1. A multi-component, longitudinally continuous extrusion suitable for use in the fenestration, decking and remodeling industries, comprising:

a first, high density composite member consisting of a thermoplastic component and a cellulosic fiber component extruded from a primary extruder into an extrusion die, wherein the first member has inner and outer sidewalls defining a high density, thin wall extrusion having at least one enclosed, hollow interior compartment; and

,

a second, low density foamed member consisting of a foamed thermoplastic polymer, coextruded with the first member in a molten state from a secondary extruder into the extrusion die so as to be laterally coextensive with and molecularly bonded to one of the sidewalls of the first member.

2. The multi-component, longitudinally continuous extrusion of claim 1, wherein the thermoplastic component of the first high density member has polyvinyl chloride as a principle component by weight.

3. The multi-component, longitudinally continuous extrusion of claim 1, wherein the foamed thermoplastic component of the second member has a substantial cellulosic fiber content.

4. The multi-component, longitudinally continuous extrusion of claim 3, wherein the foamed thermoplastic component has polyvinyl chloride as a principle component by weight.

5. The multi-component, longitudinally continuous extrusion of claim 3, wherein the foamed thermoplastic component has styrene acrylonitrile as a principle component by weight.

6. The multi-component, longitudinally continuous extrusion of claim 1, wherein the second member is laterally adjacent to, and longitudinally coextensive with the inner sidewall of the first high density member.

7. The multi-component, longitudinally continuous extrusion of claim 1, wherein the second member is laterally adjacent to and longitudinally coextensive with the outer sidewall of the first high density member.

8. The multi-component, longitudinally continuous extrusion of claim 1, wherein the second member is laterally adjacent to and longitudinally coextensive with both the inner and outer sidewalls of the first high density member.

9. The multi-component, longitudinally continuous extrusion of claim 1, including a third member consisting of a thermoplastic cap laterally adjacent to and coextensive with a laterally outermost one of the first and second members of the multi-component extrusion, wherein the thermoplastic cap is coextruded from a tertiary extruder into the extrusion die substantially simultaneously with the first and second members so as to be molecularly bonded with the laterally outermost member.

10. The multi-component, longitudinally continuous extrusion of claim 9, wherein the extrusion defines left hand and right hand sides, and wherein the thermoplastic cap has a highly weatherable thermoplastic polymer on the left hand side and a highly paintable thermoplastic polymer on the right hand side.

11. The multi-component, longitudinally continuous extrusion of claim 10, wherein the highly weatherable thermoplastic polymer has polyvinyl chloride as a principle component by weight, and wherein the highly paintable thermoplastic polymer has acrylic styrene acrylonitrile (ASA) as a principle component by weight.

12. A multi-plate extrusion die of the type having a plurality of die plates sequentially positioned so as to define upstream and downstream directions, comprising:

an introductory plate generally defining a primary aperture for passage therethrough of a primary extrudate, the primary aperture extending longitudinally through substantially each die plate of the extrusion die;

a mandrel plate downstream of the introductory plate and fluidly connected thereto for receipt of the primary extrudate and a secondary extrudate, having a first elongated mandrel substantially suspended therein by first support means for supporting the first mandrel in a spaced apart relationship within the primary aperture, wherein the first mandrel is substantially hollow and has a second mandrel substantially suspended therein by second support means for supporting the second mandrel in a spaced apart relationship within the first mandrel so as to form an elongated hollow, interstitial void between the first and second mandrels; and

,

a secondary plate positioned between the introductory and mandrel plates having means for introducing the second extrudate into the interstitial void, whereby an elongated final extrudate having at least two different longitudinally continuous, molecularly bonded thermoplastic components can exit the mandrel plate.

13. The multi-plate extrusion die of claim 12, including a capstock plate, positioned downstream of the mandrel plate, for adding a third extrudate in the form of a capstock to the final extrudate.

14. The multi-plate extrusion die of claim 12, wherein the first and second support means are elongated, tapered fins having a decreasing thickness from the upstream direction to the downstream direction.

15. A method of making a multi-component, longitudinally continuous extrusion suitable for use in the fenestration, decking and remodeling industries with a multi-plate extrusion die of the type having a plurality of die plates sequentially positioned so as to define upstream and downstream directions, comprising the steps of:

preparing a thermoplastic primary extrudate and a thermoplastic secondary extrudate;

introducing the primary extrudate in a molten state into an introductory plate generally defining a primary aperture for passage therethrough of the primary extrudate, wherein the primary aperture extends longitudinally through substantially each die plate of the extrusion die;

positioning a mandrel plate downstream of and fluidly connected to the introductory plate, wherein the mandrel plate has a first elongated mandrel suspended in a spaced apart relationship within the primary aperture and wherein the first mandrel is substantially hollow and has a second mandrel substantially suspended therein in a spaced apart relationship within the first mandrel so as to form an elongated, hollow, interstitial void between the first and second mandrels; and

,

introducing the secondary extrudate in a molten state into the interstitial void, whereby an elongated final extrudate having at least two different longitudinally continuous, molecularly bonded thermoplastic components exit the mandrel plate.

16. The method of claim 15, wherein the first extrudate is prepared so as to substantially consist of a thermoplastic component and a cellulosic fiber component, and wherein the second extrudate is prepared so as to substantially consist of a foamed thermoplastic polymer.

17. The method of claim 0.16, wherein the second extrudate includes a substantial cellulosic component.

18. The method of claim 15, including the step of providing a third thermoplastic capstock extrudate, positioning a capstock plate downstream of the mandrel plate, introducing the third extrudate in a molten state to an exterior surface of the final extrudate so as to form a cap.

19. The method of claim 18, wherein the final extrudate defines left hand and right hand sides, including the steps of simultaneously applying two different types of thermoplastic capstocks to the final extrusion, one of the thermoplastic capstock materials consisting of a highly weatherable thermoplastic polymer on the left hand side and another of the thermoplastic capstock materials consisting of a highly paintable thermoplastic polymer on the right hand side.