Composite pipes and method making same

• US 7,887,660 B2
• Filed: 10/20/2005
• Issued: 02/15/2011
• Est. Priority Date: 10/22/2004
• Status: Active Grant

• Current Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Original Assignee: Dow Global Technologies, Inc. (Dow, Inc.)
• Inventors: Aarts, Martinus W., Jeruzal, Mark B., McLeod, David G., Fehr, Bernard A.
• Primary Examiner(s): Nguyen; Khanh
• Assistant Examiner(s): Hoover; Matthew
• Application Number:
  US11/577,393
• Publication Number:
  US 20080257482A1
• Time in Patent Office: 1,944 Days
• Field of Search: 156/60, 156/184, 156186-188, 156/162, 156/171, 156/443
• US Class Current: 156/188
• CPC Class Codes: B29C 2043/3602 with means for positioning, fastening or clamping the material to be formed or preforms inside the mould
• CPC Class Codes: B29C 2043/3631 moving in a frame for pressing and stretching; material being subjected to compressing stretching
• CPC Class Codes: B29C 43/36 Moulds for making articles of definite length, i.e. discrete articles
• CPC Class Codes: B29C 51/004 Textile or other fibrous material made from plastics fibres combined with plastic layers B29C51/145; compression moulding of reinforced plastic articles in matched moulds B29C70/46; using pressure difference B29C70/44
• CPC Class Codes: B29C 70/04 comprising reinforcements only, e.g. self-reinforcing plastics
• CPC Class Codes: B29K 2023/0641 MDPE, i.e. medium density polyethylene
• CPC Class Codes: B29K 2023/12 PP, i.e. polypropylene
• CPC Class Codes: B32B 1/00 Layered products having a non-planar shape
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: D03D 15/283 synthetic polymer-based, e.g. polyamide or polyester fibres cellulose-based artificial fibres D03D15/225
• CPC Class Codes: D03D 15/46 Flat yarns, e.g. tapes or films
• CPC Class Codes: D10B 2321/021 polyethylene
• CPC Class Codes: D10B 2321/022 polypropylene
• CPC Class Codes: D10B 2401/041 thermoplastic; thermosetting
• CPC Class Codes: D10B 2505/02 Reinforcing materials; Prepregs
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 428/13 Hollow or container type article [e.g., tube, vase, etc.]
• CPC Class Codes: Y10T 428/1303 Paper containing [e.g., paperboard, cardboard, fiberboard, etc.]
• CPC Class Codes: Y10T 428/1352 Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/1359 Three or more layers [continuous layer]
• CPC Class Codes: Y10T 428/139 : Open-ended, self-supporting conduit, cylinder, or tube-type article
• CPC Class Codes: Y10T 428/1393 : Multilayer [continuous layer]
• CPC Class Codes: Y10T 428/24942 : including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/2495 : Thickness [relative or absolute]
• CPC Class Codes: Y10T 428/24975 : No layer or component greater than 5 mils thick
• CPC Class Codes: Y10T 428/264 : Up to 3 mils
• CPC Class Codes: Y10T 428/31504 : Composite [nonstructural laminate]
• CPC Class Codes: Y10T 428/31909 : Next to second addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31913 : Monoolefin polymer
• CPC Class Codes: Y10T 442/2008 : Fabric composed of a fiber or strand which is of specific structural definition

Abstract

Reinforced composite pipes and methods for making the same, generally employ at least one polymeric reinforcement phase, typically provided as an intermediate form 214. The intermediate form is typically applied over a core pipe 216, and may be consolidated. An optional jacket may be employed.

Claims

1. A method for making a composite pipe, comprising the steps of:

providing a core pipe,

covering the core pipe with an intermediate form,

heating the intermediate form, and

optionally applying a jacket over at least a portion of the intermediate form and the core pipe for protecting the core pipe with the intermediate form,

characterized in that;

the intermediate form includes at least one winding of at least one coextruded thermoplastic elongated member, wherein the elongated member comprises a first polyolefin material coextruded with a second polyolefin material that is different from the first polyolefin material and the second polyolefin material includes an isotactic polypropylene homopolymer with a peak melting temperature greater than 160°

C; and

the heating step includes heating the elongated member to one or more temperatures above the melting point of the first polyolefin material but below the peak melting temperature of the second polyolefin material for consolidating the intermediate form and for at least partially melting the at least one elongated member of the intermediate form for fusing the elongated member to the core pipe.

2. The method of claim 1, wherein the core pipe comprises a polymer.

8. The method of claim 1, wherein at least one of the polyolefin material of the intermediate form, or both includes a non-migratory process aid or surface modifier agent.

9. The method of claim 1, wherein;

at least one of the first polyolefin material and the second polyolefin material includes ethylene.

10. The method of claim 8, wherein (i) the first polyolefin material comprises a propylene-ethylene copolymer, (ii) the second polyolefin material comprises an isotactic polypropylene homopolymer having a crystallinity of at least 70%, and an isotactic pentad/triad ratio of greater than 85%;

or both (i) and (ii).

11. The method of claim 10, wherein (i) the first polyolefin material has the following characteristics:

exhibits a melt flow rate at 230°

C. per ASTM D1238 of 0.3 to 50 g/10 min;

a density per ASTM D792 of 0.858 to 0.888 g/cc;

an ethylene content of 5 to 25 wt%;

a Melting Range from 50 to 135°

C.;

a Shore A Hardness from 50 to 75; and

a flexural modulus per ISO 178 of 10 to 280 MPa;

wherein (ii) the second polyolefin material comprises a polypropylene homopolymer that exhibits a melt flow rate at 230°

C. per ASTM D1238 of less than 7 g/10 min;

a 1% secant flexural modulus of greater than 2000 MPa;

a crystallinity of least 70%;

an isotactic pentad/triad ratio of greater than 85%; and

a crystallization temperature of greater than 133°

C.;

or both (i) and (ii).

12. The method of claim 1, wherein the at least one elongated member comprises a plurality of microlayers.

13. The method of claim 1, wherein the process includes the step of providing the protective jacket, and wherein the jacket is made of a thermoplastic.

14. The method of claim 1, wherein the process includes the step of providing the protective jacket, and the step of consolidating the intermediate form occurs prior to application of the jacket over at least a portion of the intermediate form and the core pipe.

15. The method of claim 1, wherein the process includes the step of providing the protective jacket, and the step of consolidating occurs from heat realized during the step of applying the jacket.

16. The method of claim 1, wherein the pipe has least one closed end.

17. The method of claim. 1, wherein the melting points of the first and second polyolefin materials differ by at least about 20°

C.

18. The method of claim 17, wherein the melting the first polyolefin includes a propylene-ethylene copolymer having a comonomer content of about 3 to 25 wt %.

19. The method of claim 18, wherein the propylene-ethylene copolymer has the following characteristics:

exhibits a melt flow rate at 230°

C. per ASTM D1238 of 0.3 to 50 g/10 min, a density per ASTM D792 of 0.858 to 0.888 g/cc, an ethylene content of 5 to 25 wt %, a Melting Range from 50 to 135°

C., a Shore A Hardness from 50 to 75, and a flexural modulus per ISO 178 of 10 to 280 MPa.

20. The method of claim 19, wherein the melting points of the first and second polyolefin materials differ by at least about 30°

C.

3. A method for making a composite pipe, comprising the steps of:

providing a core pipe,

covering the core pipe with an intermediate form,

heating the intermediate form, and

optionally applying a jacket over at least a portion of the intermediate form and the core pipe for protecting the core pipe with the intermediate form,

characterized in that;

the intermediate form includes at least one winding of at least one coextruded thermoplastic elongated member, wherein

the elongated member comprises a first polyolefin material coextruded with a second polyolefin material that is different from the first polyolefin and includes isotactic polypropylene homopolymer with a peak melting temperature greater than 160°

C.; and

the heating step includes heating the elongated member to one or more temperatures above the melting point of the first polyolefin material but below the peak melting temperature of the second polyolefin material for consolidating the intermediate form and for at least partially melting the at least one elongated member of the intermediate form for fusing the elongated member to the core pipe,

wherein the intermediate form includes a plurality of elongated member layers, with at least one of the layers including an elongated member stretched to at least 5x.

4. The method of claim 3, wherein the at least one elongated member comprises a multilayer coextruded tape and the consolidating step includes maintaining the intermediate form at a temperature of at least 150°

C. for at least one minute, after the core pipe is covered with the intermediate form.

5. The method of claim 4, wherein the intermediate form includes at least two layers of windings.

6. The method of claim 5, wherein the process includes the step of providing the protective jacket, and wherein the protective jacket comprises a polymer.

7. The method of claim 4, wherein the resulting pipe has a hoop stress performance of withstanding a pressure of 7 MPa at 80°

C. for up to 250 hours.