COMPOSITE PIPES AND METHOD MAKING SAME

• US 20110114215A1
• Filed: 11/09/2010
• Published: 05/19/2011
• 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.
• Granted Patent: US 8,685,514 B2
• Time in Patent Office: Days
• US Class Current: 138/150
• 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. The intermediate form is typically applied over a core pipe, and may be consolidated. An optional jacket may be employed.

Claims

1. A composite pipe comprising:

two or more walls, including

i. a first wall; and

ii. a second wall disposed on the first wall;

wherein the first wall and the second wall each comprise a first layer and a second layer, wherein;

a. the first layer comprises a propylene-ethylene copolymer having an ethylene content of about 3 to 25 weight percent and a peak melting temperature below about 135°

C., and

b. the second layer comprises a polypropylene haying a peak melting temperature greater than 160°

C.

28. The composite pipe of claim 1, wherein the composite pipe further comprises a core pipe interior to both the first and second walls.

29. The composite pipe of claim 28, wherein the core pipe is a polyolefin pipe.

30. The composite pipe of claim 28, wherein the composite pipe has a burst strength of at least 20% greater than the burst strength of the core pipe, as measured according to ISO 1167 at a rate of increase of pressure of about 1 bar/min.

31. The composite pipe of claim 1, wherein the composite pipe further comprises a protective jacket over some or all of the external surface of the second wall, wherein the protective jacket increases the resistance of the composite pipe to abrasion, scratching, slitting, chemical exposure, ultraviolet light, or any combination thereof.

32. The composite pipe of claim 28, wherein the first wall and the second wall are arranged in a braided pattern over the core pipe.

33. The composite pipe of claim 1, wherein the polypropylene of the second layer is an isotactic polypropylene homopolymer.

2-27. -27. (canceled)

34. A composite pipe comprising:

i. a core pipe;

ii. a first winding; and

iii. a second winding counterwound in the opposite direction relative to the first layer;

wherein the core pipe is interior to both the first winding and the second winding;

a cross-section of the composite pipe in the transverse direction includes the first winding, the second winding and the core pipe;

wherein the first winding and the second winding each comprise

a. a first layer comprising a propylene-ethylene copolymer having a comonomer content of about 3 to 25 weight percent and a peak melting temperature below about 135°

C.; and

b. a second layer comprising a polypropylene having a peak melting temperature greater than 160°

C.; and

wherein the composite pipe has a burst strength greater than the burst strength of the core pipe, as measured according to ISO 1167 at a rate of increase of pressure of about 1 bar/min, of at least 20%.

35. The composite pipe of claim 34, wherein the cross-section of the composite pipe further comprises one or more additional windings wound or counterwound exterior to the core pipe, wherein one or more of the additional windings comprises a first layer comprising the polypropylene-ethylene copolymer, and a second layer comprising the polypropylene having a peak melting temperature greater than 160°

C.

36. The composite pipe of claim 34, wherein the first winding is wound at one angle relative to the perpendicular axis of the core pipe and the second winding is counterwound at an equal angle in the opposite direction relative to the perpendicular axis.

37. The composite pipe of claim 34, wherein the pipe further comprises a protective jacket over some or all of the external surface of the outermost winding, wherein the protective jacket increases the resistance of the pipe to abrasion, scratching, slitting, chemical exposure, ultraviolet light, or any combination thereof.

38. The composite pipe of claim 34, Wherein the cross-section of the composite pipe comprises 2 to 50 windings.

39. The composite pipe of claim 34, wherein the first winding comprises a stack of 4 or more microlayers each having a thickness of about 50 microns or less.

40. The composite pipe of claim 34, wherein the propylene-ethylene copolymer of the first layer has a melt flow rate at 230°

C. per ASTM D1238 of 0.3 to 50 g/10 min, a density as measured per ASTM D792 of 0.85 to 0.91 g/cc, an ethylene concentration of 5 to 15 weight percent, a melting range from 50 to 135°

C., a Shore A Hardness from about 25 to about 100, and a flexural modulus per ISO 178 of 5 to 1000 MPa.

41. The composite pipe of claim 34, wherein the first layer of the first winding, the second layer of the first winding, or both, further comprises a non-migratory process aid or a non-migratory surface modifier agent.

42. The composite pipe of claim 34, wherein the polypropylene having a peak melting temperature greater than 160°

C. of the second layer is an isotactic polypropylene homopolymer.

43. The composite pipe of claim 34, wherein the first winding and the second windings are of tape each having a draw ratio of at least 8.

44. The composite pipe of claim 34, wherein the composite pipe is made by a process including the step of:

providing a core pipe,

covering the core pipe with an intermediate form,

heating 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 comprises an isotactic polypropylene homopolymer with a peak melting temperature greater than 160°

C.; and

the heating step comprises 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.

45. The composite pipe of claim (New), wherein the polypropylene of the second layer has molecular orientation.

46. A composite pipe that comprises

i) a core pipe, and

ii) a consolidated intermediate form that comprises at least one stretched, coextruded elongated member comprising layers of propylene ethylene copolymer having about 3 to 15 wt. % ethylene and an intermediate layer of polypropylene homopolymer between the layers of propylene-ethylene copolymer, wherein the polypropylene homopolymer has a peak melting temperature greater than 160°

C. and the propylene-ethylene copolymer has a peak melting temperature less than 135°

C.