Plastic Composite Articles and Methods of Making Same

• US 20080265457A1
• Filed: 10/20/2005
• Published: 10/30/2008
• Est. Priority Date: 10/22/2004
• Status: Active Grant

• Current Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Original Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Inventors: McLeod, David G., Teli, Samar R., D'Hooghe, Edward L.
• Granted Patent: US 9,227,346 B2
• Time in Patent Office: Days
• US Class Current: 264/255
• 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

A reinforced composite article and method for making the same. The article and method employ at least one elongated plastic member as a reinforcement phase. An intermediate form including the elongated member is made and can be processed, for example, to form a composite article with a smooth exposed reinforcement surface.

Claims

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

a. consolidating and shaping an intermediate form that includes at least one elongated member and a plurality of repeating structural units of a first thermoplastic material having a surface portion capable of melting prior to an adjoining oriented portion;

b. placing the consolidated and shaped intermediate form into a cavity of a tool;

c. introducing a second thermoplastic material into the tool cavity; and

d. ejecting from the tool cavity a reinforced composite article that includes the consolidated intermediate form and the second thermoplastic material; and

wherein at least the first thermoplastic material comprises a non-migratory process aid or surface modifier agent in an amount less than about 10% by weight of the material of the elongated member.

2. The method of claim 1, further comprising a step of strain hardening the intermediate form.

3. The method of claim 1, wherein the second thermoplastic material is introduced into the tool cavity in a molten state.

4. The method of claim 3, wherein at least a portion of the consolidating and shaping of the intermediate form occurs simultaneously.

5. The method of claim 1, wherein the consolidating and shaping step includes a step of deforming the intermediate form by clamping the intermediate form in a manner such that while a force is applied for deforming the intermediate form, the intermediate form is free to move without deformation within a predetermined limit.

6. The method of claim 1, wherein the intermediate form is drapable prior to any step of consolidating.

7. The method of claim 1, wherein the step of introducing the second thermoplastic material includes a step of injection molding the second thermoplastic material.

8. The method of claim 1, wherein the non-migratory process aid or surface modifier agent includes an agent selected from silicones, polyolefins, halogenated polymers, or any combination thereof.

9. The method of claim 8, wherein the agent comprises a high molecular weight silicone.

10. The method of claim 9, wherein the agent comprises an alkyl siloxane.

11. The method of claim 10, wherein the agent comprises dimethylsiloxane.

12. The method of claim 1, wherein the first thermoplastic material and the second thermoplastic material are from a common family of polymers.

13. The method of claim 1, wherein the first thermoplastic material and the second thermoplastic material are polyolefinic.

14. The method of claim 13, wherein the first thermoplastic material and the second thermoplastic material include propylene-based polymers.

15. The method of claim 1, wherein the intermediate form includes a plurality of layers.

16. The method of claim 15, wherein at least two of the layers differ from each other in at least one respect, such as material type, composition of the elongated member, heat treatment of the elongated member, width of the elongated member, pattern type, whether the layer is consolidated or not, the presence of a film layer, thickness, morphology, or any combination thereof.

17. The method of claim 15, wherein the layers are joined to each other along at least a portion one of the edges of the intermediate form.

18. The method of claim 15, wherein the securing step includes thermally joining the structural units along at least a portion of at least two edges of the intermediate form.

19. The method of claim 1, further comprising a step of recycling the resulting reinforced composite article without the need to separate the materials in it.

20. The method of claim 1, wherein the elongated thermoplastic member is selected from fibres, rods, cords, yarns, tapes, filaments, straps or any combination thereof.

21. The method of claim 1, further comprising a step of coextruding at least two polyolefinic polymers for making the first thermoplastic material for the elongated member.

22. The method of claim 1, wherein the repeating structural units are derived from a single elongated member or from plural elongated members, and the structural units are assemble to define a woven form, a wound form, a knit form, a braided form, a randomly dispersed form or any combination thereof.

23. The method of claim 1, wherein the intermediate form is consolidated by a stamping step substantially at room temperature.

24. The method of claim 1, wherein the intermediate form is shaped prior to being consolidated.

25. The method of claim 1, wherein the elongated member is prepared by a method that includes the steps of extruding a thin film, slitting the film into elongated pieces and stretching the slit elongated pieces.

26. The method of claim 1, wherein the intermediate form is free of an inorganic reinforcement phase.

27. The method of claim 1, wherein the intermediate form includes a geophysical textile material.

28. The method of claim 1, wherein the intermediate form includes at least one elongated member that has at least three different components for realizing at least an A-B—

C type structure.

29. The method of claim 1, wherein the intermediate form is only partially consolidated, partially shaped, or both.

30. A shaped plastic article made according to claim 1, comprising a portion that incorporates thermoplastic repeating structural units consolidated together for exhibiting a ruck-free surface and having a relatively high degree of retained crystallinity in the units.

39. An article made according to the method of claim 1.

40. Use of an article made according to the method of claim 1.

31. A method for making a shaped composite article, comprising the steps of:

a. providing at least one elongated member of a first thermoplastic material and having a surface portion capable of melting prior to the melting of an adjoining or internal portion; and

b. processing the elongated member into an intermediate form that includes a plurality of repeating structural units that are generally free to move relative to each other, wherein the form is capable of being processed to form a shaped composite article that is ruck-free over the exposed portions of the form in the resulting composite article and has a relatively high degree of retained crystallinity in the unit;

wherein the at least one elongated member further comprises

a non-migratory process aid or surface modifier agent in an amount less than about 10% by weight of the material of the elongated member.

32. The method of claim 31, wherein the processing step (b) includes at least one processing step selected from thermoforming, vacuum forming, pressure forming, compression molding, blow molding, injection molding, rotational molding, hot pressing, laminating, extrusion blow molding, profile extruding or any combination thereof.

33. The method of claim 31, wherein the first thermoplastic material is coextruded to include a layer that includes a propylene-ethylene copolymer and an adjoining layer that includes an isotactic polypropylene homopolymer.

34. The method of claim 31, wherein the processing step (b) includes an injection molding step.

35. The method of claim 34, wherein the non-migratory process aid or surface modifier agent includes an agent selected from silicones, polyolefins, halogenated polymers, or any combination thereof.

36. The method of claim 35, wherein the agent comprises a high molecular weight silicone.

37. The method of claim 36, wherein the agent comprises an alkyl siloxane.

38. The method of claim 37, wherein the agent comprises dimethylsiloxane.

41-50. -50. (canceled)