MULTI-LAYERED FOAMED POLYMERIC OBJECTS AND RELATED METHODS

• US 20110081524A1
• Filed: 10/05/2010
• Published: 04/07/2011
• Est. Priority Date: 01/17/2007
• Status: Active Grant

• Current Assignee: Dart Container Corporation (Robert Charles Dart)
• Original Assignee: MicroGREEN Polymers, Inc. (Robert Charles Dart)
• Inventors: Branch, Gregory, Nadella, Krishna, Waggoner, Michael A., Kumar, Vipin
• Granted Patent: US 8,377,548 B2
• Time in Patent Office: Days
• US Class Current: 428/174
• CPC Class Codes: B29C 44/0415 by regulating the pressure of the material during or after filling of the mould, e.g. by local venting
• CPC Class Codes: B29C 44/0461 by having different chemical compositions in different places, e.g. having different concentrations of foaming agent, feeding one composition after the other
• CPC Class Codes: B29C 44/0484 by having different solubility of the foaming agent
• CPC Class Codes: B29C 44/06 Making multilayered articles B29C44/0407 - B29C44/0492 take precedence
• CPC Class Codes: B29C 44/3415 Heating or cooling
• CPC Class Codes: B29C 44/3446 Feeding the blowing agent
• CPC Class Codes: B29C 44/3453 Feeding the blowing agent to solid plastic material
• CPC Class Codes: B29C 44/3473 by shearing forces
• CPC Class Codes: B29L 2031/7132 Bowls, Cups, Glasses
• CPC Class Codes: B32B 27/06 as the main or only constituent of a layer, which is next to another layer of the same or of a different material next to a layer of a particular substance B32B9/045; next to a bituminous or tarry layer B32B11/046; next to a water setting substance layer B32B13/12; next to a metal layer B32B15/08; next to a glass layer B32B17/10; next to a layer formed of natural mineral fibres or particles B32B19/045; next to a wood layer B32B21/08; next to a cellulosic plastic layer B32B23/08; next to a natural or synthetic rubber layer B32B25/08
• CPC Class Codes: B32B 5/32 at least two layers being foamed and next to each other
• CPC Class Codes: Y10T 428/1376 Foam or porous material containing
• CPC Class Codes: Y10T 428/24628 Nonplanar uniform thickness material
• CPC Class Codes: Y10T 428/2495 Thickness [relative or absolute]
• CPC Class Codes: Y10T 428/24992 Density or compression of components
• CPC Class Codes: Y10T 428/249961 With gradual property change within a component
• CPC Class Codes: Y10T 428/249976 Voids specified as closed
• CPC Class Codes: Y10T 428/249977 Specified thickness of void-containing component [absolute or relative], numerical cell dimension or density
• CPC Class Codes: Y10T 428/249978 Voids specified as micro
• CPC Class Codes: Y10T 428/249979 Specified thickness of void-containing component [absolute or relative] or numerical cell dimension
• CPC Class Codes: Y10T 428/24998 : Composite has more than two layers
• CPC Class Codes: Y10T 428/249981 : Plural void-containing components
• CPC Class Codes: Y10T 428/249989 : Integrally formed skin

Abstract

The invention disclosed herein relates to relates to foamed thermoplastic material objects and articles of manufacture having an internal layered cellular structure, as well as to methods of making the same. In one embodiment, the invention is directed to a multi-layer foamed polymeric article of manufacture, comprising: a non-laminated multi-layer thermoplastic material sheet, wherein the multi-layer thermoplastic material sheet has first and second discrete outer layers sandwiching a plurality of discrete inner foamed layers, and wherein the two outer layers and plurality discrete inner foamed layers are integral with one another. The thermoplastic material may be a semi-crystalline polymer such as, for example, PET (polyethylene terephthalate), PEEK (polyetheretherketone), PEN (polyethylene napthalate), PBT (polybutylene terephthalate), PMMA (polymethyl methacrylate), PLA (polyactide), polyhydroxy acid (PHA), thermoplastic urethane (TPU), or blends thereof. The two outer layers may be unfoamed skin layers having smooth outer surfaces, and the discrete inner foamed layers may be microcellular.

Claims

1-35. -35. (canceled)

36. A multi-layer foamed polymeric article of manufacture, comprising:

a non-laminated multi-layer thermoplastic material sheet, the multi-layer thermoplastic material sheet having first and second discrete outer skin layers sandwiching a plurality of discrete inner foamed layers, wherein the two outer skin layers and plurality of discrete inner foamed layers are integral with one another, and wherein the plurality of discrete inner foamed layers include at least (i) two substantially identical second inner foamed layers positioned immediately adjacent to the two outer skin layers and (ii) a central third inner foamed layer positioned immediately adjacent to and interposed between the second inner foamed layers, wherein the thickness of each of the two second inner foamed layers is greater than the thickness of the central third inner foamed layer.

37. The multi-layer foamed polymeric article of manufacture according to claim 36 wherein the thermoplastic material is a semicrystalline polymer.

38. The multi-layer foamed polymeric article of manufacture according to claim 37 wherein the semi-crystalline polymer is selected from the group consisting of PET (polyethylene terephthalate), PEEK (polyetheretherketone), PEN (polyethylene napthalate), PBT (polybutylene terephthalate), PMMA (polymethylmethacrylate), PLA (polyactide), polyhydroxy acid (PHA), thermoplastic urethane (TPU), and blends thereof.

39. The multi-layer foamed polymeric article of manufacture according to claim 36 wherein the semi-crystalline polymer is PET (polyethylene terephthalate).

40. The multi-layer foamed polymeric article of manufacture according to claim 39 wherein the two outer layers are unfoamed skin layers having smooth outer surfaces.

41. The multi-layer foamed polymeric article of manufacture according to claim 36 wherein each of the plurality of discrete inner foamed layers are microcellular.

42. The multi-layer foamed polymeric article of manufacture according to claim 36 wherein the second inner foamed layers each include a first plurality of closed cells wherein the first plurality of closed cells has an average cell diameter ranging from about 5 to about 10 microns.

43. The multi-layer foamed polymeric article of manufacture according to claim 42 wherein the central third inner foamed layer includes a second plurality of closed cells, wherein the second plurality of closed cells has an average cell diameter ranging from about 30 to about 50 microns.

44. The multi-layer foamed polymeric article of manufacture according to claim 42 wherein the fourth inner foamed layer includes a third plurality of closed cells, wherein the third plurality of closed cells has an average cell diameter ranging from about 20 to about 40 microns.

45. The multi-layer foamed polymeric article of manufacture according to claim 36 wherein the thermoplastic material sheet is nonplanar.

46. The multi-layer foamed polymeric article of manufacture according to claim 36 wherein the density of the multi-layer thermoplastic material sheet is graded across the sheet such that the outermost layers of the plurality of discrete inner foamed layers have the greatest density of the plurality of discrete inner foamed layers.