Extruded Structure With Equilibrium Shape

• US 20080099953A1
• Filed: 11/01/2006
• Published: 05/01/2008
• Est. Priority Date: 11/01/2006
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Fork, David K., Zimmermann, Thomas S.
• Granted Patent: US 7,922,471 B2
• Time in Patent Office: Days
• US Class Current: 264/176.1
• CPC Class Codes: B29C 2049/023 using inherent heat of the preform, i.e. 1 step blow moulding
• CPC Class Codes: B29C 48/0016 using a plurality of extrusion dies
• CPC Class Codes: B29C 48/07 Flat, e.g. panels
• CPC Class Codes: B29C 48/09 Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
• CPC Class Codes: B29C 48/12 Articles with an irregular circumference when viewed in cross-section, e.g. window profiles
• CPC Class Codes: B29C 48/19 the layers being joined at their edges
• CPC Class Codes: B29C 48/21 the layers being joined at their surfaces
• CPC Class Codes: B29C 48/9135 of flat articles, e.g. using specially adapted supporting means
• CPC Class Codes: B29C 49/061 with parison holding means displaceable between injection and blow stations
• CPC Class Codes: B81B 2203/0376 rounded profile
• CPC Class Codes: B81C 1/00634 Processes for shaping materials not provided for in groups B81C1/00444 - B81C1/00626
• CPC Class Codes: B81C 99/0015 for microextrusion extrusion heads in general B29C48/30

Abstract

An extrusion head is disposed over a substrate, and material is extruded through an oblique (e.g., semi-circular or tapered) outlet orifice of the extrusion head to form an associated extruded structure having an equilibrium shape that resists settling after being deposited on the substrate. The extrusion head includes fluidic channels having a flat surface formed by a flat first (e.g., metal) sheet, and an oblique (e.g., substantially semi-cylindrical) surface formed by elongated oblique trenches that are etched or otherwise formed in a second sheet. The fluidic channel communicates with the outlet orifice, which has a flat edge formed by the first sheet, and an oblique edge formed by an end of the oblique trench. The material is extruded through the outlet orifice such that its flat lower surface contacts the substrate, and its oblique upper surface faces away from the substrate. Two materials are co-extruded to form high aspect-ratio gridlines.

Claims

1. A micro extrusion apparatus for producing an extruded structure having an equilibrium shape on a substrate, the micro extrusion apparatus comprising:

an extrusion head including;

a first sheet having a first surface and a first side edge;

a second sheet having a second surface and a second side edge,

wherein the second sheet is mounted on the first sheet such that a flat portion of the second surface abuts the first surface, and the second side edge is aligned with the first side edge, whereby the first and second side edges form a edge surface of the extrusion head, and

wherein the second surface of the second sheet defines an elongated trench extending from the second side edge and having a concave oblique surface, thereby forming a fluidic channel having an outlet orifice including a straight first edge defined by the first sheet, and an oblique second edge defined by the elongated trench; and

means for moving the extrusion head relative to the substrate while forcing material through the fluidic channel such that material is extruded from the outlet orifice and forms an associated extruded structure on the substrate, wherein the extruded structure has a flat lower surface that is formed by the flat first edge of the orifice and is in contact with the surface, and an upper surface that is formed by the curved second edge of the outlet orifice and faces away from the substrate.

2. The apparatus of claim 1, wherein said means comprises an extrusion device coupled to a source of the extrusion material, and wherein the extrusion head is fixedly mounted on the extrusion device.

3. The apparatus of claim 1, further comprising at least one of means for heating the extrusion materials before extrusion, means for cooling the substrate during extrusion, and means for curing the extruded material.

4. The apparatus of claim 1,

wherein the fluidic channel comprises a three-channel cavity including a central channel and opposing first and second side channels, wherein the central channel comprises the elongated trench, and the first and second side channels comprise second and third elongated trenches, and wherein the central channel and the first and second side channels communicate with the outlet orifice, and

wherein the apparatus further comprises means for injecting functional material into the central channel of the three-channel cavity while injecting support material into the first and second side channels of said three-channel cavity such that said functional material extruded from the outlet orifice forms an associated high aspect-ratio functional structure of said extruded structure, and said support material extruded from the outlet orifice forms associated first and second support material portions respectively disposed on opposing sides of said associated functional structure.

5. The apparatus of claim 4,

wherein the first sheet defines a first and second inlet ports respectively communicating with the first and second side channels of the three-channel cavity, and the extrusion head further comprises a third sheet having a third inlet port communicating with the central channel of the three-channel cavity, and

wherein said means for injecting the functional material and the support material comprises means for forcing the functional material through the third inlet port into the central channel while forcing the support material through the first and second inlet ports into the first and second side channels, respectively.

6. The apparatus of claim 5,

wherein the second sheet further defines an inlet opening disposed in the elongated trench adjacent to the closed end and extending entirely through the second sheet, and

wherein said means for injecting the functional material includes means for forcing the functional material through both the third inlet port and the inlet opening into the central channel.

7. The micro extrusion system according to claim 1, wherein the first and second sheets comprise metal plates.

8. A method for forming an extruded structure with an equilibrium shape on a substrate, the method comprising:

positioning an extrusion head adjacent to a surface of the substrate such that an outlet orifice defined by the extrusion head is disposed over the surface, wherein the extrusion head comprises first and second sheets defining a fluidic channel therebetween that communicates with the outlet orifice, the first sheet having a substantially flat surface that defines a flat edge of the outlet orifice, and the second sheet defining an elongated oblique trench that defines an oblique edge of the outlet orifice;

moving the extrusion head relative to the substrate while forcing material through the fluidic channel such that the material is extruded from the outlet orifice and forms an associated extruded structure on the substrate,

wherein the extrusion head is positioned relative to the substrate such that a flat lower surface of the extruded structure is formed by the flat edge of the orifice and is in contact with the surface, and an upper surface of the extruded structure is formed by the oblique edge of the outlet orifice and faces away from the substrate.

9. The method of claim 8, wherein providing the extrusion head comprises:

etching the first sheet to form said elongated oblique trench;

etching the second sheet such that the second sheet includes an inlet port passing entirely through the second sheet; and

bonding the first sheet to the second sheet such that the inlet port is aligned with the closed end of the elongated trench.

10. The method of claim 8, wherein providing the extrusion head comprises fixedly mounting the extrusion head on an extrusion device coupled to a source of the extruded material.

11. The method of claim 8, further comprising at least one of heating the extruded materials prior to extrusion, cooling the substrate during extrusion, and curing the extruded materials.

12. The method of claim 8,

wherein the fluidic channel comprises a three-channel cavity including a central channel and opposing first and second side channels, wherein each of the central channel and the first and second side channels comprise an associated said elongated trench and communicate with the outlet orifice, and

wherein forcing the material through the fluidic channel comprises injecting functional material into the central channel of the three-channel cavity while injecting the support material into the opposing first and second side channels of the three-channel cavity such that said functional material extruded from the outlet orifice forms an associated high aspect ratio functional structure of said extruded structure, and said support material extruded from the outlet orifice forms associated first and second support material portions respectively disposed on opposing sides of said associated functional structure.

13. The method of claim 12,

wherein the first sheet defines a first and second inlet ports respectively communicating with the first and second side channels of the three-channel cavity, and the extrusion head further comprises a third sheet having a third inlet port communicating with the central channel of the three-channel cavity, and

wherein injecting the functional material and the support material further comprises forcing the functional material through the third inlet port into the central channel while forcing the support material through the first and second inlet ports into the first and second side channels, respectively.

14. The method of claim 13,

wherein the second sheet further defines an inlet opening disposed in the elongated trench adjacent to the closed end and extending entirely through the second sheet, and

wherein injecting the functional material includes forcing the functional material through both the third inlet port and the inlet opening into the central channel.

15. A method for manufacturing an extrusion head for a micro extrusion apparatus, the method comprising:

etching a first sheet such that an elongated trench is defined in a surface of the sheet, the elongated trench having an open end disposed at a side edge of the sheet and an opposing closed end, the elongated trench having a generally semi-cylindrical surface;

etching a second sheet such that the second sheet includes an inlet port passing entirely through the second sheet; and

bonding the first sheet to the second sheet such that the inlet port is aligned with the closed end of the elongated trench, and such that a flat surface portion of the second sheet is disposed opposite to the elongated trench between the inlet port and the side edge, whereby the elongated trench and the flat portion of the second sheet form a fluidic channel that extends between the inlet port and an outlet orifice located at the side edge, wherein the outlet orifice has a flat edge formed by a side edge of the second sheet, and an oblique edge formed by the an end of the elongated trench.

16. The method of claim 15, wherein etching the first sheet comprises one of photochemical machining, pulsed laser machining, deep reactive ion etching, electro-discharge machining and anisotropic etching.

17. The method of claim 15, wherein etching the first sheet comprises forming three elongated trenches including a central trench and opposing first and second side trenches, wherein each of the central trench and the first and second side trenches extend from the side edge to an associated opposing closed end.

18. The method of claim 17, wherein etching the second sheet comprises forming first and second inlet ports disposed such that the first inlet port is aligned with the closed end of the first side trench and the second inlet port is aligned with the closed end of the second side trench after said bonding.

19. The method of claim 18,

wherein etching the second sheet further comprises forming an inlet opening disposed in the central elongated trench adjacent to its closed end and extending entirely through the second sheet, and

wherein the method further comprises etching a third sheet such that the third sheet includes a third inlet port passing entirely through the second sheet, and

wherein bonding the first sheet to the second sheet further comprises bonding the third sheet to a second side of the first sheet such that the third inlet port is aligned with the inlet opening.