Forming shaped abrasive particles

• US 8,753,558 B2
• Filed: 12/31/2012
• Issued: 06/17/2014
• Est. Priority Date: 12/30/2011
• Status: Active Grant

• Current Assignee: Saint-Gobain Ceramics & Plastics Incorporated (Compagnie De Saint-Gobain)
• Original Assignee: Saint-Gobain Ceramics & Plastics Incorporated (Compagnie De Saint-Gobain)
• Inventors: Kavanaugh, Michael D.
• Primary Examiner(s): SCHIFFMAN, BENJAMIN A
• Application Number:
  US13/731,771
• Publication Number:
  US 20130186005A1
• Time in Patent Office: 533 Days
• Field of Search: None
• US Class Current: 264/297.9
• CPC Class Codes: B01J 2/26 on endless conveyor belts
• CPC Class Codes: B24D 18/0063 by extrusion
• CPC Class Codes: B28B 13/0205 supplied to the moulding device in form of a coherent mass of material, e.g. a lump or an already partially preshaped tablet, pastil or the like
• CPC Class Codes: B28B 13/062 by elastically deforming the mould, e.g. bending flexible moulds
• CPC Class Codes: B28B 2005/048 in moulds carried on a conveyor of the endless-belt type
• CPC Class Codes: B28B 5/025 the moulds or the moulding surfaces being divided by separating walls and being continuously fed feeding B28B13/02
• CPC Class Codes: B28B 7/24 Unitary mould structures with a plurality of moulding spaces , e.g. moulds divided into multiple moulding spaces by integratable partitions, mould part structures providing a number of moulding spaces in mutual co-operation assemblies of individually complete moulds B28B7/26
• CPC Class Codes: B29C 48/04 Particle-shaped making granules B29B9/00
• CPC Class Codes: B29C 48/154 Coating solid articles, i.e. non-hollow articles
• CPC Class Codes: C04B 2235/6025 Tape casting, e.g. with a doctor blade
• CPC Class Codes: C09K 3/1409 Abrasive particles per se preparation of diamond C01B32/25

Abstract

A method of forming a shaped abrasive particle includes extruding a mixture into an opening in a screen within an application zone and translating the screen and belt to a release zone and separating the screen and belt to form a precursor shaped abrasive particle on the belt, wherein the screen and belt are separated at a release angle of at least about 15° and not greater than about 45°, wherein the release angle is defined as an angle between a surface of the screen and a surface of the belt.

Claims

1. A method of forming a shaped abrasive particle comprising:

extruding a mixture into an opening in a screen within an application zone; and

translating the screen and belt to a release zone and separating the screen and belt to form a precursor shaped abrasive particle on the belt, wherein the screen and belt are separated at a release angle of at least about 15° and

not greater than about 45°

, wherein the release angle is defined as an angle between a surface of the screen and a surface of the belt; and

further comprising a knife edge integrally formed with a die and configured to engage the mixture upon extrusion from a die opening, wherein the knife edge comprises an erodible surface.

2. The method of claim 1, wherein the release angle is at least about 18°

.

3. The method of claim 1, wherein the release angle is not greater than about 42°

.

4. The method of claim 1, wherein the release angle is defined as an angle between a lower surface of the screen and an upper surface of the belt.

5. The method of claim 1, further comprising a radius of release of not greater than about 6 inches.

6. The method of claim 1, further comprising a radius of release of at least about 0.2 inches.

7. The method of claim 1, further comprising moving the belt over a directional adapter coupled to a surface of the belt, wherein the directional adapter is configured to adapt at least one of the release angle and a radius of release.

8. The method of claim 1, further comprising moving the belt over a table within the application zone, wherein the belt directly contacts a surface of the table within the application zone, and wherein the table is movable between a first position and a second position to change at least one of a vertical position of the belt, a radius of release, and the release angle.

9. The method of claim 1, wherein the mixture comprises a storage modulus of at least about 1×

10⁴ Pa, wherein the mixture has a storage modulus of not greater than about 1×

10⁷ Pa.

10. The method of claim 1, wherein the knife edge abuts a portion of the screen during extruding, and wherein the knife edge comprises a contact surface having a width of at least about 0.01 mm and not greater than about 20 mm.

11. The method of claim 1, wherein the knife edge comprises a material different than the die.

12. A method of forming a shaped abrasive particle comprising:

extruding a mixture through a die opening of a die and into an opening of a screen underlying the die opening within an application zone, and

forcing at least a portion of the mixture into the opening while translating the screen under a knife edge integrally formed with a surface of the die, wherein the knife edge is configured to contact a surface underlying the die and wear away until forces between the knife edge and the surface are balanced.

13. The method of claim 12, wherein the screen is separated from an underlying belt at a release angle within a range between about 15°

and about 45°

within a release zone, wherein the release angle is defined as an angle between a surface of the screen and a surface of the belt.

14. The method of claim 12, further comprising a radius of release of not greater than about 6 inches.