Shaped abrasive particle and method of forming same

Patent metadata

Field	Value
Publication number	US-2016177152-A1
Application number	US-201414581514-A
Country	US
Kind code	A1
Filing date	Dec 23, 2014
Priority date	Dec 23, 2014
Publication date	Jun 23, 2016
Grant date	—

Abstract

A method of forming a shaped abrasive particle including forming a mixture comprising a ceramic material into a sheet and sectioning at least a portion of the sheet using a mechanical object and forming at least one shaped abrasive particle from the sheet, and where sectioning includes controlling at least one process parameter consisting of an extrusion height, a sheet moisture content, a sheet solids loading, an orientation of the sheet during sectioning, a pressure differential during sectioning, a blade spacing variation, a blade edge thickness, a ratio of blade edge thickness to blade spacing variation, and a combination of one or more of the process parameters.

First claim

What is claimed is:

1 . A method of forming a shaped abrasive particle comprising:
forming a mixture comprising a ceramic material into a sheet; sectioning at least a portion of the sheet using a mechanical object and forming at least one shaped abrasive particle from the sheet, wherein sectioning includes controlling at least one process parameter selected from the group consisting of an extrusion height, a sheet moisture content, a sheet solids loading, an orientation of the sheet during sectioning, a pressure differential during sectioning, a blade spacing variation, a blade edge thickness, a ratio of blade edge thickness to blade spacing variation, and a combination thereof.

2 . The method of claim 1 , wherein forming comprises extruding the sheet onto a belt, wherein the sheet contacts a surface of the belt after being extruded through a die opening, wherein the belt is translated while extruding, further comprising controlling an extrusion height defining a distance between the belt and a bottom surface of the die, wherein the extrusion height is greater than zero, wherein the bottom surface of the die is spaced apart from the belt, wherein the extrusion height is substantially the same as the height of the sheet or wherein the extrusion height is at least about 0.5(h), wherein “h” represents the height of the sheet or wherein the extrusion height is not greater than about 3(h).

3 . The method of claim 1 , wherein sectioning comprises completely separating a first portion of the sheet from a second portion of the sheet.

4 . The method of claim 1 , wherein sectioning comprises creating a channel partially separating a first portion of the sheet from a second portion of the sheet, the channel having a height less than a height of the first portion and second portion.

5 . The method of claim 1 , wherein sectioning is conducted on at least a portion of the sheet having a moisture content of at least 10% (Cm0), wherein “Cm0” represents the moisture content of the sheet during forming or at least about 30% (Cm0) or at least about 50% (Cm0) or at least about 75% (Cm0) or at least about 85% (Cm0) or at least about 90% (Cm0) or at least about 95% (Cm0) or wherein sectioning is conducted on at least a portion of the sheet having a moisture content that is substantially the same as the moisture content of the mixture during forming.

6 . The method of claim 1 , wherein sectioning includes applying a pressure differential to the sheet during sectioning, wherein sectioning includes applying a pressure differential via a vacuum table during sectioning, wherein sectioning includes applying a pressure differential to the sheet and limiting movement of the sheet in at least one direction during sectioning.

7 . The method of claim 1 , wherein sectioning comprises translating a plurality of blades through at least a portion of the sheet, wherein the plurality of blades are arranged in a gang configuration, wherein the plurality of blades are separated by blade spacers, wherein the blade spacers define a blade spacer variation of not greater than about 0.01 or not greater than about 0.009 or not greater than about 0.005.

8 . The method of claim 1 , wherein sectioning comprises translating a plurality of blades through at least a portion of the sheet, wherein each blade of the plurality of blades has a blade edge thickness of at least 0.001 mm thick or at least about 0.01 mm thick or at least about 0.02 mm thick or at least about 0.05 mm thick or at least about 0.1 mm thick, and not greater than about 3 mm thick.

9 . The method of claim 1 , wherein sectioning comprises translating a plurality of blades through at least a portion of the sheet, wherein at least one blade of the plurality of blades has a dulled tip, wherein at least one blade of the plurality of blades has a rounded edge, wherein at least one blade of the plurality of blades has a squared edge.

10 . The method of claim 1 , wherein sectioning comprises translating a plurality of blades through at least a portion of the sheet, wherein each blade of the plurality of blades has a blade edge thickness (BET) and wherein each of the blades of the plurality of blades are separated from each other by blade spacers defining a blade spacing variation (BSV), wherein BET>BSV, wherein BET is at least one order of magnitude greater than BSV, wherein sectioning includes using a ratio (BET:BSV) of blade edge thickness to blade spacing variation of at least about 2:1 or at least about 3:1 or at least about 4:1 or at least about 5:1 or at least about 6:1 or at least about 7:1 or at least about 8:1 or at least about 9:1 or at least about 10:1.

11 . The method of claim 1 , wherein the at least one shaped abrasive particle comprises a two-dimensional shape as viewed in a plane defined by a length and a width of the shaped abrasive particle selected from the group consisting of polygons, ellipsoids, numerals, Greek alphabet characters, Latin alphabet characters, Russian alphabet characters, complex shapes having a combination of polygonal shapes, and a combination thereof.

Assignees

• Saint Gobain Ceramics

Inventors

• Braun Paul

Classifications

• C09K3/1409 Primary

  Abrasive particles per se (preparation of diamond C01B32/25) · CPC title

• C04B2235/3218

  Aluminium (oxy)hydroxides, e.g. boehmite, gibbsite, alumina sol · CPC title

• B01J2/20

  by expressing the material, e.g. through sieves and fragmenting the extruded length · CPC title

• B29C48/355

  Conveyors for extruded articles · CPC title

• B29C2948/92647

  Thickness · CPC title