Investigation of Shaped Abrasive Particles Vol. 1: Review of US Pat. No. 6,054,093 April 25, 2000 | Publication Date: 4.2.15
Summary:
Shaped abrasive particles have been known and utilized in various capacities within the field of grinding and finishing technologies for over 15 years. Shaped abrasive particles disclosed in US Pat. No. 6,054,093 (hereinafter the “‘093 Patent”) are formed through a screen printing process, referred to as the Torre Process. The following review characterizes the Torre particles formed according to Example 1 as described in the ‘093 Patent.
The following characteristics of the Torre particles include:
- The radius of curvature
- Grooves and protrusions including the ratio between the groove depth and average thickness
- Raised corners including the ratio between the corner thickness and midpoint thickness
- Perpendicular, obtuse, and acute angles between the surfaces
Keywords:
Inherent features of Shaped Abrasive Particles (SAPs), surface, major surface, contours, concave, convex, scoop-shape, curved, radius of curvature, sloping, sidewall, side wall, hole, holes, groove, grooves, screen printing, protrusions, thickness, artifacts, depth, raised corner, angles, sharpened edge, pattern, openings, body.
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Shaped Abrasive Particle Fractions and Method of Forming Same | Publication Date: 3.30.15
Summary:
Various methods of forming shaped abrasive particles including forming shaped abrasive particles having at least one predetermined stress concentration point and at least one predetermined stress concentration vector. Forming can include processing the precursor and fracturing the precursor shaped abrasive particle substantially along the predetermined stress concentration vector to form a fractured shaped abrasive particle. A shaped abrasive particle of may include a body having a bottom surface, an upper surface, and a side surface extending between the bottom surface and the upper surface, where the upper surface defines a shovel shape including a concave surface having a tip region including at least one tip corner and at least one rear region defining at least one rear corner. The tip corner can have a tip sharpness that is greater than a tip sharpness of the at least one rear corner.
Keywords:
Sol-gel, gel, production tooling, shaped abrasive particle (SAP), screen printing, molding, fracturing, fracture, tip, tip sharpness, shovel, concave surface, tip region, mixture.
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Shaped Abrasive Particle and Method of Forming Same | Publication Date: 3.30.15
Summary:
Methods of forming shaped abrasive particles. One method includes forming a mixture into a sheet and sectioning at least a portion of the sheet using a mechanical object to form a shaped abrasive particle from the sheet. Sectioning can include controlling at least one process parameter consisting of an extrusion height, a 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, or a combination of one or more of the process parameters. Forming can include extruding the sheet onto a belt. The sheet can contact a surface of the belt after extruding through an open die. The belt can translate during extrusion. The extrusion height between the belt and a bottom surface of the die can be controlled. The extrusion height can be greater than zero. The mixture can be a gel formed for a ceramic powder material and a liquid. The gel can be characterized as a shape-stable material having the ability to hold a given shape even in the green (i.e., unfired) state. The gel can include a powder material that is an integrated network of discrete particles.
Keywords:
Shaped abrasive particle (SAP), polyhedron, pyramid, ellipsoid, sphere, prism, cylinder, cone, tetrahedron, cube, cuboid, rhomohedron, truncated pyramid, truncated ellipsoid, truncated sphere, truncated cone, pentahedron, hexahedron, heptahedron, aoctahedron, nonahedron, decahedron, Greek alphabet character, Latin alphabet character, Russian alphabet character, volcano shape, monostatic, gel, sectioning, sheet, alumina, ceramic, belt, extrude, extrusion, die, die surface, green, powder, network, discrete particles, moisture content.
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Shaped Abrasive Particle and Method of Forming Same | Publication Date: 3.30.15
Summary:
Various processes of forming shaped abrasive particles including by additive manufacturing processes. Additive manufacturing processes can include processes wherein a body of the shaped abrasive particle is formed by compiling a plurality of portions together in a particular orientation with respect to each other such that, when the plurality is compiled, each of the discrete portions can define at least a portion of the shaped abrasive particle. In particular instances, the additive manufacturing process can be a template-free process, wherein the material being manipulated to form discrete portions, and ultimately the body itself, need not be placed within a template (e.g., a mold). Rather, the material being manipulated can be deposited in discrete portions, wherein each of the discrete portions has a controlled dimension such that when the plurality is compiled, the body also has a controlled dimension. Therefore, unlike typical molding operations, additive manufacturing processes of the embodiments herein may not necessarily need to incorporate a template that is configured to contain the material being manipulated to form the body. In particular instances, an additive manufacturing process that is used to form a shaped abrasive particle can be a prototype printing process. In more particular instances, the process of forming the shaped abrasive particle can include a prototype printing of a body of the shaped abrasive particle, where the shaped abrasive particle includes a shaped abrasive particle or a precursor shaped abrasive particle. In other instances, the additive manufacturing process may include or be considered a laminated object manufacturing process. In the laminated object manufacturing process, individual layers may be formed discretely and joined together to form the body of the shaped abrasive particle. In accordance with an embodiment, the method of forming a shaped abrasive particle having a body formed by an additive manufacturing process can include deposition of a first print material as a first portion of the body at a first time, and deposition of a second print material as a second portion of the body distinct from the first portion at a second time.
Keywords:
Alumina, Alpha-Alumina, 3D, three-dimensional, 3-dimensional, printing, print, layer additive method, light photopolymerization, laser powder forming, powder bed fusion, selective laser sintering, micro-laser sintering, material extrusion robocasting, material jetting, sheet lamination, shaped abrasive particle (SAP), polyhedron, pyramid, ellipsoid, sphere, prism, cylinder, cone, tetrahedron, cube, cuboid, rhomohedron, truncated pyramid, truncated ellipsoid, truncated sphere, truncated cone, pentahedron, hexahedron, heptahedron, aoctahedron, nonahedron, decahedron, Greek alphabet character, Latin alphabet character, Russian alphabet character, volcano shape, monostatic.
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