Microsphere-based insulating materials for use in vacuum insulated structures

A method for forming an insulating microsphere for use in an appliance cabinet, the method comprising steps of:

• heating glass particles to a predetermined temperature to define molten glass particles, wherein the molten glass particles form a microsphere having an outer wall and an interior volume that defines a hollow microsphere;
• cooling the molten glass particles to an intermediate temperature, to define solid microspheres, wherein the intermediate temperature is less than approximately 400 degrees Celsius;
• and
• coating the solid microspheres with an opacifier, wherein the heating, cooling and coating steps occur within a single assembly.

A method for forming low-density microsphere aggregates, the method comprising steps of:

• leaching a plurality of microspheres to define leached microspheres, wherein each leached microsphere includes an outer wall and an interior volume, wherein each leached microsphere includes at least one of a cavity and a hole within the outer wall of the leached microsphere;
• evacuating air from within the interior volume of each leached microsphere having a hole to define an insulating space within each leached microsphere having a hole;
• coating the leached microspheres with a binder, wherein the binder engages the leached microspheres and at least partially occupies at least a portion of the holes of the leached microspheres, wherein the binder at least partially defines the insulating space of the leached microsphere having a hole;
• and
• mixing the leached microspheres and the binder within a mixer, wherein mixing of the leached microspheres and the binder results in a plurality of microsphere aggregates, wherein at least a portion of the leached microspheres within the plurality of microsphere aggregates includes the insulating space.