Processes for making a super-insulating core for a vacuum insulating structure

Patent metadata

Field	Value
Publication number	US-12065386-B2
Application number	US-202318333088-A
Country	US
Kind code	B2
Filing date	Jun 12, 2023
Priority date	Sep 28, 2016
Publication date	Aug 20, 2024
Grant date	Aug 20, 2024

Abstract

A method for forming a super-insulating material for a vacuum insulated structure for an appliance includes disposing hollow glass spheres within a rotating drum, wherein a plurality of interstitial spaces are defined between the hollow glass spheres. An anchor material is disposed within the rotating drum. The hollow glass spheres and the anchor material are rotated within the rotating drum, wherein the anchor material is mixed with the hollow glass spheres to partially occupy the interstitial spaces. A silica-based material is disposed within the rotating drum. The silica-based material is mixed with the anchor material and the hollow glass spheres to define a super-insulating material, wherein the silica-based material attaches to the anchor material and is entrapped within the interstitial spaces. The silica-based material and the anchor material occupy substantially all of an interstitial volume defined by the interstitial spaces.

First claim

What is claimed is:

1. An insulated structure for an appliance, the insulated structure comprising:
an inner liner and an outer wrapper that are attached together to define an insulating cavity therein;
a plurality of glass spheres disposed within the insulating cavity, the plurality of glass spheres defining interstitial spaces therebetween;
a coating material disposed at least partially on outer surfaces of the plurality of glass spheres, wherein the plurality of glass spheres and the coating material define an adhering base material; and
a silica-based material disposed on at least a portion of the adhering base material, wherein the coating material and the silica-based material occupy substantially all of an interstitial volume defined by the interstitial spaces.

2. The insulated structure of claim 1 , wherein the coating material is a functional group material.

3. The insulated structure of claim 2 , wherein the functional group material defines magnetic characteristics of the plurality of glass spheres to define positively charged glass spheres, and wherein the silica-based material is negatively charged and adheres to the positively charged glass spheres.

4. The insulated structure of claim 2 , wherein the functional group material is at least one of an amine functional group, a silanol functional group, and a silane functional group.

5. The insulated structure of claim 1 , wherein the coating material is a binder material.

6. The insulated structure of claim 5 , wherein the binder material generates adhesive surfaces of the plurality of glass spheres, and the silica-based material adheres to the adhesive surfaces via the binder material.

7. The insulated structure of claim 5 , wherein the binder material includes an organic binder.

8. The insulated structure of claim 5 , wherein the binder material includes at least one of cellulose, wax, polyethylene glycol, gelatin, starch, polyvinyl alcohol, polymethacrylates and sodium silicate.

9. The insulated structure of claim 1 , wherein the plurality of glass spheres are hollow glass spheres.

10. The insulated structure of claim 1 , wherein the plurality of glass spheres are nanospheres.

11. The insulated structure of claim 1 , wherein the inner liner and the outer wrapper define an insulating panel.

12. The insulated structure of claim 11 , wherein the insulating panel is a vacuum insulated panel.

13. The insulated structure of claim 1 , wherein the silica-based material includes at least one of fumed silica and precipitated silica.

14. The insulated structure of claim 1 , wherein the silica-based material at least partially includes perlite.

15. The insulated structure of claim 1 , wherein the insulating cavity defines an at least partial vacuum.

16. A method for forming a super-insulating material for a vacuum insulated structure for an appliance, the method comprising steps of:
disposing a process fluid in a rotating drum;
disposing a silica-based material into the process fluid within the rotating drum to form a silica-based liquid;
disposing glass spheres within the silica-based liquid;
mixing the glass spheres with the silica-based liquid; and
removing at least a portion of the process fluid from the silica-based liquid, wherein the silica-based material adheres to the glass spheres to define silica-coated spheres to form the super-insulating material, wherein a surface of the silica-coated spheres is indicative of the silica-based material.

17. The method of claim 16 , further comprising the steps of:
disposing a secondary insulating material into the rotating drum, wherein interstitial spaces are defined between the silica-coated spheres; and
mixing the secondary insulating material with the silica-coated spheres to define the super-insulating material, and wherein the secondary insulating material occupies substantially all of an interstitial volume defined by the interstitial spaces, wherein the step of removing the process fluid includes a chemical process, wherein a first portion of the process fluid is removed and a second portion of the process fluid binds the silica-based material to the glass spheres.

18. A method for forming a super-insulating material for a vacuum insulated structure for an appliance, the method comprising steps of:
disposing a silica-based material into a mixing drum, wherein the mixing drum includes at least one mixing impeller;
disposing an opacifier into the mixing drum, wherein the silica-based material is mixed with the opacifier;
disposing a granulation fluid into the mixing drum, wherein the granulation fluid is combined with the silica-based material and the opacifier;
removing a first portion of the granulation fluid from the mixing drum, wherein a second portion of the granulation fluid bonds with the silica-based material to define a densified silica-based mixture; and
conducting at least one milling operation wherein the at least one mixing impeller granulates the densified silica-based mixture to define the super-insulating material.

19. The method of claim 18 , wherein the first portion of the granulation fluid includes at least one solvent and the second portion of the granulation fluid includes a binding material, wherein the at least one solvent includes at least one of water, ethanol and isopropanol, and wherein the at least one solvent is removed through evaporation.

20. The method of claim 18 , wherein the second portion of the granulation fluid forms polar bonds with the silica-based material to define the densified silica-based mixture.

Assignees

• Whirlpool Co

Inventors

• Deka Lakshya J
• Vasko Eric J

Classifications

• F25D2201/14

  using subatmospheric pressure · CPC title

• F25D23/06

  Walls (F25D23/08 takes precedence; containers with thermal insulation B65D81/38) · CPC title

• F16L59/029

  layered · CPC title

• F16L59/028

  Compositions for or methods of fixing a thermally insulating material · CPC title

• C04B2201/30

  for heat transfer properties such as thermal insulation values, e.g. R-values · CPC title