RAPID DEFROSTING TRAY

Abstract

A defrosting tray includes a metal substrate, a thermal conductive ceramic coating formed on the top surface of the metal substrate, and an inorganic nanocoating formed on a top surface of the thermal conductive ceramic coating. The thermal conductive ceramic coating is configured to enhance a heat transfer capability of the metal substrate. In particular, the first ceramic coating and the first inorganic nanocoating together define a defrosting surface with sub-micron pyramidal arrays.

Claims

1. A defrosting tray comprising: a metal substrate having a top surface and a bottom surface; a first thermal conductive ceramic coating formed on the top surface of the metal substrate and configured to enhance a heat transfer capability of the metal substrate; and a first inorganic nanocoating formed on a top surface of the first thermal conductive ceramic coating; wherein the first thermal conductive ceramic coating and the first inorganic nanocoating together define a defrosting surface with sub-micron pyramidal arrays.

2. A defrosting tray as recited in claim 1, wherein the metal substrate defines a plurality of grooves in the bottom surface thereof, and the defrosting tray further includes: a second thermal conductive ceramic coating formed on the bottom surface of the metal substrate and configured to enhance the heat transfer capability of the metal substrate; and a second inorganic nanocoating formed on a bottom surface of the second thermal conductive ceramic coating; wherein the second thermal conductive ceramic coating and the second inorganic nanocoating together define a defrosting surface with sub-micron pyramidal arrays.

3. A defrosting tray as recited in claim 1, wherein the metal substrate comprises aluminum alloy.

4. A defrosting tray as recited in claim 1, wherein the first inorganic nanocoating comprises a material selected from the group consisting of Silicon dioxide and Titanium dioxide.

5. A defrosting tray as recited in claim 1, wherein the first thermal conductive ceramic coating comprises an inorganic resin doped with inorganic heat-conductive powder.

6. A defrosting tray as recited in claim 5, wherein the inorganic resin of the first thermal conductive ceramic coating is made by a sol-gel process.

7. A defrosting tray as recited in claim 6, wherein the inorganic heat conductive powder of the first thermal conductive ceramic coating comprises Silicon carbide.

8. A defrosting tray as recited in claim 7, wherein the first thermal conductive ceramic coating has a thickness in the range of about 30 to 60 μm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a front perspective view of a defrosting tray in accordance with one embodiment of the present invention;

[0014] FIG. 2 is a rear perspective view of the defrosting tray in FIG. 1;

[0015] FIG. 3 is a partially cross-sectional view of the defrosting tray shown in FIG. 1;

[0016] FIG. 4 is a partially enlarged cross-sectional view of the defrosting tray shown in FIG. 3; and

[0017] FIG. 5 depicts, in a mesoscopic level, a sub-micron pyramidal array of a surface of the defrosting tray.

DETAILED DESCRIPTION OF EMBODIMENTS

[0018] Referring to FIGS. 1 and 2, there is shown a preferred embodiment of the defrosting tray 100. At a macroscopic level, the defrosting tray 100 has a hang hole 1 to allow the tray 100 to be placed on a hook, when not in use. The defrosting tray 100 has a flat top surface 101 as shown in FIG. 1, and a bottom surface 102 in which a plurality of grooves 2 are defined, as can be seen in FIG. 2. FIG. 3 is a partially cross-sectional view of the defrosting tray 100 shown in FIG. 1. FIG. 4 is a partially enlarged cross-sectional view of the defrosting tray shown in FIG. 3.

[0019] Referring to FIGS. 3 and 4, the defrosting tray 100 includes a metal substrate 3, a thermal conductive ceramic coating 4 coated around the periphery of the metal substrate 3, and an inorganic nanocoating (not shown) coated around the periphery of the thermal conductive ceramic coating 3. In other words, the metal substrate 3 is a core layer of the defrosting tray 100; the inorganic nanocoating is the outermost layer of the defrosting tray 100; and the thermal conductive ceramic coating 3 is a middle layer in between the metal substrate 3 and the inorganic nanocoating. The inorganic nanocoating has a thickness that is so small that it is not shown in FIG. 4. Moreover, the metal substrate 3 defines in its bottom surface a plurality of concaves (not numbered) from which the grooves 2 of the defrosting tray 100 are formed.

[0020] For simplification purpose, the following description will be made only to the upper part of the defrosting tray 100. As stated, it is to be understood the structure of the lower part are identical. Referring to FIG. 4, the metal substrate 3 is preferably made of alloy with high heat conductivity, such as aluminum alloy. The thermal conductive ceramic coating 4 is formed on the top surface 30 of the metal substrate 3, by spray coating methods, to assist heat absorption and/or heat dissipation of the metal substrate 3, and thereby to enhance the heat transfer capability of the metal substrate 3. Likewise, the inorganic nanocoating is formed on the top surface of the thermal conductive ceramic coating 4 by spray coating methods. The inorganic nanocoating comprises a material selected from the group consisting of Silicon dioxide and Titanium dioxide, which has the characteristics such as anti-oxidation, anti-corrosion and abrasion resistance to provide at least basic protection for the defrosting tray 100.

[0021] To promote heat transfer, the thermal conductive ceramic coating 4 is substantially made of an inorganic resin doped with inorganic heat-conductive powder. In this embodiment, the inorganic resin of the thermal conductive ceramic coating 4 is made by a sol-gel process. The sol-gel process is a wet-chemical technique used for the fabrication of both glassy and ceramic materials. In this process, the sol (or solution) evolves gradually towards the formation of a gel-like network containing both a liquid phase and a solid phase. Typical precursors are metal alkoxides and metal chlorides, which undergo hydrolysis and polycondensation reactions to form a colloid. If the liquid in a wet gel is removed under a supercritical condition, a highly porous material with high surface area is obtained. The basic structure or morphology of the solid phase can range anywhere from discrete colloidal particles to continuous chain-like polymer networks. It is during the sol-gel process of the inorganic resin that the inorganic heat conductive powder is added into the inorganic resin to form the thermal conductive ceramic coating 4. Preferably, the inorganic heat conductive powder of the thermal conductive ceramic coating 4 comprises silicon carbide (SiC) to increase the heat conductivity of the thermal conductive ceramic coating 4 and further to provide antibacterial properties.

[0022] Referring to FIGS. 3 and 4, the metal substrate 3 has a thickness of about 6 mm. The thermal conductive ceramic coating 4 has a thickness in the range of about 30 to 60 μm, preferably of about 40 to 50 μm. However, the thickness of the inorganic nanocoating is too small to be measured. Even though the thermal conductive ceramic coating 4 and the inorganic nanocoating together are extremely thin, they have excellent durability, rigidity and high thermal stability performance.

[0023] In particular, in a mesoscopic level, the thermal conductive ceramic coating 4 and the inorganic nanocoating together define a defrosting surface with sub-micron pyramidal arrays, as depicted in FIG. 5. With the pyramidal arrays, water released by the melting of the frozen food can hardly stay on the defrosting surface of the tray 100 but slip away, and the environment air can easily enter the gaps among the frozen food and the sub-micron pyramidal arrays of the defrosting tray 100, and therefore quickly transfer heat energy into the frozen food to be defrosted. Most particularly, even if the environment temperature drops down to below zero degrees (0° C.), the defrosting tray 100 can still function well as long as there is a temperature difference between the frozen food and the ambient environment, where the heat transfer process, i.e., the thawing process, can continue.

[0024] As described above, the defrosting tray of the present invention is an environmentally-friendly device that performs the function of food thawing in the absence of electrical energy consumption and in a relatively short amount of time.

[0025] It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure.