CERAMIC COATED SCREW TOP CONTAINER

Abstract

A closable container and method of its manufacture, the container having an inner layer, an outer layer, a top and a base, the top inner layer having a coupling mechanism configured to receive a lid that seals the container using a screw top coupling mechanism, the inner layer and the outer layer made of stainless steel, the top inner layer evenly coated with a ceramic layer.

Description

FIELD

The invention relates generally to ceramic coated screw top container and more specifically to ceramic coated screw top container which is resistant to cracking when a screw top lid is attached.

BACKGROUND

Humans consume hot and cold beverages heavily, typically out of heat insulated containers that can retain the beverage temperature. Such heat insulated containers are made of stainless steel, and typically comprise 2 layers, an inner and an outer wall separated by an air insulation layer that provides insulation to maintain the temperature of the beverage.

However, taste of beverages tends to get ruined when consumed out of stainless steel cups. Ceramic cups are better suited for retention of taste of beverages. Thus, a number of double walled stainless steel cups have been improved upon through its coating with ceramic. Unfortunately, ceramic coatings are not compatible with screw top lids as the coating tends to crack under the pressure.

Thus, there is a dire need to containers that are well insulated while still retaining the taste of beverages.

SUMMARY

In one aspect, the invention provides a closable container comprising a coupling mechanism for attaching the lid wherein the coupling mechanism comprises a screw thread configured to couple with a corresponding screw thread around the lid such that when tightly coupled the lid forms a water-tight seal such that liquids within the container are retained therewithin. At least the screw thread of the closable container comprises a ceramic coating such that the ceramic layer provides a good seal when closed with a screw top lid without cracking the ceramic layer.

In another aspect, the invention provides a method for manufacturing a closable container comprising a stainless steel base configured to be sealed by a screw-top lid, the closable container comprising a coupling mechanism for attaching the lid wherein the coupling mechanism comprises a screw thread configured to couple with a corresponding screw thread around the lid such that when tightly coupled the lid forms a water-tight seal such that liquids within the container are retained therewithin. The method comprises obtaining a stainless steel container having a screw thread coupling mechanism around its opening. The method then includes spraying a ceramic coating evenly over an inner wall of the container and the screw thread coupling mechanism; and baking the container at high temperature for a predetermined period of time.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and aspects of the invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

FIG. 1 is a top view of the closable container of the invention.

FIG. 2 is a side perspective view of the closable container of the invention.

FIG. 3 is a side view of the closable container of the invention.

FIG. 4 is a side view of another exemplary embodiment of the closable container of the invention.

FIG. 2 is a flowchart representation of exemplary steps involved in the manufacture of the closable container of the invention.

DETAILED DESCRIPTION

The definitions provided herein are to facilitate understanding of certain terms used frequently herein and are not meant to limit the scope of the present disclosure.

As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” encompass embodiments having plural referents, unless the content clearly dictates otherwise.

Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein.

As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.

As noted herein, in one aspect the invention provides a closable container. Turning to the drawings, FIG. 1 is a top view of the closable container of the invention, represented generally by numeral 10. The closable container 10 comprises an inner layer 12, an outer layer 14, a top 16 and a base 18. The exemplary closable container of the invention comprises an insulation layer (not shown in the figure) between the inner layer 12 and the outer layer 14. The inner layer 12 and the outer layer 14 are typically made of stainless steel, and may be made of the same grade of stainless steel. Alternately, the inner layer 12 may be made of an 18/8 stainless steel while the outer layer may be made of an 18/0 stainless steel. One skilled in the art would know that 18/8 stainless steel represents a specific grade of stainless having a specific chemical composition containing 18% chromium (Cr) and 8% nickel (Ni). 18/8 steel is one of the most widely used material owing to its excellent corrosion resistance in mild environments, and has good weldability and mechanical properties. Similarly, 18/0 means the steel consists of 18% of chromium and 0% of nickel.

In some embodiments, the closable container 10 further comprise an insulating layer (not shown in figure) disposed between the inner layer 12 and outer layer 14. The insulating layer will provide for thermal insulation so that the temperature of the beverage is maintained for long periods of time, while the outer layer remains relatively cool thus allowing for a user to grip the container without feeling the heat or the cold of the beverage. Suitable materials useful as insulators in the invention include, for example, but not limited to, air, inert gases such as nitrogen, argon, etc., rockwool, fiberglass, polystyrene, polyurethane, cork, and the like, and combinations thereof.

The top inner layer of the closable container comprises a coupling mechanism that comprises a screw thread 20 configured to couple with a screw top lid 22. While the invention has been described using a screw top coupling mechanism, other coupling mechanisms such as snap-fit closures are also applicable in the invention, and are encompassed to be within the scope of the invention. At least the screw thread 20 comprises a ceramic surface layer, wherein the ceramic surface layer is resistant to cracking under pressure applied when the screw-top lid is fastened tightly thereto. In other exemplary embodiments, the entire inner layer is coated with a ceramic layer. The ceramic surface layer comprises a coating having a depth ranging from about 20 micrometers to about 30 micrometers.

Ceramics is a generic term applicable to a wide range of materials that are chemically carbides, oxides, nitrides, and the like, and combinations thereof. They are known to have excellent properties such as, but not limited to, chemical resistance, thermal resistance, ease of processability, excellent mechanical properties such as tensile strength and Young's modulus, and so on. The closable container of the invention comprises ceramic that is resistant to a temperature of at least about 300 degrees Celsius.

FIG. 2 is a side perspective view of the closable container 10 of the invention. In this exemplary embodiment, the closable container comprises a cylinder having two different diameters, wherein the smaller diameter cylinder is present at the bottom portion. Other shapes and configurations are also contemplated to be within the scope of the invention. In FIG. 2, the screw top lid is not shown for the sake of clarity. The closable container comprises the inner layer 12, the outer layer 14, the top 16, and the base 18, wherein the inner and outer layer are separated by an insulating layer (not shown) as described herein. The top inner layer comprises a screw thread 20 that comprises a ceramic coating, wherein the screw thread 20 is configured to receive a screw top lid.

FIG. 3 is a side view of the closable container 10 of the invention. In this exemplary embodiment, the closable container comprises a cylinder having a diameter that gently tapers from the top to the bottom. The cylinder comprises the inner layer 12, the outer layer 14, the top 16 and the base (not seen in this view), wherein the top inner layer comprises a screw thread 20 that is configured to receive a screw top lid (not shown in this figure for clarity sake).

FIG. 4 is a side view of yet another exemplary embodiment of the closable container 10 of the invention. In this exemplary embodiment, the top 16 is narrower than the body of the container, thus giving the closable container a neck portion. The closable container 10 comprises a ceramic coating on the screw thread 20 on the top inner layer.

Also as noted herein, the invention provides a method for manufacturing a closable container of the invention. Figure is a flowchart representation of the method steps involved in the method of manufacturing, generally depicted by numeral 200. The method comprises providing a stainless steel container having an inner layer, an outer layer, a top and a base shown in step 202, wherein the top inner layer comprises a screw thread coupling mechanism. Then, the method comprises spraying a ceramic coating evenly over at least the top inner layer of the stainless steel container that comprises the screw thread coupling mechanism, shown in step 204, to provide a sprayed container. Spraying is a very well-known technique in the art and is achieved in a facile manner by the use of an apparatus such as a spray gun. In a typical use case scenario, the spray gun is loaded with a solution or a uniform suspension of the material to be coated in a suitable medium. Exemplary mediums useful in the invention include water, ethanol, isopropanol, acetone, ethyl acetate, and the like, and combinations thereof.

The method then includes step 206 of baking the sprayed container at a predetermined temperature for a predetermined time to obtain the closable container of the invention. Baking can be achieved in any known apparatus known to those of ordinary skill in the art. These may include for example, a conduction oven, a convection oven, microwave oven, and the like. Exemplary time frames for baking range from about 30 minutes to about 60 minutes. In one exemplary embodiment, baking the container at high temperature comprises baking the container for 45 minutes. Exemplary temperatures for baking the sprayed container range from about 200 degrees Celsius to about 400 degrees Celsius. In one specific embodiment, baking the sprayed container is done at a temperature of about 300 degrees Celsius.

Other methods to coat the ceramic onto the stainless steel container will also become obvious to one skilled in the art and are envisioned to be encompassed within the scope of the invention. These may include, for example, but not limited to, cold sintering, pressure sintering, isostatic pressing, cold isostatic pressing, and the like, and combinations thereof.

Thus, the invention provides a new method of coating the surface of stainless steel with ceramic layer resistant to high temperatures by spraying the surface with a spray gun and baking at 300 C for 45 minutes.

While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

Claims

1. A closable container made of stainless steel comprising an inner layer, an outer layer, a top and a base, the top inner layer comprising a coupling mechanism that comprises a screw thread configured to couple with a screw top lid, wherein: at least the screw thread comprises a ceramic surface layer, wherein the ceramic surface layer is resistant to cracking under pressure applied when the screw-top lid is fastened tightly thereto.

2. The closable container of claim 1 wherein the ceramic surface layer has a depth ranging from about 20 micrometers to about 30 micrometers.

3. The closable container of claim 1 wherein the ceramic surface layer is resistant to a temperature of about 300 degrees Celsius.

4. The closable container of claim 1 wherein the inner layer is made of an 18/8 stainless steel and the outer layer is made of an 18/0 stainless steel.

5. The closable container of claim 1 further containing an insulating layer between the inner layer and the outer layer.

6. The closable container of claim 1 wherein the insulating layer comprises at least one of, air, wool, fiberglass, polystyrene, polyurethane, and combinations thereof.

7. A method for manufacturing a closable container made of stainless steel comprising an inner layer, an outer layer, a top and a base, the top inner layer comprising a coupling mechanism that comprises a screw thread configured to couple with a screw top lid, the method comprising: providing a stainless steel container;spraying a ceramic coating evenly over at least the top inner layer of the stainless container that comprises the screw thread coupling mechanism to provide a sprayed container; andbaking the sprayed container at a predetermined temperature for a predetermined time to obtain the closable container.

8. The method of claim 7 wherein the predetermined temperature ranges from about 200 degrees Celsius to about 400 degrees Celsius.

9. The method of claim 7 wherein the predetermined temperature is about 300 degrees Celsius.

10. The method of claim 7 wherein the predetermined time ranges from about 30 minutes to about 50 minutes.

11. The method of claim 7 wherein the predetermined time is about 45 minutes.

12. The method of claim 7 wherein the step of spraying the ceramic coating is with a spray gun.