WO2024063729A1

WO2024063729A1 - Thermochromic paint

Info

Publication number: WO2024063729A1
Application number: PCT/TR2023/050678
Authority: WO
Inventors: Esra Öztürk; Özge Hande YALÇIN DURAK
Original assignee: Yorglass Cam Sanayi̇ Ve Ti̇caret Anoni̇m Şi̇rketi̇
Priority date: 2022-09-22
Filing date: 2023-07-13
Publication date: 2024-03-28

Abstract

The invention relates to a method of obtaining a glass that changes color with heat, which comprises the following process steps; Coloring of a piece of glass that may have one holes or may not have any holes, which is preferably cut and grinded at the edges so as not to cut the hands of the people, with enamel paint and/or organic paint by silk¬ screen printing from a surface; Tempering of the glasses colored with enamel paint in tempering ovens at a temperature of 650-750 °C; App lication of thermochromic paints that changes color with heat by silk-screen printing to tempered glass; Baking of thermochromic painted glass by means of an IR dryer.

Description

THERMOCHROMIC PAINT

Technical Field

The invention relates to the method of applying thermochromic paint on glass to obtain glass that changes color with heat in the glass production process for use in the white goods sector (oven, refrigerator, etc.).

State of the Art

There is glass in the structures of white goods such as ovens, refrigerators, etc. according to the requirements. By means of this glass, it can easily be seen what is inside the white goods. This glass is used in every oven, and it is important for the monitoring of the product cooked in the oven by the user.

One of the studies on this subject in the known state of the technique is the United States Patent application numbered US2014355247. In this application, a transparent steam cooker is mentioned. The Turkish Patent document numbered TR2017 /21677 describes the transparent cooker design. This invention relates to a transparent cooker designed to ensure homogeneous cooking that allows to see inside during the cooking of food. The invention comprises of at least one frame forming the main body (4), at least one fixing part (7) located in the gaps in the frame (4) forming seating slots (A) by means of its protrusion, at least one inner glass suitable for placement in the seating slots (A) on the inner side of the volume where cooking takes place (3), at least one external glass suitable for placement in the seating slots (A) on the outer side of the volume (2), at least one free space (B) between the outer glasses (2) and inner glasses (3) when they are arranged parallel to each other in the seating slots (A), at least one cable channel (5) located in the frame (4), which allows the electrical cables connected to the busbars to be collected in one corner and removed to the exterior (3), at least one frame (4), at least one door that can be opened and closed, formed by the combination of an exterior glass (2) and an interior glass (6).

Although monitoring the condition of the product in the cooker is a critical requirement, it is also important how this process is performed. Studies in the known state of the technique do not create the desired effect in this regard, and there are also problems regarding applicability. In addition, since white goods are mostly located in the same room as kitchen cabinets, the glass image transparent in the middle disrupts the aesthetics of the image of the oven with cabinets. There is a need for products that show the inside of the cooker when it is used and where the glassy image disappears when it is not used.

Objective of the Invention

The present invention relates to a method of obtaining a glass that changes color with heat, which meets the requirements mentioned above, eliminates all the disadvantages and provides some additional advantages.

The primary objective of the present invention is that when the cooker starts to heat up, the thermochromic paint becomes transparent, allowing the product inside the cooker to be seen, but when the cooker is not in use the visual pollution of tray, grill, etc. products inside it is covered.

Another objective of the invention is to let the user have a clearer view of the heating of the cooker by means of the color change caused by thermochromic paint heating.

Another objective of the invention is to reduce the cooking time of paint by means of the IR dryer, to save energy and time.

In order to achieve the objectives described above, the invention is a method of obtaining a glass that changes color with heat, the said method comprising the following process steps:

A- Coloring of a piece of glass with enamel paint and/or organic paint by silk-screen printing from a surface;

B- Tempering of the glasses colored with enamel paint in tempering ovens and curing of organic paint in IR drying and/or drying oven;

C- Application of thermochromic paints that changes color with heat by silk-screen printing to tempered or cured glass;

D- Baking and/or curing of thermochromic painted glass by means of an IR dryer and/or drying oven.

The structural and characteristic features of the invention and all its advantages will be understood more clearly by means of the detailed description written below, and therefore the evaluation should be made taking into account this detailed description. Figures to Help Describe the Invention

Figure 1 - The view of a glass with enamel paint and/or organic paint applied on one surface

Figure 2- The view of a glass with thermochromic paint applied on the same surface enamel paint and/or organic paint.

Figure 3- The view of the glass obtained by the developed method with no heat applied

Figure 4- The view of the glass obtained by the developed method with heat applied

Detailed Description of the Invention

In this detailed description, the invention is described only for a better understanding of the subject and in such a way that it does not create any limiting effects.

The method of obtaining a glass that changes color with heat comprises the following process steps in its most basic form:

A- Coloring of a piece of glass that may or may not have holes, which is preferably cut and grinded at the edges so as not to cut the hands of the people, with enamel paint and/or organic paint by silk-screen printing from a surface;

B- Tempering of the glasses colored with enamel paint in tempering ovens at a temperature of 650-750 <C and curing of organic pai nt in IR drying and/or drying oven;

C- Application of thermochromic paints that changes color with heat by silk printing to tempered or cured glass (preferably at a viscosity value in the range of 8000-10000 cP);

The thermochromic paints mentioned in this document are paints that lose their color and become transparent when exposed to heat. By means of these paints, when the cookers containing the glass obtained by the mentioned method are heated, that is, when the product is used, the inside of the cooker becomes visible, and when the product cools down, the inside becomes invisible. In this way, the user easily understands when the cooker is heating up and when the cooker is not in use the interior image is not visible from the outside, providing an aesthetically pleasing appearance.

The invention also covers the use of glass that changes color with heat obtained by the developed method in cookers.

At the process step “A” of the developed method, first of all large glass panels are cut into the desired sizes by the machines without touching them. Then the cut glass is separated by the operators and fed to the line. The four sides of these separated glasses are grinded to prevent hand cutting. After the grinding process, holes are drilled in the desired size and number for the product to be mounted on the glass by means of the machines. At the last stage of the step “A" enamel paint of the desired color is applied to a surface of the perforated glasses and colored by silk printing with printing machines. Figure 1 shows an example view of the glass obtained by the process step A. At the process step “B”, the glasses colored with enamel paint are tempered in tempering ovens at a temperature of 650-750 <0 (the temperature varies depending on the type of glass, thickness and paint to be used) in order to increase the heat and impact resistance. At the process step” C", thermochromic paint is printed on the tempered glasses with printing machines on the surface the enamel has been applied. Figure 2 shows an example view of the glass obtained after the process step C. At the process step “D”, which is the final processing step, after printing with thermochromic paint, the glasses enter the IR dryer and the printing is cooked I dried. The IR dryer allows the glass to cook quickly.

The developed method was tested for the density of the paint used, the temperatures of the cookers where it will dry after printing, and the number of minutes it will stay in the cooker, as well as the surface roughness of the print formed in this direction. Thermochromic paint does not subjected to tempering because it is an organic paint. For this reason, an IR dryer is used. Due to the fact that the resistance drying used at present is heated in the drum, it is not possible to cook the paint quickly. IR drying is a preheating system installed in front of the drying oven, and the cooking event takes place in a shorter time due to the product reaching the desired temperatures during preheating. In this way, it is ensured that energy and time saving is achieved regarding natural gas requirement. By means of the IR dryer, the cooking time is reduced. The low viscosity of the thermochromic paint means that the paint is too fluid and not usable for silk-screen printing. For this reason, raw paint is added to thermochromic paint and its viscosity is preferably brought to the value in the range of 8000-10000 cP, making it suitable for silk-screen printing. The bubble problem of the thermochromic paint, the viscosity of which was made suitable, that occurs after printing is eliminated by making production with a silk T (mesh) value between 77 T-120 T.

Claims

CLAIMS A method of obtaining a glass that changes color with heat, characterized by comprising; the following steps:

A. Coloring of a piece of glass with enamel paint and/or organic paint by silk printing from a surface;

B. Tempering of the glasses colored with enamel paint in tempering ovens and curing of organic paint in IR drying and/or drying oven;

C. Application of thermochromic paints that changes color with heat by silkscreen printing to tempered or cured glass;

D. Baking and/or curing of thermochromic painted glass by means of an IR dryer and/or drying oven. The method according to claim 1 , characterized in that; the viscosity of the thermochromic paint applied in the process step” C" is in the range of 8000- 10000 cP. The method according to claim 1 , characterized in that; the glass mentioned in the process step” A” has been cut and the its edges have been grinded so that it does not cut the hands. The method according to claim 1 and claim 3, characterized by comprising; the glass mentioned in the process step” A” has no holes or has at least one hole. The method according to claim 1 , characterized in that; in the process step” B", the glasses are tempered in tempering ovens at a temperature of 650-750 <0 and the organic paint is cured in IR drying and/ or drying oven. The use of glass that changes color with heat obtained by a method according to any of the preceding claims in cookers.