Heat reflecting glass manufacturers&suppliers in China

 

what is heat-reflecting glass?

 

Heat reflecting glass, also known as sunlight controlled coated glass, is a kind of coated glass with a reflective effect on sunlight, which is usually made by physically or chemically coating one or more layers of metal or metal oxide films on the surface of high-quality float glass, and its film color gives the glass rich colors.

 

Its energy-saving principle is to produce a certain control effect on the wavelength range of 350 ~ 1800 nm sunlight through the coating and to control the reflection, transmission, and absorption of direct sunlight in the required proportion.

 

Heat-reflective glass is made of colorless and transparent flat glass coated with metal film or metal oxide film, also known as coated glass or sunlight control film glass. It is the use of pyrolysis, vacuum vapor deposition method, a cathode sputtering method, etc., in the glass surface coated with gold, silver, copper, aluminum, chromium, nickel and iron and other metals or metal oxide film; or the use of ion exchange methods such as electro-floatation, metal ions to replace the original ions on the glass surface and the formation of the heat-reflective film. Heat-reflective glass is available in gold, teal, gray, purple, brown, bronze, and light blue.

 

This is a kind of glass that forms a heat-reflective coating layer on the glass surface through chemical thermal decomposition and vacuum coating technologies. For infrared rays from the sun, its reflectivity can reach 30% to 40%, or even up to 50% to 60%. This glass has good energy-saving and decorative effects.

 

It has stronger heat-reflective properties and can effectively reflect the sun's rays, including a large number of infrared rays, so that people inside feel cool and comfortable when the sun is shining.

 

Belongs to

Coated glass

 

Features

Unidirectional light transmission, mirror effect

 

Reflectivity

30%~40%

 

Heat reflection

Heat-reflective glass has a high thermal reflectivity, such as 6mm thick float glass, the total heat reflection of only 16%, the same conditions, the total heat-absorbing glass is 40%, while heat-reflective glass can be as high as 61%, so it is often made of hollow glass or laminated glass to increase its thermal insulation properties. Metal coated heat-reflective glass and the role of one-way image transmission, that is, during the day can see the outdoor scenery indoors, while the outdoor scenery can not be seen indoors.

 

Difference expressions

Heat-reflective glass is the surface of ordinary flat glass with a certain process will be gold, silver, aluminum, copper, and other metal oxides sprayed on to form a metal film, or electrolocation, plasma exchange method to the glass surface infiltration of metal ions to replace the original ions and form a thin film, also known as sunlight control coated glass.

Production of such coated glass methods is thermal decomposition method, spraying method, dip coating method, metal ion migration method, vacuum coating, vacuum magnetron sputtering method, chemical immersion method, etc.

The distinction between heat-reflective glass and propriety tinted flat glass (heat-absorbing glass) can be expressed by the following equation.
S = A/B
where A - the absorption coefficient of the entire luminous flux of the glass.
B - the reflection coefficient of the entire luminous flux of the glass.
Note that when S>1, it is the body tinted float glass; when S<1, it is the heat-reflective glass. 

 

Characteristics of heat-reflective glass

(1) Reflective and shading effect on light (also called sunlight control ability). Heat-reflective glass transmittance of visible light in the range of 20% to 65%, can reflect up to 50% of the heat effect of sunlight in the infrared and near-infrared, while only 15% of ordinary glass. This glass can ensure that the indoor lighting is in soft conditions, effectively shielding the solar radiation energy into the room.

 

(2) One-way image transmission. Metal-coated heat-reflective glass, with one-way image transmission characteristics. The surface metal layer of coated heat-reflective glass is extremely thin so that it has the characteristics of a mirror on the light side, and on the backside as transparent as window glass.

 

That is, in the daytime, you can see the outdoor scenery indoors, while outdoors you can not see the most image of the interior of the building to play the role of shade and curtain. The situation at night is the opposite, indoor people can not see the outside, while the outdoor can clearly see the interior. This is very meaningful for the decoration of stores, etc. The use of heat-reflective glass as curtain walls and windows and doors can make the whole building into a shining glass palace. Heat-reflective glass provides good conditions for the innovation of architectural design and the treatment and composition of the facade.

 

(3) Mirror effect. Heat-reflective glass has a strong mirror effect, so it is also known as mirror glass. With this glass for glass curtain wall, the surrounding landscape and the clouds of the sky can be mapped on top of the curtain wall, forming a gorgeous picture, so that the building and the natural environment to achieve perfect harmony. Heat-reflective glass is available in gray, bronze, teal, gold, light blue, and bronze, etc. 

 

How heat-reflective glass is made

The production process of heat-reflective coated glass is generally divided into two categories: offline and online. The processes for off-line production of heat-reflective coated glass mainly include vacuum thermal evaporation and magnetron sputtering. The process of online production of heat-reflective coated glass currently mainly includes floatation in-line coating method.

 

Vacuum evaporation method: The vacuum evaporation method is the earliest developed and lowest cost method in PVD technology. The method is to load the alloy wire material on the tungsten spiral evaporator, under high vacuum (vacuum degree up to 10-2Pa), through high current, short time of fast evaporation, so that the alloy wire atoms or molecules deposited on the glass surface, thus forming a solid alloy film.

 

The process flow of producing coated glass by vacuum evaporation coating technology is: glass slicing → cleaning → evaporation coating → high-temperature baking bucket finished product packaging.

 

In the process of evaporation coating, the vacuum chamber vacuum, evaporation voltage and time, alloy wire material, etc. have important influences on the light transmission performance, reflection performance, and color of the film layer. The vacuum evaporation method of preparing coated glass small investment, low cost, but can only be coated with a single layer of the metal film, the decorative effect is not good, and the glass film uniformity, acid, and alkali resistance, and resistance to discoloration are poor.

 

Magnetron sputtering method: vacuum magnetron sputtering coating method is the film-forming material as a target, after the cathode through 550 V negative high voltage, when the vacuum reaches a certain level, it produces a glow discharge plasma, through the vacuum chamber sputtering gas dissociation into positively charged ions and electrons, positively charged gas ions are attracted to the surface of the cathode, and impact the target, so that the target emits atoms, and then deposited on the glass surface on the glass surface, gradually accumulating to form a film, the magnetic field generated by the magnet binds the regenerated electrons emitted from the cathode surface, so that the electrons and gas atoms magnetically controlled opportunities increase, while generating more ions and increasing the sputtering speed.

 

The vacuum magnetron sputtering coating method can be divided into the DC magnetron sputtering coating method and RF magnetron sputtering coating method according to the different power sources used. According to the magnetron sputtering coating, the glass process is selection, slicing → cleaning, and drying → vacuum → sputtering → vacuum conversion.

 

The vacuum magnetron sputtering coating method can be manufactured according to different needs with multiple film layers and different optical properties of coated glass. The operating parameters of the method are easy to control and the quality of the product is stable.

 

The excellent characteristics of the vacuum magnetron sputtering coating method make it quickly develop into the most dominant method of producing coated glass at home and abroad. The technology is now commonly used in developed industrial countries to produce coated glass. However, the method also has a large footprint, large investment in equipment, low productivity, high operating costs, and other shortcomings, and most magnetron coated glass products can not be toughened and other deep processing. 

 

Uses of heat-reflective glass

Heat-reflective glass has good energy-saving and decorative effects and is mainly used in buildings that avoid heat gain due to solar radiation and set up the air conditioning. It is suitable for doors and windows of various buildings, windows of automobiles and ships, glass curtain walls, and various artistic decorations.

 

The use of heat-reflective glass can also be made of hollow glass or laminated glass windows to improve its thermal insulation properties. Such as heat-reflective glass and transparent glass composition with air layer of thermal insulation glass curtain wall, the shading coefficient is only about 0.1. This glass curtain wall thermal conductivity of about 1.74 W / (m. K), then a brick thickness of two sides of the plastered brick wall insulation is better. However, if the heat-reflective glass curtain wall is used inappropriately or use too large an area, it will cause light pollution and temperature rise around the building, affecting the harmony of the environment.