Effect of zirconia protective layer on performance of Low-E coated glass.
1. Introduction
Traditional architectural glass can only meet the simple requirements of building lighting and ventilation. With the development of the times, architectural glass not only develops in the direction of large areas and even glass curtain walls, but also has new functions such as energy saving, safety, and decoration. Glass product series, specifications, and varieties are becoming more and more refined. According to different performance requirements, people pay more and more attention to the selection of glass. Coated glass has a multi-layer coating, multiple colors, and strong performance, which makes it the most widely used glass product in people's production and life. Coated glass is a method of coating one or more layers of compound and metal film on the surface of the glass to change the original performance of the glass, thereby improving the comprehensive performance of glass. Coated glass is the product of the combination of modern thin film technology and traditional building materials. The application of thin film technology in the field of building materials has led to the emergence of new coated glass with specific functions.
Zirconia oxide film has many excellent physical and chemical properties such as high refractive index, low thermal conductivity, high mechanical strength, and low friction coefficient, has good application prospects in optical films and coatings and has attracted extensive attention. In this article, the coated glass was prepared by magnetron sputtering. Through the improvement of the coating process, the effect of oxidation anchor as a protective layer on the performance of the coated glass was studied.
2. The Low-E glass coating process
At present, the most commonly used process for coated glass is magnetron sputtering. This process uses high-quality float glass as the base material. The float glass is washed and dried, and the inlet buffer chamber, coating chamber, and outlet buffer chamber are in sequence on the coating line. , inspection and other stages, and finally produce qualified Low-E coated glass. The coating is the core of the whole process. Targets of different materials are distributed in the coating chamber. Under the combined action of a magnetic field and electric field, the targets are sputtered to form the required metal or metal oxide and deposited on the glass substrate to produce coated glass...
The automatic Low-E glass coating production line
Figure 1 The Low-E glass production process flow chart
Figure 1 is a flow chart of the production process of coated glass. Using 6mm ordinary soda-lime-silicon float glass as the substrate, magnetron sputtering coating is performed, and the base layer, dielectric layer, metal copper layer, Ag layer, the dielectric layer, and so on are sputtered in sequence. Zirconia protective layer, and finally get the finished coated glass. Compared with the previous coating glass process, the main difference is that a fault target is added at the far end of the coating equipment. During the preparation of the Low-E film, metal faults are oxidized to form an oxide fault layer and deposited on the dielectric layer as a Protective layer for the entire film layer. In this paper, the influence of the zirconia protective layer on the energy of coated glass is mainly studied.
3 The influence of zirconia protective layer on the performance of Low-E glass
3.1 Product performance and color stability
According to the production process in Figure 1, the Low-E coated glass product with a normal oxidation protective layer is produced. The measured performance and color data are as follows: the visible light transmittance is 52.54%, the reflectance is 20.68%, and the reflection color is: L*= 43.90, A*=-L76, B*=-4,18, surface resistance is 8.5Q.
The normal glass surface
The Low-E glass membrane surface
Figure 2 Color contrast photos before and after UV irradiation
The coated glass sample is subjected to an ultraviolet exposure test regarding the European standard (1000h) for insulating glass. After ultraviolet irradiation, no change was found in the color of the glass surface and the film surface, and the color comparison photos are shown in Figure 2. Measure the performance and color data before and after ultraviolet irradiation at the same position: the visible light transmittance is 52.67%, the reflectance is 20.65%, the reflected color is: L*=43.70, A*=-1.73, B*=-4.19, and the surface resistance is 8.5. It can be concluded that after the ultraviolet exposure test, the properties and color of the film layer are almost completely consistent with those before the test, so the product shows excellent stability.
Figure 3 Comparison photo of abrasion resistance test of coated glass with zirconia oxide protective layer and conventional products
Based on good wear resistance, the acid and alkali corrosion resistance of the film layer was compared regarding international industry standards. After soaking in 1 mol/L HCl and NaOH solution for 24 hours, the comparison photos of the samples are shown in Figure 4. The film surface of the coated glass with a zirconium oxide protective layer is intact, and there is no obvious acidification corrosion.
Figure 4 Comparison photos of acid and alkali resistance tests between coated glass with zirconia oxide protective layer and conventional products
3.2 Product high humidity oxidation resistance and high-temperature oxidation resistance
The sample was left exposed for a week under the environmental conditions of a temperature of 50°C and a relative humidity of 95%. The film surface is shown in Figure 5. The film surface is still intact, the color is stable, and there is no oxidation. To verify the subsequent high-temperature tempering and other processing performance, the sample was bent and tempered at 700°C in the experiment, and the bending and hollow sheet processing was tested. The photo of the finished product is shown in Figure 5-b. The Low-E coated glass with the protective layer of oxidation seedlings has undergone ultra-high temperature treatment, and the film layer has no oxidation spots, and the scratch resistance of the film layer and the bonding strength with the hollow structural adhesive is good when the hollow is combined. It can be concluded that the coated glass with a zirconium oxide protective layer shows excellent resistance to temperature and humidity oxidation and high-temperature oxidation resistance. This indicates that the single-piece storage time of the coated glass with the oxidation anchor protective layer can be greatly extended, the requirements for the storage environment are reduced, and its subsequent processing capabilities such as cutting, grinding, and tempering have been greatly improved, and the subsequent processing can be significantly reduced.
a. After high temperature and high humidity test
b. After high-temperature tempering
Figure 5. Photos of coated glass with zirconia oxide protective layer after high-temperature and high-humidity inspection and high-temperature tempering
4. Conclusion and Outlook
By improving the conventional coating process, the Low-E coated glass with zirconium oxide as the protective layer was prepared by magnetron sputtering. Through comparative experiments, it was concluded that the performance and color stability of the coated glass with a zirconium oxide protective layer were better. It has stable product wear resistance, acid and alkali resistance, and oxidation resistance, which provides higher feasibility for subsequent storage, transportation, and processing. Coated glass with a zirconium oxide protective layer exhibits excellent stability, significantly improves processability, production efficiency, and product quality, plays an extremely important role in the field of glass deep processing, and promotes the development of the industry and the progress of industrial technology. With the continuous development of the production process of coated glass, toughened coated glass, a high-efficiency, low-cost, and high-performance glass product, is more and more widely used in people's production and life.
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