Method and device for strip-shaped glass feeding and mobile phone cover glass on-line 3D compression molding

Abstract

The invention discloses a method and device for strip-shaped glass feeding and mobile phone cover glass on-line 3D compression molding, and belongs to the field of glass material preparation and machining. The device sequentially comprises a melting system, a feeding system, a heating system, a mold pressing system and a protective gas system; the device further comprises a traction system; the melting system comprises a glass melting furnace; the feeding system comprises a feeding channel, a slit feeder, a silicon carbon rod, a guide roller and a traction roller; the heating system comprisesa heating furnace and a heating element; the heating furnace comprises a shearing mechanism and the mold pressing system. A reducing atmosphere or a neutral atmosphere in the heating furnace is achieved through the protective gas system in a whole process. According to the method and the device, alkali aluminosilicate glass melt can be directly pressed and formed into the mobile phone cover protective glass with the thickness of 0.6-1.5 mm in one step, so that the accurate modeling of the mobile phone cover protective glass is maintained, the surface precision of the glass is ensured, and thegrinding and polishing workload of the surface of the compression-molded glass is reduced to a maximum extent.

Description

technical field [0001] The invention relates to a high-precision 3D molding method and device for a smart phone or a large touch screen, and belongs to the field of glass material preparation and processing. Background technique [0002] At the beginning of the 21st century, with the development of science and technology, mankind ushered in the era of smartphones, represented by the iPhone released in 2007. In addition to wireless communication functions, smartphones also support Internet, mobile office, entertainment, photography and other functions. Smart phones have the characteristics of thinness, large screen, and intelligence. It abandons the mobile phone keyboard and realizes relevant input and output operations and information browsing through the touch screen. [0003] The screen size of a smart phone accounts for more than 90% of the plane of a mobile phone, and when the screen size of a mobile phone is generally larger than 5, the screen of the smart phone is pron...

AI Technical Summary

Problems solved by technology

[0009] 1. The finished product after thermal bending of the 3D cover protection glass will show side thinning, which is only 0.6-0.7 times the thickness of the original glass sheet, such as figure 1 and image 3 As shown, the assembled mobile phone product has relatively poor drop resistance, and the side of the mobile phone (that is, the edge of the 3D mobile phone cover) often breaks;

[0010] 2. The hot bending molding process of the 3D cover protective glass belongs to the secondary thermal processing molding process, which will greatly increase the production energy consumption;

[0011] 3. The hot bending temperature needs to be above the glass expansion softening point temperature Td, and the existing cover glass is a chemically strengthened alkali-aluminosilicate glass, Al 2 o 3 The content range is 13-24wt%, and its expansion and softening point temperature is greater than 750°C, which is more than 120°C higher than that of soda-lime glass. In order to reduce the glass melt and mold adhesion and the heat dissipation of the mold, only graphite molds can do it now, but It is necessary to protect the graphite mold with inert gas and seal the heating furnace. Even in this way, the surface oxidation and surface collapse of the graphite mold can only be used for 3500 times, which has become the key to restricting the surface quality of the 3D cover glass;

[0012] 4. It is also difficult to achieve precise control of the uniformity of the temperature field of the heating furnace and the pressure of the male mold;

[0013] 5. The manufacturing cost of 3D cover protection glass is relatively high, and is affected by mold loss, low production efficiency, energy consumption, etc., so the price of 3D mobile phone cover protection glass is 70-120 yuan / piece;

[0014] 6. The hot-bending manufacturing process of 3D cover protective glass is relatively difficult, and the yield rate is only 40-60%, or even lower;

[0015] 7. The efficiency of hot bending forming of 3D cover protection glass is generally not high. For example, the maximum production capacity of an 18-station glass hot bending forming machine is only 1200-1400 pieces / 24h

[0017] Traditional press molding can only produce glass products with a thickness of more than 2mm, and the mass of the glass melt is required to be greater than 100g, while the mass of the protective glass of the mobile phone cover is only 16-19g at the age of 5-6, and the thickness is required to be less than 1mm. If the quality is too small, the heat brought by the glass melt will be insufficient to maintain a relatively high and stable temperature on the inner surface of the mold. After the glass melt enters the mold, the heat of the glass melt will be absorbed quickly, resulting in rapid occurrence of glass contact with the mold. Cooling, the viscosity increases rapidly, even under the pressure of the indenter (male mold), the glass melt cannot be extended quickly, and obvious glass cold lines will appear on the glass surface in contact with the mold, such as Image 6 As shown, it is similar to the shape of the waves when they rush to the beach, which seriously affects the appearance and flatness of the glass surface. It cannot be completely disappeared by flame polishing. Grinding and polishing requires a lot of manpower and material resources.

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