A two-millimeter automotive float glass production method for improving the wave number and the edge stability

Abstract

The application discloses a two-millimeter automobile float glass production method for improving wave degree and edge stability, and belongs to the technical field of automobile glass. The application forms two different temperature control curves on the top of the well and the bottom of the well by controlling the temperature of each area of the top of the well and the bottom of the well, so that the effective discharge of gas of the glass liquid is ensured, and the micro-bubble defects in the glass product are less than 350 per hour. The suitable electric heating opening of the edge pulling machine, the tin bath and the transition roller table and other parts is controlled, so that the transverse temperature difference of the glass plate is reduced, the coincidence degree of the bending degree of the glass edge and the measured value of the point plate instrument is ensured to be 99% or above, and then the forming temperature is ensured to be 1050-1060 degrees, the parameters of the edge pulling machine are optimized, the angle of the first pair of edge pulling machines is 0-2 degrees, the angle of the last pair of edge pulling machines is 0 degrees or a negative angle, and the like. The zebra angle of the 2.0mm series float glass is ensured to be more than 50 degrees. The wave degree of the produced 2.0mm series automobile windshield glass can be more than 50 degrees, and the process requirements of the 2.0mm series automobile windshield glass can be met.

Description

Technical Field

[0001] This invention relates to the field of automotive glass technology, and in particular to a method for producing two-millimeter automotive float glass that improves the corrugation and edge stability. Background Technology

[0002] High-quality automotive glass, a crucial component of the automotive industry, is primarily used in the production of windshields, particularly in the application of premium 2.0mm float glass. The production of 2.0mm series premium float glass is a complex system, involving rigorous management and operation at every stage, from raw material quality control and batching to the melting furnace, tin bath, and annealing furnace. While my country's float glass production line technology and equipment are comparable to those of foreign counterparts, the management and operation of these lines lag significantly behind. Initially, the quality of 2.0mm series premium float glass may meet basic standards, but stable operation is short-lived, and quality fluctuations are common. Besides ensuring the production line equipment meets performance requirements, strict control over the production process and adjustment of process parameters are essential for stable production of 2.0mm series premium float glass. In particular, lax operational procedures are a major factor affecting the stable production of this type of glass.

[0003] Many float glass production lines currently in normal operation in China have a history of producing 2.0mm series float glass. However, due to the unstable yield and grade of the products, the main product defects are the unstable (low) corrugation degree, the unstable edge curvature of the glass (separation), and the large amount of microbubbles. Most domestic float glass manufacturers have found it difficult to achieve stable large-scale production and continue to linger outside the field of high-quality 2.0mm float glass production technology and market competition. Summary of the Invention

[0004] The purpose of this invention is to provide a production method for 2mm automotive float glass that improves the corrugation degree and edge stability, in order to solve the problems of unstable yield and grade of 2.0mm series automotive float glass produced by float glass production lines, as well as the problems of unstable (low) corrugation degree, unstable edge curvature (separation) and excessive microbubbles in the products.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A method for producing two-millimeter automotive float glass with improved corrugation and edge stability, based on a float glass production line, wherein the specific production process of the two-millimeter automotive float glass is as follows:

[0007] S1. The raw materials are put into the glass furnace and melted into glass liquid. The temperature of each zone of the arch and the bottom of the pool is controlled to reduce the amount of glass liquid bubbles. The micro-bubble defects are controlled to be less than 350 per hour. The temperature of the molten glass liquid entering the high-temperature zone of the tin bath is controlled to be 1050-1060℃.

[0008] S2. The pulling capacity is adjusted and controlled at 580-600 t / d as needed, and the main drive speed of the pulling is controlled at 800-900 m / h.

[0009] S3. When the molten glass, after being spread, flattened, and polished, enters the thinning area, the electric heating opening of the edge section of the edge-pulling machine is controlled at 35% and the electric heating opening of the secondary edge section is controlled at 25%. The temperature of the rear end of the edge-pulling machine is kept at 835-845℃. Twelve pairs of edge-pulling machines are used for production. By adjusting the speed difference of each edge-pulling machine and the angle of each pair of edge-pulling machines, the thickness of the thinned glass strip is kept between 1.99 and 2.01 mm.

[0010] S4. Control the outlet temperature of the tin bath at 600-603℃. P-type water tanks are installed in opposite directions in the low-temperature zone of the tin bath to control the lateral temperature difference of the glass plate at 1-2℃.

[0011] S5. After the glass strip is thinned, it enters the transition roller table. The electric heating opening of the transition roller table is controlled at 20-30% to compensate for the heat dissipation at the edge of the transition roller table and increase the temperature at the edge of the glass strip, so as to control the transverse temperature difference of the glass plate at 1-2℃.

[0012] S6. When the glass strip enters the annealing furnace, the electric heating at the edge of the annealing furnace is turned on and the opening of the air valves at the edge of the A / B zones of the annealing furnace is appropriately reduced to reduce the lateral temperature difference, so as to control the lateral temperature difference of the glass plate at 1-2℃. The curvature of the glass edge coincides with the measurement of the spot plate instrument by 99% or more.

[0013] S7. After temperature-cooling cutting, a glass plate is obtained, and the zebra angle is stable at over 50 degrees.

[0014] A further technical solution is: in S1, a P-type water tank is used at the end of the narrow section of the tin bath, and the electric heating opening at the edge of the outlet of the low-temperature zone of the tin bath is 30-50%.

[0015] A further technical solution is: in S3, the speed difference between the first pair and the second first pair of edge-pulling machines is 10m / h, the speed difference between the last pair and the second last pair of edge-pulling machines is 10m / h, and the speed difference of the other edge-pulling machines is 20-40m / h.

[0016] A further technical solution is as follows: In S3, the angles between the 12 pairs of edge-pulling machines and the relative flow direction are as follows: the first pair of edge-pulling machines is 0-2°, the second pair of edge-pulling machines is 4-8°, the third pair of edge-pulling machines is 10.5-11°, the fourth pair of edge-pulling machines is 10°, the fifth pair of edge-pulling machines is 9-10°, the sixth pair of edge-pulling machines is 11.5-12°, the seventh pair of edge-pulling machines is 10°, the eighth pair of edge-pulling machines is 8-9°, the ninth pair of edge-pulling machines is 7-8°, the tenth pair of edge-pulling machines is 7-8°, the eleventh pair of edge-pulling machines is 3-4°, and the twelfth pair of edge-pulling machines is -1-0°.

[0017] A further technical solution is as follows: In S1, according to the flow direction of the molten glass, the temperatures of each thermocouple at the melting arch of the glass furnace are, in sequence, 1510±5℃, 1538±5℃, 1594±5℃, 1616±3℃, 1615±3℃, 1594±3℃, 1560±3℃, 1451±3℃, 1423±3℃, 1181±5℃, and 1105±5℃.

[0018] A further technical solution is as follows: In S1, according to the flow direction of the molten glass, the temperatures of the thermocouples at the bottom of the melting pool of the glass furnace are, in sequence, 1077±5℃, 1140±5℃, 1134±5℃, 1140±3℃, 963±3℃, 1145±3℃, 1178±3℃, 1171±3℃, 1177±3℃, 1044±5℃, and 934±5℃.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] In this invention, the temperature of the high-temperature zone of the solder bath is increased by 1050-1060 degrees Celsius, and the electric heating at the edge of the edge-pulling machine area is increased by 35%, and the electric heating at the secondary edge is increased by 25% to compensate for heat dissipation at the edge of the solder bath. This helps to reduce the lateral temperature difference and maintain the temperature behind the edge-pulling machine at 835-845 degrees Celsius. The edge-pulling machine angle is not set to 0 degrees or a negative angle. After adjustment, the zebra angle is observed to be stable above 50 degrees.

[0021] In this invention, a P-type water bath is used at the end of the narrow section of the tin bath, and the electric heating at the edge of the tin bath outlet is increased by 30-50% to raise the temperature of the glass strip edge. The electric heating of the transition roller table is increased by 20-30% to compensate for the heat dissipation at the edge of the transition roller table and raise the temperature of the glass strip edge. The electric heating at the edge of the annealing furnace is increased, and the opening of the air valves at the edge of the A and B zones of the annealing furnace is appropriately reduced to reduce the lateral temperature difference. The curvature of the glass edge is stabilized after adjustment.

[0022] In this invention, by controlling the temperature of each zone at the top of the arch and the bottom of the pool, the melting heat load is adjusted, the hot spot and clarification temperature are increased, thereby reducing the amount of bubbles in the molten glass and ensuring that the number of microbubble defects in the glass plate is less than 350 per hour. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0024] Therefore, the following detailed description of embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0026] The following are some control parameters for a 2.0mm automotive float glass production line (only a portion is shown due to the large amount of data):

[0027] Table 1. Examples of Production Parameters for 2mm Float Automotive Glass

[0028] Table 2, Parameters of 12 Pairs of Edge-Pulling Machines

[0029] Table 3. Heating Degree of Each Zone in the Tin Bath

[0030] Table 4. Zebra Corner of 2.0mm Automotive Float Glass

[0031] Table 5. Examples of melting temperatures in glass furnaces

[0032] Table 6. Defect Status (Average Number per Hour)

[0033] Based on the above production control parameters for producing 2.0mm automotive float glass, the present invention provides the following embodiments. Example

[0034] A method for producing two-millimeter automotive float glass with improved corrugation and edge stability, based on a float glass production line, wherein the specific production process of the two-millimeter automotive float glass is as follows:

[0035] S1. The raw materials are fed into the glass furnace and melted into molten glass. The temperature of each zone at the top and bottom of the glass furnace is controlled to reduce the amount of bubbles in the molten glass. The temperature of the molten glass entering the high-temperature zone of the tin bath is controlled at 1055℃ by removing the water bath from the high-temperature zone of the tin bath. There are a total of 15 thermocouples at the top of the glass furnace according to the direction of glass flow, and 11 thermocouples along the straight flow direction of the molten glass. The temperatures of these 11 thermocouples are as follows: 1510℃, 1538℃, 1594℃, 1616℃, 1615℃, 1594℃, 1560℃, 1451℃, 1423℃, 1181℃, and 1105℃. There are a total of 19 thermocouples at the bottom of the melting pool in the glass furnace, and 11 thermocouples along the straight flow direction of the molten glass. The temperatures of these 11 thermocouples are as follows: 1077℃, 1140℃, 1134℃, 1140℃, 963℃, 1145℃, 1178℃, 1171℃, 1177℃, 1044℃, and 934℃.

[0036] By controlling the temperatures of different zones at the top and bottom of the glass furnace, the melting temperature at the top of the furnace exhibits a single-peak temperature control curve that first rises and then falls, while the melting temperature at the bottom of the furnace exhibits a double-peak temperature control curve that first rises and then falls, then rises again and finally falls again. The bottom of the furnace reaches its temperature peak before the top of the furnace, indicating that near the front of the furnace, the gas at the bottom of the furnace is discharged into the molten glass layer first. Then, as the molten glass passes near the middle of the furnace, the huge temperature difference between the top and bottom of the furnace and the overall high temperature cause the gas and some volatile substances inside the material to evaporate, meaning that a large amount of gas in the molten glass layer is discharged rapidly. Finally, the temperature difference between the top and bottom of the furnace narrows and the temperature drops, ensuring the flow of the molten glass and preventing the gas at the bottom of the furnace from rising into the molten glass layer. This step is used to adjust the melting heat load, increase the hot spot and clarification temperature, and reduce the gas content in the molten glass to ensure that the number of melts per hour is below 320.

[0037] S2. The pulling capacity is adjusted and controlled at 580-600t / d according to the situation, and the main drive speed of the pulling is controlled at 850m / h.

[0038] To achieve slow production of wide sheets in the float glass production line, ensuring uniform glass strip thickness.

[0039] S3. When the molten glass, after being spread, leveled, and polished, enters the thinning zone, the electric heating on the edge of the edge-pulling machine is controlled at 35%, and the electric heating on the secondary edge at 25%, maintaining the rear end temperature of the edge-pulling machine at 840℃. Twelve pairs of edge-pulling machines are used for production. By adjusting the speed difference between each pair and the angle of each pair, the thickness of the thinned glass strip is maintained between 1.99 and 2.01 mm. The speed difference between the first and second first pairs of edge-pulling machines is 10 m / h, and the speed difference between the last and second last pairs is also 10 m / h. The speed differences for the other pairs are... The speed difference of the edge pulling machine is 30m / h; the angles of the 12 pairs of edge pulling machines with the relative flow direction are as follows: the first pair of edge pulling machines is 1°, the second pair is 5°, the third pair is 10.5°, the fourth pair is 10°, the fifth pair is 9.5°, the sixth pair is 11.5°, the seventh pair is 10°, the eighth pair is 8.5°, the ninth pair is 7.5°, the tenth pair is 7.5°, the eleventh pair is 3.5°, and the twelfth pair is -0.5°.

[0040] Adding 35% electric heating to the edge of the edge-drawing machine area and 25% electric heating to the secondary edge area compensates for heat dissipation at the edge of the solder bath, which helps to reduce the lateral temperature difference.

[0041] Based on the premise of temperature control at the edge of the edge-pulling machine and the tin bath, the temperature of the rear end of the edge-pulling machine (the 12th pair of edge-pulling machines) is maintained at 835-845 degrees Celsius to ensure that the glass forms a strip with extensibility and that the glass edges do not solidify. Furthermore, in conjunction with the speed and angle control of the 12 pairs of edge-pulling machines, the glass is thinned and its width is fixed within the effective time it takes for the molten glass to solidify into a strip. In particular, the angle of the last pair of edge-pulling machines is set to 0° or -1°, and after adjustment, the zebra angle is observed to be stable above 50 degrees. The first pair of edge-pulling machines cuts into the flowing molten glass at a small angle; the second to sixth pairs of edge-pulling machines use a large angle to quickly pull the glass when the temperature of the molten glass is high; the angles of the seventh to eleventh pairs of edge-pulling machines gradually decrease, and the initial width and thinning are achieved by gradually controlling the glass's cooling rate. The first pair of edge-pulling machines uses a negative angle to stabilize the width of the sheet.

[0042] S4. Control the outlet temperature of the tin bath at 602℃. P-type water tanks are installed in opposite directions in the low-temperature zone of the tin bath to control the lateral temperature difference of the glass plate at 1-2℃.

[0043] The tin bath outlet temperature is 602℃, which can provide insulation or heating for the edges of the glass ribbon, controlling the temperature difference between it and the center within 1-2℃. This reduces the instability of the glass edge curvature. Using a P-type water jacket (also called a large-head water jacket), the tin bath's low-temperature zone is arranged diagonally from left to right, effectively lowering the center temperature to reduce the lateral temperature difference of the glass ribbon, creating favorable conditions for glass annealing. The outlet edge of the tin bath's low-temperature zone is electrically heated, with an opening range of 30-50% to compensate for edge heat dissipation, increasing the edge temperature and further reducing the lateral temperature difference of the glass ribbon. This ensures stable glass edge curvature.

[0044] S5. After the glass strip is thinned, it enters the transition roller table. The electric heating opening of the transition roller table is controlled at 20-30% to compensate for the heat dissipation at the edge of the transition roller table and increase the temperature at the edge of the glass strip, so as to control the transverse temperature difference of the glass plate at 1-2℃.

[0045] Control the appropriate electric heating setting of parts such as the edge-pulling machine, tin bath, and transition roller table to reduce the lateral temperature difference of the glass plate and ensure that the curvature of the glass edge matches the measurement value of the spot tester by 99% or more.

[0046] S6. When the glass strip enters the annealing furnace, the electric heating at the edge of the annealing furnace is turned on and the opening of the air valves at the edge of the A / B zones of the annealing furnace is appropriately reduced to reduce the lateral temperature difference, so as to control the lateral temperature difference of the glass plate at 1-2℃. The curvature of the glass edge coincides with the measurement of the spot plate instrument by 99% or more.

[0047] S7. After temperature-cooling cutting, a glass plate is obtained, with the zebra angle stabilized above 50 degrees and the micro-bubble defects controlled to below 350 per hour.

[0048] In this invention, by controlling the temperature of each zone at the top of the arch and the bottom of the pool, the melting heat load is adjusted, the hot spot and clarification temperature are increased, thereby reducing the amount of bubbles in the molten glass and ensuring that the number of microbubble defects in the glass plate is less than 350 per hour.

[0049] This invention provides a method for producing two-millimeter automotive float glass that improves the corrugation degree and edge stability. The produced two-millimeter automotive float glass has a zebra angle that is stable above 50 degrees and a stable edge curvature, thereby reducing the amount of air bubbles in the molten glass and ensuring that the number of micro-bubble defects in the glass plate is less than 350 per hour.

[0050] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for producing two-millimeter automotive float glass with improved corrugation and edge stability, characterized in that, Based on the float glass production line, the specific production process for two-millimeter automotive float glass is as follows: S1. The raw materials are put into the glass furnace and melted into glass liquid. The temperature of each zone of the arch and the bottom of the pool is controlled to reduce the amount of glass liquid bubbles. The micro-bubble defects are controlled to be less than 350 per hour. The temperature of the molten glass liquid entering the high-temperature zone of the tin bath is controlled to be 1050-1060℃. S2. The pulling capacity is adjusted and controlled at 580-600 t / d as needed, and the main drive speed of the pulling is controlled at 800-900 m / h. S3. When the molten glass, after being spread, flattened, and polished, enters the thinning area, the electric heating on the edge of the edge-pulling machine is controlled at 35% and the electric heating on the secondary edge at 25%, maintaining the temperature at the rear end of the edge-pulling machine at 835-845℃. Twelve pairs of edge-pulling machines are used for production. By adjusting the speed difference of each edge-pulling machine and the angle of each pair of edge-pulling machines, the thickness of the thinned glass strip is kept between 1.99 and 2.01 mm. S4. Control the outlet temperature of the tin bath at 600-603℃. P-type water tanks are installed in opposite directions in the low-temperature zone of the tin bath to control the lateral temperature difference of the glass plate at 1-2℃. S5. After thinning, the glass strip enters the transition roller table. The electric heating opening of the transition roller table is controlled at 20-30% to compensate for heat dissipation at the edge of the transition roller table and increase the temperature at the edge of the glass strip, so as to control the transverse temperature difference of the glass plate at 1-2℃. S6. When the glass strip enters the annealing furnace, the electric heating at the edge of the annealing furnace is turned on and the opening of the air valves at the edge of the A / B zones of the annealing furnace is appropriately reduced to reduce the lateral temperature difference, so as to control the lateral temperature difference of the glass plate at 1-2℃. The curvature of the glass edge coincides with the measurement of the spot plate instrument to reach 99% or more. S7. After temperature-cooling cutting, a glass plate is obtained, and the zebra angle is stable at over 50 degrees. In S1, according to the direction of glass melt flow, the temperatures of each thermocouple at the bottom of the glass furnace melting pool are as follows: 1077±5℃, 1140±5℃, 1134±5℃, 1140±3℃, 963±3℃, 1145±3℃, 1178±3℃, 1171±3℃, 1177±3℃, 1044±5℃, and 934±5℃.

2. The method for producing two-millimeter automotive float glass with improved corrugation and edge stability according to claim 1, characterized in that: In S1, the narrow section of the tin bath uses a P-type water tank, and the electric heating opening at the outlet edge of the low-temperature zone of the tin bath is 30-50%.

3. The method for producing two-millimeter automotive float glass with improved corrugation and edge stability according to claim 1, characterized in that: In S3, the speed difference between the first pair and the second first pair of edge-pulling machines is 10 m / h, the speed difference between the last pair and the second last pair of edge-pulling machines is 10 m / h, and the speed difference of the other edge-pulling machines is 20 to 40 m / h.

4. The method for producing two-millimeter automotive float glass with improved corrugation and edge stability according to claim 3, characterized in that: In S3, the angles between the 12 pairs of edge-pulling machines and the relative flow direction are as follows: the first pair of edge-pulling machines is 0-2°, the second pair is 4-8°, the third pair is 10.5-11°, the fourth pair is 10°, the fifth pair is 9-10°, the sixth pair is 11.5-12°, the seventh pair is 10°, the eighth pair is 8-9°, the ninth pair is 7-8°, the tenth pair is 7-8°, the eleventh pair is 3-4°, and the twelfth pair is -1-0°.

5. The method for producing two-millimeter automotive float glass with improved corrugation and edge stability according to claim 1, characterized in that: In S1, according to the direction of glass melt flow, the temperatures of each thermocouple at the melting arch of the glass furnace are as follows: 1510±5℃, 1538±5℃, 1594±5℃, 1616±3℃, 1615±3℃, 1594±3℃, 1560±3℃, 1451±3℃, 1423±3℃, 1181±5℃, and 1105±5℃.