Processing method for relieving stress spots of tempered glass

Abstract

The invention provides a processing method for relieving stress spots of tempered glass, and belongs to the technical field of fine and deep processing of glass. Comprising the following steps: S1, cutting: taking a glass raw sheet, cutting the glass raw sheet to a proper specification according to a processing requirement, and grinding a broken sheet bevel edge to flatten the broken sheet bevel edge, so as to prevent quality problems such as edge breakage in a subsequent edge grinding processing process, and obtaining a glass substrate; s2, edging: carrying out edging treatment on the cut glass substrate; s3, cleaning: feeding the edged glass substrate into a cleaning machine to be cleaned and blow-dried; the method provided by the invention has the advantage that the produced tempered glass has light stress spots.

Description

Technical Field

[0001] The invention belongs to the technical field of glass deep processing, and in particular relates to a processing method for alleviating stress spots of tempered glass. Background Art

[0002] During the tempering process of glass, it is necessary to keep the heat in the tempering furnace, and then the glass is quickly sent to the cooling device and quenched with low-temperature and high-speed airflow; during this process, the outer layer of the glass shrinks and hardens first. Due to the low thermal conductivity of the glass, the interior is still at a high temperature at this time. When the interior of the glass also begins to harden, the hardened outer layer will prevent the shrinkage of the inner layer, so that the outer layer that hardens first produces compressive stress, and the inner layer that hardens later produces tensile stress. Therefore, when a beam of polarized light passes through the tempered glass, due to the permanent stress (tempering stress) in the tempered glass, this beam of light will be decomposed into two beams of polarized light with different propagation speeds, that is, the birefringence phenomenon. When the two beams of light formed at a certain point intersect with the beams formed at another point, there is a phase difference at the intersection point of the beams due to the different light propagation speeds. At this point, the two beams of light will produce interference. When the amplitude directions of the two beams of light are the same, the light intensity is enhanced, resulting in a bright field of view, that is, a bright spot; when the light amplitude directions are opposite, the light intensity is weakened, resulting in a dark field of view, that is, a dark spot. As long as there is uneven stress distribution in the plane direction of the tempered glass, stress spots will be produced.

[0003] As the market's awareness of safety tempered glass increases, stress spots on tempered glass are receiving more and more attention from the market. At the same time, designers and customers in the market clearly require that stress spots on tempered glass must be invisible to the naked eye and evenly distributed. Currently, there are more and more multi-layer, extra-large, and extra-thick glass on the market, and the requirements for stress spots on tempered glass are becoming more and more stringent. In order to better serve the market and achieve customer satisfaction, we must optimize the tempering process of glass to reduce its stress spots and improve product quality. Summary of the invention

[0004] The purpose of the present invention is to provide a processing method for reducing stress spots in tempered glass in view of the above-mentioned problems existing in the prior art, aiming at reducing the generation of stress spots in the glass tempering process.

[0005] The object of the present invention can be achieved by the following technical scheme: A processing method for reducing stress spots of tempered glass, characterized in that the method comprises the following steps:

[0006] S1. Cutting: Take the original glass sheet and cut it into appropriate specifications according to the processing requirements, and grind the bevel edge of the broken sheet to make it flat, so as to prevent quality problems such as edge collapse during the subsequent edge grinding process, and obtain a glass substrate;

[0007] S2, edge grinding: edge grinding the cut glass substrate;

[0008] S3, cleaning: sending the edge-grinded glass substrate into a cleaning machine for cleaning and drying;

[0009] S4, heating the tempering furnace: setting various process parameters of the tempering furnace, and starting the tempering furnace, making the heating power of the tempering furnace 28 to 32 kilowatts, the convection power 10 to 15 watts, and continuously raising the temperature in the tempering furnace to 610 to 620 degrees Celsius;

[0010] S5, heating: the cut, polished and cleaned glass substrate is placed in the tempering furnace which has been heated, and is heated in the furnace body of the tempering furnace for 30 to 40 minutes. During the heating process, the conveying roller in the tempering furnace body will drive the glass substrate to move back and forth at a speed of 170 to 190 mm per minute until the heating is completed;

[0011] S6, out of the furnace: After the glass substrate is heated, it will leave the tempering furnace body at a speed of 380-420 mm / min driven by the conveyor roller and move to the end of the tempering furnace air grid section;

[0012] S7. Cooling: After the glass reaches the end of the wind grid section, it returns at a speed of 110-130 mm and moves back and forth on the wind grid section at this speed for 10 minutes until the glass cools to below 40 degrees Celsius. It is then taken off the sheet, so that tempered glass with lighter stress spots can be obtained.

[0013] Preferably, in the wind grid section of the tempering furnace, the distance between each air nozzle and the upper surface of the glass is 80 mm.

[0014] Advantages of the present invention:

[0015] 1. The method of the present invention optimizes various parameters of the tempering furnace during glass tempering to make the glass heated and cooled more uniformly therein, thereby achieving the effect of reducing the stress spots of the glass. DETAILED DESCRIPTION

[0016] The following are specific embodiments of the present invention, which further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0017] A processing method for reducing stress spots of tempered glass comprises the following steps:

[0018] S1. Cutting: Take the original glass sheet and cut it into appropriate specifications according to the processing requirements, and grind the bevel edge of the broken sheet to make it flat, so as to prevent quality problems such as edge collapse during the subsequent edge grinding process, and obtain a glass substrate;

[0019] S2, edge grinding: edge grinding the cut glass substrate;

[0020] S3, cleaning: sending the edge-grinded glass substrate into a cleaning machine for cleaning and drying;

[0021] S4, tempering furnace heating: set various process parameters of the tempering furnace, and start the tempering furnace, so that the heating power of the tempering furnace is 30 kilowatts, the convection power is 13 watts, and the temperature in the tempering furnace is continuously raised to between 615 degrees Celsius;

[0022] S5, heating: the cut, polished and cleaned glass substrate is placed in the tempering furnace which has been heated up, and is heated in the furnace body of the tempering furnace. The heating time is 35 minutes, and during the heating process, the conveying roller in the tempering furnace body will drive the glass substrate to move back and forth at a speed of 180 mm per minute until the heating is completed;

[0023] S6, out of the furnace: After the glass substrate is heated, it will leave the tempering furnace body at a speed of 400 mm per minute driven by the conveyor roller and move to the end of the tempering furnace air grid section;

[0024] S7. Cooling: After the glass reaches the end of the wind grid section, it returns at a speed of 120 mm and moves back and forth on the wind grid section at this speed for 10 minutes until the glass cools to below 40 degrees Celsius. It is then taken off the sheet, so that tempered glass with lighter stress spots can be obtained.

[0025] Preferably, in the wind grid section of the tempering furnace, the distance between each air nozzle and the upper surface of the glass is 80 mm.

[0026] Compared with the traditional glass tempering process, the technical parameters of the method of the present invention are compared as shown in the following table:

[0027] Serial number Tempering process parameters Traditional crafts Process of the present invention 1 Heating temperature 680℃ 615℃ 2 Heating power 65kw 30kw 3 Convection power 4W 13W 4 Glass swing speed in furnace 120mm 180mm 5 Wind fence swing speed 80 mm 120mm 6 Glass out of furnace speed 250 mm 400mm 7 Nozzle distance 55mm 80mm 8 Heating time 700S 2100S

[0028] It can be seen from the above table that in the method of the present invention, the temperature of the tempering furnace body is set to a relatively low 615°C, and the heating time is extended by 3 times. The glass is heated by slow heating at a relatively low temperature, so that the temperature of each part of the glass rises more evenly, thereby making the stress distribution of the glass uniform, and the feedback to the stress spot situation more uniform, thereby achieving the effect of reducing the stress spot of the tempered glass.

[0029] By increasing the convection power in the tempering furnace, the air exchange in the furnace is faster and the temperature in the furnace is more uniform; by speeding up the swing speed of the glass in the furnace, the glass is heated more evenly. At the same time, by speeding up the swing speed of the glass in the wind grid section and raising the wind nozzle, the cooling of the glass can be more uniform, thereby further reducing the stress spots of the glass.

[0030] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner without departing from the spirit of the present invention or exceeding the scope defined by the appended claims.

Claims

1. A processing method for reducing stress spots in tempered glass, characterized in that: This method comprises the following steps: S1. Cutting: Take the original glass sheet and cut it into appropriate specifications according to the processing requirements, and grind the bevel edge of the broken sheet to make it flat, so as to prevent quality problems such as edge collapse during the subsequent edge grinding process, and obtain a glass substrate; S2, edge grinding: edge grinding the cut glass substrate; S3, cleaning: sending the edge-grinded glass substrate into a cleaning machine for cleaning and drying; S4, tempering furnace heating: set various process parameters of the tempering furnace, and start the tempering furnace, so that the heating power of the tempering furnace is 28 to 32 kilowatts, the convection power is 10 to 15 watts, and the temperature in the tempering furnace is continuously raised to between 610 and 620 degrees Celsius; S5, heating: the cut, polished and cleaned glass substrate is placed in the tempering furnace which has been heated, and is heated in the furnace body of the tempering furnace for 30 to 40 minutes. During the heating process, the conveying roller in the tempering furnace body will drive the glass substrate to move back and forth at a speed of 170 to 190 mm per minute until the heating is completed; S6, out of the furnace: After the glass substrate is heated, it will leave the tempering furnace body at a speed of 380-420 mm / min driven by the conveyor roller and move to the end of the tempering furnace air grid section; S7. Cooling: After the glass reaches the end of the wind grid section, it returns at a speed of 110-130 mm and moves back and forth on the wind grid section at this speed for 10 minutes until the glass cools to below 40 degrees Celsius. It is then taken off the sheet, so that tempered glass with lighter stress spots can be obtained.

2. A processing method for reducing stress spots in tempered glass according to claim 1, characterized in that: In the wind grid section of the tempering furnace, the distance between each air nozzle and the upper surface of the glass is 80 mm.