Francool Technology (Shenzhen) Co., Ltd.

HomeIndustry > Glass finishing
Glass finishing

Glass processing

After forming the glass products, except for a very small number (such as bottles, etc.) can directly meet the requirements, most of the need to be processed in order to get the products meet the requirements; some flat glass before the process, the need for the original glass For processing. Processing can improve the appearance and surface properties of glass, but also for decoration.

Glass cold processing

Glass cold processing, also known as mechanical processing, at room temperature, by mechanical methods to change the glass and glass products, the shape and surface state of the process, known as cold (mechanical) processing. Cold (mechanical) processing of the basic methods are: grinding and polishing, cutting, scrub, sandblasting, carved flowers, sand sculpture, drilling and cutting.

Grinding and polishing

Glass grinding and polishing is the uneven surface of the glass processing, a smooth and smooth surface; or the shape and size of glass rough products by grinding and polishing, to achieve the required shape and size requirements, and the surface is very clean Cold processing methods. At present, the grinding and polishing of glass are mostly used for the processing of optical glass and spectacle lenses; in the special case, the rolling method of sandwiching flat glass requires grinding and polishing; and the microcrystalline glass substrate and the ultrathin glass base produced by some methods Films also need grinding and polishing. Grinding of glass is divided into rough grinding and fine grinding. Rough grinding is to grind the surface of glass or the rough surface of the product with rough abrasive or to keep the remaining part of the glass during grinding. It can grind to make the product have the required shape and size or Flat surface. Begin grinding with coarse abrasive, high efficiency, but leave concave pits and cracks on the surface of the glass, fine grinding with fine abrasive until the surface of the glass matte surface becomes more detailed, polished with a polishing material, so that the matte side The glass surface becomes a transparent, smooth surface and has a gloss. Grinding, polishing are two different processes, these two processes together, called polishing. After grinding, polishing the glass, said polished glass.

Glass grinding and polishing mechanism

Over the years, mechanical grinding, polishing mechanism, many scholars in various countries coexist, summed up, there are three different theories: grinding theory; fluid theory; chemical theory. Grinding theory: For grinding, more scholars think grinding begins. In 1665 Hooke proposed grinding is grinding the glass to a certain shape with an abrasive, and polishing is an extension of the grinding; so that the glass surface is smooth and purely mechanical. This understanding lasted until the end of the nineteenth century. Mobile layer theory: the British scholar Leilei, Pei represented, that when the glass is polished, the surface has a certain mobility, also known as plastic layer. Plastic layer of the flow, the rough surface of the polished glass surface. Chemical theory: Preston in England and Glebinchikov in the Soviet Union proposed in the glass polishing process not only mechanical action, but also the role of physics and chemistry. The above three or One of the two theories of synthesis.

(1) glass grinding mechanism

Glass grinding process, the first is the relative movement of the grinding wheel and the glass, the free abrasive under the action of the grinding wheel scratches and peel the glass surface mechanical role, while microcracks in the glass. Abrasive water used both plays a cooling role, but also with the nascent surface of the glass hydrolysis, generate silica gel, conducive to stripping, with a certain chemical effect. So repeated, the surface of the glass to form a concave rough surface, and with a certain depth of the crack layer

According to the Soviet scholar Kaschalov, it is considered that the average depth h of the depressed layer depends on the nature of the abrasive and the particle diameter. The relation is: h = K1D (16-1)

K1 - for different abrasive grinding constant, see Table 16-1

D - the average diameter of the abrasive at this time the average depth of the crack layer f and the depth of the concave layer depth h relationship f = 2.3h (16-2)

While the maximum crack depth: F = 3.7 ~ 4.0h (16-3)

Different chemical composition of the glass, its physical, mechanical, chemical and other properties are different, which on the grinding surface depth of the concave layer and crack depth have a significant impact. Table 16-2 shows the comparison of the depth of the depressed layer and the crack depth under the same grinding conditions for a variety of glass with a silicon carbide abrasive of 105-150 microns. Seen from the table, high mechanical strength of glass, the depth of the depression layer and crack depth are relatively small.

The original rough glass grinding into the precise shape or surface roughness of the product, the general grinding of 0.2 to 1 mm, or more. So use thicker abrasive to improve efficiency. However, due to coarse particles of the surface of the glass to leave the depth of the depression and the depth of the crack layer is not conducive to polishing. The depth of the concave and crack layer on the grinding surface must be reduced as much as possible so that the grain size of the abrasive should be lowered step by step so as to make the matte surface of the glass as fine as possible. In general, the average depth h of the concave layer of the matte glass surface is 3 to 4 micrometers and the maximum crack depth F is 10 to 15 micrometers.

The main factors affecting the glass grinding process

Glass grinding process marked the grinding speed and grinding quality is the amount of grinding (the amount of glass removed per unit time) and the depth of the recessed layer of ground glass. Grinding large amount of grinding efficiency, depression depth is small grinding quality. Some of the process factors have an impact on only one of them, but also on two, but often have a good effect on one and the opposite of the other. The impact of various process factors are described below.

(1) Abrasive properties and particle size

Abrasive hardness, usually high grinding efficiency, silicon carbide and silicon carbide grinding efficiency is much higher than the quartz sand. However, the hardness of the abrasive so that the grinding surface depth of the depression, which is obvious from the above formula (16-1) and Table 16-1. The relationship between the grain size of the abrasive grains and the glass removal amount is shown in Fig. 16-2. The grinding amount increases with the increase of the grain size. According to Equation 16-1, the depth of the ground glass sag increases with increasing grain size, ie the grinding quality deteriorates as the grain size increases. To this end, at the beginning of the grinding, with a coarse particle size, to improve the grinding efficiency, in order to make the glass products in a short period of time to achieve the appropriate shape or surface roughness. After that, with a fine abrasive grinding step by step, in order to gradually improve the quality of grinding, and finally meet the polishing surface quality requirements.

(2) abrasive suspension concentration and feed rate

Abrasive suspension is generally made of abrasive water suspension. Water not only disperses the abrasive but distributes evenly over the work surface, removing the ground glass debris, cooling the heat generated by the friction, and causing the glass surface to hydrolyze into a silicone film. Therefore, the amount of water on the grinding efficiency has a certain impact. Usually to measure the proportion of suspension or liquid to liquid ratio to calculate the suspension to the concentration of various sizes of abrasive have its most suitable concentration, too large or too small, all affect the grinding efficiency, as shown in Figure 16-3 As shown. Abrasive concentration is too small, but also make the grinding surface scarred.

Glass grinding fluid is water-soluble synthetic cutting fluid, which is especially suitable for cutting various glass lenses and crystal materials. It is mainly used for fine grinding. Odorless, non-hazardous substances, with excellent cooling and powder settlement properties, can provide high surface finish and good antibacterial properties, greatly improving the life of oil.

First, excellent cooling, lubrication performance and extreme pressure performance, suitable for grinding and processing needs, can improve the workpiece surface finish and finish requirements.

Second, the good washing performance, cleaning residue attached to the workpiece scraps, which will help reduce power consumption, reduce tool and wheel wear effectively extend tool life, reduce grinding and trimming frequency, energy saving. Improve production capacity.

Third, a good anti-rust properties of machine tools, workpieces and knives have a good protective effect.

Fourth, good processing visibility, high visibility cutting area to facilitate the operation of workers to observe the cutting state.

Fifth, the storage and long life, shelf life: one year, under the rational maintenance, usually only a small amount of added, cost savings.

Six, the product PH value of 8.2 ± 0.5, non-irritating, which will help protect the health of operators.

Seven, in line with national cutting fluid environmental requirements, waste disposal simple, environmentally friendly processing solution.

Glass grinding fluid product use:

1. With 20-30 times tap water or deionized water to dilute the stock solution is the working fluid, or depending on processing difficulty and the actual situation may be.

2. In the course of use, the depletion of the working fluid can be 3-5% of the concentration to be added.

3. This product is not mixed with other oils, because even a small amount of the system has been decadent rash will affect the use of new liquid effect, please dilute the product in a slow stirring state into the water, do not anti Add water to the concentrate.