KR20160045419A - Method of chamfering glass - Google Patents

Abstract

The present invention relates to a glass chamfering method and, more specifically, to a glass chamfering method which chamfers a glass by allowing a heating body having a temperature of 1200 to 1700°C to come in contact with the side corner of the glass. The heating body is satisfied with a mathematical formula 1: Pa <= 2.00 Pw, thereby preventing the abrasion of the heating body and allowing the glass to have high strength.

Description

METHOD OF CHAMFERING GLASS [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of chamfering a glass, and more particularly, to a chamfering method of a glass capable of preventing wear of a heating element and improving chamfering processability.

Glass products are regarded as essential components in a wide range of technologies and industries such as monitors, cameras, VTRs, mobile phones, video and optical equipment, automobile transportation equipment, various tableware, and building facilities. A glass having various physical properties is manufactured and used.

Touch screen is one of the key components of video equipment. A touch screen is a display and input device which is installed on a monitor for a terminal and inputs various data such as a simple touch, a character or a picture by using an auxiliary input means such as a finger or a pen, Such a touch screen is becoming increasingly important as a core component for various digital devices that transmit or exchange information to one or both of a mobile communication device such as a smart phone, a computer, a camera, a certificate, and the like, The range is expanding rapidly.

Among the components constituting such a touch screen, the upper transparent protective layer, which is directly contacted by the user, is mainly composed of plastic organic materials such as polyester or acrylic. These materials have poor heat resistance and mechanical strength, Or scratches are generated or broken. Accordingly, the upper transparent protective layer of the touch screen is being gradually replaced by a reinforced thin plate glass excellent in heat resistance, mechanical strength and hardness from the conventional transparent plastic. In addition, reinforced laminated glass is used as a transparent protection window for LCD or OLED monitor in addition to a touch screen, and its use area is gradually expanding.

The tempered glass is not a intended shape due to the large compressive stress existing on the surface when it is cut, and even if it is broken due to disordered debris, or if it is cut into the intended shape, The stress is lost and the strength is lowered. Therefore, once strengthened, it is difficult to cut into a desired size or shape irrespective of the composition of the glass.

Therefore, the cutting method of the tempered glass requires a very precise and rigid condition as compared with a conventional glass cutting method. The method introduced by this cutting method of tempered glass is as follows.

First, there is a mechanical cutting method. The system is mechanically engraved on the glass plate by dragging the diamond or carbide grinding wheel across the glass surface, and then cutting the glass plate along the scale to produce a cut edge. Typically, such a mechanical cutting method results in a lateral crack at a depth of about 100 to 150 탆, which cracks originate from the cutting line of the chewing wheel. Since the lateral crack reduces the strength of the window substrate, the cut portion of the window substrate must be polished and removed.

However, in the mechanical cutting method described above, expensive cutting wheels also need to be replaced over time, and precise cutting is not easy.

Next, there is a non-contact cutting method through a laser. The method is based on the fact that as the laser expands the glass surface by moving along a predetermined path on the glass surface past the check at the edge of the window substrate, the cooler moves along its trailing edge to stretch the surface, The crack is thermally propagated to cut the window substrate.

On the other hand, the cut surface of the tempered glass is sharp, its surface is uneven and is vulnerable to external impact, so it must be subjected to a chamfering process.

The chamfering process is generally performed by rotating the polishing wheel for chamfering, chamfering, or chamfering. Through the chamfering process, the smoothness of the cut portion is improved and the strength is increased, but it has been difficult to provide a window substrate having excellent strength in the conventional chamfering process.

International Publication WO 2005-044512 discloses a method of grinding and / or polishing the edges of a cut glass substrate to remove sharp edges, but this method of grasping, processing and transporting glass substrates has several disadvantages have. First, the particles generated during the grinding / polishing of the corners may become a source of contamination on the surface of the glass substrate, and a large scale cleaning and drying process is additionally required in the chamfering process for washing and washing the generated particles. This has the disadvantage that the manufacturing cost is increased. In addition, the generated particles and chips can enter between the belt and the glass substrate and severely damage the surface of the glass substrate. Such damage can often cause the interruption of a series of machining steps, resulting in poor machining rates.

Korean Laid-open Patent Publication No. 2012-002573 discloses a method of using a high-temperature heating element to floss it. However, there is a problem in that the heating element to be used wears easily and it is difficult to continue the chamfering process.

WO 2005-044512 Korea Patent Publication No. 2012-002573

It is an object of the present invention to provide an economical method of chamfering a glass by preventing wear of a heating element to improve a chamfering process rate.

It is still another object of the present invention to provide a method of chamfering a glass which can prevent microcracks on the glass side and exhibit high strength.

1. A chamfering method of chamfering a glass after a heating element having a temperature of 1200 to 1,700 DEG C is brought into contact with a side edge of the glass, wherein the heating element satisfies the following formula (1):

[Equation 1]

Pa ≤ 2.00 Pw

(Where Pa is the hardness of the heating element and Pw is the hardness of the glass).

2. The chopping method for glass according to 1 above, wherein the heating element satisfies the following formula:

&Quot; (2) &quot;

Pa ≤ 1.09 Pw

(Where Pa is the hardness of the heating element and Pw is the hardness of the glass).

3. The chopping method for glass according to item 1 above, wherein the total amount of heat supplied to the glass by the heating element satisfies the following formula:

 &Quot; (3) &quot;

10 Kcal? Q? 200 Kcal

(Where Q is the total amount of heat transferred by the heating element to the glass).

4. The method of claim 1, wherein the heating element is moved at a speed of 0.5 to 5 m / min.

5. The method of claim 1, wherein the heating element is at least one selected from the group consisting of molybdenum silicide, iridium, rhodium and platinum rhodium alloy.

6. The method of claim 1, wherein the glass has a Vickers hardness of 200 to 1200 kgf / mm ² .

7. The method of claim 1, wherein the glass is tempered glass.

8. The method of claim 7, wherein the tempered glass has an enhancement layer depth of 10 to 200 [mu] m.

By using a heating element having a Vickers hardness in a specific range, the present invention can prevent wear of the heating element, improve the chamfering process rate, and perform the chamfering process economically.

Further, the present invention can effectively remove the micro cracks generated on the side surface, and can have a high strength.

1 is a view schematically showing a chamfering method according to the present invention.
2 is a graph showing the abrasion constant according to the ratio (Pa / Pw) of the Vickers hardness of the heating element to the Vickers hardness of the glass.
Fig. 3 is a schematic cross-sectional view (a) and a front view (b) of a side of the chamfered glass according to the present invention.
4 is a schematic view of an embodiment of the chamfering method according to the present invention.
5 is a view schematically showing another embodiment of the chamfering method according to the present invention.

The present invention relates to a method of chamfering a glass by bringing a heating element having a temperature of 1,200 to 1,700 DEG C into contact with the side edge of the glass, and then heating the glass so that the heating element satisfies Equation (1) The present invention relates to a method of chamfering a tempered glass which can exhibit an economical yet uniform surface and excellent strength.

Hereinafter, the present invention will be described in detail.

As shown in FIG. 1, the heating element 10 is brought into contact with the edge of the glass substrate 11 to cut the edge of the glass substrate 11 by thermal stress as shown in FIG. 1, And the substrate 11 is faced. When the heating element 10 of the present invention is brought into contact with the edge of the glass substrate 11, thermal stress is generated at the corner portion where the heating element 10 is contacted due to the characteristic of the glass having a low heat transmission rate, The portion of the surface is separated. Therefore, when the heating element 10 moves in contact with the edge of the glass substrate 11 (the direction of the arrow in Fig. 1), the edge of the glass substrate 11 can be chamfered.

In the chamfering method according to the present invention, the heating body satisfies the following expression (1).

[Equation 1]

Pa ≤ 2.00 Pw

(Where Pa is the hardness of the heating element and Pw is the hardness of the glass).

If the exothermic body is out of the range of the above-mentioned formula (1), the degree of abrasion of the exothermic body becomes remarkably large, and the continuous chamfering process becomes difficult, resulting in a reduction in the chamfering process rate. If the heating element satisfies the above formula (1), wear of the heating element can be prevented and the chamfering process rate can be improved.

The chamfering method according to the present invention satisfies the above-mentioned formula (1), and FIG. 2 shows the wear constant according to the Vickers hardness ratio (Pa / Pw) of the glass to the Vickers hardness of the heating body according to the production example described later.

As shown in Fig. 2, when the ratio (Pa / Pw) of the Vickers hardness of the heating body to the Vickers hardness of the glass is 2.00 or more, it can be seen that the abrasion constant of the y axis indicating the degree of abrasion of the heating body abruptly changes. Therefore, it can be seen that when the Vickers hardness of the heating element satisfies the formula (1), which is 2.00 times or less of the Vickers hardness of the glass, abrasion of the heating element is prevented and the chamfering process rate can be improved.

In this respect, in the chamfering method according to the present invention, it is more preferable that the heating body satisfies the following expression (2).

&Quot; (2) &quot;

Pa ≤ 1.09 Pw

(Where Pa is the hardness of the heating element and Pw is the hardness of the glass).

As shown in FIG. 2, it can be seen that when the ratio (Pa / Pw) of the Vickers hardness of the heating body to the Vickers hardness of the glass is 1.09 or less, the abrasion constant of the y axis indicating the degree of wear of the heating body is maintained at approximately 1 . Therefore, when the Vickers hardness of the heating body is equal to or less than 1.09 times the Vickers hardness of the glass, the degree of wear of the heating body is remarkably reduced, and the continuous chamfering process is performed to increase the chamfering process rate.

In addition, the chamfering method according to the present invention is carried out while satisfying Equation (1) while bringing a heating element having a temperature of 1200 to 1,700 DEG C into contact with the side edge of the glass in order to exert the effect of the present invention. When the heating element having the temperature range of the present invention is brought into contact with the side edge of the glass, thermal stress is generated at the corner of the glass, and the portion from the heating element contacting portion to the predetermined depth falls off in the form of the strip.

According to the chamfering method of the present invention, it is possible to effectively remove the fine cracks generated on the side surface and improve the strength of the glass. In addition, a uniform surface can be obtained and the chamfering time can be remarkably reduced as compared with the method of the above-mentioned prior patent.

In the chamfering method according to the present invention, chamfering may not be performed if the temperature of the heating element is lower than 1200 占 폚, and tempered glass may melt when the temperature is higher than 1,700 占 폚.

In the chamfering method according to the present invention, the total amount of heat supplied to the glass is not particularly limited as far as it is capable of generating thermal stress necessary for cutting the corner portion of the glass substrate. However, for example, the following formula .

&Quot; (3) &quot;

10 Kcal? Q? 200 Kcal

(Where Q is the total amount of heat transferred by the heating element to the glass).

The total amount Q of heat transferred from the heating element to the glass can be controlled through the thermal conductivity of the glass, the temperature of the heating element, the temperature of the glass, the moving speed of the heating element, and the distance the heating element moves in the glass direction. If it is less than 10 Kcal, there is not enough heat stress to cut the corners of the glass substrate and the chamfering will not occur. If the total heat quantity is more than 200 Kcal, the thermal stress will be excessive and deformation will occur.

Further, in the chamfering method according to the present invention, the heating body contacting the side edge of the glass moves along the portion to be chamfered, and the moving speed may be 0.5 to 5 m / min. If the moving speed is less than 0.5 m / min, damage to the protective layer, increase in the amount of cutting, and melting of the glass may occur. If the moving speed is more than 5 m / min, the chamfered surface may be rough and the chamfered shape may be uneven.

In the chamfering method according to the present invention, the material which can be used as a heating element can transmit the temperature of the heating element without deforming and is not particularly limited as long as it meets the formula (1). Specific examples thereof include iridium, rhodium and platinum rhodium alloys. These alloys may be used alone or in combination of two or more.

The type of the glass substrate to be chamfered to which the chamfering method of the present invention can be applied is not particularly limited, and examples thereof include ordinary glass and tempered glass. Preferably, a glass having Vickers hardness of 200 to 1200 kgf / mm ² , more preferably 600 to 700 kgf / mm ² can be used.

Although the reinforcing glass is not particularly limited, in one preferred embodiment, the depth of the reinforcing layer may be from 10 탆 to 200 탆, in other embodiments from 40 탆 to 200 탆, and in another embodiment from 120 탆 to 200 탆.

In another aspect of the present invention, the tempered glass to which the chamfering method of the present invention can be applied may have a Young's modulus of 60 to 90 GPa, preferably 65 to 85 GPa.

An embodiment of the chamfering method according to the present invention will now be described in more detail. The top and bottom corners of the side of the glass can be inclined. FIG. 3 shows schematic cross- A front view (b) is shown.

As shown in FIG. 3, when the upper and lower edges of the glass are inclined with respect to the upper edge and the lower edge of the glass, the detailed conditions such as a specific order, number of times of tilting, There are no special restrictions.

As a more specific example, in one embodiment of the present invention, it can be performed by bringing a heating element into contact with the upper edge portion and the lower edge portion of the glass. As shown schematically in FIG. 4, the heating element can be brought into contact with the upper edge portion (1) and the lower edge portion (2) of the side surface of the glass to form an inclined surface.

In another embodiment of the present invention, the heating element may be brought into contact with the upper and lower corners of the side surface of the glass, and then the heating element may be in contact with the glass in a parallel direction. This embodiment can be adopted when it is necessary as the case where there are many tempered glass parts removed by the chamfering method. Fig. 5 schematically shows the chamfering method of this embodiment. Referring to FIG. 5, first, a heating element is brought into contact with the upper edge of the side surface of the glass to form an inclined surface up to a predetermined portion (1). Next, a heating element is brought into contact with the upper edge portion of the side surface of the glass to form an inclined surface up to a predetermined portion (2). Subsequently, a heating section is contacted in parallel with the side surface of the glass to remove the glass to a required portion (3), thereby obtaining a final cross-sectional shape.

In addition, the order of chamfering may be changed in the above embodiment of the present invention, and therefore chamfering may be performed in a different order from that shown in FIG. For example, it may be performed in the order of (2), (1) and (3), or may be performed in the order of (3), (2), and (1), but the present invention is not limited thereto.

When the inclined surface processing of the side surface of the glass is completed by the heating element as described above, the surface of the side surface of the glass can be further reinforced if necessary. Such a reinforcing process can provide a more uniform surface and excellent strength.

The reinforcing process according to the present invention includes polishing the side surface of the glass with a polishing wheel or etching the side surface of the glass with an etching solution containing hydrofluoric acid.

First, a method of polishing with a polishing wheel is a method of polishing the side surface of the glass more evenly by contacting the rotating polishing wheel with the side surface of the glass after completion of the inclined surface processing by the heating element. Thereby reinforcing the side surface of the glass by polishing fine cracks or the like present on the surface.

The polishing wheel may use a wheel made of abrasive grains such as cerium oxide. The size of the abrasive grains is preferably 5 탆 or less in terms of sufficiently exhibiting the side reinforcing effect of glass. The smaller the size of the abrasive grains, the better the polishing accuracy can be. Therefore, although the lower limit is not particularly limited, about 0.01 mu m can be used in consideration of the processing time and the like.

The rotational speed of the polishing wheel is not particularly limited and can be appropriately selected so that the side surface of the glass is sufficiently polished to obtain a desired level of strength, for example, 1,000 to 10,000 rpm.

Next, a method of etching by using hydrofluoric acid is a method of etching the surface portion of the side surface of the glass by applying an etching solution containing hydrofluoric acid to the side surface of the glass. When the side of the glass is etched with the etching solution containing hydrofluoric acid, the side of the glass shows an emboss pattern and is etched and the surface is reinforced.

The etching solution containing hydrofluoric acid may be an aqueous solution of hydrofluoric acid and may further include components known in the art as glass etching components such as hydrochloric acid, nitric acid, sulfuric acid, and other acid components required in addition to hydrofluoric acid.

The time for etching the side surface of the glass with the etching solution containing hydrofluoric acid is not particularly limited, but it is possible to raise the strength without etching the side surface of the glass excessively, for example, between 30 seconds and 10 minutes .

The temperature of the etchant containing hydrofluoric acid is not particularly limited, but is preferably 20 to 50 ° C, for example. If the temperature is lower than 20 ° C, the process time may become longer and the etching may proceed insufficiently. If the temperature is higher than 50 ° C, the process time may be shortened, but the etching may proceed unevenly.

The etchant containing hydrofluoric acid may be applied to the side of the glass in a manner known in the art, such as by spraying on the side of the glass or by immersing the sides of the glass in the etchant.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to be illustrative of the invention and are not intended to limit the scope of the claims. It will be apparent to those skilled in the art that such variations and modifications are within the scope of the appended claims.

Manufacturing example  One

The relative wear coefficient relative to Pa / Pw, which is the ratio of the Vickers hardness of the glass to the Vickers hardness of the heating body, was measured while changing the hardness of the heating body at a heating body temperature of 1300 占 폚. The results are shown in Tables 1 and 2 Respectively. In Table 1, Pa is the Vickers hardness of the heating body, and Pw is the Vickers hardness of the tempered glass.

division Glass
Vickers hardness (Pw)
(kgf / mm ² ) Heating element
Vickers hardness (Pa)
(kgf / mm ² ) Heating element
Kinds Pa / Pw Wear constant One 700 350 Silver (Ag) 0.5 0.9 2 700 448 Copper (Cu) 0.64 0.8 3 700 573 Platinum (Pt) 0.82 One 4 700 700 Molybdenum silicide (MoSi ₂ ) 1.00 One 5 700 765 Platinum rhodium alloy (Pt-Rh (10%)) 1.09 1.1 6 700 890 Platinum rhodium alloy (Pt-Rh (15%)) 1.27 1.05 7 700 1018 Rhodium (Rh) 1.45 0.5 8 700 1145 Iridium (Ir) 1.64 0.3 9 700 1400 Zirconium oxide (ZrO ₂ ) 2.00 0.12 10 700 1527 Aluminum oxide (Al ₂ O ₃₎ 2.18 0.025 11 700 1655 Silicon carbide (SiC) 2.36 0.01

According to Table 1 and FIG. 2, when Pa / Pw is 2.00 or more, which is the ratio of the Vickers hardness of the heating body to the Vickers hardness of the glass, the slope of the wear constant indicating abrasion degree of the heating body is abruptly changed. Also, when Pw / Pa is 1.09 or more, it can be seen that the slope of the wear constant changes suddenly once more.

Example  And Comparative Example

A chamfering process was performed by bringing a heating element into contact with the side edges of the cut tempered glass of Production Example 1 under the conditions shown in Table 2 below. In Table 2, Pa is the Vickers hardness of the heating body, and Pw is the Vickers hardness of the tempered glass.

division Heating element Heating element temperature
(° C) Supply calorie
(Kcal) Contact movement speed
(m / min) Material Pa / Pw Example 1 Molybdenum silicide
(MoSi ₂ ) 1.00 1200 60 2.0 Example 2 Molybdenum silicide
(MoSi ₂ ) 1.00 1350 120 1.8 Example 3 Platinum rhodium alloy (10%)
(Pt-Rh (10%)) 1.09 1700 190 1.2 Example 4 rhodium
(Rh) 1.45 1500 90 4.8 Example 5 Iridium
(Ir) 1.64 1200 13 0.7 Comparative Example 1 Aluminum oxide
(Al ₂ O ₃₎ 2.18 1200 60 2.0 Comparative Example 2 Aluminum oxide
(Al ₂ O ₃₎ 2.18 1350 120 1.8 Comparative Example 3 Silicon carbide
(SiC) 2.36 1800 89 2.0 Comparative Example 4 Molybdenum silicide
(MoSi ₂ ) 1.00 1800 120 3.0 Comparative Example 5 Aluminum oxide
(Al ₂ O ₃₎ 1.00 1900 250 6.0

Experimental Example

Table 3 shows the degree of abrasion and the measured elongation of the exothermic bodies of the Examples and Comparative Examples. The elongation was judged to be an average value of more than 50 reinforced glass.

(1) Evaluation of the degree of wear of the heating element

The number of the cut tempered glasses was less than 5, more than 10, less than 10, and more than 10, and the chamfering process of the above Examples and Comparative Examples was performed. The degree of abrasion of the heating element was evaluated according to the number of the tempered glass, and the results are shown in Table 3. When the depth of abrasion of the heating element exceeds 50 mm, microcracks are generated in the tempered glass at the time of processing, and the tempered glass after the processing is broken.

○: Heating element Wear depth 20 mm or less

?: Wear depth of heating element Greater than 20 mm and less than 50 mm

X: heating element wear depth exceeding 50 mm

division Degree of abrasion of heating element Less than 5 sheets More than 5 pieces and less than 10 pieces More than 10 pieces Example 1 ○ ○ ○ Example 2 ○ ○ ○ Example 3 ○ ○ ○ Example 4 ○ ○ ○ Example 5 ○ ○ △ Comparative Example 1 ○ △ X Comparative Example 2 ○ △ X Comparative Example 3 △ X X Comparative Example 4 ○ △ △ Comparative Example 5 X X X

Referring to Table 1, it can be seen that the degree of abrasion of the heating body was remarkably improved in the examples performed according to the conditions of the chamfering method according to the present invention, compared with the comparative examples.

However, in the comparative examples outside the condition of the present invention, it was confirmed that the degree of abrasion of the heating body was significantly larger than those of the examples.

10: Heating element
11: glass substrate

Claims (8)

A method of chamfering a glass by bringing a heating element having a temperature of 1200 to 1,700 DEG C into contact with the side edge of the glass, wherein the heating element satisfies the following formula (1):
[Equation 1]
Pa ≤ 2.00 Pw
(Where Pa is the hardness of the heating element and Pw is the hardness of the glass).
The chopping method for glass according to claim 1, wherein the heating element satisfies the following formula (2)
&Quot; (2) &quot;
Pa ≤ 1.09 Pw
(Where Pa is the hardness of the heating element and Pw is the hardness of the glass).
The method according to claim 1, wherein the total amount of heat supplied to the glass by the heating element satisfies the following equation (3)
&Quot; (3) &quot;
10 Kcal? Q? 200 Kcal
(Where Q is the total amount of heat transferred by the heating element to the glass).
The method according to claim 1, wherein the heating element is moved at a speed of 0.5 to 5 m / min.
The method of claim 1, wherein the heating element is at least one selected from the group consisting of molybdenum silicide, iridium, rhodium and platinum rhodium alloy.
The method of claim 1, wherein the glass has a Vickers hardness of 200 to 1200 kgf / mm ² .
The method of claim 1, wherein the glass is tempered glass.
The method according to claim 7, wherein the tempered glass has a depth of the reinforcing layer of 10 to 200 탆.

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