TWI705944B - Vacuum-molding apparatus for bend molding glass and methods for the use thereof - Google Patents

Abstract

A vacuum-molding apparatus for bend molding glass and a method of bend molding glass are disclosed. The vacuum-molding apparatus includes a mold protection device that protects a mold from oxidation and increases the life span of a mold. Injection of inert gas can also increase the life span of the mold.

Description

Vacuum forming device for bending mold glass and its use method

The invention relates to a vacuum forming device for bending mold and bending glass and a method for bending mold and bending glass using the vacuum forming device. The vacuum forming device can be used to manufacture curved glass and flat glass with curved parts.

Touch glass, large screens and their applications have reached a wide range of market coverage. Therefore, there is an increasing demand for curved glass. The formation of curved glass is mostly controlled by the glass transition temperature (T _g ) and softening temperature (T _s ) under discussion. Generally speaking, T _{g is} lower than 545°C, and T _{s is} lower than 765°C.

One of the most common techniques used to form curved glass is bending dies. During a typical bending mold, the part of the glass object to be bent is softened by heating, and then the gas injection system applies force to change the shape of the glass object. As the glass cools, a curved object is formed. However, the bending mold using the injection system requires precise injection control. Otherwise, this process will affect the physical properties of the glass. However, precise injection control systems are expensive and will deteriorate rapidly due to long-term operation at high temperatures.

Another method is to first soften the glass, use the upper and lower molds to bend the glass object, and then cool the glass object to form the bent glass. However, the bending mold using the mold press requires the alignment of the upper and lower molds and the complete lamination between the glass and the mold, which increases the difficulties related to mold design and processing.

Vacuum assisted molding is widely used in forming plastics. In vacuum-assisted molding, the object is preheated to a certain working temperature, a vacuum is formed between the mold and the object by a vacuum system, and the force is used to form the object, and finally it is cooled or annealed according to the characteristics, conditions and material requirements of the object Objects to meet design requirements.

In vacuum forming technology, the life of the mold and the effect of high temperature and high pressure on the mold are rarely considered. When the mold is heated to a high temperature during vacuum forming, the mold is easily damaged. Therefore, there is a need to design devices and methods for bending mold glass while protecting the mold.

According to several exemplary embodiments, the present invention provides a vacuum forming device. The vacuum forming device includes a mold having a forming surface and a plurality of suction holes, a mold protection device covering the mold, a vacuum system that generates a vacuum in the inner space of the mold, and a glass heating device that heats the glass object.

According to several exemplary embodiments, the present invention provides another vacuum forming device. This vacuum forming device includes a mold with a forming surface and a plurality of suction holes unevenly arranged on the mold, a mold protection device that covers the mold and is movable to adjust the positive pressure applied to the glass object, and is in the inner space of the mold. A vacuum system that generates a vacuum, and a glass heating device configured to heat the glass object with more heat energy on the edge of the glass object.

According to several exemplary embodiments, the present invention further provides a method of bending a glass object. This method includes covering the mold with a mold protection device, protecting the mold from oxidation by forming a dull gas environment, heating the glass object to working temperature to provide a heated glass object, generating a vacuum in the inner space of the mold while in the outer space of the mold There is a positive pressure to bend to form a heated glass object to provide a molded glass object, and to cool the molded glass object.

100: Vacuum forming device

110, 200: mold

114, 131, 151, 161: airway

115: Glass Object

118: Under Space

120: Mold protection device

120A: Lid

121: Up Space

122: electric motor

123: connecting rod

130, 160: pneumatic pump

140: Upper vacuum system

141: Upper vacuum system channel

150: Lower vacuum system

170, 380: heating device

180: Glass heating device

190: auxiliary injection device

210: forming surface

210A, 210B, 210C: area

220: suction hole

Figure 1A is a schematic depiction of an embodiment of a vacuum forming apparatus for manufacturing curved glass according to the present invention; Figure 1B is a schematic depiction of a vacuum forming apparatus with a movable protection device for manufacturing curved glass according to the present invention Figure 2 shows a mold for manufacturing curved glass according to the present invention, with a molding surface and suction holes; Figure 3 is an embodiment of the glass heating device of the vacuum forming apparatus for manufacturing curved glass according to the present invention And Fig. 4 contains a flow chart of an embodiment of a vacuum forming method using a vacuum forming apparatus for manufacturing curved glass according to the present invention.

The term "operating temperature" refers to the temperature at which glass objects can be safely bent and formed to heat. Unless otherwise mentioned, the working temperature is between the glass transition temperature (T _g ) and softening temperature (T _s ) of the formed glass.

The term "forming surface" means a mold surface area that is at least partially curved or non-planar. The expression "on the forming surface" means a position within the area defined by the forming surface and on the surface of the forming surface, so that the part of the mold in question can interact with the glass being bent.

The term "2D" means a flat surface.

The term "2.5D" means a surface that is mostly flat but includes at least one curved surface.

The term "3D" means a surface that is mostly curved.

The terms "2D", "2.5D" and "3D" can be applied to glass plates, where these terms will respectively mean flat glass, mostly flat glass, and mostly curved glass.

The vacuum forming device described herein can bend the glass into a shape by using heating to soften the glass and differential pressure (inhalation and/or air injection) to force the softened glass to contact the forming surface of the mold. The mold is installed in a mold protection device that can provide vacuum, inject dull gas, and apply local heat to the glass during the molding process. The advantage of providing vacuum or dull gas during mold bending is to reduce the oxidation and damage that occurs when the glass is bent in open air at high temperatures. The vacuum forming device and its related methods of use protect the mold by forming a dull atmosphere or vacuum around the mold to increase the life of the mold.

Referring now to the drawings, a vacuum forming apparatus 100 is shown in Figure 1A. As shown in Fig. 1A, the vacuum forming apparatus 100 includes a mold 110 having a forming surface and a mold protection device 120. The forming surface has one or more suction holes provided in the forming surface. According to several exemplary embodiments, the mold 110 includes graphite, silicon carbide, stainless steel, or a combination thereof. In other exemplary embodiments, the mold 110 is made of a suitable material (such as steel) and has a coating surface of different materials, such as a coating surface of graphite, silicon carbide, stainless steel, or a combination thereof. These materials can help prevent adhesion between the mold 110 and the molded glass object.

FIG. 2 shows a mold 200 having a forming surface 210 and suction holes 220 on the mold 200. In some embodiments, in order to enhance the molding effect, the suction holes 220 are designed to have an uneven distribution. In particular, on the forming surface, areas with higher curvature are areas that require more bending during forming and are designed to have more suction holes. A higher curvature means a higher degree of bending (or curved surface). For example, the forming surface 210 has a first area with a first curvature and a second area with a second curvature lower than the first curvature. The density of suction holes in the first area is greater than the density of suction holes in the second area. The density of suction holes in the area is defined as the number of suction holes in the entire area. As shown in Figure 2, the forming surface 210 includes a first area 210A with a first curvature C1 (consisting of two (Defined by the dashed line); a second area 210B with a second curvature C2 (defined by two dashed lines); and a third area 210C with a third curvature C3, where C3<C2<C1. The density of suction holes in those regions are D1, D2, and D3, respectively. Therefore, D3<D2<D1. This advantageously creates a higher vacuum (hence lower pressure) between the glass and the mold in the region of higher curvature, so that the glass is pressed against the mold with greater force to more closely conform to the mold. shape. The force on the glass is determined by the difference between the pressure applied to the two surfaces of the glass.

Returning to FIG. 1A, the mold 110 includes a main part 112 of the mold and a plurality of air passages 114 distributed in the main part 112 of the mold. The mold protection device 120 covers the mold 110 and defines a sealed space so that the forming surface 210 is protected therein. When the glass object 115 (for example, a flat glass object) is placed on the forming surface 210, the glass object 115 divides the space between the mold protection device 120 and the mold 110 into an upper space 121 and a lower space 118. The upper space 121 and the lower space 118 may be connected via a gap (not shown) between the flat glass object 115 and the mold 110.

One or more suction holes in the mold 110 are operatively connected to the air passage 114 to apply suction on the flat glass object 115. The suction applied to the flat glass object 115 can force the flat glass object 115 to conform to the contour of the forming surface of the mold 110. By applying suction to the flat glass object 115, the shaped glass object is manufactured to have a more precise angle and thickness than if suction is not applied.

Similarly, as shown in FIG. 1A, the vacuum forming apparatus 100 includes a pneumatic pump 130, an upper vacuum system 140, and a lower vacuum system 150. In order to protect the main mold part 112, the pneumatic pump 130 can selectively inject inert gas (for example, nitrogen or argon) into the upper space 121 and the lower space 118 through the air passage 131. The upper vacuum system 140 can generate a vacuum in the upper space 121 and the lower space 118 via the upper vacuum system channel 141 to protect the main mold part 112 from oxidation. As described above, for forming, the lower vacuum system 150 may generate a vacuum in the lower space 118 via the air passage 151.

In some embodiments, as shown in FIG. 1A, the vacuum forming device 100 includes a pneumatic pump 160, a heating device 170, a glass heating device 180, and an auxiliary spray device 190. According to several exemplary embodiments, the pneumatic pump 160 can inject dull gas into the upper space 121 and the lower space 118 via the air passage 161. According to several exemplary embodiments, the passivation gas is heated before the passivation gas is injected. In some embodiments, the pneumatic pump 160 is implemented to cool the shaped glass object, and may alternatively be used as a supplementary force to separate the shaped glass object after or during the cooling of the shaped glass. The heating device 170 is provided outside the space (upper space 121) in between the mold protection device 120 and the mold 110, and heats the upper space 121. The glass heating device 180 is disposed in the upper space 121 and partially heats the flat glass object 115. According to several exemplary embodiments, the glass heating device 180 provides uneven heat energy to the flat glass object 115, and heats certain parts (such as edges or bending parts) of the flat glass object 115 with more power for Compensate for temperature variation or enhance the molding effect. In some embodiments, certain parts of the glass heating device 180 have a higher temperature than other parts of the glass heating device 180. According to several exemplary embodiments, the glass heating device 180 includes one or more infrared (IR) heating devices for heating the glass object 115 at a specific location, such as the edge of the glass object 115.

Without being limited by theory, it is believed that the temperature difference between the flat glass object 115 and the air surrounding the flat glass object 115 produces a thermal shock, which may cause the flat glass object 115 to break. Using more heating devices allows for more accurate temperature distribution adjustments. By heating the space between the mold protection device 120 and the mold 110, the temperature difference is minimized and the thermal shock is reduced.

The auxiliary injection device 190 is provided in the vacuum forming apparatus 100 and is configured to inject gas toward the glass object 115, especially toward a position with more bends (for example, a high curvature area corresponding to the forming surface 210 of the mold) ) To help shape the glass, and especially to get better curvature in 3D glass. According to several exemplary embodiments, the auxiliary injection device 190 provides a force of more than about 762 Torr.

During the bending process, the lower vacuum system 150 can generate a vacuum in the air passage 151, thereby reducing the pressure of the lower space 118. On the other hand, the upper space 121 will have a positive pressure. With a pressure difference between the upper space 121 and the lower space 118, the flat glass object 115 is bent to a desired shape. The pressure of the lower space 118 will vary based on various factors, such as the configuration of the suction holes on the mold 110, the temperature in the mold protection device 120, the composition of the flat glass object 115, and the size of the flat glass object 115. According to several exemplary embodiments, the lower vacuum system 150 reduces the pressure of the lower space 118 to about 1 Torr to about 670 Torr.

Referring now to FIG. 1B, another embodiment of the vacuum forming apparatus 100 is shown. The device 100 in Figure 1B is substantially similar to the device 100 in Figure 1A. However, in Figure 1B, the device 100 includes a motor 122 and a connecting rod 123, which are designed to move the mold protection device 120. The mold protection device 120 includes a cover 120A configured to be movable relative to other parts of the mold protection device 120. The motor 122 drives the cover 120A of the mold protection device 120 via the connecting rod 123 to change the volume of the upper space 121, thereby changing the pressure in the upper space 121 to help bend the flat glass object 115 into a 3D glass form. In this embodiment, when the cover 120A of the mold protection device 120 is moved in the vertical direction, the volume of the upper space 121 changes, and the pressure applied on the flat glass object 115 changes. Therefore, the pressure in the upper space 121 can be adjusted by moving the mold protection device 120. Advantageously, the mold protection device 120 provides an air-tight cover around the mold 110, and the device 100 prevents air from leaking into the space between the mold 110 and the mold protection device 120.

Returning to Figure 3, shown is an embodiment of a glass heating device 380 for heating a particular position of the flat glass object 115. The heating device 380 is designed to have a shape, size, and heat radiation distribution such that certain parts (for example, edges or corners) of the glass object 115 receive more heat energy. In this embodiment, the heating device 380 has a ring structure, although other shapes are also suitable. During the bending process, the heating device 380 heats the edge of the glass object 115, so that the glass object 115 forms a corner The temperature of 384 is higher than other parts of the glass object 115. This can help prevent the glass from warping during bend formation, thus increasing the quality of the glass.

Figure 4 shows a method 400 for manufacturing curved glass using a vacuum forming device. In step 402, the mold 110 is protected. For example, the pneumatic pump 130 injects a dull gas such as nitrogen gas into the area between the mold protection device 120 and the mold 110 (for example, the upper space 121) through the air passage 131. In another example, the upper vacuum system 140 generates a vacuum in the space between the mold protection device 120 and the mold 110 (for example, the upper space 121).

In step 404, the heating device 170 and the glass heating device 180 jointly heat the flat glass object 115 to the working temperature. In step 406, the lower vacuum system 150 generates a vacuum in the air passage 114 via the air passage 151, which reduces the pressure of the lower space 118. On the other hand, the upper space 121 is at a positive pressure. The pressure difference between the upper space 121 and the lower space 118 can cause the flat glass object 115 to be bent to conform to the contour of the mold 110. The flat glass object 115 is thus bent to produce a shaped glass object with a curved surface (2.5D or 3D). According to several exemplary embodiments, the auxiliary injection device 190 is used to inject gas into the corner to help shape the flat glass object 115.

In step 408, the bent glass object is cooled. The cooling of the formed glass and the release from the mold can be accelerated by natural cooling or by using a pneumatic pump 130, a pneumatic pump 160, or both to blow or inject dull gas onto the bent glass. The use of dull gas can quickly release the glass from the mold 110 and increase the life of the mold. According to several exemplary embodiments, the passivation gas injected to cool the glass is heated to a temperature lower than the working temperature of the glass. According to several exemplary embodiments, the temperature of the injected passivation gas is about 50°C to about 150°C lower than the operating temperature. In other exemplary embodiments, two pneumatic pumps 130 and 160 are operated to provide heating dull gas for cooling. In a further aspect of the exemplary embodiment, the release of the glass from the mold 110 is subsequently performed by using the pneumatic pump 160 and the vacuum pump 140 so that a pressure difference exists between the upper space 121 and the lower space 118. A vacuum is generated in the upper space 121, while a positive pressure is provided in the lower space 118. This pressure difference forces the formed glass object 115 to be released from the forming surface 210 of the mold.

According to several exemplary embodiments, the present invention provides a vacuum molding device for manufacturing curved glass using a bending mold. The vacuum molding device includes a mold with a forming surface for bending glass, a mold protection device for protecting the mold from oxidation and damage, a vacuum system for generating a vacuum in the inner space of the mold, and a glass object for heating Glass heating device. The mold is protected by the formation of a dull atmosphere or vacuum to increase the life of the mold. According to several exemplary embodiments, the mold includes graphite, silicon carbide, stainless steel, or a combination thereof. According to several exemplary embodiments, the mold includes one or more suction holes provided on one or more edges of the mold. According to several exemplary embodiments, one or more suction holes have a higher density on the mold part having a larger curvature. According to several exemplary embodiments, the mold protection device can be moved in a vertical direction to change or adjust the positive pressure applied to the glass object.

According to several exemplary embodiments, the vacuum forming device also includes one or more pneumatic pumps for injecting dull gas into the mold protection device. According to several exemplary embodiments, the passivation gas includes nitrogen, argon, or a combination thereof.

According to several exemplary embodiments, the vacuum system includes a pneumatic pump for injecting dull gas into the mold. According to several exemplary embodiments, the passivation gas includes heated nitrogen or heated argon. According to several exemplary embodiments, the glass heating device includes one or more infrared (IR) heating devices for heating glass objects at specific locations. According to several exemplary embodiments, a glass heating device is configured so that the corners and edges of the glass object are heated to a higher temperature than other parts of the glass object.

According to several exemplary embodiments, the vacuum forming device further includes a heating device for heating the mold protection device and the space between the molds. According to several exemplary embodiments, the vacuum forming device further includes an auxiliary injection device that injects gas into the corner of the mold protection device to help shape the glass object. According to several exemplary embodiments, the auxiliary spray device is designed to provide better curvature in the 3D glass. According to several exemplary embodiments, the auxiliary injection device provides a pressure higher than 762 Torr.

According to several exemplary embodiments, the present invention further provides a vacuum forming device for forming curved glass, which includes a vacuum forming device having a forming surface and one or more suction holes provided on one or more edges of the mold. A mold, a mold protection device that covers the mold and can move in a vertical direction to adjust the positive pressure applied to the glass object, a vacuum system that generates a vacuum in the internal space of the mold, and a glass heating device that heats the glass object in a special position.

According to several exemplary embodiments, the vacuum forming apparatus further includes one or more air pumps for injecting a dull gas into the space between the mold protection device and the mold. According to several exemplary embodiments, one or more air pumps inject heated dull gas during cooling of the glass object.

According to several exemplary embodiments, the vacuum forming device further includes an auxiliary spray device that injects gas into the corner of the mold protection device to help shape the glass object.

According to several exemplary embodiments, the present invention also provides a method of bending a glass object. According to several exemplary embodiments, the glass object may be a glass sheet or any glass material having a portion capable of being bent. According to several exemplary embodiments, the material of the glass object can be any glass. Examples of suitable glass include aluminosilicate glass, borophosphosilicate glass, fluorophosphate glass, fluorosilicate glass, quartz, phosphate glass, phosphosilicate glass, soda lime glass, sodium silicate, etc. Wait.

According to several exemplary embodiments, the method of bending a glass object includes covering the mold with a mold protection device, protecting the mold from oxidation by forming a dull atmosphere or generating a vacuum in the space between the mold and the mold protection device, and The object is heated to working temperature to provide a heated glass object, a vacuum is generated in the inner space of the mold, while positive pressure exists in the outer space of the mold to bend to form a heated glass object to provide a molded glass object, and to cool the molded glass object Glass objects.

According to several exemplary embodiments, the pressure difference between the outer space of the mold and the inner space of the mold helps to bend the glass object on the mold. According to several exemplary embodiments, the method further includes changing or adjusting the positive pressure by vertically moving the mold protection device.

According to several exemplary embodiments, the method further includes injecting heated dull gas on the shaped glass object while cooling. According to several exemplary embodiments, the temperature of the heating passivation gas is lower than the working temperature. According to several exemplary embodiments, the working temperature is about 600°C to 950°C, including from about 700°C to 800°C. According to several exemplary embodiments, the temperature of the injected passivation gas is about 50°C to about 150°C lower than the operating temperature.

According to several exemplary embodiments, the glass object includes at least one surface that is 2D. Examples of glass objects used for molding include touch screens and flat glass. According to several exemplary embodiments, this progressive method can be used to shape at least one 2D surface into a shaped glass object with at least one 2.5D or 3D surface. For example, this progressive method can produce curved glass suitable for curved displays.

The present disclosure provides a method and device to form curved glass with a high-quality surface, which can be used in automobile systems or portable mobile devices. Although the present invention has been described in terms of certain embodiments, those skilled in the art will recognize that the present invention can be implemented with modifications within the spirit and scope of the appended patent application.

Any mention of space, for example, "up", "down", "above", "below", "between", "bottom", "vertical", "horizontal", "angular" , "Face Up", "Face Down", "Edge to Edge", "Left to Right", "Left", "Right", "Right to Left", "Top to Bottom", "Bottom to Top", " "Top", "Bottom", "Down to Up", "Up to Down", etc., are for illustrative purposes only and do not limit the specific orientation or position of the above structure.

The present disclosure has been described with respect to certain embodiments. After reading this disclosure, only obvious improvements or modifications to those skilled in the art are deemed to be within the spirit and scope of this application. It is understood that several modifications, changes, and substitutions are expected in the foregoing disclosure, and in some examples, some features of the present invention will be used without corresponding use Other characteristics. Therefore, it is appropriate that the scope of the appended patent application be interpreted broadly and in a manner consistent with the scope of the present invention.

100: Vacuum forming device

110: Mould

114, 131, 151, 161: airway

115: Glass Object

118: Under Space

120: Mold protection device

121: Up Space

130, 160: pneumatic pump

140: Upper vacuum system

141: Upper vacuum system channel

150: Lower vacuum system

170: heating device

180: Glass heating device

190: auxiliary injection device

Claims (19)

A vacuum forming device for forming curved glass includes: a mold having a forming surface and a plurality of suction holes; a mold protection device that covers the mold; and a vacuum system in an inner space of the mold A vacuum is generated in the mold; and a glass heating device that heats a glass object; wherein the plurality of suction holes have an uneven distribution on the mold. The vacuum forming device described in item 1 of the scope of patent application, wherein the mold includes graphite, silicon carbide or stainless steel. The vacuum forming device described in the first item of the scope of patent application, wherein the mold protection device includes a movable cover part for changing a positive pressure applied to the glass object. The vacuum forming device described in item 3 of the scope of patent application further includes a motor and a connecting rod integrated with the mold protection device to move the cover part of the mold protection device. The vacuum forming device as described in the first item of the scope of patent application further includes one or more pneumatic pumps for injecting dull gas into a space between the mold and the mold protection device. According to the vacuum forming device described in claim 1, wherein the vacuum system further includes a pneumatic pump for injecting dull gas into the inner space of the mold. The vacuum forming device according to the first item of the patent application, wherein the glass heating device includes one or more infrared (IR) heating devices. The vacuum forming device described in claim 1, wherein the glass heating device is configured to provide heat energy to the glass object with an uneven distribution, so that the corners of the glass object are heated to be higher than the glass object The other part of the high temperature is higher. The vacuum forming device described in the first item of the patent application further includes a heating device for heating the mold protection device and a space between the molds. As described in the first item of the patent application, the vacuum forming device further includes an auxiliary injection device that injects gas toward the curved part of the mold to help shape the glass object. A vacuum forming device for forming curved glass includes: a mold having a forming surface and a plurality of suction holes arranged unevenly on the mold; a mold protection device that covers the mold and is capable of Mobile to adjust a positive pressure applied to a glass object; a vacuum system that generates a vacuum in an internal space of the mold; and a glass heating device that is configured to be placed on the edge of the glass object Heat the glass object with more heat energy. The vacuum forming device according to claim 11, wherein the forming surface of the mold includes a first area having a first curvature and a second area having a second curvature, the second curvature being lower than The first curvature; and the suction holes are configured to have a first density in the first area and a second density in the second area, the second density being lower than the first density. The vacuum forming device described in claim 11 further includes one or more pneumatic pumps that inject dull gas into a space between the mold protection device and the mold; and an auxiliary injection device , Which injects gas toward a part of the mold to help shape the glass object. A method for bending a glass object includes: covering a mold with a mold protection device; protecting the mold from oxidation by forming a dull atmosphere; heating a glass object to a working temperature to provide a heated glass An object; generating a vacuum in an internal space of the mold, while a positive pressure exists in an external space of the mold to bend the heated glass object to provide a molded glass object; and Cooling the shaped glass object; wherein the mold has a plurality of suction holes, and the plurality of suction holes have an uneven distribution on the mold. The method described in item 14 of the patent application further includes changing the positive pressure by moving the mold protection device while generating a vacuum. The method described in item 14 of the scope of the patent application further includes injecting heated dull gas on the shaped glass object while cooling the shaped glass object. The method according to item 16 of the scope of patent application, wherein a temperature of the heated passivation gas is lower than the working temperature. The method according to claim 17, wherein the working temperature is about 600°C to 950°C; and the temperature of the heated passivation gas is about 50°C to about 150°C lower than the working temperature. The method described in item 14 of the scope of the patent application further includes injecting gas toward the curved part of the mold to help shape the glass object.

Images