JP2009221104A - Molten glass supply device and method of producing glass formed product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molten glass supply device capable of properly solving such unavoidable problems for high viscosity characteristics in connection with the conventional molten glass supply device for high viscosity glass which includes as improperly high heating cost caused by excessive heat radiation in a melting furnace, reduction in the grade of products derived from an excess amount of an erosion foreign material and reduction in the product yield. <P>SOLUTION: High viscosity molten glass having a property in which a temperature at which the molten glass exhibits a viscosity of 1,000 poise is 1,350°C. or higher is supplied to a forming device 5 through a melting furnace 2, a distribution portion 3 in communication with the outlet 2a of the melting furnace 2, and a plurality of branch paths 4 branching from the distribution portion 3. In the distribution portion 3, the molten glass is heated to have ≤1,000 poise viscosity and the contact surface of the inner wall of the distribution portion 3 is made from platinum, molybdenum, palladium, rhodium or the alloy. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technology for supplying molten glass, and in particular, an improvement of a molten glass supply device for supplying molten glass having high viscosity characteristics such as a glass plate for liquid crystal from a melting furnace to a molding apparatus, and the molten glass. The present invention relates to an improvement in technology for manufacturing glass molded products such as liquid crystal plate glass supplied from a melting furnace.

  In recent years, various kinds of glass substrates such as liquid crystal displays (LCD) and electroluminescent displays (ELD), flat display glass substrates, charge coupled devices (CCD), equal-magnification proximity solid-state imaging devices (CIS), CMOS image sensors, etc. The demand for cover glass such as image sensors and laser diodes, and glass substrates for hard disks and filters has rapidly increased.

  These examples of listed articles and the glass forming the articles equivalent thereto (hereinafter also referred to as high viscosity glass) are cathode ray tube (CRT) glass panels and glass funnels, window glass, articles such as bottles and tableware, Compared with glass (hereinafter also referred to as low-viscosity glass) that forms articles according to these, the characteristics are very different.

  Specifically, taking a non-alkali glass for a liquid crystal display, which is a high-viscosity glass, and a soda-lime glass for containers, which is a typical example of a low-viscosity glass, as shown in FIG. The characteristic curve A indicates that the viscosity is not lowered moderately unless it is an extremely high temperature region of about 1400 ° C. or higher, and the smooth flow of the molten glass in the molten glass supply apparatus described below cannot be maintained. On the other hand, the characteristic curve B of soda-lime glass shows that the viscosity is moderately reduced at about 1200 ° C. or less. Strictly speaking, liquid crystal display glass (characteristic curve A) has a temperature of about 1460 ° C. or more and a viscosity of 1000 poise or less, while soda lime glass (characteristic curve B) has a temperature of about 1180 ° C. The viscosity is 1000 poises or less.

  The high-viscosity glass described above generally exhibits the characteristics that when the viscosity is 1000 poise, the temperature corresponding to the viscosity is 1350 ° C. or higher, particularly 1420 ° C. or higher for high-viscosity glass. The low-viscosity glass described above exhibits a characteristic that when the viscosity is 1000 poise, the temperature corresponding to the viscosity is 1250 ° C. or less, particularly 1200 ° C. or less when the viscosity is low. Therefore, the above-mentioned high viscosity glass and low viscosity glass can be distinguished based on the relationship between temperature and viscosity.

  On the other hand, when manufacturing an article formed of the above-described high-viscosity glass, the high-viscosity glass is supplied as a molten glass to a molding apparatus, and, for example, a plate-like glass substrate or the like is molded with the molding apparatus. Therefore, when manufacturing these articles, a molten glass supply device including a melting furnace serving as a supply source of the molten glass and a supply channel for supplying the molten glass flowing out of the melting furnace to the molding device is used. Is done.

  And in this molten glass supply apparatus, in order to supply molten glass smoothly to a shaping | molding apparatus through the flow path for supply from a melting furnace, the viscosity of molten glass must be made low. In this case, as is clear from the matters already described in the comparison between the characteristic curve A and the characteristic curve B shown in FIG. 5, in order to lower the viscosity of the molten glass, the high viscosity glass is far more than the low viscosity glass. It is necessary to increase the temperature.

  Therefore, the molten glass supply device for high-viscosity glass is more difficult to flow the molten glass smoothly than the molten glass supply device for low-viscosity glass. It is necessary to use an apparatus with a small configuration. From such a request, when high viscosity glass is targeted, as disclosed in, for example, Patent Document 1 below, molten glass is supplied from a melting furnace to a molding apparatus through a single supply channel. An apparatus having a configuration (hereinafter also referred to as a single feeder) was used.

JP 2000-185923 A (FIG. 2) Japanese Patent Publication No. 48-17845 JP 62-176927 A JP-A-6-24752 JP 2000-313623 A

  By the way, the molten glass supply apparatus for high-viscosity glass needs to maintain the molten glass in the melting furnace at an extremely high temperature (for example, 1500 ° C. or higher) by a heating means. Nonetheless, when a melting furnace is provided for each supply channel as in the prior art, when supplying molten glass to a plurality of molding apparatuses through a plurality of supply channels, Since heat is radiated from the entire circumference of each of the multiple melting kilns, the amount of heat radiated per unit area is inherently large and the total heat radiated area becomes large. As a result, the total amount of heat radiated becomes enormous and heating is performed. Cause an unreasonable increase in costs.

  In addition, the refractory (such as refractory bricks) forming the melting kiln invites a situation in which the molten glass is eroded by contact with the molten glass when the molten glass reaches a high temperature. Such a situation may have the property that the refractory is easily eroded by the high-temperature molten glass, and there are many types of refractories that can be used in the low-temperature range. Refractories that are less likely to be eroded by contact with refractories can be easily selected, whereas in high temperatures, refractories that can withstand high temperatures are limited to, for example, high zirconia-based ones, and the degree of freedom of selection is small. For example, it becomes impossible to select a refractory that is hard to be eroded.

  Therefore, in this case as well, if the molten glass supply device for high viscosity glass is provided with a melting kiln for each supply channel as in the past, a plurality of supply channels are provided through a plurality of supply channels. When the molten glass is supplied to the molding apparatus of the table, the entire inner wall surface of each of the plurality of melting furnaces and the molten glass are in contact with each other, so the amount of eroded foreign matter in the molten glass flowing into each supply channel Or, the amount of extraneous glass due to erosion is unduly increased. Then, due to the eroded foreign matter and the foreign glass, the quality of the glass article molded by the molding apparatus is lowered, and further the product yield is lowered.

  On the other hand, the molten glass supply device for low-viscosity glass only needs to maintain the molten glass in the melting furnace at a temperature much lower than that of the above-mentioned high-viscosity glass, and has a unit area. Since the amount of heat radiation per unit is small, even if the heat radiation area is large, it does not lead to an excessive total heat radiation amount or an unreasonably high heating cost. Moreover, the low-viscosity glass does not deviate from the low temperature range when supplied from the melting kiln to the molding apparatus, and therefore it is possible to avoid erosion of the melting kiln for the reasons already described. Even if the contact area between the inner wall surface of the kiln and the molten glass is increased, there is no problem of deterioration of the quality of the molded product or product yield due to eroded foreign substances.

  Therefore, the problem relating to the heat radiation amount, eroded foreign matter, etc. in the melting furnace is an inherent problem of the molten glass supply device for high viscosity glass. Nevertheless, in the field of manufacturing glass articles made of high-viscosity glass, the actual situation is that there is no awareness of problems with regard to the amount of heat release, eroded foreign matter, and the like. This is because in this field of high-viscosity glass, if the basic essence of using a single feeder is destroyed, the fluidity of the molten glass deteriorates, and the molding operation by the molding apparatus, and thus the defects that are extremely noticeable. It is considered inevitable to occur, and therefore the most important issue was how to supply molten glass to the molding device in an optimal state by applying various devices to the single feeder. It is.

  For the above reasons, in the conventional molten glass supply device for high-viscosity glass, no measures have been taken to solve problems such as heat dissipation in the melting kiln and eroded foreign matter. Is the actual situation.

  The present invention has been made in view of the above circumstances, and with respect to the conventional molten glass supply technology for high-viscosity glass, an excessive heat dissipation amount of the melting furnace, which is an inherent problem because it exhibits high-viscosity characteristics, is provided. It is a technical problem to suitably avoid the problem of deterioration in the quality of a molded product resulting from an unreasonable increase in heating cost due to the above, or an excessive amount of eroding foreign matter, and thus a decrease in product yield.

  The present invention made in order to solve the above technical problem includes a melting kiln serving as a supply source of molten glass, and a supply flow path for supplying the molten glass flowing out of the melting kiln to a glass article forming apparatus. In the molten glass supply apparatus, the molten glass has a characteristic that a temperature corresponding to a viscosity of 1000 poise is 1350 ° C. or more, and the supply flow path is a distribution section that leads to an outlet of the melting furnace. And a plurality of branch passages branched from the distributor and extending toward a plurality of molding devices, the distributor having heating means for heating the molten glass so that the viscosity is 1000 poise or less. In addition, at least the contact surface with the molten glass on the inner wall surface of the distributor is formed of platinum, molybdenum, palladium, rhodium, or an alloy thereof. The distribution part preferably has a function as a volume part capable of temporarily stagnating the flow of the molten glass. However, the distribution part is merely a collection of the branch flow paths not having such a function. Part.

  Here, since the object to be supplied by this apparatus is a molten glass having a characteristic that the temperature corresponding to a viscosity of 1000 poise is 1350 ° C. or higher, this glass is clear from the matters already described. It is a high-viscosity glass and is distinguished from a low-viscosity glass. If the molten glass has a characteristic that the temperature corresponding to a viscosity of 1000 poise is 1420 ° C. or more, it is advantageous in that the distinction from the low-viscosity glass can be made clearer. The high-viscosity glass as described above includes non-alkali glass (glass having an alkali component of, for example, 0.1% or less, particularly 0.05% or less).

  According to such a configuration, since a plurality of branch flow paths extend from the melting kiln via the distribution section, the molten glass in the melting kiln passes through each of the branch flow paths, and each molding device Will be supplied. Therefore, the value obtained by dividing the heat dissipation area of the melting furnace in this case by the number of branch flow paths, that is, the heat dissipation area of the melting furnace per branch flow path is a plurality of the same volume as the melting furnace. This is much smaller than the heat radiation area of the melting kiln per supply flow path in a plurality of single feeders having the same melting kiln. In other words, when the volume of the melting kiln in the present invention is the same as the total volume of the melting kiln that each of the conventional single feeders has, the per-branch flow path of the present invention The heat dissipating area of the melting furnace is much smaller than the heat dissipating area of the melting furnace per supply channel of a single feeder in the prior art. As described above, since the heat radiation area of the melting furnace per one branch flow path is much smaller than that of the conventional apparatus (single feeder), the heat radiation amount from the melting furnace for one branch flow path is small. It is possible to avoid an excessive increase in the heating cost required for one molding line and to contribute to a reduction in product cost.

  Moreover, according to such a configuration, the value obtained by dividing the contact area with the molten glass on the inner wall surface of the melting furnace by the number of branch channels, that is, the erosion area of the melting furnace per branch channel is also a single unit. This is much smaller than the erosion area of the melting kiln per supply channel in the case of the feeder. As a result, the amount of erosion foreign matter and foreign glass in the molten glass supplied to the molding apparatus through individual branch channels is not excessive, and the contamination of the molten glass and the resulting deterioration in the quality of molded products and the decrease in product yield. The problem is avoided.

  In this case, each branch flow path may extend radially from the distribution section toward each molding apparatus, and may extend from the distribution section parallel to each other toward each molding apparatus. In order to prevent problems such as non-uniformity of glass viscosity and deterioration of fluidity, it is preferable that all of these branch flow paths extend linearly in plan view.

  In addition, as a technique related to the present invention, according to the above-described Patent Documents 2 to 5, an apparatus (hereinafter, referred to as a structure) configured to supply molten glass flowing out from a melting furnace to a plurality of branch flow paths via a distribution chamber. (Also referred to as a multi-feeder). However, this multi-feeder distributes and supplies the low-viscosity glass described above as molten glass. That is, Patent Document 2 describes “window glass”, Patent Document 3 describes “glass gob” and “glass for manufacturing containers”, and Patent Document 4 describes “glass bottle”. "And the composition of the glass that can be judged to be low-viscosity glass are listed in Table 1, and since Patent Document 5 has the description" Glass bottles and glass tableware ", these are disclosed in each of these documents. It is clear that the multi-feeder being used is intended for the low viscosity glass described above.

  Thus, in the case of a multi-feeder for low-viscosity glass, it is sufficient if a molten glass having a temperature much lower than that of the above-mentioned high-viscosity glass can be supplied from the melting kiln. Therefore, even if the heat dissipation area of the melting furnace is large, the amount of heat dissipation per unit area is small, and as described above, the amount of heat dissipation is excessive, resulting in an unreasonable increase in heating costs and thus an increase in product costs. In addition to not inviting, since the erosion of the melting furnace can be avoided in the low temperature range for the reasons already described, there is no problem of product yield reduction due to eroded foreign substances or foreign glass. For this reason, in the case of low-viscosity glass, there is no great difference between a single feeder and a multi-feeder, if attention is paid to the problem of the heat radiation amount of the melting furnace and the problem of eroded foreign matter. Therefore, this multi-feeder not only has the effect of suppressing the unreasonable increase in heating cost as described above and reducing the product cost, but also reduces the amount of eroded foreign matters and the like. It does not have the effect of improving the quality of the product and improving the product yield. If the above matter is taken into consideration, this multi-feeder is intended for low-viscosity glass, so that the gist of the present invention is different from that of the present invention.

  Furthermore, according to said structure in this invention, the advantage that a different glass article can be shape | molded simultaneously by the molten glass distributed and supplied from the same melting kiln is acquired. Moreover, even when the supply of the molten glass from one branch channel is stopped, the required molding process can be performed by supplying the molten glass to the molding apparatus through another branch channel. Therefore, when it is desired to change the molding of a glass article by one line molding apparatus to the molding of another different glass article, it is not necessary to stop all of the branch flow paths, and the branch corresponding to the line to be changed. Only the flow path is in a supply stop state, the molding apparatus is replaced and replaced, and the other molding apparatuses can be in an operating state, so that the production efficiency can be improved.

  In recent years, with the widespread use of liquid crystal display devices and the increase in the size of the panels, the demand for plate glass constituting the liquid crystal display devices is increasing rapidly, and when the panels become larger. A slight difference in composition or material property between the two glass plates sandwiching the liquid crystal tends to cause a pitch shift during the production of the panel. Therefore, a large amount of glass having a constant composition and material properties is required, and for such an increase in demand for plate glass, a conventional molten glass supply device (single feeder) may be added. According to such a simple method, plate glass produced by different single feeders has different operating conditions and blending conditions, so that the composition and material characteristics are not constant even for the same type. Invite. On the other hand, the molten glass supply apparatus according to the present invention is formed by branching a plurality of supply channels (branch channels) from the melting kiln, so that it can easily cope with the recent increase in demand for plate glass. In addition, even glass plates formed through different branch channels have the same operating conditions and blending conditions, and the composition and material properties are constant accordingly. As a result, it becomes possible to supply a large amount of plate glass having a constant composition and material properties.

  Furthermore, the molten glass supply apparatus according to the present invention includes a heating means for heating the molten glass in the distribution unit so that the viscosity becomes 1000 poises or less.

  That is, it is indispensable to smoothly distribute and supply molten glass from the distribution unit to each branch flow path. In that case, the molten glass that has flowed into the distribution unit from the melting furnace is discharged to each branch passage. When the viscosity increases due to a temperature drop, smooth distribution supply is hindered. Then, if the molten glass in a distribution part is heated with a heating means and the viscosity is maintained below 1000 poise, molten glass will be smoothly distributed and supplied to each branch flow path from a distribution part. In this case, if the flow direction of the molten glass is along a straight line, the viscosity of the molten glass may be slightly over 1000 poise to ensure a smooth flow. Therefore, it is difficult to maintain a smooth flow unless it is 1000 poises or less.

  In this case, the viscosity of the molten glass in the distribution section is made lower than the viscosity of the molten glass in the melting furnace by a heating means for heating the molten glass in the distribution chamber and a heating means for heating the molten glass in the melting furnace. That is, it is preferable to make the temperature of the molten glass in the distribution part higher than the temperature of the molten glass in the melting furnace. In this way, in addition to being able to appropriately cope with the complicated flow of the molten glass in the distribution section than in the melting furnace, the volume of the distribution section is far greater than that of the melting furnace. Since it is small, the molten glass can be easily heated at a high temperature by the heating means.

  Further, in the middle of each branch flow path, for example, immediately downstream of the distribution section of each branch flow path, as described in the following embodiment, there may be a function as a flow resistance application section (temperature adjustment section). The same applies hereinafter). In such a case, it is preferable to make the viscosity in the distribution part lower than the viscosity of the molten glass in each flow resistance imparting part, and among these three including the molten glass in the melting furnace, It is preferable to make the viscosity of the molten glass the lowest. The heating means for heating the inside of the melting furnace and the distribution section is preferably a burner, which burns oxygen so that high temperature heating (for example, heating at about 1700 ° C.) is possible. Preferably there is.

  In addition, in the molten glass supply apparatus according to the present invention, at least the contact surface with the molten glass on the inner wall surface of the distribution unit is formed of platinum, molybdenum, palladium, rhodium, or an alloy thereof (hereinafter referred to as platinum). ing. Among these, it is more preferable to form platinum or a platinum alloy which is extremely excellent in heat resistance and erosion resistance.

  That is, if platinum or the like having both heat resistance of 1350 ° C. or higher (preferably 1420 ° C. or higher) and erosion resistance is used, the heat treatment and the erosion treatment on the inner wall surface of the distribution part can be realized simultaneously. It is possible to reduce the work and labor required for this process. In addition, you may form all the wall parts of the applicable part of a distribution part with platinum etc. However, considering that this platinum etc. are expensive, the main part of a distribution part is formed with a refractory (fireproof brick etc.). It is preferable that the contact surface of the inner wall surface with the molten glass is covered with a thin plate such as platinum.

  As described above, the heat treatment and the erosion treatment are applied to the distribution section, so that the heat resistance of the distribution section is improved and it can withstand long-term use. And the occurrence of foreign glass are avoided, and problems such as deterioration in the quality of molded products and product yield due to the inclusion of eroded foreign substances do not occur.

  In addition, at least the contact surface with the molten glass on the inner wall surface of each flow resistance applying portion provided in each branch flow path described above is also formed of platinum or the like, for example, covered with a thin plate of platinum or the like at 1350 ° C. It is preferable to perform the above heat treatment and corrosion resistance treatment (preferably 1420 ° C. or higher). In addition, the same treatment can be applied to the melting kiln formed of refractory, but the volume of the melting kiln is much larger than that of the distribution section and the distribution resistance imparting section. It is advantageous in terms of cost not to perform the treatment, and it is possible to take measures to prevent the problem with respect to eroded foreign matters, etc. preferable.

  Further, the molding device as a component of the molten glass supply device according to the present invention is a plate glass molding device.

  And the glass molded product containing plate glass becomes a quality thing excellent in the quality etc. by shape | molding and manufacturing the molten glass supplied from the molten glass supply apparatus provided with the above structure with the said shaping | molding apparatus. .

  In this case, examples of the sheet glass forming apparatus include a down draw forming apparatus, an up draw forming apparatus, and a float forming apparatus, and further examples of the down draw forming apparatus include an overflow forming apparatus and a slot down forming apparatus. . Among these, it is desirable to use an overflow molding apparatus that does not require polishing of the surface of the molded sheet glass. Further, as the plate glass formed by these forming apparatuses, various image sensors such as a glass substrate of a flat display typified by a liquid crystal display or an electroluminescence display, a charge coupled device, an equal magnification proximity solid-state imaging device, a CMOS image sensor, etc. And a glass substrate of a hard disk or a filter.

  When forming these glass sheets, if the viscosity of the molten glass supplied to the forming apparatus is not uniform, undulations and the like are generated in the glass sheet, resulting in defective molding, and foreign matter due to erosion of the refractory in the molten glass. If is mixed, the plate glass becomes poor and the quality is deteriorated. These problems are particularly fatal in applications such as glass substrates for liquid crystal displays that require high quality. As described above, according to the present invention, it is possible to cope with problems such as eroding foreign substances and non-uniform viscosity, and therefore, it is particularly suitable for the above-described forming of plate glass.

  In the above configuration according to the present invention, it is preferable that the distribution unit is shallower than the melting kiln.

  In other words, the molten glass that is about to flow out of the melting furnace into the distribution section is usually such that the lower part is lower in temperature and the viscosity is relatively higher than the upper part. If the temperature of the glass is set to an extremely high temperature (for example, 1500 ° C. or higher), it may naturally occur from the relationship between the specific gravity and the temperature, considering that it is difficult to equalize the temperature. In the case of a burner, the flame (flame) of the burner is inevitably irradiated using the upper space of the molten glass in the melting furnace. The difference in viscosity is extremely large. Therefore, if the distribution portion is shallower than the melting kiln, the molten glass having a lower viscosity remains in the melting kiln, and only the molten glass having a lower viscosity flows into the distributing portion. As a result, molten glass with low viscosity can be used effectively without waste, and it can contribute to uniform viscosity of the molten glass from the upper part to the lower part of the distribution part, and further promotes defoaming from the molten glass. Is done. When the heating means is based on the electric melting method, or when the electric melting method and burner heating are used in combination, the temperature difference between the upper and lower portions of the molten glass as compared with the case where only the above-described burner heating is used. However, it is difficult to reduce the temperature difference to a reasonable level because the molten glass must be extremely heated as described above. Therefore, even when the electric melting method is adopted, the above-described advantages due to the fact that the distribution portion is shallower than the melting kiln can be naturally obtained.

  Moreover, erosion foreign matter mixed in the molten glass in the melting furnace, for example, when the melting furnace is formed of a high zirconia refractory, the zirconia mixed in the molten glass has a higher specific gravity than the molten glass. In this case, the molten glass precipitates in the lower part of the molten glass, or melts into the molten glass to become a poor molten glass and accumulates in the lower part. Even in such a case, by setting the distribution portion to be shallower than the melting furnace, only the upper molten glass having a small amount of erosion foreign matter or foreign glass mixed or melted will flow into the distribution portion. . In order to obtain such an advantage, it is sufficient to make only a part of the distribution part on the melting furnace side shallow. In addition, you may form such a part shallow bottom part in the boundary part (a part of melting furnace is also included) of a distribution part and a melting kiln.

  In such a configuration, it is preferable that the depth of the distribution unit is set to 4/5 or less of the depth of the melting kiln. Here, “the depth of the distribution section” and “the depth of the melting kiln” mean that the liquid glass is approximately the same height from the melting kiln to the distribution section when the molding process is being performed in the molding apparatus. It means the depth from the liquid level when flowing out to the surface to the respective bottom surfaces of both.

  Thus, if the depth of the distribution part is set to 4/5 or less of the depth of the melting furnace, the part of the melting glass in the lower part of the molten glass that is contaminated with the most highly viscous and eroding foreign matter is included. At least 1/5 of the amount of molten glass can be prevented from flowing into the distribution section, and 4/5 or less of molten glass including the portion that is the least viscous and not contaminated by eroding foreign substances flows into the distribution section. Will do. Therefore, only the molten glass having a reasonably low viscosity and cleanness flows into the distribution part, and the molten glass having preferable characteristics in the melting furnace is effectively used, and the viscosity of the molten glass in the distribution part is appropriately uniformized. Further, defoaming from the molten glass is promoted moderately. On the other hand, when the above set value exceeds 4/5, even the highly viscous and contaminated molten glass existing in the lower part of the melting furnace flows into the distributing part, and the molten glass in the distributing part Viscosity homogenization and defoaming promotion are likely to be hindered. In this case, in order to obtain the advantages as described above more reliably, the depth of the distribution section is preferably 3/5 or less of the depth of the melting kiln, and more preferably 1/2 or less. . In any of the above settings, the depth of the distribution section is 1/20 or more of the depth of the melting kiln in order not to waste the heating amount and heating cost for the molten glass in the melting kiln. It is preferable that

  In addition, foreign substances such as silica may be in a state of floating in the form of a film on the liquid surface of the molten glass in the melting furnace. For the purpose of removing this film-like suspended matter, two or three or more May be installed in series from the upstream side to the downstream side. In such a case, the relationship between the depth of the melting kiln and the distribution section is 4/5 or less (or 3/5 or less or 1/2 or less) of the depth of the melting furnace where the depth of the distribution section is the deepest. In addition, it is preferable that the distribution part is shallower than the melting furnace immediately adjacent to the distribution part.

  In the above configuration, the depth of the distribution unit is preferably set to 500 mm or less.

  In this way, if the depth of the distribution part is set to 500 mm or less, the distance from the bottom surface to the liquid level will not be unduly long. Therefore, the temperature difference between the upper part and the lower part of the molten glass flowing into the distribution part is appropriately set. This can be made small, which is advantageous for making the viscosity of the molten glass uniform in the distribution section. On the other hand, if the depth of the distribution part exceeds 500 mm, the distance from the bottom surface to the liquid level becomes unreasonably long, which becomes a factor that hinders the uniformization of the viscosity of the molten glass in the distribution part. In this case, in order to surely obtain the above advantages, it is preferable to set the depth of the distributing portion to 400 mm or less. When forming a large glass article such as a glass substrate for a flat display such as a liquid crystal display with a molding apparatus, it is necessary to supply a relatively large volume of molten glass from the distribution section to the branch channel. In consideration of the above, it is preferable that the depth of the distribution portion is 50 mm or more.

  Moreover, the manufacturing method of the glass molded product based on this invention made | formed in order to solve the said technical subject is a high-viscosity glass provided with the characteristic that the temperature equivalent to the viscosity of 1000 poise becomes 1350 degreeC or more with a melting kiln. A melting step for melting, a distribution step for supplying the molten glass flowing out from the melting kiln to the plurality of branch channels through a distribution unit that leads to an outlet of the melting kiln, and a melt flowing down the plurality of branch channels A molding step of forming a glass molded product by supplying glass to molding devices respectively connected to the plurality of branch channels, and in the distribution step, the molten glass is platinum, molybdenum, palladium, rhodium, or an alloy thereof. And the molten glass in the distribution step is heated so as to have a viscosity of 1000 poise or less.

  Also by implementing this manufacturing method, the basic effects of the molten glass supply apparatus already described can be obtained. And also when implementing this manufacturing method, in order to acquire each effect similar to the matter already stated, it is preferable that the said shaping | molding apparatus is a shaping | molding apparatus of plate glass (especially the glass substrate of a flat display).

  As described above, according to the present invention, a molten glass having a high viscosity characteristic with a temperature corresponding to a viscosity of 1000 poise of 1350 ° C. or higher is provided with a melting kiln, a distribution unit that leads to an outlet of the melting kiln, Since it is supplied to the molding device through a plurality of branch channels branched from the distributor, the heat dissipation area of the melting furnace per branch channel is far greater than that of the conventional device (single feeder) Thus, the heating cost required for each molding line can be reduced, and the product cost can be reduced. In addition, the erosion area of the melting kiln per branch flow path is much smaller than that of conventional equipment, and erosion foreign substances and foreign substances in the molten glass supplied to the molding equipment through individual branch flow paths. By reducing the amount of glass, it is possible to avoid problems such as contamination of the molten glass and deterioration of the quality of molded products and product yield due to the contamination. Further, the molten glass distributed and supplied from the same melting furnace provides the advantage that different kinds of glass articles can be simultaneously formed, and the supply of the molten glass from one branch channel is stopped. However, it is possible to supply the molten glass to the molding apparatus through another branch flow path and execute a required molding process. Moreover, since the branch flow path is formed by branching from the melting kiln, it can easily cope with the recent increase in demand for plate glass without adding another molten glass supply device, and different branch flows Even in the case of a plate glass formed through a path, the operating conditions and the blending conditions are the same, so that a large amount of plate glass having a constant composition and material properties can be supplied.

  In addition, according to the present invention, the molten glass in the distribution unit is configured to be heated so that the viscosity is 1000 poise or less, so that the flow of the molten glass in the distribution unit is more complicated than in the melting furnace. In spite of this, the molten glass is smoothly distributed and supplied from the distributor to each branch channel. That is, it is indispensable to smoothly distribute and supply molten glass from the distribution unit to each branch flow path. In that case, the molten glass that has flowed into the distribution unit from the melting furnace is discharged to each branch passage. When the viscosity increases due to a temperature drop, smooth distribution supply is hindered. Therefore, if the molten glass in the distribution section is heated so that its viscosity is maintained at 1000 poise or less, a smooth flow can be achieved despite the generation of a complicated and complicated flow in the distribution section. Can be maintained.

  Furthermore, according to the present invention, since at least the contact surface with the molten glass on the inner wall surface of the distribution portion is formed of platinum, molybdenum, palladium, rhodium or an alloy thereof, the heat treatment and resistance to the inner wall surface of the distribution portion can be achieved. The erosion process is realized at the same time, and the work and labor required for these processes can be reduced. In addition, the heat treatment and the erosion treatment are applied to the distribution section in this way, so that the heat resistance of the distribution section is improved and it can withstand long-term use, and the distribution section newly erodes. A situation where foreign matter or foreign glass is generated is avoided, and problems such as deterioration of the quality of the molded product and product yield due to mixing of eroded foreign matter in the molding apparatus do not occur.

It is a partially broken schematic perspective view which shows the whole structure of the molten glass supply apparatus which concerns on embodiment of this invention. It is a cross-sectional top view which shows the principal part of the molten glass supply apparatus which concerns on embodiment of this invention. It is a vertical side view which shows the principal part of the molten glass supply apparatus which concerns on embodiment of this invention. 4 (a) to 4 (e) are respectively longitudinal sectional front views showing baffle plates installed in a branch flow path that is a component of the molten glass supply apparatus according to the embodiment of the present invention. It is the graph which compared the characteristic of the high viscosity glass with which this invention is applied, and the characteristic of the low viscosity glass which concerns on a prior art.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partially broken perspective view showing a schematic configuration of a molten glass supply apparatus according to an embodiment of the present invention, FIG. 2 is a transverse plan view showing a main part of the molten glass supply apparatus, and FIG. It is a vertical side view which shows the principal part of a glass supply apparatus. In the following description, the direction between the upstream side and the downstream side of the molten glass supply apparatus is also referred to as the front-rear direction, and the direction orthogonal to the front-rear direction in the horizontal plane is also referred to as the left-right direction.

  First, based on FIG.1 and FIG.2, the whole structure of the molten glass supply apparatus which concerns on embodiment of this invention is demonstrated. The molten glass supply apparatus 1 includes a substantially rectangular melting furnace 2 serving as a molten glass supply source, a distribution chamber (distribution unit) 3 communicated with an outlet 2 a of the melting furnace 2, and the distribution chamber 3. A plurality of branch flow paths 4 communicated at substantially equal intervals to the downstream end of each of the flow paths, and the downstream ends of these branch flow paths 4 communicate with a plurality of molding devices 5, respectively. Note that the number of paths through the branch flow path 4 to the molding apparatus 5 is three in the illustrated example, but may be two, or may be four or more. Moreover, the melting kiln 2 may be arranged in a state where two or more are connected in series or in parallel from the upstream side to the downstream side, for example.

  The melting furnace 2 has a bottom wall 21, side walls 22 to 25, and an arched ceiling wall 26 that covers the entire area above the bottom wall 21, and each of these walls is formed of a high zirconia refractory (refractory brick). At the same time, flames F of a plurality of burners are irradiated from above the left and right side walls 22 and 23 toward the upper space of the molten glass. And the flame F of these burners is maintaining the temperature of 1500-1650 degreeC by heating the molten glass with which the inside of the melting furnace 2 is filled from upper direction.

  The downstream side wall 24 of the melting furnace 2 has an outlet 2a formed at the center in the left-right direction. The outlet 24a is connected to the melting furnace 2 via a narrow outlet 6 having the outlet 2a at the upstream end. The distribution chamber 3 is in communication. The distribution chamber 3 has a bottom wall 31, side walls 32 to 35, and an arched ceiling wall (not shown) that covers the entire area above the bottom wall 31, and each of these walls has a high zirconia refractory (refractory brick). ). The outflow channel 6 has a bottom wall 61, side walls 62 and 63, and an arched ceiling wall (not shown) covering the entire upper area thereof. These walls are also made of a high zirconia refractory (refractory). Brick). And from the upper side of the left and right side walls 32 and 33 of the distribution chamber 3, the flame F of the burner is irradiated toward the upper space of the molten glass filled inside. In this case, the temperature of the molten glass in the distribution chamber 3 is maintained at 1600 ° C to 1700 ° C.

  The distribution chamber 3 is smaller in volume than the melting furnace 2, and a thin plate made of platinum or a platinum alloy is stretched on the inner wall surface (at least the inner wall surface portion in contact with the molten glass) of the bottom wall 31 and the side walls 32 to 35. In addition, a thin plate made of platinum or a platinum alloy is similarly stretched on the bottom wall 61 of the outflow passage 6 and the inner wall surfaces of the side walls 62 and 63. The distribution chamber 3 is elongated in the left-right direction, and the downstream end of the outflow passage 6 is opened at the center in the left-right direction of the upstream side wall 34. And in the center part of the distribution chamber 3 in the front-rear and left-right direction, a straightening wall part 37 that is long in the left-right direction is fixed with a flow space between all the side walls 32 to 35. The rectifying wall portion 37 is also formed of a high zirconia refractory (refractory brick), and a thin plate made of platinum or a platinum alloy is stretched on the outer surface thereof.

  In this case, as shown in FIG. 3, the distribution chamber 3 is shallower than the melting furnace 2. That is, the depth dimension X to the bottom surface 21a of the melting furnace 2 is longer than the depth dimension Y to the bottom surface 31a of the distribution chamber 3 on the basis of the liquid level L of the molten glass when the apparatus 1 is in operation. Has been. Specifically, the depth dimension Y of the distribution chamber 3 is 4/5 or less, preferably 3/5 or less, more preferably 1/2 or less of the depth dimension X of the melting furnace 2, and 1 / 20 or more. The depth dimension Y of the distribution chamber 3 is 500 mm or less, preferably 400 mm or less, and 50 mm or more. In this embodiment, the outflow path 6 has the same depth as the distribution chamber 3, and a step D is formed at the boundary between the melting furnace 2 and the outflow path 6.

  As shown in FIGS. 1 and 2, a plurality of small outlets 3a are formed at substantially equal intervals on the downstream side wall 35 of the distribution chamber 3, and each of these small outlets 3a is connected to the upstream end. A plurality of branch passages 4 communicate with the downstream side of the distribution chamber 3 through the narrow small outflow passages 7. The plurality of branch channels 4 are arranged in parallel to each other, and all of the individual branch channels 4 extend on a straight line in plan view.

  A plurality of flow resistance imparting chambers (flow resistance imparting portions) 8 that open at the downstream ends of the small outflow passages 7 are formed at the upstream end of each branch flow path 4, that is, at a position immediately downstream of the distribution chamber 3. Has been. These flow resistance imparting chambers 8 are long in the front-rear direction and have a smaller volume than the distribution chamber 3. And each distribution | circulation resistance provision chamber 8 has the surrounding walls 81-85 which form a flow path, and the ceiling wall (illustration omitted) which covers the whole upper area, These each wall is a high zirconia refractory ( Refractory brick). The small outflow passage 7 has passage walls 71 to 73 and a ceiling wall (not shown) covering the entire area above the passage walls 71 to 73, and these walls are also formed of a high zirconia refractory (refractory brick). ing. Each distribution resistance imparting chamber 8 is shallower than the distribution chamber 3.

  Further, a thin plate made of platinum or a platinum alloy is stretched on the inner wall surface (at least the inner wall surface portion in contact with the molten glass) of the surrounding walls 81 to 85 of each flow resistance imparting chamber 8, and the passage of the small outflow passage 7 Similarly, thin plates made of platinum or a platinum alloy are stretched on the inner wall surfaces of the walls 71 to 73. Then, the molten glass in the flow resistance imparting chamber 8 is energized and heated by flowing an electric current through the above-described thin plate made of platinum or platinum alloy by an energizing heating means (not shown). Further, in each flow resistance imparting chamber 8, temperature detection means (temperature sensor) (not shown) for detecting the temperature and viscosity of the molten glass is disposed. Based on signals from these temperature detection means. Thus, the energization amount when performing the above-described energization heating, and thus the heating amount is controlled. Accordingly, each flow resistance imparting chamber 8 also serves as a temperature adjustment chamber (temperature adjustment unit). And by performing such control, the temperature of the molten glass in each flow resistance provision chamber 8 is maintained at 1500 to 1650 degreeC.

  In each of the flow resistance imparting chambers 8, baffle plates 9 made of a plurality of platinum or platinum alloys for constricting the flow while changing the flow direction of the molten glass flowing through the chamber are provided at predetermined intervals in the front-rear direction. Are fixed in parallel. And as a result, these baffle plates 9 provide resistance to the molten glass flowing through each flow resistance applying chamber 8, in other words, any of the low-viscosity part and the high-viscosity part of the molten glass. Is prevented from flowing immediately without receiving resistance at the upstream end of each branch flow path 4. Therefore, these baffle plates 9 and thus each flow resistance imparting chamber 8 constitutes a distribution pressure adjusting means for making the supply pressure uniform when the molten glass is distributed and supplied from the distribution chamber 3 to each branch flow path 4. It is.

  FIGS. 4A to 4E are front views showing baffle plates 9 arranged in order from the upstream side in each flow resistance applying chamber 8. In addition, the chain line L described in each figure shows the liquid level of the molten glass at the time of this apparatus 1 operation | movement.

  The baffle plate 9 at the most upstream position shown in FIG. 4 (a) has a rectangular shape covering a cross section corresponding to a substantially lower half of a rectangular flow path cross section in the flow resistance applying chamber 8, and is melted. The glass flow is lowered after the direction is changed upward. The second baffle plate 9 from the upstream side shown in FIG. 4 (b) has a rectangular shape covering a cross section corresponding to a substantially upper half or a substantially upper third of the flow path cross section of the flow resistance imparting chamber 8. Then, the flow of the molten glass is raised after being squeezed while changing the direction downward. The third baffle plate 9 from the upstream side shown in FIG. 4 (c) has a rectangular shape that covers the center portion excluding both sides in the width direction of the flow path cross section of the flow resistance imparting chamber 8 from the top to the bottom. Thus, the molten glass flow is collected after being separated on both sides in the width direction. The fourth baffle plate 9 from the upstream side shown in FIG. 4 (d) is a plate-like body that covers the entire surface of the flow passage cross section of the flow resistance imparting chamber 8, and a plurality of through holes 9a having a relatively larger diameter on the upper side. In which the flow of molten glass is gathered after being narrowed down at a plurality of locations with a vertical difference. The fifth baffle plate 9 from the upstream side shown in FIG. 4 (e) is a plate-like body that covers the entire surface of the flow path cross section of the flow resistance imparting chamber 8, and a plurality of through holes having a relatively large diameter on the lower side. 9a is formed, and the molten glass flows are gathered after being narrowed down at a plurality of locations with a vertical difference. As described above, the direction of the flow of the molten glass is changed or squeezed to actively transfer heat between the low viscosity portion and the high viscosity portion, thereby improving the heat transfer efficiency. The plate 9 can also perform the rectifying action of the molten glass in the individual flow resistance imparting chambers 8, and thus the viscosity equalizing action. Accordingly, each flow resistance imparting chamber 8 also serves as a viscosity homogenizing chamber (viscosity uniformizing portion).

  The molten glass supplied from the melting furnace 2 shown in FIG. 1 and FIG. 2 to each molding device 5 through the distribution chamber 3 and each flow resistance imparting chamber 8 has a temperature corresponding to a viscosity of 1000 poise of 1350 ° C. or higher. Has a characteristic of 1420 ° C. or higher, and is preferably alkali-free glass. The strain point of the glass is 600 ° C. or higher, preferably 630 ° C. or higher, and the liquid phase viscosity of the glass is 300000 poise or higher, preferably 600000 poise or higher. And the composition of glass is as follows, when it shows by the mass%, for example.

_{SiO 2: 40~70%, Al 2} O 3: 6~25%, B 2 O 3: 5~20%, MgO: 0~10%, CaO: 0~15%, BaO: 0~30%, SrO : 0 to 10%, ZnO: 0 to 10%, alkali metal oxide: 0.1% or less, clarifier: 0 to 5%. In this case, the glass composition is preferably as follows. _{SiO 2: 55~70%, Al 2} O 3: 10~20%, B 2 O 3: 5~15%, MgO: 0~5%, CaO: 0~10%, BaO: 0~15%, SrO : 0 to 10%, ZnO: 0 to 5%, alkali metal oxide: 0.1% or less, clarifier: 0 to 3%.

  In addition, each molding apparatus 5 to which molten glass is supplied from each flow resistance applying chamber 8 through the downstream branch flow path 10 is a plate glass molding apparatus represented by a liquid crystal plate glass (glass substrate for liquid crystal display). It is.

  In addition, although each wall of the above-mentioned predetermined component is all formed with a high zirconia refractory, each wall of the component other than the melting furnace 2 is formed with a refractory other than the high zirconia. Also good.

  According to the molten glass supply apparatus 1 having the above configuration, the plurality of branch flow paths 4 extend from the melting furnace 2 through the distribution chamber 3 toward the molding apparatus 5 side. The molten glass exhibiting high viscosity characteristics in 2 is supplied to each molding device 5 through each of the branch flow paths 4. That is, a melting step of melting high-viscosity glass having a characteristic corresponding to a viscosity of 1000 poise of 1350 ° C. or more in the melting furnace 2, and the molten glass flowing out of the melting furnace 2 is discharged from the outlet 2 a of the melting furnace 2. A distribution step of supplying the plurality of branch flow paths 4 to the plurality of branch flow paths 4 through the distribution chambers 3 connected to the flow path, and supplying molten glass that has flowed down the plurality of branch flow paths 4 to the molding devices 5 respectively connected to the plurality of branch flow paths 4. A molding step of molding a glass molded product is performed.

  Therefore, the value obtained by dividing the heat radiation area of the melting furnace 2 (particularly the heat radiation area of the side walls 22 to 25) by the number of the branch flow paths 4, that is, the heat radiation area of the melting furnace 2 per branch flow path 4 is The supply flow path of a plurality of single feeders having a plurality of melting kilns whose total volume is the same as the volume of the melting kiln 2 is much smaller than the heat dissipation area of one melting kiln. As a result, the amount of heat released from the melting kiln 2 for each branch channel 4 is not excessive, and an undue increase in heating cost required for one molding line can be avoided. In addition, the value obtained by dividing the contact area with the molten glass on the inner wall surface of the melting furnace 2 by the number of the branch channels 4, that is, the erosion area of the melting furnace 2 per branch channel 4 is also a single feeder. In this case, the supply flow path is much smaller than the erosion area of the melting furnace per one. As a result, the amount of erosion foreign matter in the molten glass supplied to the molding apparatus 5 through the individual branch flow paths and the amount of foreign glass due to erosion are not excessive, and the molten glass is contaminated and the quality of the molded product is deteriorated due to this. And the problem of reduced product yield is avoided.

  Furthermore, if a plurality of molding devices 5 are different, different types of plate glass can be simultaneously molded by the plurality of molding devices 5 by the molten glass distributed and supplied from the same melting furnace 2. Moreover, even if the supply of the molten glass from one branch flow path 4 is stopped, the molten glass can be supplied to the molding apparatus 5 through the other branch flow path 4 to perform a required forming process. When it is desired to change the forming of the sheet glass by the forming device 5 of one line to the forming of another different plate glass, only the branch flow path 4 corresponding to the line to be changed is stopped and the forming device is replaced and replaced. The other molding apparatus 5 can be in an operating state. In addition, in a high viscosity glass such as glass for liquid crystal, the molding temperature becomes high, and the molding apparatus and the like are easily damaged, but even if one of the branch flow paths 4 is in a supply stop state for repair, Other molding apparatuses can be kept in operation.

  Moreover, since the branch flow path 4 is formed by branching into a plurality from the melting furnace 2, it can easily cope with the recent increase in demand for plate glass without adding another molten glass supply device, and is different. Even plate glass formed through the branch channel 4 has the same operating conditions and blending conditions, so that a large amount of plate glass having a constant composition and material properties can be supplied.

  In addition to the natural phenomenon due to the relationship between specific gravity and temperature, the molten glass that is about to flow out from the melting furnace 2 into the distribution chamber 3 is irradiated with the burner frame F in its upper space. However, since the distribution chamber 3 is shallower than the melting furnace 2, the lower viscosity molten glass remains in the melting furnace 2. Only the molten glass with low viscosity at the top flows into the distribution chamber 3. As a result, the molten glass having a low viscosity can be effectively used without waste, the viscosity of the molten glass can be made uniform from the upper part to the lower part of the distribution chamber 3, and defoaming from the molten glass is further promoted. Is done.

  Moreover, since zirconia, which is a component of a refractory eroded by the molten glass coming into contact with the melting furnace 2, has a higher specific gravity than the molten glass, a contaminated molten glass in which the zirconia is dissolved in the molten glass is Accumulate at the bottom. Even in such a case, since the distribution chamber 3 is shallower than the melting furnace 2, the contaminated molten glass is appropriately prevented from flowing into the distribution chamber 3.

  The molten glass that has flowed into the distribution chamber 3 is irradiated with the burner frame F by oxyfuel combustion and heated so that its viscosity is 1000 poise or less. 3, the molten glass can be smoothly distributed and supplied to the flow resistance imparting chamber 8 of each branch flow path 4. The molten glass that has flowed into the distribution chamber 3 from the melting furnace 2 is prevented from going straight by the rectifying wall portion 37 disposed in the center of the distribution chamber 3, and the flow is appropriately dispersed in the left-right direction. After that, since it is distributed and supplied to each flow resistance applying portion 8, a situation in which molten glass is supplied in a concentrated manner in the flow resistance applying chamber 8 in the central portion in the left-right direction is avoided. At this time, the temperature of the molten glass in the distribution chamber 3 is maintained at 1600 ° C. to 1700 ° C., the temperature of the molten glass in the melting furnace 2 (1500 ° C. to 1650 ° C.) and the temperature of the flow resistance imparting chamber 8 (1500 ° C. ˜1650 ° C.). On the other hand, since the inner wall surface of the distribution chamber 3 is covered with platinum or a platinum alloy, the durability against heat does not deteriorate, and the problem of contamination of the molten glass due to eroded foreign matter or foreign glass also arises. Absent.

  Further, each flow resistance application chamber 8 into which molten glass flows from the distribution chamber 3 is provided with a plurality of baffle plates 9, so that it is appropriate for the molten glass flowing through these flow resistance application chambers 8. Resistance is given. Therefore, even when the viscosity and the flow direction of the molten glass passing through the distribution chamber 3 and reaching the respective flow resistance imparting chambers 8 are different from each other, each pressure when being distributed and supplied to each flow resistance imparting chamber 8 is different. Is made uniform by applying the above-mentioned appropriate resistance.

  In addition, since the molten glass flowing through the flow resistance application chamber 8 is subjected to direction change and squeezing action by the baffle plate 9, heat transfer between the molten glasses having different viscosities in the individual flow resistance application chambers 8. Is promoted, and the viscosity of the molten glass is made uniform. In addition, in this flow resistance imparting chamber 8, the temperature of the molten glass is controlled using the temperature detecting means, so that it is possible to supply molten glass having a very accurate viscosity to the molding device 5 in response to the request. Become. Thereby, generation | occurrence | production of shaping | molding defects, such as thickness variation and waviness of the plate glass shape | molded with the shaping | molding apparatus 5, is avoided.

1 Molten glass supply device 2 Melting kiln
2a Outlet of melting furnace 3 Distribution room (distribution section)
4 Branch channel 5 Molding device

Claims (4)

In a molten glass supply apparatus comprising a melting furnace serving as a supply source of molten glass, and a supply channel for supplying molten glass flowing out of the melting furnace to a molding apparatus for glass articles,
The molten glass has a characteristic that a temperature corresponding to a viscosity of 1000 poise is 1350 ° C. or more, and the supply flow path is branched from the distribution section and a distribution section leading to the outlet of the melting furnace. And a plurality of branch channels extending toward a plurality of molding devices,
The distribution unit includes heating means for heating the molten glass so that the viscosity is 1000 poise or less, and at least the contact surface with the molten glass on the inner wall surface of the distribution unit is made of platinum, molybdenum, palladium, rhodium, or these An apparatus for supplying molten glass, characterized by being formed of an alloy of   The molten glass supply apparatus according to claim 1, wherein the forming apparatus is a sheet glass forming apparatus. A melting step for melting high-viscosity glass having a characteristic corresponding to a viscosity of 1000 poise of 1350 ° C. or more in a melting furnace, and a distribution unit for passing the molten glass flowing out of the melting furnace to an outlet of the melting furnace A distribution step of supplying the plurality of branch flow paths via the plurality of branch flow paths, and a molding process of forming the glass molded product by supplying the molten glass flowing down the plurality of branch flow paths to a molding apparatus that respectively leads to the plurality of branch flow paths And
In the distribution step, the molten glass comes into contact with platinum, molybdenum, palladium, rhodium, or an alloy thereof, and the molten glass in the distribution step is heated to have a viscosity of 1000 poise or less. Manufacturing method of molded products.   The said shaping | molding apparatus is a shaping | molding apparatus of plate glass, The manufacturing method of the glass molded product of Claim 3 characterized by the above-mentioned.

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