JP2009084100A - Fused silica roll for glass transfer and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fused silica roll for glass transfer reduced in fault due to the adhesion of silica particles separated from a roll to the surface of glass and can therefore be stably used even at the stage early from the start of use and to provide a method for producing the same. <P>SOLUTION: A fused silica roll having a modulus of elasticity of 45 GPa or higher and a surface roughness Ra of 0.5 μm or smaller is produced by casting a slurry containing a raw fused silica powder material into a mold and molding it, drying the obtained molding, firing the dried molding at 1,150-1,250°C, and subjecting its external surface to grinding and lapping. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fused siliceous roll for transporting glass used when transporting a glass product in a heat treatment furnace and a method for producing the same.

The window glass for automobiles is formed by softening a flat plate glass in a high-temperature heat treatment furnace and performing a strengthening and bending process.
In the heat treatment furnace, a roll conveyor is generally used as a means for conveying glass, and the material of the rolls constituting the glass is mainly siliceous from the viewpoint of thermal shock resistance, thermal conductivity, and the like. It is.

In the above-mentioned roll for glass conveyance, from the viewpoint of maintaining the quality of the glass product, it is required not to contaminate the glass being conveyed or to prevent the glass surface from being uneven or scratched.
For this, for example, a technique for forming a coating layer such as chromium oxide or yttrium oxide on the surface of a siliceous roll is disclosed.
JP 2007-153656 A JP 2003-300742 A

  However, when an oxide coating layer of a different material is formed on the surface of the siliceous roll base material, a residual stress is generated in the coating layer due to a difference in thermal expansion coefficient between the base material and the coating layer. For this reason, when such a roll is used for conveying automobile window glass or the like, the temperature fluctuation and temperature distribution are largely biased, and the coating layer is easily peeled off due to a load due to mechanical stress. .

  Therefore, it is preferable that the siliceous roll is composed of a single high-purity siliceous material as much as possible.

  However, when a conventional siliceous roll is used, there has been a problem that streaky haze enters the treated glass in a direction perpendicular to the glass traveling direction.

Such fogging of the glass is so thin that it is difficult to identify it visually if it is not irradiated with light. However, in the microscopic observation, the size is about several to several tens of μm, and depending on the location, it is several tens of μm. It could be confirmed as a number of white spots.
Analysis of these white spots is a high-purity silica component equivalent to that of the roll material, and is considered to be cloudiness caused by adhesion of silica particles degranulated from the roll to the glass surface.

  The present invention was made in order to solve the above technical problem, and even at the initial stage of use of the roll, problems due to adhesion of silica particles degranulated from the roll to the glass surface are suppressed and used stably. It aims at providing the fused siliceous roll for glass conveyance which can be manufactured, and its manufacturing method.

The fused siliceous roll for conveying glass according to the present invention is characterized in that the elastic modulus is 45 GPa or more and the surface roughness Ra is 0.5 μm or less.
By using a roll whose elastic modulus and surface roughness are controlled as described above, it is possible to prevent the silica particles from coming off from the roll, and that the glass surface is fogged due to the roll. Can be suppressed.

The method for producing a fused siliceous roll for conveying a glass according to the present invention is a method for producing the fused siliceous roll, wherein a slurry containing a fused silica powder raw material is poured into a mold and molded, and the obtained molding is obtained. After the body is dried, it is fired at 1150 ° C. or higher and 1250 ° C. or lower, and the outer surface is subjected to grinding and lapping.
According to such a production method, the fused siliceous roll according to the present invention as described above can be suitably obtained.

As described above, the fused siliceous roll for conveying glass according to the present invention can suppress the occurrence of fogging due to the adhesion of silica particles degranulated from the roll to the glass surface, and can be used stably. It can apply suitably for the glass conveyance roll conveyor in the inside.
Moreover, according to the manufacturing method which concerns on this invention, the above fused siliceous rolls which can suppress the malfunction which arises in the glass conveyed can be obtained suitably.

Hereinafter, the present invention will be described in more detail.
The fused siliceous roll for conveying glass according to the present invention is characterized by having an elastic modulus of 45 GPa or more and a surface roughness Ra of 0.5 μm or less.
By controlling the elastic modulus and surface roughness of the fused siliceous roll as described above, it is possible to prevent the detachment of the silica particles from the roll even under a high temperature environment in the heat treatment furnace. Thereby, it is possible to suppress the occurrence of streak fogging caused by the rolls as described above on the glass surface, and it is possible to use the glass stably without causing any defects.

  When the elastic modulus is less than 45 GPa, hardness is insufficient and degranulation tends to proceed.

  Further, when the surface roughness Ra exceeds 0.5 μm, the silica particles on the roll surface are likely to fall out due to the contact with the glass at the initial stage of use of the roll.

The fused siliceous roll according to the present invention as described above is formed by pouring a slurry containing a fused silica powder raw material into a mold, drying the obtained molded body, and firing at 1150 ° C. or more and 1250 ° C. or less, It can be obtained by grinding and lapping the outer surface.
By firing at the above-mentioned temperature, the elastic modulus of the siliceous roll can be improved, and Ra can be reduced in surface roughness by applying lapping treatment to the surface.

When the calcination temperature is lower than 1150 ° C., a siliceous roll having a sufficiently high elastic modulus cannot be obtained.
On the other hand, when the firing temperature exceeds 1250 ° C., crystallization of the glass component proceeds, and cooling cracks are likely to occur due to a difference in thermal expansion from the glass component.

  Moreover, it is preferable to grind the fired body with a rotary lathe or a centerless lathe.

After the grinding, lapping is performed.
Specifically, this lapping treatment is preferably performed with a sheet, polishing cloth or the like on which diamond abrasive grains are dispersed.

In addition, in order to remove the few silica particles which have been shed after the roll production, it is preferable to perform high-pressure washing in which pressurized water is sprayed on the product roll, or a process of peeling off after sticking an adhesive tape on the roll surface.
By such post-treatment, it is possible to further suppress the adhesion of the silica particles due to the roll to the surface of the glass to be conveyed.

EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not restrict | limited by the following Example.
[Example 1]
A slurry obtained by mixing fused silica powder having an average particle diameter of 5 μm with water was poured into a gypsum mold and molded. The obtained molded body was dried and then fired at 1190 ° C. in an air atmosphere.
After grinding the outer periphery of the obtained fired body with a rotary lathe, the outer surface is rotated with a roll and a polishing cloth sprinkled with diamond abrasive grains is applied to the outer surface to perform lapping treatment. A 2300 mm roll was produced.

[Comparative Example 1]
A molded body obtained in the same manner as in Example 1 was dried and then fired at 1100 ° C. in an air atmosphere as a roll.

[Reference Example 1]
After grinding the outer periphery of the fired body obtained in the same manner as in Comparative Example 1 with a rotary lathe, the surface was lapped to produce a roll.

[Reference Example 2]
The fired body obtained in the same manner as in Example 1 was used as a roll without being lapped on the surface.

About each roll produced in the said Example and comparative example, the elasticity modulus was measured by "the elastic modulus test method JIS R1602 of fine ceramics", and surface roughness Ra was measured by the surface roughness meter (JIS B0601 conformity). .
Moreover, the glass for motor vehicles was conveyed using each roll, the abrasion property in 10 hours after 4 hours was evaluated, and the adhesiveness of the silica particle to the glass surface was evaluated.
These results are summarized in Table 1.
In addition, evaluation of adhesiveness in Table 1 is judged by the number of silica particles that are peeled off after sticking the adhesive tape on the roll surface and attached to the adhesive tape. ○: Adhesion amount is small, ≦ 5 / mm ² , Δ: Adhesion amount is 5 to 15 / mm ² , X: Adhesion amount is large,> 15 / mm ²

As shown in Table 1, by applying lapping to the surface (Reference Example 1) compared to the conventional product (Comparative Example 1), the surface roughness is reduced and the wear at the beginning of roll use is improved. Further, it was confirmed that heat treatment at 1190 ° C. (Reference Example 2) improved the elastic modulus and improved the wearability 10 hours after the start of use.
Further, it was confirmed that the adhesion of silica particles to the glass was suppressed by firing at 1190 ° C. and lapping the fired body (Example 1).

Claims (2)

  A fused siliceous roll for conveying glass, having an elastic modulus of 45 GPa or more and a surface roughness Ra of 0.5 μm or less.   A method for producing a fused siliceous roll according to claim 1, wherein a slurry containing a fused silica powder raw material is poured into a mold and molded, and after the obtained molded body is dried, the temperature is 1150 ° C or higher and 1250 ° C or lower. A method for producing a fused siliceous roll for conveying a glass, characterized by firing and grinding and lapping the outer surface.