Stemware manufacturing method and stemware

Abstract

[Problem] To provide a method for manufacturing stemware that can produce optical effect and easily manufactured, and is not easily broken in spite of being made of glass. [Solution] A glass reservoir part 11 is formed at the bottom section of a bowl part 1, white glass C is inserted into the glass reservoir part 11, and then the glass reservoir part 11 is stretched in the longitudinal direction of the white glass C to form a stem part 2. Thereafter, stemware A is manufactured by forming a plate part 3 at an end section of the stem part 2.

Description

Method for manufacturing stemware and stemware

[0001] The present invention relates to a method for manufacturing stemware and stemware. Specifically, it relates to a method for manufacturing stemware that enables optical effects, can be easily manufactured, and is difficult to break despite being made of glass, and to the stemware.

[0002] Stemware refers to a drinking glass provided with a handle at the bottom of the glass, and generally corresponds to a wine glass or a champagne glass. Stemware is composed of a bowl part into which a beverage is poured, a stem part that serves as a handle, and a plate part that serves as a base.

[0003] Here, wine, champagne, etc. are daily beverages and are also enjoyed at festive occasions such as celebrations and parties, so they are often placed on a colorfully decorated table.

[0004] However, many stemwares are not only simple in shape but are formed of a single material, transparent glass, and lack glamour. For this reason, they have an appearance that is not suitable for occasions such as parties.

[0005] Therefore, in order to solve this problem and optically create an atmosphere, as shown in Patent Document 1, a "light-emitting glass" in which a light-emitting member is assembled inside the stem part is disclosed. That is, this light-emitting glass is one in which a light-emitting member using a chemiluminescent agent as a light source is arranged inside the stem part.

[0006] Japanese Patent Application Laid-Open No. 8-299144

[0007] However, the light-emitting glass described in Patent Document 1 requires the stem part to be hollow in order to insert the light-emitting member, and it was difficult to manufacture with a glass material. Also, it was difficult to ensure the strength in the hollow stem part, and even if it could be manufactured, it was very fragile.

[0008] While manufacturing the luminescent glass described in Patent Document 1 (luminescent glass having a hollow stem) from a material other than glass (for example, plastic) would facilitate manufacturing and ensure strength, plastic materials would be inferior to glass in terms of gloss and brilliance.

[0009] This invention was conceived in view of the above points, and aims to provide a method for manufacturing stemware that allows for optical effects, can be manufactured simply, and is resistant to breakage despite being made of glass, as well as stemware itself.

[0010] To achieve the above objective, the present invention provides a method for manufacturing stemware, comprising: a ball portion forming step of forming a ball portion of a predetermined shape having a glass reservoir portion made of molten transparent glass at its bottom; an insertion step of inserting colored glass into the glass reservoir portion; a stem portion forming step of melting the colored glass inserted into the glass reservoir portion and then stretching the glass reservoir portion with the colored glass contained within to form a stem portion; and a plate portion forming step of attaching molten transparent glass to the end of the stem portion to form a plate portion of a predetermined shape.

[0011] Here, a ball-shaped portion is formed in a ball-shaped portion having a glass reservoir made of molten transparent glass at the bottom. This process forms a glass reservoir at the bottom of the ball-shaped portion, which serves as a base for inserting colored glass in the insertion process described later.

[0012] Furthermore, by inserting colored glass into the glass reservoir, the colored glass can be placed inside the transparent glass of the glass reservoir (the transparent glass of the glass reservoir can contain the colored glass). Here, "containment" does not only mean that the "entire" colored glass is placed inside the glass reservoir, but also that a "part" of the colored glass is placed inside the glass reservoir (i.e., another part of the colored glass is placed outside the glass reservoir).

[0013] Furthermore, after melting the colored glass inserted into the glass reservoir, a stem forming process is performed in which the glass reservoir, with the colored glass still inside, is stretched to form the stem. This process creates a stem at the bottom of the ball portion that has a central part made of colored glass and a peripheral part made of transparent glass arranged around the central part.

[0014] Here, the stem, which consists of a central part made of colored glass and a peripheral part made of clear glass arranged around the central part, appears to glow when light is shone from above (specifically, the colored glass itself appears to emit light). Furthermore, the stem, which consists of a central part made of colored glass and a peripheral part made of clear glass arranged around the central part, can be given a special aesthetic appeal and create a sense of splendor even when no light is shone on it.

[0015] On the other hand, if the stem is made of "colored glass only" (without clear glass) or "clear glass only" (without colored glass), it will be difficult to see the stem glowing even when light is shone from above. Furthermore, if the stem is made of "colored glass only" (without clear glass) or "clear glass only" (without colored glass), even when no light is shone on it, the simple structure of the stem (colored glass only, clear glass only) will not create an elegant appearance.

[0016] Furthermore, by stretching the glass reservoir while it contains colored glass (in other words, by stretching the glass reservoir while it is solid), the stem can be formed relatively easily (at least, it is easier to form the stem compared to forming a hollow stem).

[0017] Furthermore, by extending the glass reservoir at the bottom of the ball section to form the stem section (in other words, by forming the stem section integrally with the ball section), it is possible to obtain a beautiful stemware with a morphological unity, as there is no joint (seam) between the ball section and the stem section.

[0018] Furthermore, if the "ball portion of a predetermined shape" and the "stem portion of a predetermined shape" are manufactured separately and then joined together, the joint (seam) will be noticeable, and the joint will become larger (thicker), thus compromising the overall integrity of the form.

[0019] Furthermore, by forming a plate portion in a plate portion formation process, in which molten transparent glass is attached to the end of the stem portion to form a plate portion of a predetermined shape, the plate portion can be formed integrally with the stem portion. As a result, there is no joint (seam) between the stem portion and the plate portion, and a visually appealing stemware with a unified form can be obtained.

[0020] Furthermore, if the "stem portion of a predetermined shape" and the "plate portion of a predetermined shape" are manufactured separately and then joined together, the joint (seam) will be noticeable, and the joint will become larger (thicker), thus compromising the overall integrity of the form.

[0021] Furthermore, if the insertion process involves inserting white glass, which is colored glass containing sodium siliceous fluoride, at a ratio of 1.3 wt% to 3.5 wt% relative to the weight (total weight) of the transparent glass, it is possible to form a "stem portion having a central part made of white glass and a peripheral part made of transparent glass arranged around the central part," which makes the stem portion appear to shine even more brightly when light is shone from above.

[0022] When a beverage (for example, wine) is poured into the bowl and light is shone from above, the light reflecting the color of the beverage will enter the stem. However, if the center is made of "white glass," the stem will appear to emit light in the color of the beverage (specifically, the white glass itself will appear to emit light in the color of the beverage).

[0023] In this case, if the proportion of sodium siliceous fluoride relative to the weight (total weight) of the transparent glass is less than 1.3 wt%, the white glass becomes too close to colorless and transparent (too little white), and the transmittance of the white glass becomes too high. As a result, diffuse reflection of incident light within the white glass becomes difficult, and the stem becomes less visible as a reflection.

[0024] On the other hand, if the proportion of sodium siliceous fluoride relative to the weight (total weight) of the transparent glass exceeds 3.5 wt%, the white glass becomes too close to white (too white), and the transmittance of the white glass becomes too low. As a result, incident light has difficulty penetrating the white glass, and the stem becomes difficult to see through.

[0025] Furthermore, when the insertion process involves inserting white glass, which is colored glass containing sodium siliceous fluoride at a ratio of 2.0 wt% to 3.5 wt% relative to the weight (total weight) of the clear glass, it becomes easier to form the white glass in a straight line within the stem.

[0026] Here, if the proportion of sodium siliceous fluoride relative to the weight (total weight) of the transparent glass is less than 2.0 wt%, when the glass reservoir is stretched to form the stem while the colored glass (white glass) is embedded inside, the white glass tends to become irregularly distorted and twisted.

[0027] Furthermore, while a higher proportion of sodium siliceous fluoride results in a straighter and more beautiful shaft without the white glass becoming irregularly distorted or warped, as mentioned above, if the proportion of sodium siliceous fluoride exceeds 3.5 wt% relative to the weight of the transparent glass (total weight), the stem will become shiny and difficult to see.

[0028] Furthermore, if the insertion process involves inserting the rod-shaped colored glass into the glass reservoir, and the stem formation process involves stretching the glass reservoir in the longitudinal direction of the rod-shaped colored glass to form the stem, the glass reservoir becomes easier to stretch linearly, making the formation of the stem relatively easy.

[0029] For example, by positioning the colored glass in the center of the glass reservoir (the center of a plane perpendicular to the longitudinal direction of the colored glass) so that the "longitudinal direction of the colored glass" coincides with the "tensile direction of the glass reservoir," and by focusing on making the colored glass form a straight line, the glass reservoir can be easily stretched linearly.

[0030] Furthermore, if the insertion process involves heating the rod-shaped colored glass to a degree that allows it to maintain its shape, and then inserting the colored glass into the glass reservoir, the colored glass can be easily inserted into the desired position (for example, the center of a plane perpendicular to the longitudinal direction of the colored glass), and after insertion, the glass reservoir can be stretched. In other words, because the colored glass is rod-shaped, it can be easily inserted into the desired position. Also, since the colored glass is preheated (but only to a degree that allows it to maintain its shape), after insertion into the glass reservoir (molten transparent glass), heat transfer from the glass reservoir further melts the colored glass, allowing the glass reservoir to be stretched after insertion.

[0031] Furthermore, if the stem formation process involves heating the glass reservoir where the colored glass is inserted, and then stretching the glass reservoir to form the stem, even if the colored glass inserted into the glass reservoir is not fully melted, the transparent glass and colored glass can be heated together and maintained at an appropriate temperature during the process, making it easy to stretch both the transparent glass and the colored glass.

[0032] Furthermore, in order to achieve the above objectives, the stemware of the present invention comprises a ball portion made of transparent glass, a central part made of white glass that supports the ball portion, a stem portion arranged around the central part and having a peripheral part made of transparent glass, and a plate portion made of transparent glass on which the stem portion is erected, and is manufactured by a manufacturing method comprising: a ball portion forming step of forming the ball portion of a predetermined shape having a glass reservoir portion made of molten transparent glass at the bottom; an insertion step of inserting the white glass into the glass reservoir portion; a stem portion forming step of melting the white glass inserted into the glass reservoir portion and then stretching the glass reservoir portion with the white glass enclosed inside to form the stem portion; and a plate portion forming step of attaching molten transparent glass to the end of the stem portion to form the plate portion of a predetermined shape.

[0033] In this case, if the glass is composed of "a central part made of white glass containing sodium silica fluoride at a ratio of 1.3 wt% to 3.5 wt% relative to the weight (total weight) of the transparent glass, and a stem part arranged around the central part and having a peripheral part made of transparent glass," then when light is shone from above, the stem part will appear to shine even more brightly (specifically, the white glass itself will appear to be emitting light).

[0034] Furthermore, when a beverage (for example, wine) is poured into the bowl and light is shone from above, the light reflecting the color of the beverage enters the stem. However, because the center is made of "white glass," the stem appears to emit light in the color of the beverage (specifically, the white glass itself appears to emit light in the color of the beverage).

[0035] Furthermore, the "stem section, which consists of a central part made of white glass and a peripheral part made of transparent glass arranged around the central part," gives the stem section a special aesthetic appeal and creates a sense of elegance even when no light is shone on it.

[0036] Here, if the proportion of sodium silice fluoride relative to the weight (total weight) of the transparent glass is less than 1.3 wt%, the white glass becomes too close to colorless and transparent (too little white), and the transmittance of the white glass becomes too high. As a result, diffuse reflection of incident light within the white glass becomes difficult, and the stem becomes difficult to see through. Therefore, it is preferable, but not limited to, a proportion of sodium silice fluoride of 1.3 wt% or more relative to the weight (total weight) of the transparent glass.

[0037] On the other hand, if the proportion of sodium silice fluoride relative to the weight (total weight) of the transparent glass exceeds 3.5 wt%, the white glass becomes too close to white (too white), and the transmittance of the white glass becomes too low. As a result, incident light has difficulty penetrating the white glass, and the stem becomes difficult to see due to its reflective surface. Therefore, it is preferable, but not limited to, a proportion of sodium silice fluoride of 3.5 wt% or less relative to the weight (total weight) of the transparent glass.

[0038] The method for manufacturing stemware according to the present invention allows for optical presentation, is easy to manufacture, and produces stemware that is resistant to breakage despite being made of glass. Furthermore, the stemware according to the present invention allows for optical presentation, is easy to manufacture, and is resistant to breakage despite being made of glass.

[0039] This is a schematic diagram illustrating an example of stemware to which the present invention is applied. This is a process diagram illustrating an example of a method for manufacturing stemware to which the present invention is applied. This is a schematic diagram illustrating the ball portion formation process. This is a schematic diagram illustrating the insertion process. This is a schematic diagram illustrating the stem portion formation process. This is a schematic diagram illustrating the plate portion formation process.

[0040] The following describes embodiments for carrying out the invention (hereinafter referred to as "embodiments"). The description will be in the following order: 1. First embodiment 2. Second embodiment 3. Modified examples

[0041] <1. First Embodiment> [Explanation of Configuration]FIG. 1 is a schematic diagram for explaining an example of stemware to which the present invention is applied. The stemware A shown here includes a ball portion 1 into which a beverage is poured, a stem portion 2 that extends continuously from the bottom 10 of the ball portion 1 to support the ball portion 1 and serves as a handle when using the stemware A, and a disc-shaped plate portion 3 on which the stem portion 2 is erected and that supports the ball portion 1 and the stem portion 2.

[0042] The ball portion 1 is made of transparent glass G, has a height of about 110 mm, a diameter of the lower overhanging portion of about 80 mm, and a mouth diameter of about 55 mm, and is formed in a shape that gradually narrows upward.

[0043] The stem portion 2 is composed of a central portion 20 made of white glass C and a peripheral portion 21 made of transparent glass G over substantially its entire length, with the peripheral portion 21 covering the outside of the central portion 20, and is formed in a substantially cylindrical shape with a length of about 100 mm and a diameter of about 4.5 mm (where the diameter of the central portion 20 is 1.5 mm to 2.5 mm).

[0044] The plate portion 3 is made of transparent glass G and is formed in a disc shape with a height of about 10 mm and a diameter of about 80 mm.

[0045] Here, the transparent glass G that constitutes the ball portion 1, the peripheral portion 21 of the stem portion 2, and the plate portion 3 contains the components shown in Table 1.

[0046]

[0047] In addition, the white glass C that constitutes the central portion 20 of the stem portion 2 contains "sodium fluorosilicate", which is a white pigment, in addition to the components of the above-mentioned transparent glass G. Specifically, sodium fluorosilicate is contained at a ratio of 3.0 wt% with respect to the weight (total weight) of the transparent glass G.

[0048] [Effects] When a translucent beverage W (for example, red wine) is poured into the ball portion 1 of the Stemware A described above, and light L is shone from above, the color of the beverage W (red in the case of red wine) is reflected in the light L' that passes through the ball portion 1. Then, the light L' that passes through the ball portion 1 (light reflecting the color of the beverage W) enters the central part 20 of the stem portion 2, and the central part 20 appears to emit the color of the beverage W, thus enabling optical effects.

[0049] Specifically, the "light L' reflecting the color of the beverage W" incident on the central part 20 is diffusely reflected within the central part 20, causing the central part 20 to exhibit the color of the beverage W. Furthermore, the peripheral part 21 acts as a lens, making the color of the central part 20 easier to see, and as described above, the central part 20 appears to emit the color of the beverage W. The "light L' reflecting the color of the beverage W" can occur in two ways: (1) when it is incident directly on the central part 20 from the transparent glass G (when the light L' is parallel to the vertical axis), and (2) when it exits the transparent glass G into the air and then incident on the central part 20 (when the light L' has a predetermined angle with the vertical axis).

[0050] Here, for convenience, only light L from vertically above is shown in Figure 1. However, if light L from an oblique direction (a direction having a predetermined angle with the vertical axis) passes through the ball portion 1 and light L' from an oblique direction is incident on the central part 20, the central part 20 will similarly appear to emit the color of the beverage W.

[0051] Furthermore, in the Stemware A to which the present invention is applied, the stem portion 2 is solid, making it easier to ensure strength compared to a hollow stem portion (for example, the stem portion of the light-emitting glass described in Patent Document 1). Therefore, a small diameter of approximately 4.5 mm can be achieved, and combined with the optical effect described above, a special aesthetic can be given to the stem portion.

[0052] [Modification 1] In the first embodiment described above, the explanation is given using the case where the transparent glass G contains the components shown in Table 1 as an example, but it is not limited to these components.

[0053] [Modification 2] In the first embodiment described above, a white glass C containing sodium siliceous fluoride at a ratio of "3.0 wt%" relative to the weight (total weight) of the transparent glass G is used as an example, but it is not necessarily limited to "3.0 wt%".

[0054] Table 2 shows the relationship between the "ratio of sodium silica fluoride to the weight (total weight) of transparent glass G" and the "transmittance".

[0055]

[0056] Table 2 shows that when the proportion of sodium siliceous fluoride relative to the weight (total weight) of transparent glass G is "1.0 wt% or less" or "1.2 wt%", the transmittance of the central part 20 exceeds 90%. When the transmittance exceeds 90%, diffuse reflection of incident light within the central part 20 is difficult to occur, resulting in poor color development in the central part 20.

[0057] Furthermore, Table 2 shows that when the proportion of sodium siliceous fluoride relative to the weight (total weight) of transparent glass G is "4.0 wt% or more", the transmittance of the central part 20 is 0%. When the transmittance is 0%, incident light cannot enter the central part 20, and the color development of the central part 20 is poor.

[0058] Therefore, the proportion of sodium siliceous fluoride relative to the weight (total weight) of the transparent glass G does not necessarily have to be "3.0 wt%", but in order to produce good color in the center 20, it is preferable that it be "1.3 wt% to 3.5 wt%".

[0059] <2. Second Embodiment> The method for manufacturing the stemware A described above will now be explained. That is, an example of a method for manufacturing stemware to which the present invention is applied will be explained.

[0060] [Description of Manufacturing Method] Figure 2 is a process diagram of an example of a method for manufacturing stemware using the present invention, and stemware A is manufactured in the following steps: (1) Melting step (2) Ball part formation step (3) Insertion step (4) Stem part formation step (5) Plate part formation step (6) Annealing process step (7) Finishing and inspection step

[0061] The following provides a detailed explanation of each of the above-mentioned steps (1) to (7).

[0062] (1) Melting process In one example of a method for manufacturing stemware to which the present invention is applied, first, sodium oxide and the like are added to silica to obtain the component ratio of transparent glass G shown in Table 1, and it is heated to 1250°C in a glass melting furnace (not shown) to melt it (see reference numeral ST1 in Figure 2).

[0063] After the transparent glass G has melted, a suitable amount of the molten transparent glass G is removed from the glass melting furnace using a blowpipe (a hollow rod-shaped object) B. Specifically, the transparent glass G is wound around one end of the blowpipe B, and a suitable amount of seed glass is removed from the glass melting furnace.

[0064] (2) Ball Formation Process The 1250°C high-temperature glass (seed glass) removed from the glass melting furnace is cooled to approximately 800°C in approximately 90 seconds, and air is blown into the other end of the blowpipe B (the end opposite to the end on which the transparent glass G is wound) to form a hollow spherical shape from the wound transparent glass G.

[0065] Next, as shown in Figure 3, a hollow, spherical transparent glass G is placed in a mold M, and air is blown into it from the other end of the blowpipe B (indicated by the symbol Br in Figure 3 as "blowing air"), inflating the sphere to form a ball portion 1 and a glass reservoir portion 11 at the bottom of the ball portion 1 (see symbol ST2 in Figure 2).

[0066] (3) Insertion process After forming the ball portion 1 and the glass reservoir portion 11, the glass reservoir portion 11 is heated to a temperature of approximately 800°C using a gas burner, and as shown in Figures 4(a) and 4(b), 20 mm to 30 mm of the tip of the rod-shaped white glass C is inserted near the center of the glass reservoir portion 11 along the longitudinal direction of the white glass C.

[0067] Next, a gas burner is used to heat the boundary between the "inserted portion of the white glass C" and the "exposed portion of the white glass C (the portion that is not inserted)" to melt the white glass C, forming a state in which a white glass C approximately 20 mm to 30 mm in length is inserted into the glass reservoir 11, as shown in Figure 4(c) (see reference numeral ST3 in Figure 2).

[0068] (4) Stem Formation Process Starting from the state in which the white glass C is inserted into the glass reservoir 11 (with the white glass C covered with transparent glass G), the stem 2 is formed by gradually stretching the glass reservoir 11 using a tool such as pincers D, as shown in Figure 5 (see reference numeral ST4 in Figure 2).

[0069] When the glass reservoir 11 is stretched, the white glass C inserted inside it is also stretched, and a stem portion 2 can be formed along its entire length, consisting of a central part 20 made of white glass C and a peripheral part 21 made of transparent glass G.

[0070] Furthermore, by stretching the glass reservoir 11 while paying attention to ensuring that the white glass C is stretched in a straight line, a relatively straight stem portion 2 can be formed.

[0071] (5) Plate portion formation process After forming the stem portion 2, as shown in Figure 6(a), molten transparent glass G (seed glass) is attached to the end of the stem portion 2 (the end opposite to the ball portion 1), and as shown in Figures 6(b) and 6(c), a disc-shaped plate portion 3 is formed by shaping it using water-soaked wooden trowels E1, E2, etc. (see reference numeral ST5 in Figure 2).

[0072] Furthermore, since the central part 20, made of white glass C, extends to the end of the stem part 2 (the end opposite to the ball part 1), the position for attaching the seed glass can be easily determined.

[0073] (6) Annealing process After forming the plate portion 3, the stemware A is placed in an annealing furnace at approximately 230°C, and the furnace temperature is lowered to approximately 80°C to 90°C over approximately 3 hours, after which the stemware A is removed (see reference numeral ST6 in Figure 2). This annealing process removes internal stress in the stemware A and improves the performance of the glass.

[0074] (7) Finishing and Inspection Process The finishing process involves removing the excess transparent glass G portion, polishing the opening of the ball portion 1 to make it flat, and further heating the opening of the ball portion 1 to approximately 300°C to smooth the edges (see reference numeral ST7 in Figure 2).

[0075] The inspection process involves checking for overall scratches and distortions (see symbol ST7 in Figure 2). Furthermore, because the stem portion 2 has a central part 20 made of white glass C, it is easy to inspect whether the stem portion 2 is straight.

[0076] [Effects] In the method for manufacturing stemware to which the present invention described above is applied, the glass reservoir portion 11 formed in the ball portion forming step ST2 is stretched in the stem portion forming step ST4 to form the stem portion 2, thereby eliminating the joint (seam) between the ball portion 1 and the stem portion 2, and allowing the ball portion 1 and the stem portion 2 to be formed integrally.

[0077] Furthermore, by integrally forming the ball portion 1 and the stem portion 2, light L' (see Figure 1) transmitted through the ball portion 1 easily enters the stem portion 2, making the central part 20 appear to emit the color of the beverage W.

[0078] [Modification 3] In the second embodiment described above, the ball portion forming step ST2 is explained using as an example a method of forming the ball portion 1 by placing a spherical transparent glass G into a mold M (a so-called "molding method by mold blowing"). However, it is sufficient if the ball portion 1 and the glass reservoir portion 11 can be formed, and it is not necessarily required to use a mold M. For example, a method of forming the ball portion 1 and the glass reservoir portion 11 by blowing air while rotating a blowpipe B in the air without using a mold M (a so-called "free-blowing" molding method) is also acceptable.

[0079] [Modification 4] In the second embodiment described above, the insertion process involves inserting only the tip of a rod-shaped white glass C into the glass reservoir 11, and then leaving the tip (20 mm to 30 mm) in the glass reservoir 11 while melting the white glass C. However, it is sufficient to form a state in which a 20 mm to 30 mm length of white glass C is inserted, and other methods are also acceptable. For example, a white glass C with a total length of about 20 mm to 30 mm may be inserted into the glass reservoir 11.

[0080] [Modification 5] Furthermore, as in Modification 2 described above, the proportion of sodium siliceous fluoride relative to the weight (total weight) of transparent glass G is not necessarily limited to "3.0 wt%".

[0081] Table 3 shows the relationship between the "ratio of sodium silica fluoride to the weight (total weight) of transparent glass G" and the "degree of distortion of the central part 20". Table 3 also shows the "transmittance" and the "degree of color development of the central part 20" (the same information as in Table 2).

[0082]

[0083] Table 3 shows that when the proportion of sodium siliceous fluoride relative to the weight (total weight) of transparent glass G is "1.0 wt% or less", "1.2 wt%", "1.3 wt%", and "1.5 wt%", distortion occurs in the central part 20 (white glass C) during the stem formation process ST4.

[0084] Therefore, the proportion of sodium siliceous fluoride relative to the weight (total weight) of the transparent glass G does not necessarily have to be "3.0 wt%", but in order to suppress distortion of the central part 20 (white glass C) and form it neatly and straight, it is preferable that it be "2.0 wt% or more". Furthermore, as described in Modification 2, in order to give the central part 20 good coloration, it is preferable that it be "1.3 wt% to 3.5 wt%". Accordingly, in order to form the central part 20 (white glass C) neatly and straight and give it good coloration, it is preferable that it be "2.0 wt% to 3.5 wt%".

[0085] <3. Modifications> In the first and second embodiments described above, the explanation is given using the case where the central part 20 is made of white glass C as an example. However, the central part 20 does not necessarily have to be white and may be made of a material other than white. However, in order to make the color of the beverage W more easily visible when the "light L' reflecting the color of the beverage W" incident on the stem part 2 is diffusely reflected within the central part 20 and the central part 20 appears to be colored, it is preferable that the central part 20 be white (that is, it is preferable that the central part 20 be made of white glass C containing a white pigment in transparent glass G).

[0086] A Stemware B Blown glass C White glass G Clear glass 1 Ball section 10 Bottom section 11 Glass reservoir section 2 Stem section 20 Center section 21 Peripheral section 3 Plate section

Claims

1. A method for manufacturing stemware, comprising: a ball portion forming step of forming a ball portion of a predetermined shape having a glass reservoir portion made of molten transparent glass at the bottom; an insertion step of inserting colored glass into the glass reservoir portion; a stem portion forming step of melting the colored glass inserted into the glass reservoir portion and then stretching the glass reservoir portion with the colored glass contained within to form a stem portion; and a plate portion forming step of attaching molten transparent glass to the end of the stem portion to form a plate portion of a predetermined shape.

2. The method for manufacturing stemware according to claim 1, wherein the insertion step involves inserting white glass, which is the colored glass containing sodium siliceous fluoride, in a proportion of 1.3 wt% to 3.5 wt% relative to the weight of the transparent glass.

3. The method for manufacturing stemware according to claim 2, wherein the insertion step involves inserting white glass, which is the colored glass containing sodium siliceous fluoride, in a proportion of 2.0 wt% to 3.5 wt% relative to the weight of the transparent glass.

4. The method for manufacturing stemware according to claim 1, wherein the insertion step involves inserting the rod-shaped colored glass into the glass reservoir, and the stem forming step involves stretching the glass reservoir in the longitudinal direction of the rod-shaped colored glass to form the stem.

5. The method for manufacturing stemware according to claim 1, wherein the insertion step involves heating the rod-shaped colored glass to an extent that it can maintain its shape, and then inserting the colored glass into the glass reservoir.

6. The method for manufacturing stemware according to claim 1, wherein the stem portion forming step involves heating the glass reservoir in which the colored glass is inserted, and then stretching the glass reservoir to form the stem portion.

7. Stemware comprising: a ball portion made of transparent glass; a central part made of white glass that supports the ball portion; a stem portion arranged around the central part and having a peripheral part made of transparent glass; and a plate portion made of transparent glass on which the stem portion is erected, the stemware being manufactured by a manufacturing method comprising: a ball portion forming step of forming the ball portion of a predetermined shape having a glass reservoir portion made of molten transparent glass at its bottom; an insertion step of inserting the white glass into the glass reservoir portion; a stem portion forming step of melting the white glass inserted into the glass reservoir portion and then stretching the glass reservoir portion with the white glass contained within to form the stem portion; and a plate portion forming step of attaching molten transparent glass to the end of the stem portion to form the plate portion of a predetermined shape.

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