JPS63295446A - Production of glass bottle - Google Patents

Abstract

PURPOSE:To obtain a thick-walled glass bottle with high precision without performing molding by directly incorporating a glass block in a finishing die to blow it and molding it into the nearly same outside diameter as a final product and molding the inner shape while sagging the bottom face part of the bottle in the case of cooling and solidifying the bottle. CONSTITUTION:A glass block 4 is dropped into a finishing die 20 and the mouth part of a product is formed by sucking it between a plunger 3 and the finishing die 20. The plunger 30 is pulled down and a buffle plate 7 is provided on the finishing die 20. Both the outer shape and the inner shape of the product are blown and molded by supplying air through an air supply port 30 of a base 21. The molded glass bottle 31 is subjected to preliminary cooling while slowly rotating the finishing die 20 incorporated therewith. In an inverted state, a bottom part 35 is recessed to the inside and the center of the bottom part 32 of the inner shape is recessed and in an ordinary state, the bottom part 35 is expanded to the lower part and the bottom part 32 is made to a nearly spherical shape. After repeating this deformation, the inner shape of the glass bottle 31 is molded into a final shape and the bottle 31 is cooled and solidified. Then the sagged part naturally formed in the bottle 31 is ground down and removed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing glass bottles by blow molding.

[Prior art, 1. There are various known methods for manufacturing glass bottles, but the most typical forming method is ciparison (roughly formed into an intermediate shape close to the final shape) by preforming. It is known that the parison is molded, and then this parison is transferred to a finishing mold and finished into the final shape. Figure 8~
Fig. 12 shows the molding process of a conventional molding method in which such preforming and finishing molding are performed by blow molding. ), 2 is neck ring, 3
First, as shown in FIG. 8, a plunger supplies a certain amount of molten gob, ie, glass gob 4, pulled up from the melting furnace, into the mold of the rough W11. At this time, the glass gob 4 is fed into the mold 1 from above and at the same time is vacuum-suctioned from the gap between the neck ring 2 and the plunger 3, so that the outer shape of the mouth part is formed by the neck ring 2. be done. Note that the mold shape of the crude product 1 is smaller than the outer shape of the final product. After the mouth is formed, the plunger 3 is lowered to blow air through the neck ring 2 into the glass lump 4 as shown in FIG. 9, thereby forming the parison 5. At this time,
A baffle plate T is installed on the upper surface of the mold assembly 1 as required. Next, the parison 5 is taken out of the mold 1, turned over so that the opening 6 is facing up (Fig. 10), and placed in a finishing mold (blow mold) 8 (Fig. 11).
.

In this installed state, the parison 5 is slightly smaller than the shape of the finishing mold 8, and an appropriate gap 9 is formed between it and the pattern mold 8. Then, when air is blown into the parison 5 from the neck ring 2 to expand the parison 5 in the radial direction,
As shown in FIG. 12, a glass bottle 10 in the final shape is molded, which is sufficiently cooled and solidified in a finishing mold 8, and then removed from the mold 8 to complete the production of the glass bottle 10. do.

[Problem that the invention seeks to solve]

By the way, in the manufacture of bottles, especially beer bottles, milk bottles, etc., high precision is required for the internal capacity and shape dimensions. In that case, products with a relatively large internal capacity compared to the external shape of the bottle (thin-walled products) can be molded using automatic molding machines without any particular problems, but if the internal capacity is relatively large compared to the external shape of the bottle, such as a perfume bottle, there is no particular problem. However, when it comes to manufacturing thick-walled products with extremely small internal capacities, there is a drawback in that high dimensional accuracy and internal capacity cannot be obtained.

That is, as mentioned above, the external dimensions of the parison 5 blow-molded using the set mold 1 are υ smaller than the internal dimensions of the finishing mold 8.
Since it is small, it is necessary to put the parison 5 into the finishing mold 8 and then blow in air to match the shape of the finishing mold 8. Therefore, when air is blown, the internal volume of the product increases by that amount. This is because if an extremely small internal capacity is intended, the capacity will become larger than necessary. At the stage of blowing air into mold 1, the internal capacity is already almost satisfied, and there is almost no room for blowing air in the final molding process.

In addition, in thick-walled products, especially when the wall thickness at the bottom of the bottle is large, this part cools down slowly and maintains a higher temperature than the thin-walled parts, so after taking the product out of the finishing mold 8, It is necessary to cool the product sufficiently in the finishing mold 8 so that the outer shape of the product is not deformed. However, when cooling this thick portion, the internal shape of the bottle tends to change due to thermal contraction of the glass, and from this point of view as well, it is difficult to obtain the required internal capacity.

Furthermore, the two-step molding method of a preforming process and a final molding process requires two wrinkles, which has the disadvantage of increasing mold costs.

Therefore, the present invention solves the above-mentioned drawbacks and
It is possible to obtain a thick-walled product with an extremely small internal capacity compared to the external shape of the product with high precision in the external shape and internal capacity by combining K with a finishing forming process and a cooling process without performing a preforming process. The purpose of this invention is to provide a method for manufacturing a glass bottle.

[Means for solving problems]

In order to achieve the above object, the method for manufacturing a glass bottle according to the present invention includes a step of supplying a certain amount of glass gob into a finishing mold and blowing it into an inner and outer shape close to that of the finished product, and a finishing mold. A process of pre-cooling the glass bottle in the mold by rotating it upside down for a certain period of time, and removing the glass bottle from the finishing mold and placing it on a heat insulating plate, and then rotating the bottle upside down for a certain period of time. A step of forming the inner shape of the glass bottle into a final shape by hanging it down into the central hole of the plate, and cooling and solidifying the glass bottle;
This process consists of the step of removing the bottom flap of the cooled and solidified glass bottle.

[Effect]

In the present invention, the glass gob is directly put into a finishing mold and blown up without going through the process of forming a parison using a set mold.
The bottle is molded into an outer shape that is almost the same as the final product, and when the bottle is cooled and solidified, the bottom of the bottle hangs down to form the inner shape into the final shape.

[Example] Hereinafter, a method for manufacturing a glass bottle according to the present invention will be described in detail with reference to FIGS. 1 to 7.

FIG. 1 is a longitudinal sectional view of a finishing mold used in the present invention, and FIG. 2 is a plan view of the same mold. In these figures, 2G is a finishing mold formed with the same shape as the outer periphery of the glass bottle that will be the internal final product, 21 is a base that holds the plunger 3 vertically movably, and the finishing mold 20 is mounted on this base. is set up. Reference numeral 22 denotes a split mold holder for clamping the finishing mold 20, and each of the holders 22 has a semicircular shape, and has a pair of holder bodies 22A and 22B holding the finishing mold 20t with their openings facing each other. , a connecting bin 23 that rotatably (opens/closes) one end of these holder bodies 22A, 22B, a mold clamping shaft 24, a mold clamping handle 25, and a double nut 26 that tightens the free ends of the holder bodies 22A, 22B. and each holder main body 22A
, 22B are respectively protruded from the outer peripheral surface of the Kusui Sensha 27A.
, 27B, and these horizontal axes 27A.

27B are provided on the same straight line perpendicularly intersecting the center line of the mold 20 so as to face the finishing mold 20 between them. Note that the finishing mold 20 is formed into two parts for mold release.

Now, to explain the method of manufacturing a glass bottle in the order of steps, Fig. 1 shows that the plunger 3 is raised, fitted into the lower end opening of the finishing mold 20, and the glass lump 4t is dropped into the finishing mold 20 at the same time. This figure shows a step of molding the outer shape of the product opening by vacuum suctioning the glass gob 4 from between the plunger 3 and the finishing mold 20. This process of forming the mouth of the product is exactly the same as the conventional process of forming the mouth of the product using the mold 1 shown in FIG.

Various materials with different compositions are used as the glass lump 4 depending on the product, such as lead glass (sto:so
- sowt%, pbo: 25-30wt%)
is used. The amount of glass gob 4 is determined by the external shape and internal volume of the final product.

FIG. 3 is a diagram showing the process of forming the outer shape and the inner shape, which is performed after the process of forming the mouth of the product described above.

At this time, the plunger 3 shown in FIG. 1 is pulled down by the cylinder, a baffle plate T is installed on the finishing mold 20, and air at a predetermined pressure (approximately IKyβ) is supplied from the air supply hole 30 of the pace 21 to the finishing mold. By being supplied to the lower end opening of the mold 20, the outer shape and inner shape of the product are blow-molded. This process of forming the outer shape and inner shape by blowing is similar to the conventional parison forming process shown in FIG. However, in the conventional parinon molding process, the external shape is smaller than the final product, whereas in this backing method, the external shape is almost the same as the final product, which is different from the conventional method. They are different. Further, the internal capacity of the glass bottle 31 formed in this process is smaller than the internal capacity of the final product, and its internal shape is, for example, as shown in FIG. It has a substantially elliptical shape that is longer in the transverse direction than in the axial direction. Such a shape of the bottom portion 32 is obtained by forming the bottom portion of the bottle 31 to be sufficiently thick.

FIG. 4 and FIG. 5 show a process of pre-cooling the glass bottle 31 whose outer and inner shapes have been molded. , 27B t' The rotation is performed while slowly rotating in the vertical plane as the center of rotation. Finishing mold 20
The zero rotation speed is about 5 times/- to 20 times/m, and the glass melon 31 is rotated 2 to 10 times, but this varies depending on the temperature, viscosity, material, etc. of the glass melon 31. In addition, during the pre-cooling process, the glass bottle 31 in the finishing mold 20 has plasticity, so
As shown in FIG. 4, in an inverted state with the mouth 6 facing downward, the bottom 35 is recessed inside the bottle 31 and the internally shaped bottom 32
In the normal state with the mouth 6 facing upward as shown in FIG. 5, the bottom portion 35 bulges below the finishing mold 20, making the bottom portion 32t approximately spherical. Then, while repeating such deformation of the bottom portion 35 several times, the temperature of the glass bottle 31 decreases to a predetermined temperature. This pre-cooling process is performed on the horizontal axis 27A.

Since the glass bottle 31 is rotated 1120t for finishing around 27B', there is no change in the outer shape of the glass bottle 31, especially the outer circumferential shape, which has the advantage of maintaining the final shape.
7? - Every time the finishing mold 20 rotates, the bottom 3 of the glass bottle 31 is
5 deforms up and down and constantly changes its internal shape, so it is not affected by thermal contraction of the bottom portion 35.

Note that the finishing mold 200 rotations may be performed manually by rotating the mold upside down.

When the temperature of the glass bottle 31 drops to a predetermined temperature due to preliminary cooling, the glass bottle 31t is removed from the finishing mold 20 (Fig. 6) and is heated through a heat insulator with a central hole 37 made of carbon, graphite, etc. The glass bottle 31 is placed on a plate 36, and the inner shape of the glass bottle 31 is formed into a desired final shape, and the bottle 31 is cooled and solidified. During the final shaping process of the inner shape, the center of the bottom of the glass bottle 31 is still soft, so it hangs down into the center hole 3T of the heat insulating plate 36 and solidifies. Therefore, the inner shape of the glass bottle 31 extends downward into a substantially oval shape, and the inner capacity increases by the volume of the hanging portion 38.

In this case, depending on the temperature, bottom wall thickness, viscosity, hole dimensions and depth dimensions of the central hole 3T, etc., the volume of the lower part 380 of the hanging portion 380 should be made almost constant just before the step of forming the inner shape of the glass bottle 31. Therefore, if this volume is taken into account and the inner shape of the glass bottle 31 is formed in the outer shape and inner shape forming process shown in FIG. 3, a final product with a highly accurate inner volume can be manufactured. Can be done. In addition, the hanging portion 38 of the glass bottle 31
Since this is naturally formed due to the weight of the bottom of the bottle, the inner bottom portion 32 extends downward to form an ideal elliptical shape. However, the shape of the bottom part 32 is similar to that of the heat insulating plate 36.
By changing the large dimensions and depth dimensions of the central hole 3T, it is also possible to form it into a shape other than an ellipse, for example, a curved surface close to a flat surface.

Next, the hanging portion 38 is removed by polishing to obtain a glass bottle as a final product. The hanging portion 3B can be removed by polishing using a method conventionally used for patterning. For example, the hanging portion 3B may be removed by polishing with an abrasive using a grinding machine. Additionally, the outer surface of the final product is polished if necessary.

In addition, the bottom part 3 of the glass bottle 31 molded in this example
The internal temperature of the thick wall of No. 5 was approximately 1000° C. in the mouth forming process shown in FIG. 1, and the external shape was as shown in FIG.

Approximately 900°C in the internal shape forming process, Figures 4 and 5
Approximately 800°C in the pre-cooling process shown in the figure, approximately 700°C immediately after forming the M shape from the finishing mold shown in Fig. 6, and approximately 600°C at the start of the internal shape forming and cooling process installed on the heat insulating plate 36 in Fig. 7. Met. In addition, the softening point of the glass lump 4 measured by thermal expansion coefficient measurement etc. is 500 to 550°C.
Met.

〔Effect of the invention〕

As described above, the method for manufacturing a glass bottle according to the present invention does not involve forming a crude parison, but directly blow-molding the outer and inner shapes of the glass bottle using the finished mold. The molding process can be simplified. In addition, after blow-forming the outer and inner shapes, the glass bottle is pre-cooled while being rotated upside down using a finishing machine, which allows the bottom of the bottle to be deformed up and down.
Even if the bottom of the bottle is thick, the inner shape is not affected by heat shrinkage and maintains a smooth shape until the final shaping process. In addition, the bottle taken out from the finishing mold after pre-cooling is placed on a heat insulating plate and its bottom is allowed to hang down into the central hole of the plate while cooling and solidifying, so that the internal volume of the bottle is reduced. Not only does the volume of the υ part increase, making it easier to obtain the desired internal volume, but the internal shape also changes depending on the diameter of the center hole of the heat insulating board.
The depth can be changed freely by changing the depth, and it is particularly suitable for manufacturing thick-walled bottles such as perfume bottles whose internal capacity is extremely small compared to the external shape.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a finished mold showing the mouth forming process of the manufacturing method according to the present invention, Fig. 2 is a plan view of the same mold, and Fig. 3 is a process of forming the outer shape and inner shape of the glass bottle. Figures 4 and 5 are diagrams showing the preliminary cooling process of the glass bottle, and Figure 6 is a diagram showing the state immediately after the glass bottle is taken out from the finishing mold.
FIG. 7 is a diagram showing the final shaping of the inner shape of a glass bottle and the cooling process, and FIGS. 8 to 12 are diagrams showing the molding process by the conventional blow-molding method for glass bottles. 1...Mold, 2...Neck ring, 3...11
- plunger, 4...glass lump, 5...glass bottle, 6...fist/mouth, T...spit/baffle play), 8,
20...Finish m, 22...Holder, 27A,
27B...Horizontal shaft, 36...Insulation board, 37...
...Central hole, 3B... hanging part.

Claims (1)

[Claims] A certain amount of molten glass gob is fed into a finishing mold, the mouth is formed, the outer and inner shapes are blown to approximate the final shape, and the blown glass bottle is placed in the mold. In this state, the finishing mold is rotated upside down for a certain period of time to pre-cool the glass bottle, and then the glass bottle is taken out from the finishing lid and placed on a heat insulating plate, and the bottle is placed in the center of the bottom of the bottle. The inner shape of the glass bottle is made into a final shape by letting the part hang down into the central hole of the heat insulating plate, and the glass bottle is cooled and solidified, and after that, the hanging part of the bottom of the glass bottle is removed. A method of manufacturing glass bottles.