JP5004242B2 - Glass container - Google Patents

Description

  The present invention relates to a glass container used as glass tableware such as glass bottles, cups, and dishes for storing various contents such as beverages, foods, and medicines.

  The bottom surface of a glass container such as a glass bottle or glass tableware is subjected to a mechanical shock when released from the bottom mold during the molding process or a thermal shock such as a rapid cooling of the ground surface after molding. Chatter (fine surface cracks) is likely to occur. Moreover, the breakage of the glass container is often caused by contact damage on the ground contact surface of the container bottom. Therefore, in order to prevent the occurrence of such bottoming and contact scratches, it is known that a large number of protrusions generally referred to as “knurling” are provided on the bottom surface of the glass bottle. So far, there are knurlings composed of protrusions of various shapes (Patent Documents 1, 2, etc.).

The knurling is performed by providing protrusions at regular intervals along the outer periphery of the bottom surface.
By applying knurling, bottoming and contact flaws during molding are concentrated on the surface of the knurling, and the strength reduction caused by the bottoming does not reach the container bottom body (parts other than the protrusions). In the inspection of the bottom of the glass bottle, there is a problem that the shadowing due to the knurling is often disturbed and the visibility is poor in the visual inspection.

On the other hand, glass containers such as milk, yogurt and pudding do not like knurling, and containers without knurling are often used. This is considered to be because it is difficult to remove dirt (oil dirt, carbon dirt, etc.) between the protrusions of the knurling and gives an unpleasant impression to the consumer.
In the case of a glass container without knurling at all, there is no disturbing protrusion, which is convenient for inspection of the bottom. However, although it varies depending on the difference in environmental temperature between summer and winter, there is a problem that approximately 30 to 60% of the product becomes defective due to the bottom defect.
JP 2006-264715 A Japanese Utility Model Publication No. 64-9112

  It is an object of the present invention to develop a glass container that is less prone to bottom defects, can be easily wiped even if dirt adheres to the bottom surface without causing trouble in the bottom inspection.

The present invention has an annular ridge along the outer peripheral portion of the bottom surface of the container, the curvature radius (R ₁ ) of the top of the ridge is 3 mm or less, and the height (H) of the ridge is 0.05 to The glass container is 0.4 mm and has a lowermost portion in contact with the installation surface at the top of the ridge.

The top part is the part where the bottom surface is in contact with the installation surface and the cross-sectional shape is a convex curve downward (in the present invention, the protruding shape of the glass is convex and the glass is dented. The shape is expressed as concave). The reason why the radius of curvature (R ₁ ) of the top portion is 3 mm or less is that the volume of the ridge is small, so that the ridge portion can be kept at a high temperature during molding, and the bottom tends to come off during mold release. It is because it is hard to come out. Furthermore, when the conveyer moves immediately after molding, the contact area with the conveyer becomes small, so that the protruding portion is difficult to cool and the bottom is unlikely to occur. That is, it is possible to suppress the occurrence of bottoming caused by the shape of the ridges, compared to the conventional knurling in which the curvature radius of the top exceeds 3.0 mm.
A more preferable range of the radius of curvature (R ₁ ) at the top is 0.1 to 0.3 mm.

Appropriate height (H) of the top is 0.05 to 0.5 mm. If the height is less than 0.05, the difference from the bottom surface is too small, and it is difficult to exert the function as a knurling to prevent contact scratches with the grounding surface. This is because the convex shape is too conspicuous and may interfere with the bottom inspection.
A more preferable range of the height (H) of the top is 0.1 to 0.3 mm.

In this invention, the lowest part of a protrusion can be located outside the inner end of the bottom inner surface concave curved surface part currently formed in the container bottom inner surface outer peripheral part.
If it does in this way, when the bottom face of a container is seen, a protrusion will become hardly conspicuous by the lens effect of a bottom inner surface concave curved surface part.

Moreover, in this invention, the lowest part of a protrusion can be located outside the outer end of the bottom inner surface concave curved surface part currently formed in the container bottom inner surface outer peripheral part.
If it does in this way, since the position of a protrusion is located in the wall thickness of a container trunk | drum, when it looks at the bottom face of a container, it will become further inconspicuous so that a protrusion can hardly be visually recognized.

According to the present invention, it is possible to make the bottom protrusion inconspicuous without impairing the knurling function of preventing bottoming and contact damage and the stability of the container. Therefore, it is difficult for the shadow to be disturbed by the bottom inspection in the inspection machine, and the inspection range can be kept wide.
Moreover, since the protrusion is annular, even if dirt is attached to the bottom surface, it can be easily removed by wiping with a cloth or the like.
Furthermore, even when coating is performed on the bottom surface, leakage of coating liquid and liquid pool are reduced as compared with conventional knurling.

  1 to 3 relate to a glass container 1 according to an embodiment of the present invention. FIG. 1 is a bottom view, FIG. 2 is an explanatory view of a main part of a bottom shape cut through the center, and FIG.

  The glass container 1 is a milk bottle having an outer diameter of about 77 mm and a capacity of 200 ml. An annular ridge 4 is formed on the bottom surface 21 along the outer periphery (FIG. 1). The ridge 4 is composed of a top portion a and slope portions b and c on both sides thereof. The top portion includes a lowermost portion A in which the bottle bottom is in contact with the installation surface, and the cross-sectional shape is a downward convex curve, and is a region indicated by “a” in FIG. In this embodiment, the radius of curvature of the apex a is 0.2 mm.

  Slope portions (regions indicated by “b” and “c” in FIG. 2) are formed on both sides of the top portion. The cross-sectional shape of the slope portion is preferably a straight line or a gentle concave curve. In the case of the present embodiment, it is a gentle concave curve.

As shown in FIG. 2, both sides of the ridge 4 is a convex curve of radius of curvature R _2, the broken line p that connects the two sides of the curve at the same radius of curvature R ₂ are as no protrusion 4 This is a virtual line when virtual. In the present invention, the height (H) of the ridge is a distance between AB when a point where a perpendicular line passing through the lowermost part A of the ridge and an imaginary line intersect is defined as B. The height (H) of the protrusion in this example is 0.2 mm.
Usually, the curvature radii of both side portions of the ridge 4 are equal, and therefore, the imaginary line can be easily set by connecting the both side portions with the same curvature radius. When the curvature radii of the both sides are different, a virtual line is set by connecting with a straight line.

As shown in FIG. 3, a concave inner surface of the bottom inner surface d is formed on the outer peripheral portion of the inner surface of the bottle bottom. The inner end D of the bottom inner concave curved surface portion d is where the convex curve of the bottom portion 2 on the inner peripheral side changes to a concave curve. The outer end E of the bottom inner concave curved surface portion d is where the concave curve of the bottom inner concave curved surface portion d changes to a straight line of the body portion 3.
Assuming that a perpendicular passing through the lowermost portion of the protrusion 4 is q, q is preferably outside the inner end D of the bottom inner surface concave curved surface portion d, and outside the outer end E of the bottom inner surface concave curved surface portion d. More desirably. In the case of the present embodiment, the lowermost part A (the perpendicular q passing through) of the protrusion 4 is outside the outer end E of the bottom inner concave curved surface part d.

  The glass container of this example was turned upside down, and the bottom surface was observed from directly above, but the presence of the protrusions was almost visually recognized because the position of the protrusions 4 was located in the wall thickness of the container body 3. could not.

When the glass container of this example was molded, it was about 1% that became a defective product due to the defect of the bottom.
In addition, when a glass container having the same shape as that of the present example was formed except that no protrusion was formed, about 50% of the products became defective due to defects in the bottom.
When the glass container of this example was automatically inspected by the bottom inspection device, it operated normally and no inconvenience occurred.
Although carbon was adhered to the bottom surface of the glass container of this example, the dirt could be easily removed by lightly wiping with a cloth.

  In the above-described embodiment, the ridge is formed in a complete annular shape without a break, but it is also possible to make a break in the ridge. However, if dirt adheres to the cut, it becomes difficult to remove the dirt.

2 is a bottom view of the glass container 1. FIG. It is a principal part explanatory drawing of the bottom face shape which carried out the center longitudinally similarly. It is a substantially center longitudinal cross-sectional view similarly.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass container 2 Bottom part 21 Bottom face 3 Trunk part 4 Projection a Top part b Slope part c Slope part d Bottom inside concave curved surface part

Claims (3)

An annular ridge is provided along the outer periphery of the bottom surface of the container, the radius of curvature (R ₁ ) of the top of the ridge is 3 mm or less, and the height (H) of the ridge is 0.05 to 0.5 mm. A glass container having a lowermost portion in contact with the installation surface at the top of the protrusion.   2. The glass container according to claim 1, wherein a lowermost portion of the protrusion is positioned outside an inner end of a bottom inner surface concave curved surface portion formed on a container bottom inner surface outer peripheral portion.   2. The glass container according to claim 1, wherein a lowermost portion of the ridge is located on an outer side of an outer end of a concave surface of the bottom inner surface formed on the outer peripheral portion of the inner surface of the container bottom.

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