JPS5962402A - Manufacture of liquid vessel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a method of manufacturing a liquid container for hot filling.

Beverages, especially milk, juice, alcohol, etc., are heat sterilized and then filled into containers, which is hereinafter referred to as hot filling. ) Many cases are sealed. In that case, the volume of the liquid and trapped air decreases in the process of returning the entire container to room temperature. Steel cans are rigid, so they maintain their outer shape against the negative pressure that occurs inside them. Even in the case of square paper containers, each side is recessed into the inside of the container, but since the shape of the ridgeline does not collapse, the appearance is maintained for the time being. However, in containers with circular cross-section bodies made of materials with low rigidity such as paper, plastic, and aluminum foil, the surface of the container shell is irregularly indented, significantly reducing its commercial value. For these containers, methods have been used to absorb the reduction in internal volume with lids, inner walls, etc. However, conventional methods have not been sufficient in terms of the robustness, simplicity, and adaptability to volume reduction of the finished container.

The present inventor found that the dent on the outer shell of the container could be eliminated by pressing the other surface with external force and maintaining its deformation, and based on this finding, the present invention was accomplished.

The method for manufacturing a liquid container of the present invention involves forming a pot into a container consisting of a body made of a material such as paper, plastic, or aluminum foil, and a bottom plate or top plate that is reversible or deformable, or a bottom plate and a top plate. After filling and sealing, the container is cooled from the outside, or after cooling, the bottom plate or the top plate, or the bottom plate and the top plate are pushed into the container by external force and deformed, so that the inside of the container is deformed in the above process. This consists of preventing or correcting deformations such as dents in various parts of the outer shell of the container caused by the generated negative pressure.

The present invention will be specifically described below based on the accompanying drawings.

FIG. 1 is a process explanatory diagram of the liquid container manufacturing method of the present invention, and the process progresses from FIG. 0 to FIG. Figure (A) is a front sectional view of an example of an empty container used in the manufacturing method of the present invention. The body section is composed of a body section 1 and a bottom plate 2, which may have a circular or square cross-sectional shape. The bottom plate 2 is characterized in that its central portion protrudes outward (downward) and can be turned inward (upward) by external force. In some cases, the bottom plate 2 is the top plate 5. Figure (b)
indicates the process of hot filling the container. The container 1 is filled with a heated solution 4 from the filling nozzle 3 . Beverages are usually heated and filled to about 60 to 93°C and combined with a solution to sterilize the inside of the container.

FIG. 29 is a front sectional view of the container immediately after the top plate 5 is heat-sealed to the body 1 and sealed after hot filling. At this stage, the solution 4 is in a hot state, and the upper space inside the container is filled with saturated steam. There is no deformation of container 1 yet. Figure 1) is a front sectional view of the container after the cooling process has progressed and deformations such as dents have appeared on the outer shell of the container. Generally, after being filled and sealed, the container is rapidly cooled with shower water. This is because if the high temperature state continues for a long time, the quality of the internal solution will deteriorate. If you are not concerned about this, you can leave it naturally (leaving it naturally is also a form of cooling). In any case, when the temperature of the solution sealed in the container decreases from high temperature to room temperature, the volume of the liquid and gas inside the container decreases, as described above. The amount of volume reduction is the filling temperature, the volume of the liquid in its verse,
Determined by the volume of air in the headspace. 2 for vending machines
Taking a 50 cc liquid container as an example, it will be 10 to 20 cc, and the ratio will be about 5 to 10. However, the present invention is not limited to the above-mentioned capacity, and can be applied to smaller containers, 1 t, 2 t, and even larger containers. Now, in containers mainly made of materials with low rigidity such as paper, plastic, and aluminum foil, deformations such as dents occur in weak parts of the outer shell of the container as the internal volume decreases. In the figure, the body 1 and the top plate 5 are dented. Bottom plate 2
is not deformed in this case, because the material and shape have been selected to have a certain degree of rigidity so that no noticeable dents will occur under the negative pressure generated inside the container.

However, you may also choose a material that allows the bottom plate to deform to some extent. However, if the bottom plate 2 has a weak structure like the body 1 and the top plate 5, the container itself will lose its robustness, which is not desirable. Figure (e) is a cross-sectional view of the container showing a step of correcting the deformation of the container, and is also a main part of the present invention. A rod 6 with a disk whose front surface is approximately spherical is applied to the bottom plate 2 and pushed up to correct the dents generated in the body 1 and the top plate 5.

The reversal and deformation of the bottom plate 2 also include cases in which the reversal and deformation of the bottom plate 2 are limited to only a partial portion rather than the entire surface. Also, invert the top plate 5 in the same way as the bottom plate 2,
It can also be transformed. It is applied to reduce the amount of deformation of the bottom plate and top plate individually, or when the amount of change in the internal volume of the container is particularly large. Note that even if the dents are not completely corrected, the product value will be greatly improved. In some cases, a body with a circular cross section does not need to be perfectly circular as long as it looks circular.

In addition, if the radius of curvature of the cross section of the corner of the rectangular body is larger, the feel of the container when held, the rolling stand of a vending machine, etc. will be improved. Furthermore, pushing the bottom plate up creates positive pressure inside the container, which is effective in preventing outside air from entering.

Figures ) and (e) are methods for mechanically restoring deformations such as dents, but by pushing up the bottom plate 2 as dents occur, that is, in parallel with cooling, It is also possible to adopt a method that does not cause dents in the body 1, top plate 5, etc. Figure (f) is a front sectional view showing the shape of the final product. Since the bottom plate 2 has a certain degree of rigidity, it maintains the shape pushed up by the rod 6, and there are almost no dents in the body 1 and top plate 5.

Figures 2 to 4 show other examples of liquid containers manufactured by the manufacturing method of the present invention. Both figures) are front sectional views of empty containers, and figures (
F) is a front sectional view of the container in the final product form, and corresponds to @) and (F) in FIG. Compared to Figures 1 and 2 and Figure 1, the structure of the seam between the bottom plate and the body is different.

Both figures 3 and 4 show a bottom plate with numerous annular folds,
In Figure 3, when the bottom plate is pushed up, its annular folds are stretched, and in Figure (f), the bottom plate becomes a substantially spherical surface that is convex toward the inside of the container. In Figures 1 and 4, the shape of the pleats remains the same, but the bottom plate is inverted4.The bottom plate shape is good as long as it can be inverted or deformed by external force with little elongation of the material.

There are spherical surfaces, elliptical surfaces, and surfaces with a flat top and a curved surface. The top plate can also be given a similar function.

Next, touch on the ingredients in each part of the container. Depending on the patent required for the bottom plate, there may be conflicts, but in that case, the bottom plate may have a shape with expansion and contraction, such as an annular fold as shown in FIGS. 3 and 4. Valuable below are concrete row composites. PE/At/PE,
PH7Atj heat-resistant resin, composite plastic film,
and single films such as PE, PP, and PET. Aluminum foil (A-Z) - For example, in a 250CC container, if the thickness is 80μ or more, it will not dent inside the container due to the negative pressure generated inside the container. Polyethylene (PR) is 2
The thickness may be 0 to 50 μm. There are heat-resistant resins with gas barrier properties of about 10 CC/d/24 hours,
Can be used in containers that do not require strict gas barrier properties. A composite material of PE/paper/adhesive/At/PE can also be used by imparting reversibility and deformability to the structure.

In the present invention, a flexible body is more suitable for the body than a rigid body. The required properties are water resistance and gas barrier properties.

and adaptability (that is, flexibility) to the negative pressure generated inside the container, and rigidity to maintain the shape of the container. Next, specific examples of composite materials will be given. PE/Paper/Paper layer adhesive/At
/PEPET, PP/Nylon/A7/PP.

PH7PP/Nylon/PP/PE, and PP/
Nylon/PVA/PP etc. In other words, these are paper processed products, plastic molded products, and plastic film processed products. Further A, foil 9. It is also possible to target steel foil and other metals.

An example will be given. The shape is as shown in Fig. 1, and the body is P.
H7300 f/nt'' paper/adhesive/At/PE, the lid plate is made of PE/120 μA, t/heat-resistant resin, and the bottom plate is made of 30 μPB/100 μAt/heat-resistant resin.

Ma11 Next, the effects of the present invention will be discussed.

11) The present invention prevents or corrects deformation of a hot-filled liquid container due to thermal changes, such as denting, by using an unprecedented method of forcibly pushing the bottom plate in.

(2) The container produced by the manufacturing method of the present invention has a body,
There is tension on the top plate, and the product value is a dog.

The curvature of the bottom plate itself consists of a beautiful curve.

(3) The container produced by the manufacturing method of the present invention can have a certain degree of rigidity on the bottom plate, and as a result, the container itself is robust. It also has a simple structure.

9- (4) The manufacturing method of the present invention absorbs the decrease in the internal volume of the container by inverting or deforming the bottom plate, and by appropriately setting the shape of the curvature of the bottom plate, the amount of decrease in the internal volume of the container can be adjusted. Can respond to

(5) The container produced by the manufacturing method of the present invention can have a body that is close to a perfect circle, and the radius of the corners of the body that is intermediate between a circle and a square can be made large, so it has good rolling properties and is suitable for vending machines. Ideal for

(6) A wide range of materials can be selected for containers produced by the manufacturing method of the present invention. The material for the body and top plate may be hard or soft. There is also considerable freedom in selecting the material for the bottom plate.

[Brief explanation of drawings]

Figure 1 is a process explanatory diagram of the liquid container manufacturing method of the present invention, and Figures 2 to 4 are other examples of liquid containers produced by the manufacturing method of the present invention. 1...Body part, 2...Bottom plate, 3...
- Filling nozzle, 4...solution, 5...top plate. Patent applicant Honshu Paper Co., Ltd. 10- Figure 1 (a) (b)
(c) (d) (cliff,)
(F) Figure 2 (A) (F) (4) 3rd Z <,)

Claims (1)

[Claims] A body made of materials such as paper, plastic, and aluminum foil;
A container consisting of an invertible or deformable bottom plate or top plate, or a bottom plate and a top plate is hot-filled and sealed, and then while or after cooling the container from the outside, the bottom plate or top plate, Or, by pushing the bottom plate and top plate into the inside of the container by external force and deforming them, it is special to prevent or correct deformation such as denting of various parts of the container outer shell caused by the negative pressure generated inside the container in the above process. A method for manufacturing a liquid container.