JP2601992B2 - Blow molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow article provided with a small-diameter mouth at one end of a body, such as a synthetic resin bottle, a glass bottle, or a tubular container having a mouth into which a screw cap is fitted. And an apparatus used for producing the same by a blow molding method.

[0002]

2. Description of the Related Art Generally, a conventional mold used in a blow molding method has a hollow article A ' divided vertically by half, as shown in FIG. It is divided into two blocks 21a and 21b so as to enclose it.
21a is brought into close contact with the die 22 and the tip of the parison B 'is sandwiched. In this state, air is blown into the parison B' from the nozzle 24 of the die 22, so that the parison B 'follows the inner surfaces of the blocks 21a and 21b. spread is deformed so as, 'the blocks 21a Once hardened is, by separating the 21b hollow article (product) a' parison B derived is a.

However, in the case where the mold 21 is formed into a simple split mold by the two blocks 21a and 21b,
As shown in FIG. 13 (b), there is a problem that a streak-like parting line 24 appears on the outer peripheral surface of the hollow article A 'at the joint surface between the blocks 21a and 21b, and the appearance is deteriorated. Was. To solve this problem, both blocks 21a,
The two blocks 21a and 21b are machined with high precision.
A countermeasure is taken so that no gap is formed at the joint of b.

However, as described above, the blocks 21a, 21
Precise processing of b increases the cost, which reduces the merit of the blow molding method that hollow articles can be mass-produced at low cost, and the parting line 24 is caused by both block bodies. 21a, 21b
Not only the gap generated at the joint of
The reason is also that the cooling of the parison B 'is delayed at the joint of the blocks 21a and 21b.
Even if 1b is precisely processed, the parting line 24 has not been completely eliminated.

Therefore, when manufacturing a hollow article which dislikes the parting line 24, such as a container for cosmetics, as shown in FIG. 14, an opening A2 'is manufactured by an injection molding method and this opening is formed. A body A1 'obtained by cutting a tube formed by extrusion of a synthetic resin is joined to A', and the bottom is closed by heat sealing. However, in the means for joining the tube body A1 'to the mouth A2',
Not only is the manufacturing apparatus significantly complicated, but also there is a problem that a joint failure between the mouth A2 'and the body A1' may occur.

For the purpose of improving the gas barrier property, for example, a multilayer tube as shown in FIG. 15 is sometimes formed. However, the injection molding method generally allows only a single layer to be formed. To the mouth A2 '
In the means for joining 1 ', there is a limit in improving the gas barrier property of the mouth A2', so that a hollow article (container)
There is a problem that the improvement of the gas barrier properties of the whole A 'is limited.

[0007] Furthermore, since this joint type is manufactured with the bottom of the body portion A1 'opened, there is another problem that it cannot be applied to the manufacture of a hollow article in the shape of a bottle. An object of the present invention is to solve these problems.

[0008]

The hollow article according to the present invention
Producing for blow molding apparatus. Fits on the outer peripheral surface of the trunk A1 of the hollow article A
A cylindrical body forming die 1 having a cavity 5 formed therein;
A cavity 7 having a shape to be fitted to the mouth A2 of the hollow article A was formed.
Close contact with the mouth forming die 2 and the outer surface of the bottom A3 of the hollow article A
Of the bottom-forming mold 4 having an inner surface shape and the opening-forming mold 2
Parison B is supplied to the place 7 and the cavity 5 of the body forming die 1.
And a means (3) for. The mouth forming mold 2 intersects with the axis of the hollow article A.
Blocks 2a and 2b
Is a split mold consisting of . The bottom molding die 4 fills the cavity 5 of the body molding die 1.
It is movable so that it can be opened and closed . Forming the bottom of the cavity 5 in the body forming die 1
The portions facing the mold 4 are the blocks 2a and 2b of the mouth- forming mold 2.
Were separated from each other and the bottom molding die 4 was moved.
Large so that the hollow article A can be pulled out from the bottom in the state
Open ".

The apparatus of the present invention is applicable to various blow molding methods.
it can. For example, a parison with an open end
General that extrudes into the device and expands it
For bottom blow molding method
As described in item 2, the split mold consisting of multiple blocks
And close the block in this bottom mold
By doing so, the tip of the parison can be pinched.

In addition, a parison whose tip is closed is shot.
After molding by the extrusion molding method, air is
`` Injection blow molding
Method, it is not necessary to configure the bottom molding die as a split mold.
Without opening the same part
Hollow object after molding can be inserted into and removed from the parison molding die
Intersects the axis of the body forming die so that
Any configuration is possible as long as it can be moved in any direction. Further , the present invention can be generally applied to manufacture hollow articles having various cross-sectional shapes with various materials, such as when manufacturing hollow articles made of synthetic resin or when manufacturing glass bottles.

[0011]

According to the present invention, since the body forming die is not a split mold composed of a plurality of blocks but a single form, at least the body of the manufactured hollow article has a parting line. Does not occur. On the other hand, since the mouth-forming mold is a split mold, a parting line is formed at the mouth of the molded hollow article, but since the mouth is generally covered with a cap, even if a parting line is formed at the mouth. Almost no appearance problems. Further, in the present invention, since the hollow article is formed by inflating one parison, the structure of the mold apparatus is smaller than that of the means for joining the chirping body to the mouth manufactured by the injection molding method. Can be significantly simplified.

Therefore, according to the present invention, it is possible to produce a hollow article having an excellent appearance in which a parting line does not occur in the body without impairing the advantage of the blow molding method that the hollow article can be easily produced. Having. Especially,
The molded container is moved from the bottom while the mold is moved.
Because it is to be removed, the shoulder of the container is
It can be covered, so the container shoulder
It is possible to minimize the occurrence of a steering line. In addition, since the entire hollow article is formed by using one parison as a raw material, and forming the parison in multiple layers, the entire hollow article is formed in multiple layers, for example, improvement of gas barrier properties and improvement of appearance. It is particularly suitable when the hollow article is composed of multiple layers for the purpose of.

Further, since the body of the hollow article is molded with the bottom, even a bottle-shaped free-standing hollow article is manufactured without any parting line in the body. You can do it.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
This will be described based on 2). FIGS. 1 to 9 show a first embodiment according to the second aspect of the present invention.
Body forming mold 1 for forming body A1 of hollow article A
Above the body forming mold 1, a mouth forming mold 2 for forming the mouth A2 of the hollow article A, and a push as an example of a means for supplying a cylindrical parison B are provided. while the output for <br/> die 4 is disposed on the lower surface of the body part mold 1, the bottom mold 4 for molding the bottom portion A3 of the hollow article a is provided .

The body forming die 1 is of a single form ,
A cavity 5 in which the trunk A1 of the hollow article A fits is formed therein. That is, it is formed in a hollow cylindrical shape.
You. Void of its 5 is largely opened downwardly to allow extraction of the molded hollow article A downward. Body molding
The shoulder 1 is formed so as to cover the shoulder of the container A.
In this case, since the shoulder portion of the hollow article A is tapered, the upper part of the cavity 5 is formed in a tapered shape with an upper constriction.
Is set slightly larger than the outer diameter D2 of the male screw A4.

As shown in FIG. 3, the body molding die 1 has:
A plurality of cooling water supply holes 6 are formed so as to extend in the axial direction (the cooling water supply holes 6 may be formed in a ring shape so as to surround the cavity 5, or may be formed with the axis of the cavity 5. It may be formed so as to extend linearly in a direction orthogonal to it. The mouth forming mold 2 is composed of two block bodies 2a and 2b mounted on the upper surface of the body forming mold 1 so as to be able to approach and separate in a direction perpendicular to the axis of the hollow article A. In the mating surfaces of the blocks 2a and 2b, semi-circular voids 7 in plan view for forming the mouth A1 of the hollow article A are respectively formed. Grooves 7a for forming the male screw A4 of the mouth A1 of the hollow article A are formed in both of these cavities 7.

Inside the die 3, there are provided an annular hole 8 for extruding the parison B, and a nozzle 9 for pre-blowing the extruded parison B. A hot wire type cutter 10 for cutting the parison B is horizontally movably arranged at a portion between the die 2 and the mouth forming die 2. Both blocks 2a, 2 in the mouth forming die 2
On the upper surface of b, a counter plate 11 for fixing the upper end surface of the formed mouth portion A1 is fixed.

The bottom molding die 4 is divided into two blocks 4a and 4b which can approach and separate from each other in a direction perpendicular to the axis of the hollow article A.
Reference numerals a and 4b are mounted on the lower surface of the body forming die 1 so as to be horizontally movable. Both blocks 4 in this bottom molding die 4
The mating surfaces of a and 4b are formed so as to extend linearly in a plan view, so that the lower end of the parison B can be sandwiched between the blocks 4a and 4b so as to be closed and trimmed, that is, the parison B is pinched off. I can do it.

Although it is needless to explain, both blocks 2a and 2b of the mouth forming die 2 and the bottom forming die 4
As means for moving the two blocks 4a, 4b toward and away from each other, for example, as shown in FIG. 8, each block 2a, 2b,
Guide protrusions D formed on the side surfaces of 4a, 4b are slidably fitted into guide grooves E 'formed in the machine frame E, and each block 2a, 2b, 4a, 4b is connected to an air cylinder, a hydraulic cylinder, or a rack. Various means can be adopted, such as moving by various mechanisms such as a pinion and a pinion.

In the above configuration, the hollow article A is manufactured in the following order. That is, first, the parison B is extruded into the mold device by the die 3 with the mouth-forming mold 2 and the bottom-forming mold 4 opened, and then the mouth-forming mold 2 and the bottom-forming mold 4 are closed. Then, the lower end of the parison B is pinched off by the blocks 4a and 4b of the bottom molding die 4, and the upper end of the parison B is cut by the cutter 10. Blow and spread the upper end of parison B in a trumpet shape.

Then, the entire mold apparatus is horizontally moved below the nozzle pins, and as shown in FIG.
Is lowered while ejecting air from the nozzle 12a, and the nozzle pin 12 is inserted into the cavity 7 of the mouth-forming mold 2 while the parison B is expanded, thereby forming the hollow article A. The nozzle pin 12 is provided with a flange 12b that fits tightly on the counter plate 11. By fitting the flange 12b into the counter plate 11, the upper end surface of the mouth A2 is processed to a predetermined size. ing.

Finally, both blocks 2a and 2b of the mouth forming die 1 and both blocks 4a and 4b of the bottom forming die 4
And the molded hollow article A is withdrawn from the body molding die 1 downward with the bottom thereof first. The extraction of the hollow article A is performed, for example, by adsorbing a vertically movable vacuum suction tool to the bottom surface of the hollow article A, or by compressing the hollow article A from above.
It can be carried out by various means, such as by blowing it out.

Generally, the mouth A of the hollow article A
Burrs appear on the upper end and the bottom of 2 as shown by dashed lines A4 and A5 in FIG. As described above, since the trunk A1 is molded by the trunk molding die 1 having a single form, the parting of the trunk A1 is performed by a blow molding method in which only one parison B is inflated. The hollow article A having an excellent appearance without lines can be easily manufactured. Particularly, since the hollow article A is formed by one parison B, the entire hollow article A can be formed by a plurality of layers by forming the parison B into a plurality of layers as shown in FIG. Therefore, the improvement of the gas barrier property, which is the object of the parison B having a plurality of layers, can be achieved without deteriorating the appearance by the parting line.

The bottomed hollow article A thus produced
As shown in FIG. 9A, the mouth A2 is left as it is.
9A, or as shown in FIG. 9B, the bottom of the hollow article A is cut off, the content is filled from the bottom, and then closed by heat sealing or the like. Symbol C is a cap. When the hollow article A is used in the form shown in FIG. 9A, a parting line is formed by the bottom molding die 4 at the bottom of the hollow article A. There is no. Further, when the parting line is used in the form of FIG. 9B, the part where the parting line appears can be cut off, so that there is no problem of the parting line at the bottom part.

The present invention can be applied not only to the embodiment in which the parison B is extruded downward by the die 3 as in the above embodiment, but also to a blow molding apparatus of a type in which the parison B is extruded in the horizontal direction. No. In the first embodiment, the hollow article A is formed in a circular shape. However, the present invention is not limited to the hollow article A having a rectangular cross section shown in FIG. 10 as a second embodiment. It goes without saying that the present invention can be applied to the production of the hollow article A.

In addition to the case of manufacturing a hollow article A having a body A1 having a straight shape, a third embodiment shown in FIG.
It can also be used for the production of a hollow article A having a downward swelling shape as shown in FIG. 7A and a hollow article A having a beer barrel shape as shown in FIG. FIG. 11 (b)
In the case of a shape in which the upper and lower middle portions are swelled as described above, the body A1 is easily narrowed and deformed, so that there is no problem in extracting the hollow article A.

[0027] Shown in FIG. 12 is a fourth embodiment of the present invention is applied to equipment for injection blow molding.

The apparatus of this embodiment has a male mold 15 having a shape that fits tightly into the mouth A2 of the hollow article A, and a mouth molding for forming a mouth molding cavity between the male mold 15. A mold 16 and a female mold 17 for forming a cavity for parison molding together with the male mold 15;
Body forming mold 1 for forming body A1 of hollow article A
8 and a bottom molding die 19 for molding the bottom of the hollow article A. Male mold 15 and female mold 17
A parison supply means according to claim 1 is constituted.

Of these, the mouth-forming mold 16 is formed as a split mold by two blocks 16a and 16b.
7 is movable in the axial direction of the male mold 15. The bottom molding die 19 is formed in a single form, and the hollow article A
In both the axial direction and the radial direction. Soshi
Then , the bottom molding die 19 is moved so that the body molding die 18 is opened toward the female mold 17, and the mouth molding die 16 is approached and the female mold 17 is moved to the mouth molding die. 16, the parison B is formed and the mouth A2 of the hollow article A is formed by injecting a molten synthetic resin from the runner 20 formed in the female mold 17 in this state. After the female mold 17 is separated from the bottom mold 1
9 closing the bottom of the barrel portion molding mold 18 at, performs molding of hollow articles A by ejecting air into the parison B from the nozzle of the male 15 in this state.

The hollow article A is extracted from the body forming die 18 with the bottom first.

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a plan view as viewed from IV-IV in FIG. 1;

FIG. 5 is a sectional view showing a molding state.

FIG. 6 is a cross-sectional view showing a step of finishing the mouth.

FIG. 7 is a view showing a state where a formed hollow article is being extracted.

FIG. 8 is a cross-sectional view showing an example of a mounting means of the mouth forming die or the bottom forming die.

FIG. 9 is a view showing a use state of the hollow article.

FIG. 10 is a cross-sectional view of a body molding die according to a second embodiment.

FIG. 11 is a longitudinal sectional view of a third embodiment.

FIG. 12 is a sectional view of a fourth embodiment.

13A is a cross-sectional view of the related art, and FIG.
It is a cross-sectional view of the manufactured hollow product products in the apparatus.

14 is a cross-sectional view of a hollow product articles produced by other prior art.

15 is a cross-sectional view of a case of forming the body portion of the hollow object article in a plurality of layers.

[Explanation of symbols]

 Reference Signs List A hollow article A1 trunk A2 mouth B parison 1,18 trunk molding die 2,16 mouth molding die 3 die as a line of parison supply means 4 bottom molding die 5 empty space in trunk molding die 7. Void space for mold

Claims (2)

(57) [Claims] 1. A hollow article A having a mouth A2 at one end of a body A1.
A blow molding apparatus for manufacturing a hollow article A , wherein the hollow article A has a shape fitted on an outer peripheral surface of a body portion A1.
Cylindrical mold 1 for forming a hollow portion, in which a cavity 5 is formed;
A mouth formed with a cavity 7 shaped to fit in the mouth A2 of the article A
The mold 2 closely adheres to the outer surface of the bottom A3 of the hollow article A.
Void 7 of inner surface shaped bottom molding die 4 and mouth molding die 2
And the parison B is supplied into the cavity 5 of the body forming die 1.
Means 3, wherein the mouth-forming mold 2 intersects the axis of the hollow article A
From multiple blocks 2a and 2b
The bottom mold 4 opens and closes the cavity 5 of the body mold 1.
The lower part of the cavity 5 in the body forming die 1 is movable.
The part facing the molding die 4 is the blocks 2a, 2 of the mouth molding die 2.
b and the bottom mold 4 is moved.
Size so that the hollow article A can be pulled out from the bottom
Blow molding device, characterized in that it is well-opened . 2. A "claim 1", the bottom mold 4
Are a plurality of blocks that can be freely attached and detached in the radial direction of the hollow article A.
This is a split type consisting of locks 4a and 4b.
4a and 4b are brought into close contact with each other to clamp the tip of parison B
A blow molding apparatus characterized by the following.