JPS6085922A - Method and device for manufacturing tubular container made of synthetic resin - Google Patents

Abstract

PURPOSE:To obtain a tubular container made of synthetic resin having no fear of bursting and defective sealing by making the monotonous tubular container into a thing having fresh impression by adding cubical decoration to the same, by a method wherein simultaneously with molding of a cylindrical trunk part whose inside is smooth and homogenous a convex belt pattern is molded unitarily on the outside of the trunk part. CONSTITUTION:Convex belt patterns 6, 7 are formed on a predetermined position of the outside of a trunk part 1 unitarily in an axial direction of the trunk part 1. These belt patterns 6, 7 are molded desirably by resin of a different color tone from the other part of the trunk part 1 and they are molded at a time at the time of molding of the trunk part 1. On the one hand, the inside of the trunk parts 1 indicates smooth circular state and the resin exposed on the inside of the trunk parts 1 is turned into a homogenous state completely. A neck part 2 which is provided with a delivery hole 3 is welded on the top of the trunk part 1 through a shoulder part 4, the bottom 5 of the trunk part 1 is crushed into a flat state and sealed through a nonwelding device.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synthetic resin tube container used in a wide range of fields such as cosmetics, foods, and pharmaceuticals. The present invention relates to a manufactured tube container, its manufacturing method, and manufacturing apparatus.

In conventional tube containers, a cylindrical body is formed by extrusion molding, and then a desired pattern is added to the outer surface of the body by printing, hot stamping, or the like. However, such decoration through secondary processing not only increases the number of manufacturing steps and causes cost increases, but also makes it impossible or extremely difficult to express three-dimensional patterns. This makes the tube container with a monotonous appearance even less varied. In addition, when molding a body part, it is a well-known technique to mold a part of the peripheral wall with a resin of a different color tone from the other parts over the entire wall thickness, but it is also known that Colored to make it stand out in a convex shape,
Moreover, it has still not been possible to mold the inner surface into a smooth annular body with no unevenness. Therefore, it has been considered impossible to create three-dimensional patterns by extrusion molding on products whose bottoms are crushed and sealed, such as tube containers.

The present invention was made in view of the above-mentioned circumstances, and
The purpose is to provide a synthetic resin tube container that has a three-dimensional pattern on the outer surface of the body and that pattern is formed at the same time as the body is molded, and a method and apparatus for producing the same reliably and relatively easily. Our goal is to provide the following.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a tube container according to an embodiment of the present invention, and reference numeral 1 in the figure represents a substantially cylindrical body formed by extrusion molding from a synthetic resin. ,
A neck part 2 with a spout hole 3 and a cap (not shown) screwed onto it is welded via a shoulder part 4, and a bottom part 5 of the body part 1 is flattened and heat welded or the like. sealed by means of As shown more clearly in FIG.
-6.7-7 are integrally formed in the axial direction of the body. These band patterns are preferably made of resin of a different color tone from the rest of the body 1, and are
It was molded at the same time as the molding of. On the other hand, torso 1
The inner surface has a smooth circular shape, and has band patterns 6 and 7.
does not reach this inner surface, so the resin exposed on the inner surface is completely homogeneous.

As can be understood from the above, in this tube container, the convex band pattern 6.7 gives a remarkable change to the appearance of the body 1, giving a completely different impression from conventional decorations. It has become. This effect can be further enhanced by making the resin forming the band patterns 6 and 7 different in color from the other parts, and since they are molded without any troublesome secondary processing, the cost is reduced. It also has advantages. Furthermore, since the inner surface of the body 1 is completely smooth and homogeneous,
There is no risk of punctures or poor sealing of the bottom portion 5.

Next, FIG. 3 shows an apparatus used for manufacturing the above-mentioned tube container, and this apparatus has a pipe for circulating cooling water in the center.
1 penetrates through it, and an outer mold 12 attached around the core mold, and the outer surface of the core mold 10 and the outer mold 12
A space having a circular cross section and forming a flow path section 13 is defined between the inner surfaces of the tube.

The core mold 10 is formed to gradually become smaller in diameter toward the tip, and accordingly, the cross-sectional area of the flow path portion 13 is smaller than the tip (downstream side).
It gets smaller the further you go. The outer mold 12 is the die body 1
2a, first die chip 12b and second die chip 1
2c, which are arranged in this order in close contact with each other from the proximal end side to the distal end side of the core die 10, and the flow path section 13 is connected to the extrusion port 1 on the distal end surface of the second die tip 12c.
It ends at 4.

A main extrusion molding machine 15 is attached to the die body 12a of the outer mold 12, and the tip of this molding machine 15 is attached to the die body 12a.
It communicates with a first sprue 17 that is annularly opened at the base end of the flow path section 13 through a runner 16 that is bored in the flow path section 13 . On the other hand, the first die chip 12b is equipped with a first auxiliary extruder 18.
is attached, and its tip communicates with a second sprue 20 opened in the middle of the flow path section 13 via a runner 19, and a second auxiliary extrusion molding machine is attached to the second die chip 12c. 21 is attached, and its tip communicates via a runner 22 with a third sprue 23 that opens further downstream than the second sprue 20 of the flow path section 13 . These auxiliary extrusion molding machines 18 and 21 are installed with a positional relationship shifted by 90 degrees from each other, and as shown in FIGS. 4 and 5, each runner 19 and 22 has a semicircular shape. Diversion section 19
sprues 20-20 and 23-, which have openings 20-a and 22a, and are locally opened at both ends of each branch section or into the channel section 13;
23, respectively. Therefore, the second sprue 20-
20 and the third sprue 23-23 are 90 degrees apart from each other with respect to the center.
The sprues of each pair are in symmetrical positions, while being offset by . In addition, at the positions where these sprues open, the cross-sectional area of the flow path portion 13 is slightly and temporarily reduced by providing recesses 24-24 on the outer surface of the core mold 10 at those portions as shown in FIG. It is preferable to increase the amount.

The tip 10a of the core mold 10 is formed into a small diameter cylindrical shape and extends forward beyond the extrusion port 14 of the second die tip 12c, and the outer diameter of the tip 10a is adjusted to the desired inner diameter of the body 1. It will be set accordingly. As described later, this tip 1
0a plays a role as a cooling part, and a pipe 11 passing through the center of the core mold 10 opens in the tip part 10a to circulate cooling water. The member indicated by the reference numeral 25 in the figure is a roll for taking off the molded product.

The method for manufacturing the body 1 as shown in FIG. 2 using the apparatus having the above-mentioned configuration will be explained below. First, the first thermoplastic resin 26 is melted from the main extrusion molding machine 15. The first resin is caused to flow into the flow path section 13 and flow down. As described above, the flow path section 13 has a smaller cross-sectional area on the tip side, so the flow velocity of the resin 26 increases as it goes downstream, and the pressure becomes higher downstream due to the viscosity of the resin itself. . Next, while continuing the flow of the first resin 26, the first and second auxiliary extruders 18 and 2
The thermoplastic synthetic resins 27 and 27a from No. 1 to No.
Since the third sprues 20-20 and 23-23 are locally opened, the second resin is added in a band shape to the outside of the first resin flowing down the flow path section 13. become,
The pressure in the added portion becomes higher than that in the other portions. However, in the flow path section 13, the flow is faster and the pressure is higher on the downstream side, so the uniform diffusion of pressure is inhibited, and the second resin 27, 27a does not mix with the first resin 26. The strip-shaped resin is extruded from the extrusion port 14 together with the first resin 26 into the atmosphere. Then, the extruded resin is suddenly released from the high pressure state, so
It expands and the wall thickness increases, but at this time, the part where the second resin was added was under even higher pressure than the other parts, so the expansion rate was higher than the other parts, and the wall thickness also increased. do. This condition is illustrated in FIG. 6, where the portion to which the second resin has been added protrudes more than the other portions both in the outward and inward directions. After that, the inner surface of the resin extruded into a sleeve is brought into close contact with the outer surface of the cooling part (core-shaped tip) 10a, and the sleeve is cooled while regulating its inner diameter, so that only the outer second resin is cooled. A molded product 28 having a predetermined inner diameter and protruding in a band shape is obtained (see FIG. 1). After this molded product 28 is taken up by the roll 25, the body part 1 is formed by cutting it into a predetermined length, and the outer protruding parts are formed into strip patterns 6-6, 7.
-7.

Although it is necessary that the first resin 26 and the second resin 27.27a are compatible, it is preferable that the second resin has a different color tone from that of the first resin.
For example, a first resin material mixed with a pigment may be used as the second resin. Of course, the second resins 27 and 27a may have different colors. In addition, as shown in the figure, a flow path section 13 in which a sprue 20.23 opens.
When the recess 24 is provided in the recess 24, the pressure of the first resin 26 at this part is temporarily reduced, so that the second resin 27,
27a has a clearer band pattern without expanding in the circumferential direction.

When the height (thickness) of the band pattern 6.7 of the body part 1 formed using the above method and mounting was measured, it was about 20 to 25% of the wall thickness of the body part. Increase this thickness.

That is, if it is desired to further enhance the three-dimensional effect of the band patterns 6 and 7, the cross-sectional shape of the flow path portion 13 can be changed as shown in FIG. 8 or 9. That is, in the embodiment shown in FIG.
0-20, a groove 30-30 having a width approximately equal to the width of the sprue, and downstream of the third sprue 23-23, a groove 31-31 having a width approximately equal to the width of the sprue, In the embodiment shown in FIG. 9, similar grooves 40-40 and 4 are formed on the inner surface of the outer mold 12.
1-41 is formed. In the case of the former example (FIG. 8), the wall thickness of the part where the second resin 27, 27a is added is larger in the inner part than in other parts, and therefore When released, the expansion coefficient increases, and the inner diameter is restricted by the cooling section 10a, so that all of this expansion portion bulges outward.
The thickness of the band patterns 6 and 7 increases. In this case, the amount of the second resins 27, 27a can be made larger than in the above embodiment. In addition, the embodiment shown in FIG. 9 has a band pattern 6.
It is more obvious that the thickness of 7 can be increased. As a result of experiments, it has been confirmed that the thickness of the band pattern can be made approximately 2 to 3 times that of the above-mentioned embodiments using these embodiments.

In the experimental example described above, two pairs of band patterns 6-6 and 7-7 were formed on the outside of the body 1, but the positional relationship of the band patterns is not limited to this. Of course, it can be changed arbitrarily.

Further, the shape of the body portion 1 can be various other than circular.

As described above, in the synthetic resin tube container according to the present invention, a convex band pattern extending in the axial direction is formed integrally with the outer surface of the body when the body is molded. Since the inner surface of the tube is smooth and homogeneous, it is possible to add three-dimensional decoration to a monotonous tube container to give it a new impression, and there is no risk of punctures or seal failures, and the cost is low. It has various advantages such as:

Further, in the method according to the present invention for manufacturing the tube container described above, a cylindrical flow path portion is defined between a core mold and an outer mold attached around the core mold, and the flow path portion The diameter of the channel gradually decreases from the proximal end to the distal end, and while the molten first thermoplastic synthetic resin from the main extrusion molding machine flows into the channel from the proximal end, A sprue communicating with the auxiliary extrusion molding machine is locally opened on the way, and the first
A second thermoplastic synthetic resin having compatibility with the resin is flowed into the outside of the first resin in a band shape, and the first resin and the second resin are poured into the outside from the tip side without mixing. Then, by cooling the extruded resin while regulating its inner diameter, a cylindrical body is formed using the first resin, and at the same time, a convex shape is formed on the outer surface of the body using the second resin. Since the band pattern is integrally molded, it is possible to form a three-dimensional pattern reliably and without primary processing.

Furthermore, the apparatus according to the present invention for manufacturing the tube container has an outer mold attached around the core mold, and a diameter gradually decreasing toward the tip between the outer surface of the core mold and the inner surface of the outer mold. a main extruder forming a cylindrical flow path and communicating with a sprue opened at the proximal end of the flow path to provide a molten first synthetic resin into the flow path; A unit that communicates with one or more sprues locally opened in the middle of the passage and provides a band-shaped molten second synthetic resin on the outside of the first resin flowing down inside the passage. Alternatively, multiple auxiliary extrusion molding machines are attached to each of the outer molds, and the resin extruded into a cylindrical shape from the tip of the flow path is cooled while regulating the inner diameter to form a body with a predetermined inner diameter. Since a cooling section is provided for this purpose, it is relatively simple and can be manufactured efficiently.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a synthetic resin tube container according to an embodiment of the present invention, FIG. 2 is a perspective view of the body of the container, and FIG.
The figure is a cross-sectional view showing an apparatus according to an embodiment of the present invention for manufacturing the container, FIG. 4 is a cross-sectional view taken along the line AA in FIG. 3, and FIG. 5 is a cross-sectional view taken along the line B-B in FIG. , FIG. 6(a) is an enlarged sectional view for explaining the state of the extruded resin;
B) is a sectional view showing the state of the resin before cooling, FIG. 7 is a sectional view after cooling, and FIGS. 8 and 9 are sectional views showing other embodiments of the manufacturing apparatus according to the present invention. be. 1...Body part 2...Neck part 5...Bottom part 6.7...Band pattern 10.
... Core type 10a ... Cooling section 12 ...
Outer mold 13...Flow path section 15...Main extrusion molding machine 17.20.23...Gate 18.21...Auxiliary extrusion molding machine 2
6...First thermoplastic synthetic resin 27.27a...Second thermoplastic synthetic resin 30.
31.40, 41... Concave groove 14mm'1 Applicant i'i Ill 17 shares 8he? 1
Agent Stamp 1 - (S 1° (+li Fig. 1 S Fig. 2 Plane Fig. 4 @ 5 Fig. 2P Fig. 8 L) r t * Fig. 9

Claims (5)

[Claims] (1) A synthetic resin tube container having a neck for attaching a quilt tube to one end of a cylindrical body formed by extrusion molding, and the other end of the body being sealed flat. A convex band pattern extending in the axial direction is formed on the outer surface of the body, and the inner surface of the body is smooth and homogeneous, and the band pattern is formed integrally with the body during molding. A synthetic resin tube container characterized by being formed into. (2) defining a cylindrical flow path between the core mold and an outer mold attached around the core mold, and making the flow path gradually smaller in diameter from the proximal end toward the distal end; The molten first thermoplastic synthetic resin from the main extruder is allowed to flow into the channel from the base end side, while a sprue communicating with the auxiliary extruder is locally opened in the middle of the channel. A second thermoplastic synthetic resin having compatibility with the first resin is allowed to flow into the outside of the first resin from the sprue in a band shape, and the first resin and the second resin are mixed. By extruding the extruded resin to the outside from the tip side without letting it cool, and then cooling it while regulating the inner diameter of the extruded resin, a cylindrical body is formed with the first resin and at the same time the second resin is extruded. A method for manufacturing a synthetic resin tube container, characterized in that a convex band pattern is integrally molded on the outer surface of the body using resin. (3) Attach an outer mold around the core mold, define a cylindrical flow path portion that gradually becomes smaller in diameter toward the tip between the outer surface of the core mold and the inner surface of the outer mold, and a main extrusion molding machine that communicates with a sprue opened at the proximal end of the flow path to provide the molten first synthetic resin into the flow path; and one or more extruders that are locally opened in the middle of the flow path. One or more auxiliary extrusion molding machines are attached to the outer mold to provide a belt-like molten second synthetic resin on the outside of the first resin flowing down in the flow path communicating with the sprue. A tube container made of synthetic resin, characterized in that it is provided with a cooling part that is attached to each of the parts and cools the resin extruded into a cylindrical shape from the tip of the flow path part while regulating the inner diameter to form a body part with a predetermined inner diameter. manufacturing equipment. (4) A groove having a width substantially equal to the width of the sprue is formed on the outer surface of the core mold on the downstream side of the sprue that communicates with the auxiliary extrusion molding machine. An apparatus for manufacturing a synthetic resin tube container as described in 2. (5) A groove having a width substantially equal to the width of the sprue is formed on the inner surface of the outer mold that is downstream of the sprue that communicates with the auxiliary extrusion molding machine. 4. The apparatus for manufacturing a synthetic resin tube container according to item 3.