JPS60168406A - Straw and its production - 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 Technical Field The present invention relates to a telescopic straw and a method for molding and manufacturing the same.

Prior Art Attaching a straw to a liquid beverage container has been practiced for a long time because it is convenient to handle and use.
For example, in the case of a small milk container 7 as shown in FIG. 1, the side surface 8 of a rectangular container formed by folding cardboard coated with a synthetic resin material is covered with a packaging material 10 and integrated along the diagonal direction. It is designed to store a straw 9. With this configuration, a long straw 9 can be attached to a relatively small container without causing any inconvenience to the user.

However, recently, as cylindrical containers have come to be used for liquid beverages, the length of the straws attached to these containers has increased.
If the length or diameter of the container is longer than that, it will be difficult to handle. YZ et al. who really want a long integrated drawer have no choice but to handle it separately from the container. However, this would miss one of the attractive features of product packaging containers.

Therefore, an assembly straw has been proposed to be attached to such a small container. That is, this kind of assembly straw
At least two straw materials of different diameters are fitted together in a telescopic manner, and when not in use, one straw member is retracted into the other member (2), thereby reducing its axial length. The idea is to reduce the size so that it can be accommodated in a small space, and to make it easier to handle.

Among the above-mentioned assembly straws, assembly straws made of thin plastic tubes have conventionally been assembled in a telescopic manner by assembling a large-diameter tube 1 and a small-diameter tube 2 that fits into it, as shown in Fig. 2(a). A curling ring 3, 4 is placed on the outside or inside of the corresponding end of each tube, and this is used as a stopper when the straw is extended. However, with this structure, the two pipes are in sliding contact only at the ends, so
When it is stretched to its maximum extent, as shown in the reduced view of FIG. 2(b), there is no component that resists the bending force, and it tends to bend at the joint, making it difficult to use.

In addition, in the above 1-1 method of curling the tube end of the assembled straw, conventionally, curling the tube end of the assembled straw is
By pressing the end of the plastic tube 2 against the molding hot plate 6 as shown in Figure 3, the tube edge can be heated and softened and expanded outward to form the stopper 4, and the inside can be curled. It is known that this can be easily done by changing the shape of the hot plate 6, but in the middle of the tube,
No efficient processing method has been found to form convex portions on the river surface.

OBJECTS Therefore, the present invention provides a telescoping telescoping TI straw that has better shape retention and higher integrity than conventional assembled straws, and that the straw To provide a processing method for efficiently forming a tube in which a uniform convex portion is formed on the circumferential surface of a plastic tube in the vicinity of the center of the tube, which is necessary as a component of a plastic tube. The gist of the straw and its manufacturing method is as described above in the claims section, and an embodiment thereof will now be described with reference to Drawing C2.

Embodiment 1 FIG. 4 shows an embodiment of the straw of the present invention, a two-stage straw.
1 and 2 are thin-walled, hard thermoplastic tubes, and the large-diameter tube 1 is a cross-sectional view of the assembled one.
The inner diameter of the pipe is DI, the outer diameter of the small diameter pipe 2 is dl, and of course D1>d
However, one end of the large-diameter pipe 1 is curled 3 to reduce the inner diameter to D2, forming the relationship D2≧d, at least in practice. On the other hand, the other end of the small diameter tube 2 is also curled 4 to enlarge its outer diameter to d2, but the relationship D1≧d2>r)2 must be maintained. However, the elasticity of the plastic material should be effectively used between the light and d2 and between D2 and dl. The structure of each member of the straw described above can be easily formed by the means described in the prior art section, and the members are fitted and assembled together from the uncurled ends. When attached and telescopically pulled out, a straw is formed as shown in the second figure, the drawbacks of which are as explained in the same paragraph.

Therefore, in this embodiment, as shown in the figure, a convex portion 5 is provided on the circumferential wall of the small diameter tube 2 at a certain distance along the axial direction from the curling portion 4 of the small diameter tube 2, and its outer diameter is approximately d2. It is. The axial distance ρ between the curling 4 and the convex portion 5 is usually 2
~20 stays.

By providing the protrusion 5 on the circumferential surface of the small diameter pipe 2 in this way, when the small diameter pipe 2 is pulled out from the curling 3 direction @ζ2 large diameter pipe 1, the protrusion 5 protruding on the small diameter pipe 2 hits the curling ring 3 at the end of the large-diameter tube 1, causing a stopper action, and the length of the tube stops increasing due to contact with the recess.The cross-sectional view shown in Figure 4 shows this state. At this time, the curled end of the small diameter pipe 2 remains within the large diameter pipe 1, so the connection between the large diameter pipe 1 and the small diameter pipe 2 is limited to the axial direction (at least the curling 4 and the protrusion 5). Since the straw is held by two separate points of contact, even if a bending force is applied from the outside to the straw made up of these tubes, the second (
b) There is no risk of the axis being bent as shown.

Also, if you try to shorten this straw to an arbitrary length after it has been stretched to its maximum limit, the curling part of the small diameter pipe
The phenomenon that the end of the large diameter pipe 1 frictionally engages with the inner diameter wall of the large diameter pipe 1 and makes it difficult to contract does not occur.

Furthermore, the small diameter pipe 2 is in sliding contact with the inner diameter wall of the large diameter pipe 1 through the curling part 4 and the convex part 5, and the curling part 3 and the outer wall of the small diameter pipe 2, which are provided separately in the axial direction. , it produces a moderate resistance to the expansion and contraction operations of the tube, and when the external force is removed, it maintains its shape, has a great ability to maintain the status quo, and does not expand or contract due to weak and untimely external forces. The straw of this embodiment also has the advantage that when the convex portion 5 is formed by the method described below, an unsightly protrusion or protrusion appears on the outside.

7f. In this type of assembly straw, if the axial length of the small diameter tube 2 is slightly longer than that of the large diameter tube 1, for example, long enough to be pinched with your fingertips, the small diameter tube 2 can be separated from the tube 1. There is no risk of a failure such as rx < 7x. Needless to say, this type of assembly draw can fit into a convenient length, approximately the length of V2.
It has the feature of being adjustable to the length desired by the user.

Embodiment 2 As explained in the embodiment shown in the fourth figure, the straw of the present invention substantially connects the large diameter pipe and the small diameter pipe by curling 4
Since it is supported by three parts, the convex part 5 and the convex part 5, it can resist the force of bending with respect to the axis, so even if the part corresponding to the convex part 5 is provided on the large diameter pipe 1 side, the same effect can be obtained. . That is, as shown in FIG. 5, the protrusion 5 in the straw shown in FIG. By forming a stopper for the support, two-point support is possible.

However, in this embodiment, when the convex portion is formed using the following means, the outer protrusion or convex shape of the convex portion appears on the outer periphery of the large diameter tube 1, and may come into contact with the fingertip (1) during use.

Embodiment 3 FIGS. 7 to 10 sequentially show the steps of molding a plastic tube having a convex portion 5 in the middle as shown in FIG. 6, which is an important component of the straw of the present invention. Figure 7 is a plan view of the apparatus, Figure 8 is a side view, Figure 9 is a view of the apparatus from the workpiece supply side, and Figure 10 is a view of the apparatus from the processed side. It is. In the figure,
11 is a table, on which a plastic tube 2 is placed.
Guides 15.15 for the tube ends used when rolling are arranged side by side on both the left and right sides, and the distance between the guides is arranged to become narrower as it goes downstream.

Also, along the table 11, at intervals close to the diameter of the plastic tube 2, the endless conveyor belt 12 of the tube 2 is guided by guides 15.
．． 15, and the belt 12 is provided so as to avoid the area where the convex portion 5 of the plastic tube 2 is to be formed. The plastic tube is conveyed while being sandwiched between the surface of the table 11 and the conveyor belt 12. The heater 13 is installed so as to extend in the transport direction of the plastic tube 2 and along the movement locus of the portion where the convex portion 5 is to be formed. Further, on the surface of the table 11 facing the heater 13, an escape groove 14 for the plastic tube convex portion 5 is bored.

In the apparatus having the above configuration (2), when a thermoplastic tube 2 of a required length is fed from the supply side between the conveyor belt 12 and the table 11, both ends of the tube 2 are connected to the guide plate 15.
15 and is transferred while being rotated by a belt 12, while the portion to be formed into a convex portion is uniformly heated and softened by a heater 13 provided extending in the transfer direction of the tube. As the tube 2 is sequentially transferred to the side where the distance between the guides 15 and 15 that guide both ends is narrower, a compressive force is applied to the center of the tube in the axial direction, and the material in the softened portion escapes in the radial direction of the tube cross section. As the pipe length becomes shorter, a convex portion 5 is formed in the softened portion.

The softened portion of the tube 2 is cooled until it is attached to the terminal end/discharge side of the conveyor belt 12, and the formed convex portion 5 is fixed.

The relief groove 14 cut into the table 11 is for preventing the formation of the convex portion 5.

The thus formed plastic tube with projections is approximately as shown in FIG. 6, and the position of the projection 5 in the axial direction of the tube is determined by the mounting position of the heater 13 with respect to the guide 15.15. The plastic tube with the convex portion is Example I
The means described in Section 2 (from the second point, it is useful as a member constituting an assembly straw).

In addition, in the above device C2, the heater 13 is connected to the table 1.
The same effect can be obtained even if it is installed in the relief groove 14 on the first side.

Until now, no effective method has been found for forming a convex part in the axial direction of a thin tube such as a straw. It is possible to form a convex portion evenly and accurately in a required portion of a large amount of stroke member.

Effects As described above, the straw of the present invention (according to 2) can be stored compactly by processing and assembling either a small-diameter plastic tube or a large-diameter plastic tube based on the manufacturing method of the present invention. This makes it possible to easily and inexpensively obtain an assembled straw with a stable axis when used in an extended state.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a known straw-shaped beverage container, FIG. 2(a) is a cross-sectional view of a telescopic assembled straw, and FIG. 2(b) is a perspective view of a straw that is extended to its maximum extent. FIG. 3 is a reduced sectional view of the state, FIG. 3 is a tube end curling forming hot plate, FIG. 4 is a sectional view of one embodiment of the straw of the present invention ←Reference←fi÷, and FIG. 5 is another embodiment of the present invention. , and FIG. 6 are members constituting the straw of the present invention, which were molded by method C2 of the present invention, and FIGS. 7 to 10 illustrate the steps of the method of the present invention. 7 shows a plan view of the apparatus, FIG. 8 shows a side view, FIG. 9 shows the processing apparatus as seen from the supply side of the plastic pipe, and FIG. 10 shows the processing apparatus as seen from the discharge side. This shows that. 1... Large diameter pipe 2... Small diameter pipes 3 and 4... Curling part 5... Convex part D1...
・Large diameter tube inner diameter dl...Small diameter tube outer diameter D2...Inner diameter d2 of curling part 3...Outer diameter U of curling part 4 and convex part 5...
Axial distance 11 between curling part 4 and convex part 5...
Table 12...Transport belt 13...Heater 1
4...Escape groove 15...Guide agent Makoto Kon (b no. 7, 9, 1312 -9chi-

Claims (2)

[Claims] (1) Consisting of at least two or more thermoplastic tubes, said tubes being in a fitting relationship with other adjacent tubes;
The two pipes in the above relationship have symmetrical pipe ends inside and outside:
In an assembled straw that is curled to act as a stopper when pulled out in one direction, a protrusion in at least the same direction as the curling is formed on the pipe wall at a distance from the curling part of one of the pipes. A straw 6 characterized by being provided with a section. (2) Convex part of the plastic pipe By uniformly heating and softening the part to be formed over the entire circumference and applying pressure in the direction of shortening the pipe length along the longitudinal axis of the pipe, and cooling it, a convex part will be formed on the midway circumferential surface of the pipe. A method for manufacturing a plastic tube with a convex portion for one side of a straw.