JPH0454567B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention is utilized in the technical field of apparatus for manufacturing synthetic resin tubes, and particularly relates to an apparatus for manufacturing synthetic resin tubes having irregular patterns.

(Prior Art) It has been widely practiced in the past to melt a synthetic resin, extrude it with an extruder, and mold it into a cylindrical shape using a circular die. It has also been practiced to add a linear color pattern in the axial direction (striped pattern in the circumferential direction) to the extruded synthetic resin tube.

On the other hand, an extrusion die for periodically changing the thickness, thickness, or color of a continuously extruded molded product in the flow direction is disclosed in Japanese Patent Application Laid-Open No. 134865/1983. However, in this extrusion die, a rotating part is provided in at least one of the plurality of channels for the molten synthetic resin, and the channel opening provided in this rotating part is connected to the channel opening provided in the fixed part. Repeated communication and blockage,
The flow of the molten synthetic resin is interrupted, but the resin that comes out of this passage has a passage between the rotating part and the fixed part so that the resin as a whole is connected in the circumferential direction.As a result, the flow of the molded product that is continuously extruded is This method changes the thickness, thickness, or color periodically in the flow direction, and is different from the object, structure, and effect of the present invention, which will be described later.

(Problems to be Solved by the Invention) As described above, it has conventionally been easy to provide a synthetic resin tube with a regular linear color pattern in the axial direction or the circumferential direction. On the other hand, despite the demand for synthetic resin tubes with irregular color patterns, no manufacturing equipment has been established. This invention attempts to solve these problems.

(Means for Solving the Problems) Means for solving the above problems in the present invention will be explained below with reference to the drawings. In this figure, it should be understood that the parts indicated by parallel diagonal lines downward to the left are parts that are fixed to each other, and the parts indicated by parallel diagonal lines downward to the right are parts that rotate together.

The apparatus for manufacturing synthetic resin tubes having an irregular pattern has at least two inlets on the upstream side of the resin flow, namely, a first inlet 6a for supplying transparent resin, and a second inlet for supplying non-transparent resin. Entrance 6
b, and the annular passage 12 of the annular die 12 on the downstream side.
The first inlet 6a of the inlets has an annular opening on the downstream side inside and outside the annular passage 12a, or at least on the outside, and is opened around the axis of the annular die 12. A rotatable rotating part 1c is provided, and this rotating part 1c
, passages 92a arranged on a certain pitch circle,
and passages 9b... arranged on pitch circles each having a diameter different from this, and the passages 92a,
Each of all the passages including 9b... does not communicate with the first inlet 6a at all but communicates with the second inlet 6.
b... or the passage 9
A specific passage among 2a, 9b... is the first entrance 6.
a, and the remaining passages are provided to communicate with the second inlets 6b..., and the passages 92a, 9b...
A distribution plate 10 integral with the rotating part 1c and a convergence plate 11 are provided downstream of the distribution plate 10 and the annular passage 12a, and the distribution plate 10 has through holes 10a, 10a.
...but the convergence plate 11 also has channels 11a, 11
a... are provided, each of the passages 92a, 9b... is connected to each of the through holes 10a, 10a, and each of the through holes 10a, 10a... is connected to each of the passages 11a, 1.
1a..., each flow path 11a, 11a...
are in communication with the annular passage 12a, respectively, and the positions in the circumferential direction at the outflow ends of the flow passages 11a, 11a... of the convergence plate 11 correspond to the passages 92a, 9b...
This is an apparatus for manufacturing synthetic resin tubes having irregular patterns arranged in the order corresponding to the following.

(Function) The colored resin pumped from the second inlets 6b passes through the rotating passages 9b, the through holes 10a, and the flow paths 11a, and reaches the annular passage 12a. Alternatively, a portion of the transparent resin pumped from the first inlet 6a passes through the passage 92a, the through hole 10a and the flow passage 11a,
This leads to an annular passage 12a. In any case, the transparent resin or colored resin is used in the rotating flow path 11a.
, 11a, . . . , and flow into the annular passage 12a with their outflow ends parallel to each other in the circumferential direction.

On the other hand, the transparent resin layer pumped from the first inlet 6a flows inside and outside the annular passage 12a, or at least outside, without rotating. Thus, the annular passages 12a are arranged in parallel while rotating.
The mixed layer of a plurality of types of resin that has flowed into is buffered by the non-rotating transparent resin layer against the wall surface of the non-rotating annular passage 12a, and the plurality of types of resins are strongly stretched (sheared) in the flow direction. In other words, the pattern is not oriented only in the vertical direction, and flow turbulence occurs between the layers, facilitating the formation of irregular patterns. Furthermore, among the inner and outer wall surfaces of the annular passage 12a, at least one layer of resin that is in contact with the outer wall surface can be made highly transparent, so that the irregular patterns formed in the mixed layer can be visually observed, and the various types of resin in the mixed layer can be visually observed. The unevenness caused by the mixture of synthetic resins in the outer layer becomes smooth due to the use of a single type of synthetic resin in the outer layer.

(Example) Examples of the present invention will be described in detail below with reference to the drawings.

1 is a rotating shaft that supports an annular die 12,
The center portion thereof is hollow, and contains a non-rotating cooling water supply channel 1a and a drainage channel 1b. In addition, the cooling water supply path 1a is a small diameter pipe fitted into the drainage path 1b, and the drainage path 1b is formed in the gap between this small diameter pipe and the large diameter pipe.

2 is a gear integral with the shaft 1, and is configured so that the shaft 1 can be rotated by transmitted power from a power source (not shown).

3 is a support part, and a thrust washer 4 and a bush 5 are interposed between the shaft 1 and the support part 3.
Support with play. Further, on the outer periphery of the support portion 3, a first inlet 6a and a second inlet 6 as resin supply passage inlets are provided.
b, third entrance 6c (only two locations are shown in the figure,
In this embodiment, a total of three locations are opened.

The resin supply passage in the support part 3 connected to the first inlet 6a is a cylindrical passage 71a, 72a, 7.
3a, and the second inlet 6b has a resin supply passage (cylindrical) 7b in the support part 3.
A third inlet 6c (not shown) is communicated with a resin supply passage (cylindrical) 7c in the support portion 3.

Furthermore, these fixed side resin supply passages 72a,
73a, 7b, and 7c and the resin supply passage in the rotating part 1c integrated with the rotating shaft 1 are communicated at four cylindrical periphery contact sliding parts 8 between the support part 3 and the rotating part 1c. That is, the resin supply passage 72a is connected to eight passages (cylindrical) 92a of the rotating part 1c via a circumferentially continuous groove 72b that is opened facing the sliding part 8 at its downstream end.
Similarly, the resin supply passage 73a is connected to the passage (cylindrical) 93a of the rotating part 1c via the groove 73b, and the resin supply passage 7b is connected to the rotating part 1c via the groove 7bb.
Similarly, the resin supply passage 7c is connected to the four passages (cylindrical) 9b of the rotating part 1c via the grooves 7cc, and to the four passages (cylindrical) 9c of the rotating part 1c, respectively, through portions 8.

These resin supply passages on the fixed side are arranged so that the distance from the entrance of each resin supply passage is constant, that is, each passage that supplies the same resin has the same flow resistance and the same amount of resin. (Details are not shown) so that the following information is supplied. That is, the groove 13 provided on the end face of each block of the passage on the fixed side is formed in the shape of a circular arc in the end face, and is constructed so that the distance is constant. Regarding the structure of such a passage, please refer to the Japanese Patent Application Laid-Open No. 1983-1997, which was published before the application was filed.
It is well known from the publication No.-32918.

Furthermore, the outlet ends (the left end in FIG. 1) of the passages 92a, 9b, and 9c are selectively communicated on the circumference through a through hole 10a bored in a distribution plate 10 fixed integrally with the rotating part 1c. Ru. That is, through hole 1
0a, as shown in FIGS. 2 and 3,
For the passage 92a, on the same pitch circle and with a circumference of 8
For passage 9b, the positions are on the same pitch circle and four equal parts of the circumference, and for the passage 9c, they are on the same pitch circle and four equal parts of the circumference, but they are all out of phase with each other. Constructed with different tightening and perforations.

Furthermore, these through holes 10a are arranged at their outlet ends (first
(left end in the figure) are brought together to the center by a flow path 11a of a convergence plate 11 that is fixed integrally with the rotating part 1c.

Thus, the end surface 3a of the fixed-side support portion 3 and the front (left side in FIG. 1) end surface of the rotating convergence plate 11 are assumed to slide on each other on an annular surface, and near the inner periphery of the annular sliding portion. In addition to the annular outlet end 11b of the flow path 11a, there are resin supply passages 71a and 93a.
The outlet end of is open. The outer periphery of the water pipe fixedly installed inside the rotating shaft 1 and the inner periphery of the support portion 3 constitute an annular passage 12a of the die 12 communicating with these outlet ends and its front outlet 12b.

Further, in this embodiment, a plurality of resin supply passages 7
b, 7c, 71a, 72a and 73a,
7b, 7c and 72a constitute a specific group,
It should be understood that the other 71a and 73a each constitute a separate group, and the plurality of resin supply passages are divided into three groups.

The distribution plate 10 and the convergence plate 11 are connected to the rotating part 1
Although a separate part is integrally fixed to c, this may be an integral structure.

The following describes in detail the process by which tubes with irregular patterns are manufactured in accordance with embodiments of the above-mentioned apparatus.

Now, a colorless and transparent molten synthetic resin is being pumped through a first inlet 6a, a white non-transparent molten synthetic resin is being fed through a second inlet 6b, and a blue non-transparent molten synthetic resin is being fed through a third inlet 6c (not shown). do.

The colorless and transparent resin from the first inlet 6a branches into resin supply passages 71a, 72a and 73a. The transparent resin that has passed through the resin supply passage 71a is annularly supplied to the outer side of the annular passage 12a, and the transparent resin that has passed through the resin supply passage 73a is supplied to the inner side of the annular passage 12a. Then, between these outer and inner transparent resin layers, a colorless transparent resin from the passage 92a, a white non-transparent resin from the passage 9b, and a blue non-transparent resin from the passage 9c pass through the passage 11a. 10a and the flow paths 11a, they are supplied alternately in the circumferential direction.

If the synthetic resin tube is extruded in this state while extruding the resin while keeping the shaft 1 fixed, a tube with a linear pattern in the axial direction, that is, a band-shaped striped pattern arranged in the circumferential direction is produced.

During this time, the synthetic resin is flowing from upstream to downstream, so the transparent resin changes in the circumferential direction as described above.
It is thought that the white and blue band-shaped layers form a spiral pattern by the rotation of the shaft 1, but in reality, the band-shaped layers are formed inside the layer when flowing into the stopped annular passage 12a. The outer surface is covered with a non-rotating layer that communicates with the resin supply passages 71a and 93a. Therefore, when the band-shaped layer flows into the annular flow path 12a, it is sheared in the rotational direction between it and the non-rotating portion, and at this time, the irregularity in which the spiral pattern is significantly distorted at the interface between them is generated. It is something that creates a pattern. In reality, the color of the streamwise bands is significantly disturbed by the circumferential shear, and the pattern thus produced is never the same twice and changes depending on the various conditions at the time. (See actual item attached for reference).

As mentioned above, in this embodiment, the first inlet 6a
A case has been described in which a colorless and transparent molten synthetic resin is pumped from the second inlet 6b, a white non-transparent molten synthetic resin is pumped from the third inlet 6c (not shown), and a blue non-transparent molten synthetic resin is pumped from the third inlet 6c (not shown).

Here, the transparent material does not necessarily have to be colorless, as long as it has high transparency, and if the white non-transparent and blue non-transparent materials have low transparency, how do you select the respective color tone? There is no problem.

In this embodiment, the passage 92a is the first inlet 6
Although the one communicating with a is shown, this does not necessarily have to be communicating with the first inlet 6a. That is, the passage 92a does not necessarily need to be supplied with transparent resin, and therefore the passage 92a does not necessarily need to be supplied with transparent resin.
There is no problem in communicating with an entrance other than the entrance 6b.

When passing through the flow path shown in FIG. 1, the annular body in the annular passage 12a has a transparent resin layer forming an inner layer and an outer layer, and non-transparent resin and transparent resin represented by white and blue colors alternately in the circumferential direction. It is composed of three layers, an intermediate layer and an intermediate layer that communicate with each other separately.

In other words, shearing against the wall surface is not directly applied to the intermediate layer where the pattern is formed.
It is added indirectly through an outer layer of a clearer transparent resin. It is therefore understood that suitable irregular patterns can be formed without the colored intermediate layer undergoing any significant orientation with respect to the flow direction. According to experiments conducted by the inventor of the present invention without the resin layers of the inner and outer layers, the pattern formed in the intermediate layer is not irregular, and the blue part is oriented in the flow direction. This can be understood from the fact that it looks like this.

Hereinafter, how the various molten synthetic resins described above are mixed in color will be explained again, although this will overlap in part with the above.

1 Colorless and transparent molten synthetic resin from the first inlet 6a,
From the second inlet 6b, a white non-transparent molten synthetic resin,
Blue non-transparent molten synthetic resin is pumped through the third inlet 6c.

2 The colorless and transparent molten synthetic resin is supplied through the resin supply passage 71
It branches into a, 72a, and 73a. Of these, those that have passed through the resin supply passage 71a are connected to the annular passage 1.
2a (not rotating) is supplied to the outside of the cylindrical side surface. Those that have passed through the resin supply passage 72a are from the rotating passage 92a, the eight passage holes 10a on the maximum pitch circle among the passage holes 10a of the distribution plate 10, and the eight passages 11a at the longest among the passages 11a.
from the annular outlet end 11b (rotating) to the annular passage 12a (fixed).

3 The white non-transparent molten synthetic resin is transferred to the resin supply passage 7.
via b (no rotation) and 9b (rotation),
Further, among the through holes 10a, 4 on the intermediate pitch circle
The annular outlet end 11b reaches the annular passage 12a via the four intermediate-length passages 11a among the passage holes 10a and passages 11a.

4 The blue non-transparent molten synthetic resin is passed through the resin supply passage 7
via c (no rotation) and 9c (rotation),
Furthermore, the four through holes 10a on the shortest pitch circle among the through holes 10a, and the shortest four among the flow paths 11a.
The annular outlet end 11
b to the annular passage 12a.

5 As described above, the cylindrical annular passage 12a (not rotating) has a colorless transparent molten synthetic resin that does not rotate in the circumferential direction on the outermost and innermost sides, and a colorless transparent molten synthetic resin that does not rotate in the circumferential direction between the outermost and innermost sides. While rotating, colorless transparent, white non-transparent, and blue non-transparent molten synthetic resins are extruded in layers in a band-like striped pattern arranged in the circumferential direction.

6. The band-shaped striped layer described above is supplied while being rotated so as to be sandwiched between the transparent inner and outer layers provided in contact with the cylindrical annular passage 12a (not rotated) as described above. As a result, the surface of the striped pattern layer is sheared in the circumferential direction between it and the transparent layer in contact with it, and the original shape (striped pattern) is disturbed and an irregular pattern is formed.

(Effects of the Invention) According to the present invention, when manufacturing a synthetic resin tube with an irregular pattern, colors can be varied in the circumferential direction by a rotating distribution plate commonly interposed in a plurality of resin supply passages. By extruding the molten synthetic resin and providing another non-rotating resin supply passage in contact with it, the rotating mixed layer of various colors receives a unique orientation in the flow direction without directly contacting the circumferential surface of the die. Without this, the colors in the mixed layer may mix irregularly.

As described above, according to the apparatus of this invention, it is not only possible to manufacture synthetic resin tubes with irregular patterns that could not be manufactured conventionally, but also the unevenness does not appear directly on the outer surface and the texture and appearance are good. This has a unique effect.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional side view of one embodiment of this invention;
The figure is a view taken along the - arrow in FIG. 1, and FIG. 3 is a view taken along the - arrow in FIG. 1c... Rotating part, 6a... First inlet, 6b...
Second entrance, 7b, 7c, 71a, 72a, 73a
...Resin supply passage, 92a, 9b...Passway, 10
...Distribution plate, 10a, 10a...Through hole, 11
... Convergence plate, 11a, 11a ... Channel, 12
...Annular die, 12a...Annular passage.

Claims (1)

[Claims] 1 An apparatus for manufacturing synthetic resin tubes having an irregular pattern, which has at least two inlets on the upstream side of the resin flow, namely, a first inlet 6a that supplies transparent resin, and a first inlet 6a that supplies non-transparent resin. The annular passage 12a of the annular die 12 is provided on the downstream side of the two inlets 6b...
The inlet 6a has an annular opening on the downstream side inside and outside the annular passage 12a, or at least on the outside, and is provided with a rotating part 1c rotatable around the axis of the annular die 12. 1c, there are passages 92 arranged on a certain pitch circle.
a, and passages 9b each arranged on a pitch circle having a diameter different from the passages 9b, and the passages 92
Each of all the passages including a, 9b... either communicates with any of the second inlets 6b without communicating with the first inlet 6a, or a specific passage among the passages 92a, 9b... is the first
It communicates with the inlet 6a, and the remaining passages are connected to the second inlet 6b...
The passage 92a,
9b... and the annular passage 12a, there is a distribution plate 10 integrated with the rotating part 1c, and a convergence plate 11 on the downstream side thereof.
are provided, and the distribution plate 10 has through holes 10a,
10a..., but the convergence plate 11 also has a flow path 11a.
, 11a... are provided, and each passage 92a,
9b... are connected to the respective through holes 10a, 10a..., and each through hole 10a, 10a... is connected to each of the flow paths 11.
a, 11a..., and each flow path 11a, 1
1a... are respectively communicated with the annular passage 12a, and the flow passages 11a, 11a... of the convergence plate 11 are connected to the annular passage 12a, respectively.
The circumferential position at the outflow end of the passage 92 is
An apparatus for manufacturing synthetic resin tubes having irregular patterns arranged in the order corresponding to a, 9b, .