JPH03227216A - Plastic spiral winding pipe, manufacture thereof and manufacturing equipment - Google Patents

Abstract

PURPOSE:To strengthen a spiral projecting part which is cut, split and weakened and to retain the shape and to obtain a spiral wiring pipe which is excellent in pressure resistant strength properties and shape retaining properties and has high quality by filling fluid substance into the hollow part formed in a pipe main body via the cut and split part through which a core material is taken out and solidifying the fluid substance. CONSTITUTION:A plastic spiral winding pipe 51 is constituted of a pipe main body 53 spirally having hollow parts 52 and the filled layers 54 which are formed by filling the mixed material being in a fluid state into the hollow parts 52. The pipe main body 53 is formed of the inner pipe parts 55 described hereunder and the spiral projecting parts 56 integral to the surfaces thereof. The inner pipe parts 55 are formed by comparting the hollow parts 52 along the lengthwise direction of the plastic bandlike bodies 1 in these insides while spirally winding the said bodies 1. In the spiral projecting parts 56, the filled layers 54 are formed by filling the mixed material being in a fluid state into the hollow parts 52 via the cut grooves C as the continuously cut and split parts which are formed by cutting and splitting the outermost circumferential parts of the bodies 1. The cover plate parts 2 are joined so as to cover the cut grooves C.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention is directed to a plastic spirally wound pipe, such as a corrugated pipe buried underground, which has peaks and valleys on its surface. The present invention relates to a pressure tube that has a corrugated appearance and a smooth inner surface, and a method and apparatus for manufacturing the same.

(B) Conventional technology Conventionally, this type of synthetic resin pipe has been made by extruding a molten plastic strip from an extruder and inserting it into the axis of a virtual cylinder or the like having a predetermined angle with respect to the direction of extrusion. It is obtained by winding the strip in a spiral, overlapping the ends (fin pieces) of the strip, and welding them together [see, for example, FIGS. 16(A) and 16(B)]. However, for example, when forming a mountain part with an inverted U-shaped cross section,
The discharge port of the mold provided at the tip of the extruder is formed with an inverted U-shaped cross section, and the strip is wound around one can, or it is extruded with a letter-shaped cross section and shaped during winding around the core of the extruder. It is conceivable to provide a plastic tube with an inverted U-shaped cross section and then wind it around the shaft to obtain a plastic tube of the desired shape. In the case of the heart, the ends of the band overlap each other,! When the two are brought together and wound around the shaft at a temperature at which they are completely fused together, the strip is in a semi-molten state, so the strip with an inverted U-shaped cross section deforms, making it difficult to maintain the designed shape.

To prevent this, the band is cooled until it retains its shape to a certain extent, and then it is wound around the shaft, but at this time, the cooling of the band has progressed, so the rigidity of the inverted U-shaped cross section is strong. However, there is a problem that winding is not easy, and even if the strips are overlapped and pressed, the temperature is lower than that at which the strips can be welded, so they cannot be joined to each other. In order to solve these contradictory problems of shape preservation and bonding, for example,
Methods described in JP-A No. 2-29213 and Japanese Unexamined Patent Application Publication No. 63-219982 have been proposed.

According to the former publication, a heated and molten thermoplastic resin tape discharged from an outside die of an extruder is applied to a spiral protrusion provided on the outer peripheral surface of the front end of a virtual cylindrical rotating shaft so as to straddle this spiral protrusion. A portion of the thermoplastic resin tape that is wound later than the thermoplastic resin tape that is wound first at an inclined angle! The first step is to form an outer tube with unevenness by supplying and winding it with nine matching knees, and cooling the second one into a spiral shape. The heated and melted thermoplastic resin tape discharged from the inside die of the extruder is wound onto the smooth circumferential surface of the rear end of the virtual cylindrical rotating shaft at an inclined angle to the thermoplastic resin tape that is first wound. On the other hand, there is a second step in which tapes are wound from behind so that they partially overlap and are wound spirally to form an inner tube. The outer tube is guided to the rear end of the body and combined with the inner tube formed on the smooth peripheral surface of the rear end, and when the inner tube is still at a temperature lower than the melting point and higher than the softening point. The outer surface of the concave part of the tube is pressed with a pressure roll that is in contact with the rotating shaft body to fuse both the inner and outer tubes, and this is cooled and hardened to make the inner surface smooth and to continuously produce a tube body with spiral protrusions on the outer surface. A method for manufacturing a corrugated pipe with a smooth inner surface has been proposed.

According to the latter publication, a method for manufacturing a synthetic resin pipe having spiral peaks and valleys on the surface and forming a flat inner wall, is made so that it conforms to the cedar-like shape of the peaks. Using a strip-shaped molding material (or core material), this molding material is spirally wound around a rotating shaft for molding, and a semi-molten strip-shaped molding material is spirally wound so as to cover the molding material. By this winding, both ends of the adjacent band-shaped molded material are polymerized and welded at the troughs, and the tops of the peaks are cut into slits, and the mold body is extracted from the slit marks, and then the slit marks are removed. A method of manufacturing a synthetic resin pipe has been proposed in which a belt-shaped material made of the same synthetic resin as the belt-shaped molded material is integrally welded to the top of the peak in order to close the pipe. According to this method, since the core material (mould) is used, the hollow peaks retain their shape, and the valleys are easy to join because the band is in a semi-molten state, and the inside of the peaks are hollow pipes. It is what the body is made up of.

(c) Problems to be Solved by the Invention However, both of the above-mentioned proposed examples have the following problems.

The former method involves a first step of forming an outer pipe by forming spiral irregularities on a resin tape using a spiral protrusion provided on the outer circumferential surface of the virtual cylindrical shaft of rotation, and a first step of forming an outer pipe by forming spiral protrusions on the outer circumferential surface of the virtual cylindrical shaft of rotation. This method consists of a second step of pressing a resin tape onto the back surface of the outer tube to form an inner tube, and as this method produces a tube body with a smooth inner surface through these steps, l) the equipment becomes larger and When manufacturing tubes with different diameters, ridge shapes, and ridge pitches, a series is required for each size. In this case, it is necessary to stop manufacturing during the time required to replace the equipment, and a method of replacing the virtual cylindrical rotating shaft body may be considered, but there is a problem in that it requires a large amount of man-hours and time.

2) Since the spiral protrusion is hollow, the pressure resistance is insufficient for piezoelectricity, and there is also the problem that it is easily damaged when an impact is applied to the protrusion during construction.

In the latter method, 1) In the case of the proposed example, the strip is wound around the shaft together with the core material (mould), and both ends of the strip are polymerized and welded, and then the peaks of the strip that have been cooled are The top part is cut into a slit shape, the core material is forcefully extracted from the cut part, and the opening surface of the peak part is then covered with a strip of pond material, so the peak part is capped or slit. First, it is difficult for the two open strips to touch each other and for the top of the peak to maintain a horizontal surface.
As shown in Figure 7 (A) and (B), it is difficult to form the cuts flush with each other (the desirable state is shown in Figure 13).
. These are as follows: - The core material is forcibly removed from the slit, so the strip is expanded. - The opening of the hollow part in the shape of the opening breaks the stress balance, causing residual strain. - The shaft core is cooled. Because of this, the difference in shrinkage rate of the resin will cause distortion due to the temperature difference between the lower part of the band at the peaks and troughs near the axis and the top of the peak. ■The core material is built into the space of the band. The inside retains its shape, but when it is slit with a cutting blade and the core material is extracted,
Because of the spiral protrusions, there is a phenomenon (problem) that the opening side wall K tends to fall backwards as shown in FIG. 18 due to torsional reaction in the direction of travel.

Since these phenomena vary depending on room temperature and molding temperature, great care is required in managing them in order to make the opening surfaces flush.

2) Since the opening pieces at the top of the mountain do not come into contact with each other, and as mentioned in 1), the opening pieces are in different states, making it difficult for each other, so the belt-shaped material that becomes the lid body uniformly closes the openings. It is difficult to separate, and there is a risk of separation (see Figure 19 (A) and (B)).
.

3) After cutting the top of the peak and removing the core material, the peak has cooled and retained its shape, so it is not possible to weld and integrate the strips made of the same synthetic resin using a pressure roller or other means. Due to the difficult phenomenon described in 1), complete melting and integration requires considerable care and management.

4) The flat compressive strength of this type of helical tube changes depending on the pitch of the ridges, and also changes depending on the height and wall thickness of the ridges. In particular, flat strength can be increased by increasing the height of the ridges, as well as the thickness of the tops of the ridges and the wall thickness of the tube connecting the ridges. For this reason, the melting of the top part of the ridged portion and the lid member J) into a melted body has an important meaning.

5) Therefore, in order to dramatically increase flat compressive strength, it is possible to faithfully form the hollow part of the mountain part with synthetic resin, metal, etc., but it is necessary to form the hollow part of the mountain part faithfully with synthetic resin, metal, etc. Comparing economic efficiency, metal pipes have the problem of corrosion and deterioration due to rusting during long-term use (30 to 50 years), and concrete pipes are corroded by chemicals, solvents, etc., resulting in the generation of residual gas and the length of the pipe during manufacturing. There are restrictions and there are problems with construction.

6) This type of tube with a mountain or hollow shape can provide the ideal strength per unit weight when viewed from the perspective of pressure resistance and flat strength, but if it is not handled carefully during transportation and construction, it will accumulate. , If a shock is applied to the mountain part during unloading, it is likely to be damaged.

7) On the other hand, in today's society, the problem of plastic pollution is being talked about. In other words, plastic products are consumed in large quantities in the fields of films, sheets for plastic greenhouses, feed, containers such as detergent bottles, bags, packaging materials, electric parts, household goods, etc., and two types of waste plastics are used. Regarding disposal 1. Countermeasures are taken such as incinerating the waste and discarding it in a landfill, but the former has a powerful firepower, so the incinerator is likely to be damaged, and the latter causes air pollution due to waste smoke. Landfills also have their limits, causing problems such as illegal dumping.

(d) Means for Solving the Problems and Their Effects The present invention provides an inner tube portion formed by winding a plastic strip in a spiral shape and partitioning a hollow portion along the longitudinal direction, and an inner tube portion integrally formed on the surface of the inner tube portion. Consisting of a spiral convex part, this spiral convex part was formed by cutting the outermost part thereof, and the continuous core material was taken out after being inserted into the hollow part in advance and maintaining the shape of the spiral convex part. It consists of a pipe main body comprising a continuous cut part, and a filling layer formed by filling and solidifying a fluid mainly composed of molten plastics into the hollow part through the continuous cut part. It is a spirally wound plastic tube.

That is, in the present invention, in the hollow portion formed in the main body of the pipe,
By filling and solidifying the fluid through the cut portion from which the core material was taken out, the bonding of the strip is strengthened and weakened.
By strengthening and retaining the shape of the two helical convex portions, it is possible to provide a high quality spirally wound tube with excellent pressure resistance, shape retention, etc.

In the present invention, the fluid used to form the packed bed is mainly composed of plastics in a molten state, but the plastics are not particularly limited, but it is preferable to use so-called "waste plastics". .

This waste plastic includes waste vinyl film and polyethylene film used in agricultural greenhouses, battery cases, detergent bottles, containers, shipping containers, plastic roofing materials, flooring materials, office equipment, household goods, and electrical appliances. Any thermoplastic synthetic resin waste materials such as utensils, parts, fruit net bags, packaging containers, etc. can be used. These film-like bodies and molded products are coarsely and finely pulverized using a crusher, a pulverizer, or a pulverizer. These are called recycled raw materials, and may have some dust, dirt, etc. attached to them. On the other hand, as a subcomponent of the fluid, non-melting coarse particles other than thermoplastic synthetic resins can be used, and specific examples include inorganic materials such as cement, sand, coal slag, iron powder, and glass. , rice husk, wood chips, wood, and crushed FRP may be used.

A drum-type tumbler-1 stirring blender is usually used to mix waste plastics and coarse particles other than thermoplastic resins. The blending ratio of these two may be selected and used, but for example, waste plastics is preferably 30 to 50%, and the coarse particles are kneaded with the molten resin and become viscoelastic, and are used for filling. It is desired that the product be extruded into a rod shape from the mold of the extruder. As the extruder for kneading, a single screw extruder having a deep groove type screw or a twin screw extruder having a structure in which two screws engage are suitable.

From another point of view, the present invention can provide the following method (a) and apparatus (b) for manufacturing a spirally wound plastic tube.

■A molten plastic strip is fed from an extruder around a roughly cylindrical mandrel so that its cross section is hollow and some overlap, and is wound spirally. The inner tube part and the spiral convex part on the outside of the inner tube part are integrally formed by the process, and at this time, a continuous core material is inserted into the hollow part formed by the molten plastic strip to form the spiral convex part. After that, the outermost peripheral part of the spiral convex part is cut to take out the continuous core material, and then a fluid mainly composed of molten plastic is poured into the hollow part from the cut part. A method for manufacturing a spirally wound plastic tube, which comprises filling and solidifying the tube.

■ An extruded material that extrudes a molten plastic strip so that its cross section becomes curved, and the strip from this extruded material is wound spirally, and the back side of the strip is rolled in the direction of the strip. A hollow portion is formed along the length, and a part of the band-like body to be wound later is overlapped with the previously-wound part of the band-like body, and a spirally wound tube having a spiral convex portion on the surface is connected. A rotating mandrel, an endless core material,
After the spirally wound tube is held on the rotating mandrel for two or more rotations, a cutter for cutting off the outermost peripheral part of the spiral convex portion, and a cutter for cutting the outermost peripheral part of the spiral convex portion, and a cutter for cutting the core material first and then wrapping it around the strip-shaped body,
A guide roller that is inserted into the hollow portion when the rolled strips are overlapped and then guided to be taken out from the cut portion of the spiral convex portion; and a fluid filling means for filling a fluid mainly composed of molten plastic into a plastic spirally wound tube.

(e) Examples Hereinafter, the present invention will be described in detail based on examples shown in the drawings. Note that the present invention is not limited to this.

First, in FIG. 1, the plastic spirally wound pipe 51 is mainly made of a pipe construction method 53 having a hollow part 52 in a spiral shape, and a filling layer 54 formed by filling the hollow part 52 with a mixed material in a fluid state. More specifically, in the former pipe construction method 53, the hollow portion 52 is formed inside the plastic strip 1 along the longitudinal direction of the strip 1 while spirally winding the plastic strip 1. It is divided into an L inner tube section 55 and a spiral convex section 56 integral with its surface.

In the spiral convex portion 56, a band-shaped body! The mixed material in a fluid state is filled into the hollow portion 52 through the continuous cutting groove C formed by cutting the outermost peripheral portion of the groove C to form the filling layer 54, and then the filling layer 54 is formed. A cover plate part 2 is joined to cover the area. As will be described later, the above-mentioned kerf C is for taking out the core material 29 used for shape retention during the manufacture of the spirally wound plastic tube.

Next, the manufacturing method and manufacturing apparatus S of the plastic spirally wound tube 51 having the above configuration will be described in detail.

This embodiment apparatus S shown in FIGS. 2 to 5 is applied to the production of plastic spirally wound pipes (hereinafter also referred to as synthetic resin pipes in which the pipe diameter and the helical pitch of the reinforcing strips can be changed). In the figure, 11 is a main body box, and the face plate 12 is removed from inside the box ll.
A support shaft 13 is provided in a protruding manner through the support shaft! Several molding shafts (or rotating mandrels) 14 are arranged along an imaginary cylindrical surface centered at 3 and 5 holes.

Each of the above-mentioned molded shafts 14 is composed of a short shaft 15 and a long sleeve 16 that are connected to each other via a universal joint 17. By bending, the long axis 16 is made to be slightly inclined (that is, not parallel) to the support shaft 13. Further, each of the short shafts 15 is interlocked and connected to a driving means 18 via an extendable and bendable connecting shaft 19, etc., especially in the main body box 11 shown in FIG. They are designed to be driven all at once in the same direction.

Further, the support shaft 13 is fitted with a piece member 20, 21, 22 that is movable on the axis, and each piece member 2
By pivotally mounting the short shaft 15 and the long shaft 16 to the 0.21.22 via connecting rods 23 and 24.25, respectively, the forming shaft 14 can be expanded and contracted on the support shaft 13. I'm trying to support you as much as possible. Note that each piece member 20.21.
22 is an operating shaft 26 disposed along the support shaft 13.
It is configured to be moved in the axial direction by the rotational operation of , and is spline-fitted to the receiving member 22 which is fitted onto the free end side piece member 22 and the support shaft 13 so as to be movable only in the axial direction, By changing the circumferential position of the piece member 22 on the receiving member 22', the inclination angle of each forming shaft 14 with respect to the support shaft 13 can be changed.

In the above-mentioned embodiment device S, a plurality of forming shafts 14 are used in order to vary the diameter of the synthetic resin pipe to be molded and the helical pinch of the reinforcing strip. If it is not variable, a general molded shaft may be used. The general molded shaft mentioned here is a conventionally known one,
For example, the molding shaft may have any structure, such as a molding shaft constructed by using a main molding shaft and having a large number of roller shafts arranged and supported in an inclined manner on the outer circumference by a cylindrical cage.

Therefore, the strip material wound around each of the molding shafts 14, that is, the strip l, is made of, for example, polyolefin-based synthetic resin such as polyethylene resin or polypropylene resin, or vinyl chloride W resin. Therefore, it is extruded into a desired shape, for example, a flat plate, from the molding die 28 of the extrusion molding means 27, and is supplied in a semi-molten state to the above-mentioned molding shafts 14 so as to extend between the upper parts of each molding shaft i4. Wrap in a spiral. Then, as shown in FIGS. 3 and 7, a molding core 29 (to be described later) is formed on each molding shaft 14 to form a U-shaped section 1a and a plate-shaped section extending from the lower end of one side of the U-shaped portion lλ. The long side portion 1b and the plate-shaped short side portion 1c extending from the lower end on the other side are formed in series. The strip material 1 is usually made entirely of a hard synthetic resin, but the U-shaped portion la and the short side portion 1c may be made of hard material, and the long side portion 1b may be made of a soft synthetic resin. The entire structure may be made of soft synthetic resin.

On the other hand, a flexible endless molding core 29 is wound in advance in a spiral shape so as to extend around each of the molding shafts 14 .

This molding core mold 29 is made of a single flexible belt material D) having approximately the same cross-sectional shape as the U-shaped portion 1a molded from the strip material 1, for example. 14 in advance, the winding end is extended loosely to the winding start end, and both ends are connected to form an endless shape. Incidentally, a groove 30 such as a 7-shaped groove is formed on the top of the core mold 29 to allow the entry of a cutter 34, which will be described later.
A guide roller 31 is provided at the starting end where the core 29 enters during winding to regulate the entry position of the core 29.

In addition, as with the molding core mold 29 described above, if necessary,
The core mold 2 is wound spirally around each forming shaft 14.
An endless presser mold 32 is wound spirally so as to be located between the two ends. This presser die 32 is a strip material! It is for pressing between the spiral core molds 29, and has flexibility like the core mold 29, and extends the end of the winding to the start of the winding, and connects both ends to form an endless shape. However, after the strip material 1 is formed on the core die 29, this presser die 32 is wound onto it. In the figure, 33 is a presser die 32: ).

Thus, as described in F2 above, the strip material I is spirally wound using the molding core mold 29 and the presser mold 32 on each molding shaft 4 to flatten the inner surface of the tube wall A and form a V wall. A synthetic resin pipe with a spiral reinforcing strip B on the outer periphery of A is molded, and then, as described later, a kerf C is continuously formed at the top of the reinforcing strip B, and a core mold 29 is formed from the kerf C. Immediately after that, the kerf C is expanded and overfilled with a fluidized mixture, and then,
The kerf C is configured to be closed, and a cutter 34 is disposed in front of the synthetic resin pipe in the helical advancing direction, and a kerf expanding means 57 is provided in front of the cutter 34 in the helical advancing direction. , a mixture filling means 58 for overfilling the mixture in a fluid state, and a molding die 36 of the extrusion molding means 35.
Finally, a semi-molten strip material 2 is supplied and attached to the neck portion of the reinforcing strip B, and the kerf C is closed.

The chip expanding means 57, as shown in FIG. Member 59
It mainly consists of a screw llll62 extending upward from the screw shaft, and a nut 63 that is screwed onto this screw shaft and can adjust the vertical position of the expansion member 59 depending on the screwed position. In addition, 64
65 is a horizontal arm of the main body of the apparatus; 65 is a longitudinal adjustment member that is supported by the arm so as to be movable back and forth, passes through the screw shaft 62 and supports the nut 63; and 66 is a handle for positioning this member.

Next, the mixture filling means 58 mainly consists of a filling nozzle 68 extending from the second extruder 67.

In addition, as the strip material 2 as the lid plate portion, a coin synthetic resin of the same quality as the strip material 1 is usually used, but instead of this, a soft synthetic resin such as a soft polyethylene resin is used as the strip material 1, and a strip material A hard synthetic resin such as a hard polyethylene resin may be used as the material 2 to improve friction resistance without impairing flexibility.

Next, the operation of the manufacturing apparatus S described above will be explained (particularly as shown in FIG. 6).

First, the semi-molten strip material 1 extruded from the die 28 of the extrusion coloring means 27 in a flat plate shape is wound so as to extend between the forming shafts 14 which are driven and rotated in unison. At this time, since a core mold 29 for molding has been wound on each of the molding shafts 14 in advance, this strip material l is formed into a core mold 29 with a U-shaped portion 1λ, a long side portion 1b, and a short side portion. 1c, and since each forming axis 14 is slightly inclined, the strip material 1 is wound spirally, and the long side portion of the preceding strip material 1 on lb.
The U-shaped portion 1a and short side portion 1c of the subsequent strip material 1 are overlapped and integrally welded to form a synthetic resin tube with a flat inner surface of the tube wall A and a spiral reinforcing strip B on the outer periphery. Molded sequentially. In particular, the U-shaped portion 1a forms a spiral reinforcing strip B, and the long and short side portions 1b overlap with each other.
, a tube wall A is formed on the IC, and the inner surface of this tube wall A is flat.

On the other hand, a presser die 32 is supplied to the outer periphery between the reinforcing strips B of the synthetic resin pipe that is sequentially molded as described above, so that the long and short side portions 1b and lc that overlap each other are pressed together, and the overlapping state is This increases the welding process and makes the welding more reliable.

Next, a cutter 34 is inserted into the top of the reinforcing strip B of the synthetic resin pipe that is continuously molded on each molding shaft 14 to continuously form a cut groove C on the top of the reinforcing strip B. Cut groove C
The core mold 29 is pulled out from within the reinforcing strip B and returned to the winding start end. At this time, the cutter 34
In this case, the cutting edge penetrates into the V-shaped groove 30 of the core mold 29, and the cutting can be performed completely. Note that the reinforcing strip B is cooled to such an extent that the shape does not shift when the core mold 29 is extracted.

Next, the core mold 29 is extracted, and the L cut groove C is further expanded by the expanding means 57 immediately after the core die 29 is extracted, and the fluidized mixture is overfilled from the expanded cut groove C by the filling nozzle 68. (fill so that it slightly overflows from the kerf C).

After that, the semi-molten strip material 2 is supplied from the die 36 of the extrusion molding means 35 to the neck part of the reinforcing strip B, and the reinforcing strip BIJ
The kerf C in the i part is opened together with the mixed material overflowing from the hollow part. This strip material 2 is made of the same synthetic resin as the strip material 1, and is formed into a plate shape having the same width as the top of the reinforcing strip B.

Further, the cut groove C is expanded when the core mold 29 is extracted,
Furthermore, since it is widened by the widening means 57, there is a possibility that it will not be completely closed after that and will be in a calibrated state, but the semi-molten band material 2 will enter into the kerf C and it will not close completely. The department will be overflowing. In this way, a part of the reinforcing strip B is interposed in the divided portion of the reinforcing strip B divided by the kerf C, and plays the role of an adhesive to firmly join the top portions of the reinforcing strip B. Of course, this joining effect has the effect of eliminating rainwater intrusion and leakage into the spiral pipe. More importantly, filling the hollow portion with the mixed material prevents the spiral protrusions from deforming, and furthermore, the pressure resistance and flatness strength as a whole is dramatically improved. Also, since it makes effective use of cheap waste plastics that have been discarded, it can contribute to society.

Furthermore, since the hollow parts can be filled with cheap waste plastics, great pressure resistance can be obtained, and as shown in Figure 9, it is possible to make the strip material extremely thin, which eliminates the use of expensive new raw materials. If you are able to save money and require even more pressure resistance strength, extremely high strength can be obtained by adding synthetic resin equivalent to the saved area weight to the valley portions.

As described above, since the thickness of each side wall of the spiral convex strip portion of the strip material can be made thin, the opening operation by the expanding means can be easily performed.

In addition, since the tip of the nozzle used to fill the waste plastic comes into contact with the spiral convex strip of the strip, it is preferable to treat the surface with a material that improves heat resistance, abrasion resistance, and lubricity, such as Teflon resin. Coating is more preferred.

Further, the rotors 60 and 61 in the expanding means 27 come into rotational contact with the inner surface of the hollow portion, that is, the inner surface of the opening side wall, and can smoothly expand the kerf C.

Here, for reference, the effect of measuring the resistance to strong sense of the plastic spirally wound tube 51 as shown in FIG. 1 obtained by the embodiment apparatus S shown in FIGS. 2 to 5 will be listed.

■Pressure test method A cut sample of a spirally wound plastic tube 54 with a length of 500 x m was held at 23°C ± 2°C for more than 4 hours, and a compression back mold was applied at a compression speed of 10 x 1 minute according to the parallel plate loading method. The load at 5% and 10% vertical strain was kept constant. Note that the compressive strength is expressed in terms of IR.

■Results As shown in Table 1.

(2) As described above, it can be seen that the pressure resistance of the present invention is sufficiently strong compared to the conventional example.

■ Molding was carried out under the same conditions as above, with 70 vt% of crushed plastic waste and 3°wt% of raw materials mixed with crude materials other than plastics, but the strength was almost the same as in (1) and it was found that the strength was improved. It could be confirmed.

Unlike the above embodiments, as shown in FIG. 14, the strip material 2A can be wound into a tube while partially overlapping and welding in a spiral shape to close each groove, and furthermore, as shown in FIG. Such structures may be stacked on top of each other.

That is, in the third extrusion II (not shown), by continuously winding and covering the wide strip material 24 connecting at least two peaks between the peaks, a tube with a smooth outer surface can be obtained. Such a tube can be suitably used as a pressure-resistant propulsion tube that requires both pressure resistance and longitudinal rigidity (see Figure 14).
. Furthermore, by repeating these methods, it is possible to manufacture a double-layered pipe with two layers 2A and 2B, and further three layers if necessary, as shown in FIG. In this case, it is also possible to fill the neck space with waste plastics.

In the illustrated example, the synthetic resin pipe molded as described above clearly shows the joining boundaries of the strip material 1 and the strip material 2, but in reality, all of the same materials are heat welded. are integrated. Furthermore, in order to more accurately shape the spiral convex portion of the synthetic resin pipe, a pressing member (or pressing roller) 69 may be provided as shown in FIG.

(F) Effects of the Invention According to the present invention, by filling and solidifying the fluid into the hollow part formed in the main body of the pipe through the cut part from which the core material has been taken out, the spiral convexity weakened due to the cut is removed. By strengthening and retaining the shape of the shaped portion, a high-quality spirally wound tube with excellent pressure resistance, shape retention, etc. can be provided.

[Brief explanation of drawings]

FIG. 1 is a side view including a partial cross section of a cut piece showing an embodiment of the spirally wound plastic tube according to the present invention, FIG. 2 is a plan view of the apparatus for manufacturing the spirally wound tube, and FIG. 3 is the same. 4 is a plan view including a partial cross section of the auxiliary forming roller arrangement portion; FIG. 5 is a side view also including a partial cross section; FIG. 6 is an explanatory view of the forming process; Figure 7 is a longitudinal sectional view of the strip material formed on the forming shaft, Figure 8 is a longitudinal sectional view of the strip material of different shapes, and Figure 9 is the forming shaft, the strip material, and the core mold 29.
, a configuration explanatory diagram illustrating the relationship with the supply direction of the expanding means 57, etc., FIG. A front view of a material extrusion nozzle, FIGS. 12 and 13 are enlarged cross-sectional explanatory views of main parts showing other configuration examples of main part cross sections of plastics spirally wound pipes, and FIGS. 14 and 15 respectively show other configurations. 16(A) is a side view including a partial sectional view showing a conventional example of a plastic spirally wound pipe; FIG. 16(B) is an enlarged sectional view of the essential parts; Fig. 17 (A) and (B) are explanatory diagrams of the main part cross-sectional structure when the spiral convex part is provided with a cut part, and Fig. 18 is a main part cross-section showing the relationship between the inclination of the cut part and the direction of movement. Structural explanatory diagrams, FIGS. 19(A) and 19(B) are explanatory diagrams of the main part structure when the torn part as shown in FIGS. 17(A) and (B) is closed. 1... Plastic strip, 14...
Molding shaft, 29...Core material, 31...Guide roller, 34...Cutter, 51...
・Plastic spirally wound pipe, 52...Hollow part, 53...Pipe main body, 54...Filled layer,
56... Spiral convex strip, 57... Cut groove expansion means, 58... Mixed material filling means, B... Reinforcement strip, C. ...kerf, S...
...Manufacturing equipment for plastic spirally wound tubes. Figure 1 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 (A) Figure 16<8) II Figure 17 (A) Figure 17 Figure (B) Figure 18 mtLWluUnomukai Figure 19 (A)

Claims (1)

[Scope of Claims] 1. Consisting of an inner tube portion formed by winding a plastic strip in a spiral shape and partitioning a hollow portion along the longitudinal direction, and a spiral convex portion integrated on the surface of the inner tube portion; The spiral convex part is formed by cutting the outermost peripheral part thereof, and includes a continuous cut part from which the continuous core material is taken out after being inserted into the hollow part in advance and maintaining the shape of the spiral convex part. A spirally wound plastic tube comprising: a tube main body; and a filling layer formed by filling and solidifying a fluid mainly composed of molten plastics into the hollow portion through the continuous cut portion. 2. The plastic according to claim 1, wherein the tube main body further comprises a lid plate attached to the outermost peripheral portion of the spiral convex portion to close the continuous cut portion after filling with the fluid. Spiral-wound tube. 3. The spirally wound plastic tube according to claim 1, wherein the fluid is a fluid mixture of molten plastic and non-melting coarse particles made of a material other than plastic. 4. A molten plastic strip is fed from an extruder around a substantially cylindrical mandrel so that its cross section is hollow, and some parts overlap, and the material is wound spirally. As a result, the inner tube part and the spiral convex part on the outside of the inner tube part are integrally formed, and at this time, a continuous core material is inserted into the hollow part formed by the molten plastic strip to form the spiral convex part. After that, the outermost peripheral part of the spiral convex part is cut to take out the continuous core material, and then a fluid mainly composed of molten plastics is injected from the cut part into the hollow part. 1. A method for manufacturing a spirally wound plastic tube, characterized by filling and solidifying the plastics spirally wound tube. 5. Claim 4, wherein the filling of the fluid into the hollow portion is overfilling.
The manufacturing method described in. 6. The manufacturing method according to claim 4, wherein the torn part is expanded in advance when filling the hollow part with the fluid from the torn part. 7. An extruded material that extrudes a molten plastic strip so that its cross section becomes curved, and while winding the strip from this extruded material in a spiral shape, the back side of the strip is coated in the longitudinal direction of the strip. A hollow part is formed along the , and a part of the band-shaped body to be wound later is overlapped with the part of the band-shaped body wound earlier, and a spirally wound tube having a spiral convex portion on the surface is connected. a rotating mandrel formed by forming a rotating mandrel, an endless core material, a cutter that cuts the outermost portion of the spiral convex portion after the spirally wound tube is held on the rotating mandrel for two or more rotations, and the core material, After the belt-shaped body that was wound earlier,
A guide roller that is inserted into the hollow portion when the rolled strips are overlapped and then guided to be taken out from the cut portion of the spiral convex portion; and a fluid filling means for filling a fluid mainly composed of molten plastic into a plastic spirally wound tube.