JPS6352573B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and an apparatus for forming an airtight coating layer made of synthetic resin on the outer surface of a cylindrical fabric, and particularly relates to a method and an apparatus for forming an airtight coating layer made of synthetic resin on the outer surface of a cylindrical fabric. The present invention provides a method and apparatus suitable for manufacturing a lining material for lining underground pipelines.

As a method of lining a pipe as described above, a string-like material is inserted into a flexible and airtight cylindrical lining material, and one end of the lining material is fixed to one end of the pipe in a ring shape. There is a known method in which the string-like material is pulled through the pipe while applying fluid pressure, the lining material is pulled into the pipe while being turned over, and the lining material is bonded to the inner surface of the pipe by the fluid pressure. . This method does not require digging the entire pipe, it is sufficient to form manholes only at both ends of the pipe to be lined, and even if there is a bend in the pipe, the lining material can be removed easily and in a short time. This method is attracting attention as an extremely excellent method.

The present invention seeks to produce a lining material for use in such a lining method.

Since this lining material needs to be turned over by fluid pressure, it is necessary that the lining material has airtightness. In addition, since the fluid pressure is applied, it is necessary to have a pressure resistance to the extent that it can withstand the fluid pressure, and for that purpose, it is necessary to have a flexible and strong cylindrical fabric layer. It is said that Furthermore, the lining material is bonded to the pipe via an adhesive, and the lining material needs to hold a large amount of adhesive, so
The cylindrical fabric layer should be exposed on the outer surface of the lining material after being turned over, that is, on the inner surface of the lining material before being turned over, and the airtight layer should be provided on the outer surface.

In addition, if the pipe has a small diameter and has many curved pipes within the pipe system,
The lining material is required to have extensibility in both its longitudinal and radial directions. In other words, it is necessary for the lining material to be correctly attached to both the inside and outside of the bent pipe section of the pipe system, and for this purpose, the lining material must be able to extend in its length direction. There must be. In addition, in small-diameter pipes, the pipe diameter changes locally at curved pipe parts, etc., and the rate of change is large, so the lining material needs to be lined correctly to follow the change in pipe diameter. Radial extensibility is also required.

An example of the structure of such a lining material is the structure shown in FIG.

That is, the lining material 1 is formed by forming a coating layer 3 of thermoplastic synthetic resin on the outer surface of a cylindrical fabric 2. The tubular fabric 2 is made by weaving warp threads 4 and weft threads 5 into a tubular shape, and the warp threads 4 are threads formed by winding crimped synthetic fiber threads around urethane elastic material. The threads are used as all or part of the warp yarns 4, and the weft yarns 5 are crimped synthetic fiber yarns. Further, as the synthetic resin forming the covering layer 3, a polyester elastic resin is used.

This lining material 1 is flexible, strong, and airtight, and has appropriate extensibility in the length direction and radial direction of the lining material 1, and is extremely suitable as a lining material for the above-mentioned pipe line. It is something that

By the way, as a method for manufacturing such a lining material 1, a thermoplastic synthetic resin tube is drawn and pasted inside a cylindrical fabric 2, and this is turned over so that the cylindrical fabric 2 is on the inside and the coating layer of the tube is on the outside. A possible method is to use it as the lining material 1. However, this method has poor productivity, and the friction caused when the thermoplastic synthetic resin tube is drawn into the cylindrical fabric causes distortion in the cylindrical fabric and the thermoplastic synthetic resin tube, resulting in a uniformly stretchable lining. I can't get the material.

There is also a method of coating the outer surface of a cylindrical fabric with a synthetic resin by extrusion molding to form a coating layer.
This method has excellent productivity and stable quality, but as mentioned above, in the case of lining materials that are extensible in the longitudinal and radial directions,
Difficult to process. That is, generally when extrusion molding a coating layer on the surface of a cylindrical fabric, the cylindrical fabric is passed through an extrusion head of an extruder, and the cylindrical fabric is pulled from the front and advanced. A synthetic resin material is extruded onto the surface of the material to form a coating layer. Therefore, in the case of a cylindrical fabric that has extensibility as described above, when the cylindrical fabric is passed through the extrusion head of an extruder, a considerably large tension is applied to the cylindrical fabric, causing it to stretch, resulting in the fabric being unmanufactured. The extensibility of the lining material is impaired. Moreover, since the cylindrical fabric also expands and contracts in the radial direction, it tightens the mandrel fed into the cylindrical fabric during extrusion molding, increasing frictional resistance and causing the cylindrical fabric to stretch excessively.

The present invention has been made in consideration of the above circumstances, and provides a method and apparatus for manufacturing a lining material that can appropriately line a pipeline having a curved pipe, the method and device being an extrusion method. The object of the present invention is to provide a method and apparatus that can prevent tension from acting on a cylindrical fabric during molding and produce a lining material that has sufficient stretchability in the longitudinal and radial directions. be.

Accordingly, the method of the present invention allows the cylindrical fabric to be fed from above and taken down downward to advance at a constant speed while moving through the extrusion head without applying tension to the cylindrical fabric. A cylindrical mandrel tip having an outer diameter approximately equal to or slightly smaller than the inner diameter of the cylindrical fabric is inserted into the cylindrical fabric at the tip of the extrusion head to extrude the cylindrical fabric. held in a cylindrical shape, and extruding a thermoplastic synthetic resin tube having an inner diameter approximately equal to or slightly larger than the outer diameter of the cylindrical fabric from the extrusion head on the outer periphery of the cylindrical fabric; The apparatus of the present invention is characterized in that by reducing the pressure inside the thermoplastic synthetic resin tube, the thermoplastic synthetic resin tube is tightly coated on the outer surface of the cylindrical fabric. An extrusion head capable of extruding a cylindrical thermoplastic synthetic resin tube and having a cavity along its central axis, and a cylindrical fabric placed between the extrusion head and the extrusion head within the cavity at the tip of the extrusion head. a mandrel chip which is arranged with a gap through which the extrusion material can pass, and which is supported by a support means provided above the extrusion head via a rod having a diameter sufficiently smaller than the inner diameter of the cylindrical fabric; A flat molding device that molds the ears of the cylindrical fabric provided at the tip, a suction device that reduces the pressure in the cavity, and a cylindrical fabric provided above the extrusion head that actively moves the cylindrical fabric into the extrusion head. It is characterized by comprising a feeding device for feeding, a cooling device for cooling the cylindrical fabric with a coating layer formed on the outer surface, and a taking device for taking the cylindrical fabric with the coating layer formed on the outer surface. be.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows an embodiment of the apparatus of the present invention.

Reference numeral 6 denotes an extrusion device, and an extrusion head 7 is attached to the tip thereof facing downward. The extrusion head 7 consists of an outer shell 8 and a core 9, with a resin passage 10 formed therebetween.
An annular discharge port 11 is formed at the tip of the tube. Further, a cavity 12 is formed in the center of the core body 9, and a suction member 13 is provided at the rear of the cavity 12. The inner diameter of the tip of the cavity 12 is approximately equal to or slightly larger than the outer diameter of the cylindrical fabric 2.

Reference numeral 14 denotes a mandrel tip, which has a cylindrical shape whose outer diameter is approximately equal to or slightly smaller than the inner diameter of the cylindrical fabric 2, and is placed at the front end of the cavity 12 of the extrusion head 7. It is positioned with a slight gap between it and the inner surface of the cavity 12, and a flat molding device 15 made of a substantially inverted U-shaped chip is attached to its front end.

A rod 16 is also attached to the rear of the mandrel tip 14 and extends rearwardly through the cavity 12 of the extrusion head 7. Rod 1
A holder 17 having a generally cannonball-shaped cross section is attached to the rear end of the holder 6, and a small roller 18 is rotatably supported on both shoulders of the holder 17, and is supported by a support roller 19. .

20 is a feeding device. The feeding device 20
As shown in FIG. 3, a pair of feed rollers 22a and 22b are rotatably supported on a frame 21,
One roller 22a can be brought into contact with and separated from the other roller 22b by a cylinder 23. Therefore, the feeding rollers 22a, 22
Annular grooves 24a and 24b are carved in the center of b, and the rod 16 is inserted into the grooves 24a and 24b.
4b. The feed roller 22
a and 22b are rotated in synchronization with each other by gears 25a and 25b, and are actively driven by a gear 25c coupled to a motor 26.

Reference numeral 27 denotes a preheating furnace, which blows hot air through a hot air blowing port 28 to heat the inside of the preheating furnace.

The suction member 13 has a suction port 27 connected to a vacuum pump 30 to reduce the pressure inside the cavity 12.

A water bath 31 is provided below the extrusion head 7.
A reversing roller 32 is rotatably supported inside. Reference numeral 33 in FIG. 4 is a pump inserted into the water bath 31, and the pump 33 is connected to a pair of water injection nozzles 35 via a water conduit 34. The water injection nozzle 35 is
It is provided opposite both edges of the flat molding device 15, and is designed to spray water toward both edges of the flat molding device 15.

36 is a guide roller, 37 is a take-up device, and each has a pair of rollers 38a, 3.
A pair of endless belts 39 stretched across 8b
a, 39b.

Thus, 2 is a cylindrical fabric. The tubular fabric 2
is wound around a reel 40 in a flat folded state, and is pulled out from the reel 40 and fed from above the device via a guide roller 41. The cylindrical fabric 2 is then placed over the outside of the holder 17, passes between the small roller 18 and the support roller 19, moves downward, and then passes through the feeding device 2.
The cylindrical fabric 2 is held between two feeding rollers 22a and 22b, and by driving the feeding rollers 22a and 22b with a motor 26, the cylindrical fabric 2 is actively fed downward.

The cylindrical fabric 2 first enters the preheating furnace 27, where it is heated by hot air. The tubular fabric 2 is then introduced into the cavity 12 of the extrusion head 7. Further, the cylindrical fabric 2 passes through the cavity 12 of the extrusion head 7, covers the mandrel tip 14 at its lower end, is inflated to a substantially circular cross section, and forms a gap between the mandrel tip 14 and the front end of the extrusion head 7. Proceed downward through the gap.

On the other hand, the thermoplastic synthetic resin extruded from the extruder 6 passes through the resin passage 10 of the extrusion head 7,
At the tip of the extrusion head 7, the thermoplastic synthetic resin tube 42 is extruded from the discharge port 11.

At this time, since the pressure inside the cavity 12 is reduced, the air inside the thermoplastic synthetic resin tube 42 also
The air is sucked through the grains of the cylindrical fabric 2 and the pressure is reduced. Therefore, the thermoplastic synthetic resin tube 42
The diameter shrinks as the internal pressure is reduced. At this time, the thermoplastic synthetic resin tube 42 is still at a high temperature and has plastic deformability immediately after being extruded, so it comes into close contact with the outer surface of the cylindrical fabric 2 and is firmly bonded to the covering layer 3. It forms.

Subsequently, the cylindrical fabric 2 with the coating layer 3 formed on the outer surface, that is, the lining material 1, is coated with a mandrel chip 1.
By the flat molding device 15 fixed to the lower part of 4,
It is expanded into a flat state. Since the inside of the lining material is depressurized as mentioned above, the mandrel tip 1
If the lining material 1 that has passed through 4 is allowed to proceed downward as it is, the lining material 1 will be suddenly crushed by the external pressure and will try to fold flat.
Because the position of the folding ears is not determined, it is difficult to fold it correctly. The flattening device 15 functions to determine the position of the ears so that they are always folded in the correct position.

Further, water is sprayed by the water jet nozzle 35 onto the positions corresponding to both ears molded by the flat molding device 15. Although this step is not necessarily an essential step in the present invention, if the lining material 1 is folded completely flat while the covering layer 3 has plastic deformability, the covering layer 3 at the edges will be stretched. As a result, the coating layer 3 becomes thinner, causing unevenness in the thickness of the coating layer 3, which is undesirable. Therefore, as in this embodiment, it is preferable to spray water onto the positions corresponding to both ears to rapidly cool the coating layer 3 to prevent uneven thickness. Although it is possible to rapidly cool the entire lining material 1, it is not preferable because the adhesive strength between the cylindrical fabric 2 and the covering layer 3 may decrease and the material may peel off during use as a lining material. .

The molded lining material 1 is processed by the flat molding device 1.
5, progresses downward, folds flat,
It enters the water bath 31, where it is completely cooled down sufficiently. Then, the traveling direction is reversed by a reversing roller 32 in the water bath 31, and taken up by a take-up device 37 and wound onto a take-up reel 43.

In the present invention, the cylindrical fabric 2 and the lining material 1 are
It is advanced by the feeding device 20 and the taking-off device 37. It is preferable that the speeds at which both the cylindrical fabric 2 and the lining material 1 are fed and taken off are substantially constant. If the picking-up speed of the lining material 1 by the picking-up device 37 is too fast, the lining material 1
This is not preferable because the cylindrical fabric 2 is elongated, which not only impairs the extensibility of the lining material 1 but also increases the frictional resistance between the cylindrical fabric 2 and the mandrel tip 14 and the flat forming device 15. Conversely, the feeding device 20
If the feeding speed of the cylindrical fabric 2 is high, slack will occur in the cylindrical fabric 2, the advancing speed of the cylindrical fabric passing through the mandrel tip 14 will change, and the coating layer 3
The thickness of the lining material 1 becomes uneven and a uniform lining material 1 cannot be obtained.

In the present invention, while actively feeding the cylindrical fabric 2 into the extrusion head 7 at the rear of the extrusion head 7, the lining material 1 is taken up from the front of the extrusion head 7. Excessive tension is not applied to the lining material 1, and the extensibility of the lining material 1 is not impaired due to elongation during processing. Therefore, the frictional resistance between the mandrel chip 14 and the flat molding device 15 is small, and the tension does not increase. In addition, the extrusion head 7
The thermoplastic synthetic resin tube 42 is extruded from the tip and is pressed onto the outer surface of the cylindrical fabric 2, so that the coating layer 3 is directly molded onto the outer surface of the cylindrical fabric 2 in the extrusion head 7. Unlike the conventional case, it does not become a resistance to the advancement of the cylindrical fabric 2.

As shown in the above description, the present invention is a method and apparatus suitable for manufacturing pipe lining materials.
The present invention is not limited to the lining material for pipes, and can be generally applied to form a synthetic resin coating layer on the outer surface of a cylindrical fabric. for example,
A tubular fabric having a coating layer produced according to the present invention,
By turning the inner and outer surfaces inside out, flexible hoses such as fire hoses can be manufactured.

[Brief explanation of the drawing]

FIG. 1 is a partially exploded perspective view of a lining material manufactured in the present invention. FIG. 2 is a central vertical sectional view showing one embodiment of the device of the present invention. FIG. 3 is a - sectional view in FIG. 2. FIG. 4 is a central vertical sectional view taken along a plane perpendicular to the plane of the paper from the extrusion head 7 to the reversing roller 32 in FIG. DESCRIPTION OF SYMBOLS 1... Lining material, 2... Cylindrical fabric, 3... Covering layer, 7... Extrusion head, 12... Cavity, 13...
...Suction member, 14...Mandrel tip, 15...
... Flat molding device, 16 ... Rod, 17 ... Holder, 18 ... Small roller, 19 ... Support roller, 20 ... Feeding device, 31 ... Water bath, 35 ... Water injection nozzle, 37 ... Taking-off device, 42...Thermoplastic synthetic resin tube.

Claims (1)

[Scope of Claims] 1. A method for extruding a cylindrical fabric by feeding the cylindrical fabric from above and pulling it downward to advance at a constant speed while passing through an extrusion head without applying tension to the cylindrical fabric. At the tip of the head, a cylindrical mandrel tip having an outer diameter approximately equal to or slightly smaller than the inner diameter of the cylindrical fabric is inserted into the cylindrical fabric to hold the cylindrical fabric in a cylindrical shape. However, on the outer periphery of the cylindrical fabric,
A thermoplastic synthetic resin tube having an inner diameter approximately equal to or slightly larger than the outer diameter of the cylindrical fabric is extruded from the extrusion head, and the inside of the thermoplastic synthetic resin tube is reduced in pressure to form the thermoplastic synthetic resin tube. A method for forming an airtight coating layer on the outer surface of a cylindrical fabric, the method comprising closely coating the outer surface of the cylindrical fabric. 2. Forming an airtight covering layer on the outer surface of the cylindrical fabric according to claim 1, wherein the cylindrical fabric has great extensibility in its length direction. Method. 3. Claim 1, characterized in that while the thermoplastic synthetic resin tube still has plastic deformability, only the portion that will become the ear portion when folded flat is rapidly cooled. A method of forming an airtight coating layer on the outer surface of a cylindrical fabric. 4. Between an extrusion head capable of extruding a cylindrical thermoplastic synthetic resin tube in a downward direction and having a cavity formed along its central axis, and the extrusion head in the cavity at the tip of the extrusion head. a mandrel chip arranged with a gap through which the cylindrical fabric can pass, and supported by a support means provided above the extrusion head via a rod having a diameter sufficiently smaller than the inner diameter of the cylindrical fabric; A flat molding device is provided at the tip of the mandrel tip to mold the selvage of the cylindrical fabric, a suction device is provided to reduce the pressure in the cavity, and a cylindrical fabric is provided above the extrusion head into the extrusion head. A feeding device that actively feeds the fabric, a cooling device that cools the cylindrical fabric with a coating layer formed on the outer surface, and a take-up device that takes up the cylindrical fabric with the coating layer formed on the outer surface. An apparatus for forming an airtight coating layer on the outer surface of a cylindrical fabric. 5. The supporting means supports a holder having a generally bullet-shaped cross section attached to the upper end of the rod, a pair of small rollers pivotally supported on the shoulders of the holder, and the small rollers from outside the cylindrical fabric. Claim 4, characterized in that it consists of a support roller.
An apparatus for forming an airtight coating layer on the outer surface of a cylindrical fabric as described in 1. 6. The apparatus for forming an airtight coating layer on the outer surface of a cylindrical fabric according to claim 5, wherein the feeding device is provided below the holder. 7. Claim 4, characterized in that the speed at which the cylindrical fabric is fed by the feeding device and the speed at which the cylindrical fabric is picked up by the take-up device are substantially constant. A device for forming an airtight coating layer on the outer surface of a cylindrical fabric. 8. The device for forming an airtight coating layer on the outer surface of a cylindrical fabric according to claim 4, wherein the flat molding device is a chip having a substantially inverted U shape. 9. The cooling device is characterized by comprising a water bath provided below the extrusion head, and a pair of water injection nozzles provided directly below the extrusion head to face each other with the cylindrical fabric sandwiched between them. do,
An apparatus for forming an airtight coating layer on the outer surface of a cylindrical fabric according to claim 4.