WO2014162827A1

WO2014162827A1 - Method for manufacturing tube and manufacturing device

Info

Publication number: WO2014162827A1
Application number: PCT/JP2014/056221
Authority: WO
Inventors: 福岡徹也; 江畑勝紀
Original assignee: テルモ株式会社
Priority date: 2013-04-01
Filing date: 2014-03-10
Publication date: 2014-10-09
Also published as: JP2016106043A

Abstract

The present invention provides a method for manufacturing a tube and a manufacturing device capable of manufacturing a tube with high dimensional accuracy while enhancing working performance without using a center line. A tube-manufacturing method for extrusion-molding a plastic tube (1), wherein, using a first mold (21) for molding the exterior surface of a tube-shaped inner layer (2) while extruding molten resin and a first mandrel (23) for molding the interior surface of the inner layer (2), the first mandrel (23) being disposed inside the first mold (21) and being insulated from the first mold (21) or cooled. Resin is extruded from a first flow channel (29) formed between the first mold (21) and the first mandrel (23) and the interior surface of the inner layer (2) is cooled by the first mandrel (23), whereby a tube (1) is molded without the provision of a center line to the inside of the inner layer (2).

Description

Tube manufacturing method and manufacturing apparatus

The present invention relates to a method and an apparatus for manufacturing a tube, and more particularly to a method and an apparatus for manufacturing a tube that do not use a core wire.

In recent years, extrusion methods have been widely used in various fields to produce tubular tubes. When manufacturing a tube by the extrusion molding method, a heated and melted resin is continuously extruded from the mold on the core wire that moves through the mold, and the core wire is pulled out after the resin is solidified. Then, a resin tube is manufactured (see, for example, Patent Document 1).

For tubes that do not require high dimensional accuracy, such as rubber hoses, a method is also used in which a resin melted by heating and melting is continuously extruded from a mold into a tubular shape without using a core wire (for example, Patent Document 2, Patent). Reference 3).

JP 2008-183226 A JP 2010-131754 A JP-A-6-64062

As described above in

Patent Documents

2 and 3, the method using no core wire has high workability because there is no step of removing the core wire, but it is difficult to obtain high dimensional accuracy. Further, in the method using the core wire as in Patent Document 1, high dimensional accuracy can be obtained, but since the core wire needs to be finally pulled out, workability is lowered.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a tube manufacturing method and a manufacturing apparatus capable of manufacturing a tube with high dimensional accuracy while improving workability without using a core wire. And

A tube manufacturing method for achieving the above object is a tube manufacturing method for forming a resin tube by extrusion molding, and a mold for molding the outer surface of a tubular resin layer while extruding a molten resin, And a mandrel that is disposed inside the mold and is insulated or cooled from the mold to mold the inner surface of the resin layer, and from the flow path formed between the mold and the mandrel In this manufacturing method, the resin is extruded, the inner surface of the resin layer is cooled by the mandrel, and the tube is formed without providing a core wire inside the resin layer.

Further, a tube manufacturing apparatus that achieves the above object is a tube manufacturing apparatus for forming a resin tube by extrusion molding, and is a metal for forming the outer surface of a tubular resin layer while extruding molten resin. A manufacturing apparatus that includes a mold and a mandrel that is insulated or cooled from the mold and molds the inner surface of the resin layer, and molds the tube without providing a core wire inside the resin layer.

In the tube manufacturing method and manufacturing apparatus configured as described above, since the tube is formed using a cooled or heat-insulated mandrel, the inner surface of the resin layer extruded into a tubular shape is quickly cooled by the mandrel and easily solidifies. Thus, the tube can be manufactured with high dimensional accuracy while improving workability without using a core wire.

If the mandrel has a heat insulating member provided so that at least part of the mandrel protrudes more in the extrusion direction than the mold, the mandrel exposed from the mold is effectively insulated from the mold and maintained at a low temperature. Thus, the resin layer in contact with the mandrel can be cooled.

If the mandrel has a cooling mechanism that can be cooled, the mandrel can be actively cooled to cool the resin layer more effectively.

The cooling effect of the mandrel can be further enhanced if at least a part of the cooling mechanism is provided so as to protrude from the mold toward the extrusion direction.

If the reinforcing body is braided on the outer surface side of the resin layer molded by the mold and mandrel, when braiding the reinforcing body, at least the inner surface of the resin layer is solidified or cured, Even without a core wire, the shape of the resin layer can be maintained satisfactorily.

If the second resin layer is extruded on the outer surface side of the resin layer formed by the mold and mandrel, at least the inner surface of the resin layer is solidified when the second resin layer is formed. Or since it is hardened | cured, even if there is no core wire, the influence of the heat from a 2nd resin layer can be reduced as much as possible, and the shape of a resin layer can be maintained favorable.

It is the schematic which shows the manufacturing apparatus of the tube which concerns on this embodiment. It is a schematic sectional drawing which shows a 1st extrusion molding machine. It is a schematic sectional drawing which shows the tube manufactured. It is a schematic sectional drawing which shows the modification of a 1st extrusion molding machine. It is a schematic sectional drawing which shows the other modification of a 1st extrusion molding machine. It is a schematic sectional drawing which shows the further another modification of a 1st extrusion molding machine. It is a schematic sectional drawing which shows the further another modification of a 1st extrusion molding machine.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

The tube manufacturing apparatus 10 according to this embodiment manufactures the tube 1 by extruding resin without using a core wire. As shown in FIG. 3, the tube 1 manufactured in the present embodiment includes an inner layer 2 (resin layer) constituting the innermost layer, a reinforcing body 3 formed for the purpose of reinforcement outside the inner layer 2, and a reinforcing body. 3 is provided with an outer layer 4 (second resin layer) covering the outer side of 3. In addition, although the manufactured tube 1 can be applied suitably for medical instruments, such as a catheter, a use is not limited to medical use.

As shown in FIG. 1, the manufacturing apparatus 10 includes a first extruder 20 that forms the inner layer 2 by extruding a heat-melted resin into a tubular shape, and a braiding machine 30 that braces the reinforcing body 3 on the outer surface of the inner layer 2. The second extruder 40 for forming the outer layer 4 by extruding a separate resin into a tubular shape on the outer surface of the reinforcing body 3, the cooling device 50 for cooling the formed tube 1, and the take-up machine 60 for taking up the tube 1. And a winder 70 that winds up the tube 1. The first extruder 20, the braiding machine 30, the second extruder 40, the cooling device 50, the take-up machine 60, and the winder 70 are arranged side by side in the tube 1 extrusion direction.

As shown in FIG. 2, the first extruder 20 includes a first mold 21 that extrudes while heating the resin, a first extruder 22 that sends out the resin melted by a screw or the like into the first mold 21, A tubular first mandrel 23 which is disposed inside the first mold 21 and molds the inner surface of the resin.

The first mold 21 includes a tubular die 24 for forming the outer surface of the tubular inner layer 2 to be pushed out while accommodating the resin inside and guiding the resin, a heater for heating the resin, and the like. Heating means 25. The die 24 is configured by connecting a plurality of

members

24A, 24B, and 24C arranged in the extrusion direction in which resin is extruded, for example, by screwing. The heating means 25 is disposed so as to cover the outer periphery of the die 24.

The first mandrel 23 is disposed inside the die 24, forms a first flow path 29 that flows while the resin is accommodated between the first mandrel 23, and shapes the inner surface of the extruded tubular inner layer 2. The first mandrel 23 includes a first base end member 26A, a second base end member 26B, a heat insulating member 27, and a front end member 28 arranged in the extrusion direction.

26 A of 1st base end members and the 2nd base end member 26B are arrange | positioned inside the 1st metal mold | die 21, The base end side (opposite direction of extrusion) of the 1st base end member 26A is the 1st metal mold | die 21. It is fixed to. The heat insulating member 27 has a base end screwed into and connected to the second base end member 26B, and is formed of a member having a higher heat insulating effect than the second base end member 26B. The distal end member 28 is connected to the proximal end side by screwing a heat insulating member 27.

The first mandrel 23 is formed so as to reduce in diameter toward the extrusion direction as a whole. The first mandrel 23 is arranged such that at least a part of the heat insulating member 27 and the tip member 28 protrude in the extrusion direction from the first mold 21. The heat insulating member 27 plays a role of suppressing heat transfer from the first mold 21 to the tip member 28.

In the present embodiment, the distal end side of the first mandrel 23 is reduced in diameter from the heat insulating member 27, but the portion to be reduced in diameter is not limited to this. For example, the proximal end side of the heat insulating member 27 is reduced in size. The diameter may be reduced, or the diameter may be reduced by the tip member 28 on the extrusion direction side of the heat insulating member 27. Further, the first mandrel 23 may not be reduced in diameter in the extrusion direction.

As the material of the first mold 21, the first base end member 26A, the second base end member 26B, and the front end member 28, for example, stainless steel or the like can be applied.

The heat insulating member 27 is made of a material having a heat insulating effect higher than that of the second base end member 26B to which the heat insulating member 27 is connected. For example, a resin material such as a fluorine-based resin, ceramic, a foam thereof, or the like can be applied.

As shown in FIG. 1, the braiding machine 30 continuously applies the strands, which are the reinforcing bodies 3, with a braid having a predetermined interstitial distance on the outer surface of the inner layer 2 extruded in a tubular shape from the first extruder 20. It is a wrapping device. In addition, the reinforcing body 3 composed of the strands may be wound around the core wire while changing the winding direction, such as horizontal winding in the same direction, right-hand winding, left-hand winding, etc., and the winding pitch, interstitial distance, circumferential direction The inclination angle with respect to the angle may be changed depending on the position, and the configuration is not particularly limited.

The strands used for the reinforcing body 3 can be platinum (Pt) / tungsten (W), stainless steel, Ni—Ti, or other metal wires, resin fibers, carbon fibers, glass fibers, or the like. Two or more may be used together.

The second extrusion molding machine 40 extrudes a resin layer to be the outer layer 4 on the outer surface of the reinforcing body 3 in a tubular shape, a second mold 41 that extrudes while heating the resin, and a resin melted by a screw or the like. And a second mandrel 43 which is disposed inside the second mold 41 and forms the inner surface of the outer layer 4. . Inside the second mandrel 43, a tubular body in which the reinforcing body 3 is braided on the inner layer 2 is inserted. The resin is pushed out from the second flow path 44 formed between the second mold 41 and the second mandrel 43, and is coated on the outer surface of the tubular body in which the reinforcing body 3 is braided on the inner layer 2.

The cooling device 50 is a device that cools and solidifies the resin extruded from the first extruder 20 and the second extruder 40. The structure of the cooling device 50 is not particularly limited, and water cooling, air cooling, or the like can be applied.

The take-up machine 60 includes a roller 61 (or a rotating belt) that is rotated by a driving source such as a motor, and can continuously take up the cooled and solidified tube 1.

The winder 70 is rotated by a driving source such as a motor and can continuously wind up and collect the solidified tube 1.

The resin that is extruded by the first extruder 20 to form the inner layer 2 is not particularly limited as long as it is an extrudable resin, and preferred examples include polyethylene, polyamide-based polymer, and polyester-based polymer.

The resin that is extruded by the second extruder 40 to form the outer layer 4 is not particularly limited as long as it is an extrudable resin. For example, polyolefin (for example, polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene -Vinyl acetate copolymer, ionomer, or a mixture of two or more thereof, etc.), polyvinyl chloride, polyamide, polyester elastomer, polyamide elastomer, polyurethane, polyurethane elastomer, polyimide, fluororesin, or other polymer materials or mixtures thereof The thermoplastic resin can be applied. Preferable examples of the resin forming the outer layer 4 include polyethylene, polyamide polymer, and polyester polymer.

Next, a method for manufacturing the tube 1 will be described.

First, in the first extrusion molding machine 20, the heat-melted resin is moved into the first mold 21 by the first extrusion machine 22. The resin that has moved into the first mold 21 is pushed out of the first mold 21 through the first flow path 29 between the die 24 and the second mandrel 43 to form the tubular inner layer 2. At this time, at least a part of the heat insulating member 27 and the tip member 28 are arranged so as to protrude in the extrusion direction from the first mold 21, and the heat from the first mold 21 to the tip member 28 is absorbed by the heat insulating member 27. Since the transmission is suppressed, the temperature of the tip member 28 is lower than the case where the first mandrel 23 is not provided with the heat insulating member 27. For this reason, the resin that has come into contact with the heat insulating member 27 and the tip member 28 is cooled to be solidified, and is in a solidified state or a state in which the temperature is lowered and hardened without being completely solidified. The resin whose temperature is lowered and solidified is further pushed out in the extruding direction and separated from the first mandrel 23 to form the inner layer 2. Since the solidified or cured resin is not easily deformed, the tubular inner layer 2 with high dimensional accuracy can be formed without using a core wire. In particular, when a resin having a low melting point and difficult to solidify unless cooling is applied to the inner layer 2, a great effect is exhibited.

Next, strands are braided on the outer surface of the formed inner layer 2 by a braiding machine 30 to form the reinforcing body 3. The reinforcing body 3 is formed on the outer surface of the inner layer 2 or in a state where the strands have digged into the outer surface of the inner layer 2. At this time, since at least the inner surface of the inner layer 2 is solidified or cured, the deformation of the inner layer 2 by the reinforcing body 3 is suppressed and the shape of the inner layer 2 can be maintained well even without a core wire.

Next, in the second extruder 40, the heat-melted resin is moved into the second mold 41 by the second extruder 42, and the second flow between the second mold 41 and the second mandrel 43 is moved. Resin is pushed out from the path 44. Thereby, the outer layer 4 is formed by extruding and coating the resin on the outer surfaces of the inner layer 2 and the reinforcing body 3. At this time, since at least the inner surface of the inner layer 2 is solidified or hardened, even if the molten resin that becomes the outer layer 4 is coated, the influence of heat from the outer layer 4 received by the inner layer 2 is reduced as much as possible. The shape of can be maintained well.

Thereafter, the cooling device 50 cools the tubular body constituted by the inner layer 2, the reinforcing body 3 and the outer layer 4 to solidify all the resin, and the manufacture of the tube 1 is completed. The tube 1 moves while being continuously taken up by the take-up machine 60, and is collected by the winder 70. Alternatively, it is possible to cut the tube 1 in a straight line without winding.

As described above, according to the present embodiment, the first mold 21 (mold) that molds the outer surface of the inner layer 2 (resin layer) while extruding the molten resin, and the inner side of the first mold 21 are arranged. And a first mandrel 23 (mandrel) that is insulated from the first mold 21 and forms the inner surface of the inner layer 2, and is formed between the first mold 21 and the first mandrel 23. Resin is extruded from the flow path 29, the inner surface of the inner layer 2 is cooled by the first mandrel 23, and the tube 1 is formed without providing a core wire inside the extruded inner layer 2. Therefore, since the inner surface of the inner layer 2 extruded into a tubular shape is rapidly cooled and solidified by the first mandrel 23, or is not completely solidified, the temperature is lowered and cured, so that no core wire is used. In addition, the tube 1 can be manufactured with high dimensional accuracy while improving workability.

In addition, since the first mandrel 23 has a heat insulating member 27 that is provided so that at least part of the first mandrel 23 protrudes more in the extrusion direction than the first mold 21, the first mandrel 23 exposed from the first mold 21 is the first mold. The inner layer 2 can be cooled while being effectively insulated from the mold 21 and maintained at a low temperature.

In this embodiment, when braiding the reinforcing body 3 on the outer surface side of the inner layer 2 (resin layer) formed by the first mold 21 and the first mandrel 23, at least the inner surface of the inner layer 2 is solidified or Since it is cured, the shape of the inner layer 2 can be maintained well without using a core wire.

Further, when the outer layer 4 (second resin layer) is extruded on the outer surface side of the inner layer 2 (resin layer) formed by the first mold 21 and the first mandrel 23, at least the inner surface of the inner layer 2 is Since it is solidified or hardened, the shape of the inner layer 2 can be favorably maintained by reducing the influence of heat from the outer layer 4 received by the inner layer 2 as much as possible without using a core wire.

Note that the present invention is not limited to the above-described embodiment, and various modifications can be made by those skilled in the art within the technical idea of the present invention. For example, in the present embodiment, the distal end member 28 is completely insulated by the heat insulating member 27 without contacting the second proximal end member 26B disposed in the first mold 21, but is shown in FIG. As described above, the heat insulating member 82 may be partially provided between the distal end member 81 and the second base end member 26B to be partially insulated. In addition, the same code | symbol is attached | subjected to the site | part which has the function similar to the above-mentioned structure, and description is abbreviate | omitted.

Further, as shown in FIG. 5, a cooling mechanism 92 that can actively cool the tip member 91 may be provided instead of the heat insulating member. The cooling mechanism 92 is connected to a refrigerant supply means 93 provided outside the first mold 21 through a supply pipe 94 and a discharge pipe 95. A flow path 96 through which a refrigerant can flow is formed inside the cooling mechanism 92, and after the refrigerant supplied from the supply pipe 94 flows through the flow path 96 and cools the tip member 91 of the first mandrel 90. The refrigerant is discharged from the discharge pipe 95. The refrigerant supply means 93 is provided with a heat exchanger or the like, and can cool the refrigerant collected from the discharge pipe 95 and supply it to the supply pipe 94 again. The refrigerant is not particularly limited, and water, air, silicone oil, Freon, fluorine oil, or the like can be applied. By providing the cooling mechanism 92, it is possible to arbitrarily adjust the temperature at which the extruded resin is cooled, and effective cooling is possible. The cooling temperature can be appropriately set depending on the resin to be applied, and is preferably lower than the melting point of the resin by 100 ° C. or more.

In addition, since the cooling mechanism 92 is provided so that at least part of the cooling mechanism 92 protrudes more in the extrusion direction than the first mold 21, the effect of cooling the first mandrel 90 can be further enhanced. The cooling mechanism 92 exerts a great effect particularly when a resin having a low melting point and difficult to solidify unless cooling is applied to the inner layer 2. In addition, since the cooling mechanism 92 can be actively cooled from the outside, it can also be provided in the first mold 21.

Further, as shown in FIG. 6, both the heat insulating member 101 and the cooling mechanism 102 may be provided in the first mandrel 100. If the cooling mechanism 102 is provided in the extrusion direction as compared with the heat insulating member 101, the cooling effect by the cooling mechanism 102 becomes more effective. The cooling mechanism 102 can have the same configuration as the cooling mechanism 92 described with reference to FIG.

Further, as shown in FIG. 7, the first mandrel 110 may be electrically cooled by a Peltier element 113 (cooling mechanism) including a heat absorbing plate 111 and a heat radiating plate 112. The Peltier element 113 can absorb the heat by the heat absorption plate 111 and can radiate the heat by the heat radiating plate 112 by passing a current through the electric wire 114. In order to efficiently cool the heat radiating plate 112 of the Peltier element 113, it is preferable to provide a cooling means 115. A configuration similar to the cooling mechanism 92 described with reference to FIG.

Further, the cross-sectional shape of the tube to be molded does not have to be circular, but can be arbitrarily set, and may be, for example, elliptical, semicircular, polygonal, or the like. In this embodiment, only one passage is formed by the first mandrel 23 inside the tube 1, but a plurality of mandrels are provided in the first extruder so that a plurality of passages are provided. May be. In this case, a heat insulating member and a cooling mechanism can be provided in each of the plurality of mandrels.

Further, the tip member may be constituted by the heat insulating member or the cooling mechanism without providing the tip member on the tip side of the heat insulating member or the cooling mechanism of the first mandrel. Further, at least one of the reinforcing body and the outer layer may not be provided in the manufactured tube.

Furthermore, this application is based on Japanese Patent Application No. 2013-075611 filed on April 1, 2013, the disclosures of which are referenced and incorporated as a whole.

1 tube,
2 Inner layer (resin layer),
3 Reinforcing body,
4 outer layer (second resin layer),
10 Production equipment,
21 First mold (mold),
23, 90, 100, 110 First mandrel (mandrel),
27, 82, 101 heat insulation member,
29 1st flow path (flow path),
40 Second extrusion molding machine,
91 tip member,
92, 102 cooling mechanism,
113 Peltier element (cooling mechanism).

Claims

A method of manufacturing a tube for forming a resin tube by extrusion molding,
A mold that molds the outer surface of the tubular resin layer while extruding molten resin, and a mandrel that is disposed inside the mold and is insulated or cooled from the mold to mold the inner surface of the resin layer. The tube is formed without extruding the resin from a flow path formed between the mold and the mandrel to cool the inner surface of the resin layer by the mandrel, and without providing a core wire inside the resin layer. A method of manufacturing a tube for forming a tube.
2. The method of manufacturing a tube according to claim 1, wherein the mandrel has a heat insulating member that is provided so that at least a part of the mandrel protrudes toward the extrusion direction from the mold.
The method of manufacturing a tube according to claim 1 or 2, wherein the mandrel has a cooling mechanism capable of being cooled.
The method for manufacturing a tube according to claim 3, wherein at least a part of the cooling mechanism is provided so as to protrude from the mold toward the extrusion direction.
The method for producing a tube according to any one of claims 1 to 4, wherein a reinforcing body is braided on an outer surface side of the resin layer formed by the mold and a mandrel.
The method for producing a tube according to any one of claims 1 to 5, wherein a second resin layer is extruded on the outer surface side of the resin layer formed by the mold and mandrel.
A tube manufacturing apparatus for forming a resin tube by extrusion molding,
A mold for molding the outer surface of the tubular resin layer while extruding molten resin;
A mandrel that is insulated or cooled from the mold to mold the inner surface of the resin layer,
A tube manufacturing apparatus for forming the tube without providing a core wire inside the resin layer.
The tube manufacturing apparatus according to claim 7, wherein the mandrel includes a heat insulating member provided so that at least a part thereof protrudes more toward the extrusion direction than the mold.
The tube manufacturing apparatus according to claim 7 or 8, wherein the mandrel has a cooling mechanism capable of being cooled.
The tube manufacturing apparatus according to claim 9, wherein at least a part of the cooling mechanism is provided so as to protrude from the mold toward the extrusion direction.
The tube manufacturing apparatus according to any one of claims 7 to 10, further comprising a braiding machine for braiding a reinforcing body on an outer surface side of the resin layer formed by the mold and a mandrel.
The tube according to any one of claims 7 to 11, further comprising a second extruder for extruding a second resin layer on an outer surface side of the resin layer formed by the mold and the mandrel. Manufacturing equipment.