JP2017202615A - Extrusion molding apparatus and method for producing tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extrusion molding apparatus which can thicken a resin layer partitioning a space between flow channels while keeping a thickness of a resin layer between an outer face of a tube and the flow channel, and a method for producing a tube.SOLUTION: The extrusion molding apparatus comprises: a die having a first flow channel which forms an outer face of a tube and flows a resin forming a first resin layer between the outer face and the flow channel therethrough, and a second flow channel which is inside of the first resin layer in a cross section perpendicular to a direction where the resin flows and through which a resin forming a second resin layer between the flow channels flows; one resin supply section which supplies the resin to the first flow channel and the second flow channel; and a resin adjustment section which adjusts a first temperature being a temperature of the resin flowing through the first flow channel in a downstream side end of the die and a second temperature being a temperature of the resin flowing through the second flow channel, the resin adjustment section adjusting the temperature of the resin in such a way that the temperature becomes a temperature equal to or higher than the melting temperature of the resin and equal to or lower than a thermal decomposition temperature, and the second temperature becomes higher than the first temperature.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an extrusion apparatus for manufacturing a tube having at least two flow paths and a method for manufacturing the tube.

  Tubes that are inserted into tubular organs such as blood vessels, gastrointestinal tracts, ureters, or body tissues and that send or collect fluid are known. Patent Document 1 discloses a medical tube having a plurality of flow paths (lumens). In a tube having a plurality of flow paths, when an internal pressure is applied to one flow path, the resin layer separating the flow paths is deformed, blocking other flow paths or reducing the cross-sectional area. Malfunction may occur. Such a defect makes it difficult, for example, to inject and suck a necessary amount of liquid and to insert an instrument. Therefore, there is a demand to increase the thickness of the resin layer that separates the flow paths from each other and suppress deformation.

JP 2008-92969 A

  However, it is costly to change the mold that increases the gap between the portions that form the resin layer separating the flow channels. Simply increasing the amount of resin discharged from the extruder to the mold tends to increase the thickness of the resin layer between the outer surface of the tube and the flow path, and separates the flow path from the flow path. It is difficult to increase the thickness of the resin layer.

  Therefore, an object of the present invention is to manufacture a tube having at least two flow paths, while maintaining the thickness of the resin layer between the outer surface of the tube and the flow paths, between the flow paths and the flow paths. An object of the present invention is to provide an extrusion molding apparatus and a method for producing a tube, in which a separating resin layer can be thickened.

  The extrusion molding apparatus of the present invention is an extrusion molding apparatus for producing a resin tube having at least two flow paths, and forms an outer surface of the tube and a first resin layer between the outer surface and the flow path. A first flow path through which the resin to be formed flows, and a second flow through which the resin forming the second resin layer between the flow paths and the flow paths is inside the first resin layer in a cross section orthogonal to the direction in which the resin flows. A mold having a flow path, one resin supply section for supplying resin to the first flow path and the second flow path, and a temperature of the resin flowing in the first flow path at the downstream end of the mold. A resin adjustment unit that adjusts the temperature and a second temperature that is the temperature of the resin flowing in the second flow path, and the resin adjustment unit is a temperature not lower than the melting temperature of the resin and not higher than the thermal decomposition temperature, The temperature of the resin is adjusted so that the second temperature is higher than the first temperature.

  The tube manufacturing method of the present invention is a method of manufacturing a resin tube having at least two flow paths, and forms the outer surface of the tube and forms the first resin layer between the outer surface and the flow path. A first flow path through which the resin flows and a second flow path through which the resin forming the second resin layer between the flow path and the flow path is inside the first resin layer in a cross section orthogonal to the direction in which the resin flows. And a step of supplying resin from a single resin supply unit to a mold having a first temperature and a temperature of the resin flowing in the first flow path at the downstream end of the mold. And a step of adjusting the temperature of the resin so that the second temperature is higher than the first temperature when the temperature is set to the second temperature.

  In the extrusion molding apparatus and the tube manufacturing method, the temperature of the resin flowing through the second flow path is higher than the resin flowing through the first flow path at the downstream end of the mold, that is, the portion where the resin is extruded from the mold. Therefore, the melt viscosity of the resin flowing through the second flow path is lower than that of the resin flowing through the first flow path. This increases the discharge amount (the amount of resin flowing through the cross section) of the mold part forming the second flow path compared to the mold part forming the first flow path, so the thickness of the second resin layer compared to the first resin layer. It becomes easy to increase the amount. As a result, in manufacturing a tube having at least two flow paths, the resin layer that separates the flow paths from each other is made thicker while maintaining the thickness of the resin layer between the outer surface of the tube and the flow paths. can do. Here, the upstream side and the downstream side refer to the upstream side and the downstream side in the direction in which the resin flows in the extrusion molding apparatus.

  The resin adjusting unit may set the temperature difference between the first temperature and the second temperature to 5 ° C. or more and 50 ° C. or less.

  The extrusion molding apparatus of the present invention is an extrusion molding apparatus for producing a resin tube having at least two flow paths, and forms an outer surface of the tube and a first resin layer between the outer surface and the flow path. A first flow path through which the resin to be formed flows, and a second flow through which the resin forming the second resin layer between the flow paths and the flow paths is inside the first resin layer in a cross section orthogonal to the direction in which the resin flows. A mold having a flow path, one resin supply section for supplying resin to the first flow path and the second flow path, and a melt viscosity of the resin flowing into the first flow path at the downstream end of the mold. A resin adjusting unit that adjusts the first viscosity and a second viscosity that is a melt viscosity of the resin flowing in the second flow path, and the resin adjusting unit has a lower second viscosity than the first viscosity. Adjust the melt viscosity of the resin.

  The tube manufacturing method of the present invention is a method of manufacturing a resin tube having at least two flow paths, and forms the outer surface of the tube and forms the first resin layer between the outer surface and the flow path. A first flow path through which the resin flows and a second flow path through which the resin forming the second resin layer between the flow path and the flow path is inside the first resin layer in a cross section orthogonal to the direction in which the resin flows. And a step of supplying the resin from one resin supply section to the mold having the first viscosity and the resin flowing in the second flow path at the downstream end of the mold. And adjusting the melt viscosity of the resin so that the second viscosity is lower than the first viscosity.

  In the extrusion apparatus and the tube manufacturing method, the melt viscosity of the resin flowing through the second flow path is lower than the resin flowing through the first flow path at the downstream end of the mold, that is, the portion where the resin is extruded from the mold. Lower. This increases the discharge amount (the amount of resin flowing through the cross section) of the mold part forming the second flow path compared to the mold part forming the first flow path, so the thickness of the second resin layer compared to the first resin layer. It becomes easy to increase the amount. As a result, in manufacturing a tube having at least two flow paths, the resin layer that separates the flow paths from each other is made thicker while maintaining the thickness of the resin layer between the outer surface of the tube and the flow paths. can do.

  The resin adjusting unit may set the difference in melt viscosity between the first viscosity and the second viscosity to 1 g / 10 min or more and 50 g / 10 min or less.

  The mold has a first mold part having a first flow path and a second flow path, and a second mold part having a third flow path for supplying resin to the first flow path and the second flow path. The resin adjustment unit includes a first heater disposed outside the third flow path in the second mold part, and a second heater disposed outside the first flow path in the first mold part. The heating amount of the first heater may be larger than the heating amount of the second heater. In the extrusion molding apparatus, the temperature of the resin flowing through the first flow path can be made higher than the temperature of the resin flowing through the second flow path with an easy configuration.

  The first heater is set so that the temperature of the second mold part heated by the first heater is higher than the temperature of the first mold part heated by the second heater in a range of 5 ° C. or more and 50 ° C. or less. The heating amount of the second heater may be set. In the above extrusion molding apparatus, a sufficient melt viscosity difference can be generated between the melt viscosity of the resin flowing in the first flow path and the melt viscosity of the resin flowing in the second flow path. The thickness of the resin layer separating the flow path can be increased while maintaining the thickness of the first resin layer between the flow path and the flow path.

  Even if the heating amounts of the first heater and the second heater are set such that the difference in melt viscosity between the resin flowing through the third flow path and the resin flowing through the first flow path is 1 g / 10 min to 50 g / 10 min. Good. In the above extrusion molding apparatus, a sufficient melt viscosity difference can be generated between the melt viscosity of the resin flowing in the first flow path and the melt viscosity of the resin flowing in the second flow path. The thickness of the resin layer separating the flow path can be increased while maintaining the thickness of the first resin layer between the flow path and the flow path.

  The resin may include at least one selected from polyamide resin, polyamide elastomer, polyurethane resin, polyether resin, polyester resin, polyimide resin, and polyethylene resin.

  The resin may include either a polyamide resin or a polyamide elastomer.

  The tube may have two flow paths. In the extrusion molding apparatus, it is possible to increase the thickness of the resin layer separating the flow path and the flow path while maintaining the thickness of the resin layer between the outer surface of the tube and the flow path.

  The tube may be a medical tube. In the above extrusion molding apparatus, it is possible to manufacture a medical tube having a thick resin layer separating the flow path and the flow path while maintaining the thickness of the resin layer between the outer surface of the tube and the flow path. .

  The tube may be a catheter tube. In the extrusion molding apparatus, it is possible to manufacture a catheter tube having a thick resin layer separating the flow path and the flow path while maintaining the thickness of the resin layer between the outer surface of the tube and the flow path. .

  ADVANTAGE OF THE INVENTION According to this invention, the resin layer which separates between a flow path and a flow path can be thickened, maintaining the thickness of the resin layer between the external surface of a tube, and a flow path.

It is an example of the medical tube manufactured with the extrusion molding apparatus concerning this embodiment. It is sectional drawing when cut along the flow direction of resin in the extrusion molding device of one embodiment. It is the front view which looked at the extrusion molding apparatus of FIG. 2 from the downstream end side in the resin flow direction. (A) It is a perspective view which shows the point contained in FIG. (B) It is the front view which looked at the edge part side. It is the perspective view which decomposed | disassembled and showed some components of the extrusion molding apparatus of FIG. It is an example of the medical tube manufactured with the extrusion molding apparatus which concerns on a modification. (A) It is a figure for demonstrating the cross section of the metal mold | die used for the Example and the comparative example. (B) It is a figure for demonstrating the dimension of the tube manufactured by the Example and the comparative example.

  Hereinafter, a resin tube 1 for medical use (hereinafter simply referred to as “tube 1”) having two lumens (flow channels) manufactured by an extrusion molding apparatus 10 according to an embodiment will be described with reference to the drawings. . In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In the following description, in the flow path through which the resin flows, the side to which the resin is supplied (extruder 90 side) is referred to as the upstream side, and the side from which the resin is extruded (the tip 11a side of the mold 11) is the downstream side. That's it.

  As shown in FIG. 1, the tube 1 includes a first lumen (flow path) 3, a second lumen (flow path) 4, a first resin layer 6, and a second resin layer 7. .

  The first lumen 3 is formed by an inner peripheral surface 3a having a substantially circular shape when viewed from the flow path direction. The second lumen 4 has an inner peripheral surface 4a as a portion along the inner peripheral surface 3a of the first lumen 3 and an inner peripheral surface 4b as a portion along the outer surface 1a of the tube 1 when viewed from the flow path direction. ,have. The second lumen 4 has a so-called crescent-shaped inner peripheral surface as viewed from the flow path direction. The first lumen 3 and the second lumen 4 are formed by being surrounded by the first resin layer 6 and the second resin layer 7.

  The first resin layer 6 forms the outer surface 1 a of the tube 1 and forms a resin layer between the outer surface 1 a and the inner peripheral surface 3 a of the first lumen 3 or the inner peripheral surface 4 b of the second lumen 4. The first resin layer 6 is formed of a resin material. Examples of the resin material include at least one selected from polyamide resin, polyamide elastomer, polyurethane resin, polyether resin, polyester resin, polyimide resin, and polyethylene resin. For example, the first resin layer 6 can be either a polyamide resin or a polyamide elastomer.

  The second resin layer 7 forms a resin layer between the first lumen 3 and the second lumen 4. In other words, the second resin layer 7 is a partition wall that separates the first lumen 3 and the second lumen 4. More specifically, the second resin layer 7 forms a resin portion between the inner peripheral surface 3 a of the first lumen 3 and the inner peripheral surface 4 a of the second lumen 4. The first resin layer 6 is formed of a resin material. Examples of the resin material include at least one selected from polyamide resin, polyamide elastomer, polyurethane resin, polyether resin, polyester resin, polyimide resin, and polyethylene resin. For example, the first resin layer 6 can be either a polyamide resin or a polyamide elastomer. The first resin layer 6 and the second resin layer 7 are formed of the same resin material.

  Next, the extrusion molding apparatus 10 used when manufacturing the tube 1 mentioned above is demonstrated. The configuration and operation of the extrusion molding apparatus 10 will be described with reference to FIGS. The extrusion molding apparatus 10 according to the present embodiment includes a tube 1 having two lumens of a first lumen 3 and a second lumen 4 by a resin continuously supplied from one extruder (resin supply unit) 90. To manufacture. As shown in FIG. 2, the extrusion molding apparatus 10 includes an extruder 90, a die box 20 as a mold 11, a mandrel 30, a point 40 and an outer die 50, a fixture 71, and a first heater (resin adjustment Part) 61 and a second heater (resin adjusting part) 65.

  The extruder 90 supplies resin to the mold 11 described in detail later. The extruder 90 is a well-known single-screw extruder that uses a screw or the like that can be rotationally controlled as an element part. The extruder 90 generally adjusts the amount of the resin material supplied to the mold 11 by controlling the screw and / or valve.

  The die box 20 is a rectangular parallelepiped mold part formed of a material having excellent thermal conductivity such as stainless steel, chromium molybdenum steel, and cemented carbide. As shown in FIG. 2, the die box 20 has a rectangular parallelepiped main body 21. A through-hole 23, a forward projecting portion 25, and a resin supply hole 27 are formed in the main body portion 21. The main body 21 has a side surface 21a and a side surface 21b that face each other. Hereinafter, for convenience of explanation, a direction in which the side surface 21a and the side surface 21b face each other is referred to as a front-rear direction A. Hereinafter, the side surface 21a is referred to as “rear surface 21a” and the side surface 21b is referred to as “front surface 21b”.

  The through hole 23 is a tapered hole that penetrates the rear surface 21a and the front surface 21b. The through hole 23 is formed so that the cross-sectional area gradually decreases from the rear surface 21a toward the front surface 21b. As shown in FIG. 5, the mandrel 30 is inserted into the through hole 23 from the rear surface 21 a side. The front protrusion 25 is an annular portion that protrudes forward from the front surface 21b. The inner diameter of the front protrusion 25 matches the inner diameter of the through hole 23. The resin supply hole 27 is a hole that communicates from the side surface 21 c orthogonal to the rear surface 21 a and the front surface 21 b to the through hole 23. The resin supply hole 27 is connected to the extruder 90 via the flow path 91, and supplies the resin supplied from the extruder 90 to the mold 11.

  The mandrel 30 is inserted into the through hole 23 of the die box 20 to form a part of the mold 11 (second mold part). The mandrel 30 is a mold part that guides the resin forming the first resin layer 6 (see FIG. 1) and the second resin layer 7 (see FIG. 1) in the tube 1 to the downstream side of the mold 11 in the front-rear direction A. Yes, it is made of a material having excellent thermal conductivity, such as stainless steel, chromium molybdenum steel and cemented carbide. The mandrel 30 includes a resin guiding portion 33, an insertion portion 37, and a fixing portion 39.

  The resin guiding portion 33 is configured by an outer peripheral surface 33a that tapers toward the front surface 21b in the front-rear direction A. A resin guiding groove or the like may be formed on the outer peripheral surface 33a. The interpolating portion 37 is an internal space portion into which a point 40 described in detail later is inserted, and penetrates the mandrel 30 in the front-rear direction A. The fixing portion 39 has a size and shape as viewed from the front-rear direction A larger than the through hole 23 in the die box 20 and is fixed to the rear surface 21a of the die box 20. The fixing portion 39 is fixed to the rear surface 21a of the die box 20 with, for example, a bolt (not shown).

  As shown in FIG. 5, the mandrel 30 is inserted from the rear surface 21 a side in the through hole 23 of the die box 20 to form a part of the mold 11. A gap is formed between the inner peripheral surface 23a of the through hole 23 of the die box 20 and the outer peripheral surface 33a of the resin guiding portion 33, and a resin flow path (third flow path) G1 supplied from the extruder 90 is provided. Forming.

  The point 40 is inserted in the insertion part 37 of the mandrel 30. Point 40 is a mold part for forming the first resin layer 6 and the second resin layer 7 in the tube 1 and is formed of a material having excellent thermal conductivity such as stainless steel, chrome molybdenum steel and cemented carbide. Yes. The point 40 includes an attaching / detaching portion 43, a resin guiding portion 45, a tube forming portion 47, and a gas flow path 49.

  The detachable portion 43 is a portion that is inserted into the insertion portion 37 of the mandrel 30. The detachable portion 43 has a protruding portion 43 b that protrudes from the insertion portion 37 when inserted into the insertion portion 37 of the mandrel 30. A spiral groove is formed on the outer peripheral surface 43a of the protrusion 43b in the detachable portion 43. The point 43 is fixed to the mandrel 30 by screwing a protruding portion 43 b protruding rearward in the front-rear direction A from the insertion portion 37 of the mandrel 30 into a nut 35 or the like disposed outside the mandrel 30. The resin guiding portion 45 is configured by an outer peripheral surface 45a that tapers toward the front in the front-rear direction A. The resin guiding portion 45 guides the resin flowing from the mandrel 30 to the tube forming portion 47. Specifically, as shown in FIG. 2, a gap is formed between the inner peripheral surface 57a of the insertion portion 57 of the outer die 50 and the outer peripheral surface 45a of the resin guide portion 45 of the point 40, and the extruder A flow path G2 of resin supplied from 90 is formed. The resin guide 45 guides the resin to the flow path (first flow path) G3 and the flow path (second flow path) G4, which will be described in detail later.

  As shown in FIG. 4B, the tube forming part 47 includes a first tube forming part 48a, a first air flow path 48b, a second tube forming part 48c, and a second air flow path 48d. Have. The first tube forming part 48 a and the second tube forming part 48 c protrude forward from the resin guiding part 45 in the front-rear direction A. There is a gap between the first tube forming portion 48a and the second tube forming portion 48c, and a flow path G4 that forms the second resin layer 7 (see FIG. 1) is formed.

  As shown in FIG. 5, the point 40 is inserted into the insertion portion 37 of the mandrel 30 from the front surface 21 b with respect to the mandrel 30 inserted from the rear surface 21 a of the die box 20.

  The outer die 50 is inserted into the front projecting portion 25, and the resin guiding portion 45 and the tube forming portion 47 at the point 40 are inserted. The outer die 50 is a mold part that forms the first resin layer 6 (see FIG. 1) in the tube 1, and is formed of a material having excellent thermal conductivity such as stainless steel, chrome molybdenum steel, and cemented carbide. Yes. The outer die 50 has a large-diameter portion 53, a small-diameter portion 55 whose outer shape viewed from the front-rear direction A is smaller than the large-diameter portion 53, and an insertion portion 57.

  As shown in FIG. 5, it is extrapolated to a point 40 fixed in a state of protruding from the die box 20. At this time, the position of the tip 40a of the point 40 and the position of the tip 50a of the outer die 50 are the same. That is, the tip 40 a of the point 40 and the tip 50 a of the outer die 50 form a tip (downstream end) 11 a of the mold 11. The resin supplied from the extruder 90 to the mold 11 is extruded from the tip end portion 11 a of the mold 11.

  As shown in FIG. 5, the outer die 50 is extrapolated from the front surface 21 b side of the die box 20 to the point 40 to form a part of the mold 11 (first mold part). As shown in FIG. 2, a gap is formed between the inner peripheral surface 57 a of the insertion portion 57 of the outer die 50 and the outer peripheral surface 45 a of the resin guide portion 45 of the point 40, and is supplied from the extruder 90. A resin flow path G2 is formed. Further, a gap is formed between the inner peripheral surface 57a of the insertion portion 57 of the outer die 50 and the outer peripheral surface 47a of the tube forming portion 47 (the outer peripheral surfaces 48e and 48f shown in FIG. 4B). A flow path G3 of resin supplied from the machine 90 is formed.

  The fixture 71 is a member that presses and fixes the point 40 and the outer die 50 from the front side in the front-rear direction. Specifically, the front end portion 50a of the outer die 50 is pressed by the front surface 71c. A spiral groove is formed in a part of the outer peripheral surface 25a of the front protrusion 25 and a part of the inner peripheral surface 71a of the fixture 71 so as to be screwed together. Thereby, the fixture 71 can be easily attached to and detached from the die box 20.

  The first heaters 61 are, for example, bar heaters that are disposed at the four corners of the die box 20 and extend in the axial direction. The first heater 61 is disposed outside the through hole 23 of the die box 20. The first heater 61 heats the resin flowing through the flow path G <b> 1 by heating the main body 21 of the die box 20. The second heater 65 is a band heater, for example, disposed on the outer peripheral surface 71 b of the fixture 71. The second heater 65 heats the resin flowing through the flow path G2 and the flow path G3 by heating the outer die 50. Specifically, the second heater 65 heats the outer die 50 via the fixture 71 and the front protrusion 25 of the die box 20. The length of the first heater 61 in the front-rear direction A can be 2 to 4 times the length of the second heater 65 in the front-rear direction A.

  The heating amount of the first heater 61 is set to be larger than the heating amount of the second heater 65. Specifically, the outer die 50 in which the temperature (first temperature) of the main body 21 (a part of the second mold part) in the die box 20 heated by the first heater 61 is heated by the second heater 65. The heating amounts of the first heater 61 and the second heater 65 are set so as to be higher in the range of 5 ° C. or more and 50 ° C. or less than the temperature (second temperature of the first mold part). Yes. That is, the heating amount of the first heater 61 and the second heater 65 is such that the temperature difference between the resin flowing in the flow path G1 inside the first heater 61 and the resin flowing in the flow path G2 inside the second heater 65 is 5. It is set to be 50 ° C. or higher. In addition, 5 degreeC or more is preferable, as for the lower limit of the said temperature, 7 degreeC or more is more preferable, and 10 degreeC or more is especially preferable. The upper limit of the temperature is preferably 50 ° C. or lower, more preferably 45 ° C. or lower, and particularly preferably 40 ° C. or lower.

  The temperature of the first heater 61 and the second heater 65 may be adjusted in the case of a heater whose heating amount can be adjusted, or when a heater whose heating amount cannot be set is used. Alternatively, a heater having a heating ability that can achieve the above temperature difference may be selected and installed.

  The operation of the extrusion apparatus 10 configured as described above will be described. When the tube 1 is formed using the extrusion molding apparatus 10, the mold 11 is heated. The mold 11 is heated by the first heater 61 and the second heater 65. Specifically, the outer die 50 (first mold) heated by the second heater 65 is heated at the temperature of the main body 21 (a part of the second mold part) in the die box 20 heated by the first heater 61. The mold 11 is heated so that it is higher in the range of 5 ° C. or more and 50 ° C. or less than the temperature of a part of the part. Thereafter, the resin melted and heated in the extruder 90 is supplied to the resin supply hole 27.

  As shown in FIG. 2, the resin supplied from the extruder 90 to the resin supply hole 27 passes through the resin supply hole 27, the flow path G <b> 1 between the die box 20 and the mandrel 30, the outer die 50, and the point 40. It reaches the tube forming part 47 at the point 40 described in detail in the upper part via the flow path G2 between the two. The resin reaching the tube forming portion 47 is divided into a flow path G3 formed along the outer peripheral surface 47a and a flow path G4 formed inside the outer peripheral surface 47a in the cross section orthogonal to the front-rear direction A. It flows to the tip 40a of 40.

  The resin supplied from the extruder 90 is heated by the first heater 61 when passing through the flow path G1. The gap of the flow path G1 (the distance between the inner peripheral surface 23a of the through hole 23 and the outer peripheral surface 33a of the resin guide portion 33 when viewed from the front-rear direction A) is, for example, about 2.0 mm, Since the resin is very small compared to the size, when the resin flows for a while in the flow path G1, the temperature at which the first heater 61 heats the main body 21 of the die box 20, that is, the heat generation temperature of the first heater 61 is substantially the same. Become. Similarly, the gap (the distance between the inner peripheral surface 57a of the insertion portion 57 of the outer die 50 and the outer peripheral surface 47a of the tube forming portion 47) when viewed from the front-rear direction A is about 0.4 mm, for example. Since the resin 11 is very small compared to the entire size of the mold 11, the second heater 65 heats the fixture 71, the front protrusion 25 of the die box 20 and the outer die 50 when the resin flows through the flow path G3 for a while. That is, that is, substantially the same as the heat generation temperature of the second heater 65.

  Here, the heat generation temperature of the first heater 61 is set to be higher than the heat generation temperature of the second heater 65 in a range of 5 ° C. or more and 50 ° C. or less. That is, the temperature of the resin flowing through the flow path G3 (the heat generation temperature of the second heater 65) is lower than the temperature of the resin flowing through the flow path G1 (the heat generation temperature of the first heater 61). Therefore, the temperature of the resin that has flowed from the flow path G1 into the flow path G3 via the flow path G2 decreases toward the downstream side.

  On the other hand, since the flow path G4 is located on the inner side (farther than the flow path G3) than the flow path G3 in the cross section viewed from the front-rear direction, the flow path G4 is hardly affected by the heat generated by the second heater 65. For this reason, the amount of decrease when the resin flows through the flow path G4 is smaller than when the resin flows through the flow path G3. As a result, the temperature of the resin flowing through the flow path G4 is higher than the temperature of the resin flowing through the flow path G3, and the melt viscosity of the resin flowing through the flow path G4 is higher than the melt viscosity of the resin flowing through the flow path G3. Get smaller.

  In such a state, the resin flowing through the flow path G3 and the flow path G4 is injected with compressed air from the first air flow path 48b and the second air flow path 48d, as shown in FIGS. It is pushed out from the front end portion 11a of the mold 11 in a state of being damaged.

  The tube 1 having a shape as shown in FIG. 1 adjusts, for example, the amount of resin discharged from the tip portion 11a of the mold 11 or takes up the resin from the tip portion 11a of the mold 11 (extruder 90). The thickness of the tube 1 can be adjusted by adjusting the discharge amount from the first air flow path 48b and the second air flow path 48d. By adjusting, the inner size of the first lumen 3 and the second lumen 4 can be adjusted.

As described above, the tube 1 having the shape as shown in FIG. 1 is manufactured.
Such a tube 1 is a tube used inside a human body. For example, in addition to a balloon catheter in which a guide wire is inserted into the first lumen 3 and an inflation device is inserted into the second lumen 4, a penetration catheter, It is used in medical instruments used in living body lumens such as digestive organ catheters.

  In the extrusion molding apparatus 10 and the tube manufacturing method, the temperature of the resin flowing through the flow path G4 is higher than the resin flowing through the flow path G3 at the tip portion 11a of the mold 11, that is, the portion where the resin is extruded from the mold 11. Since it is high, the melt viscosity of the resin flowing through the flow path G4 is lower than that of the resin flowing through the flow path G3. As a result, the discharge amount (the amount of resin flowing through the flow path cross section) of the mold part that forms the flow path G4 increases as compared with the mold part that forms the flow path G3. 7 can be easily increased in thickness. As a result, in manufacturing the tube 1 having two flow paths (the first lumen 3 and the second lumen 4), the first resin between the outer surface 1a of the tube 1 and the first lumen 3 or the second lumen 4 is used. The second resin layer 7 separating the first lumen 3 and the second lumen 4 can be thickened while maintaining the thickness of the layer 6.

  In the extrusion molding apparatus 10, the first heater 61 disposed outside the flow path G1 in the main body 21 of the die box 20 and the second heater 65 disposed outside the flow path G3 in the outer die 50 are provided. And the heating amount of the first heater 61 is set to be larger than the heating amount of the second heater 65. In the extrusion molding apparatus, the temperature of the resin flowing through the flow path G3 can be made higher than the temperature of the resin flowing through the flow path G4 with an easy configuration.

  In the extrusion molding apparatus 10, the temperature of the main body 21 of the die box 20 heated by the first heater 61 is in the range of 5 ° C. or more and 50 ° C. or less as compared with the temperature of the outer die 50 heated by the second heater 65. The heating amount of the first heater 61 and the second heater 65 is set so as to be higher. For this reason, a difference in melt viscosity can be generated between the melt viscosity of the resin flowing in the flow path G3 and the melt viscosity of the resin flowing in the flow path G4, so that the outer surface 1a of the tube 1 and the first lumen 3 or the second The second resin layer 7 separating the first lumen 3 and the second lumen 4 can be made thicker while maintaining the thickness of the first resin layer 6 between the two lumens 4.

  Next, deformation of the second resin layer (flow path) 7 separating the first lumen (flow path) 3 and the second lumen (flow path) 4 can be suppressed by the extrusion molding apparatus 10 of the above embodiment. The point which can manufacture the tube 1 is demonstrated using Example 1, Example 2, and Comparative Example 1 shown below. In addition, this invention is not limited to the structure of the metal mold | die 11 shown below, and the manufacturing conditions of Example 1 and Example 2. FIG.

  In Example 1, Example 2 and Comparative Example 1 shown below, the double-lumen mold 11 detailed in the above embodiment and an extruder 90 which is a uniaxial extruder are used as a resin raw material. Resin was extruded from a polyamide elastomer equivalent to Shore D72 under the following conditions (Example 1, Example 2 and Comparative Example 1) to produce a double lumen tube 1 as shown in FIG.

  Thus, the thickness of the resin layer of three places in the manufactured tube 1, ie, the 1st between the external surface 1a of the tube 1 and the internal peripheral surface 4b of the 2nd lumen | rumen 4 shown by FIG.7 (b). The thickness T11 of one resin layer 6, the thickness T12 of the second resin layer 7 between the inner peripheral surface 4a of the first lumen 3 and the inner peripheral surface 4a of the second lumen 4, and the outer surface 1a of the tube 1 and the first The thickness T13 of the first resin layer 6 between the inner surface 3a of the lumen 3 was measured with a micro high scope, and the results are shown in Table 1 below.

Example 1
The temperature of the die box 20 (first heater 61) was set to 210 ° C., and the temperature of the outer die 50 (second heater 65) was set to 200 ° C. Further, when the temperature of the die box 20 is set to 210 ° C., the MFR (melt viscosity: Melt Flow Rate) of the resin flowing through the flow path G1 is 6.0 (g / 10 min). The MFR of the resin flowing through the flow path G3 when set to 200 ° C. was 4.1 (g / 10 min). Moreover, the speed (extrusion speed or take-off speed) of the resin extruded from the tip portion 11a of the mold 11 was 15 m / min. The MFR here is a value measured in accordance with JIS K7210 (the same applies to Example 2 and Comparative Example 1).

(Example 2)
The temperature of the die box 20 (first heater 61) was set to 300 ° C., and the temperature of the outer die 50 (second heater 65) was set to 260 ° C. Further, the MFR of the resin flowing through the flow path G1 when the temperature of the die box 20 is set to 300 ° C. is 38.0 (g / 10 min), and the resin flows when the temperature of the outer die 50 is set to 260 ° C. The MFR of the resin flowing through the path G3 was 23.0 (g / 10 min). Moreover, the speed (extrusion speed or take-off speed) of the resin extruded from the tip portion 11a of the mold 11 was 15 m / min.

(Comparative Example 1)
The temperature of the die box 20 (first heater 61) was set to 210 ° C., and the temperature of the outer die 50 (second heater 65) was set to 210 ° C. Further, the MFR of the resin flowing through the flow path G1 when the temperature of the die box 20 is set to 210 ° C. is 6.0 (g / 10 min), and the resin flows when the temperature of the outer die 50 is set to 210 ° C. The MFR of the resin flowing through the path G3 was 6.0 (g / 10 min). Moreover, the speed (extrusion speed or take-off speed) of the resin extruded from the tip portion 11a of the mold 11 was 15 m / min.

  From the results of Example 1, Example 2, and Comparative Example 1, by setting the temperature of the die box 20 higher than the temperature of the outer die 50, the outer surface 1a of the tube 1 and the inner peripheral surface 4b of the second lumen 4 are set. Without changing the thickness T11 of the first resin layer 6 between the first resin layer 6 and the thickness T13 of the first resin layer 6 between the outer surface 1a of the tube 1 and the inner peripheral surface 3a of the first lumen 3. It was confirmed that the thickness T12 of the second resin layer 7 between the inner peripheral surface 3a of the lumen 3 and the inner peripheral surface 4a of the second lumen 4 can be increased.

  Although one embodiment has been described above, the present invention is not limited to the above embodiment.

<Modification 1>
In the above embodiment, the first heater 61 and the first heater 61 and the second heater 61 are arranged so that the temperature of the resin flowing through the flow path G4 is higher than the temperature of the resin flowing through the flow path G3. Although the example in which the temperature of the resin is adjusted by the two heaters 65 has been described, the present invention is not limited to this. For example, a resin adjustment unit that adjusts the first viscosity that is the melt viscosity of the resin that flows in the flow path (first flow path) G1 and the second viscosity that is the melt viscosity of the resin that flows in the flow path (second flow path). The resin adjusting unit may adjust the melt viscosity of the resin so that the second viscosity is lower than the first viscosity. The melt viscosity here is an MFR value measured according to JIS K7210.

<Modification 2>
In the above embodiment, the temperature of the main body 21 in the die box 20 heated by the first heater 61 is higher than the temperature of the outer die 50 heated by the second heater 65 in the range of 5 ° C. or more and 50 ° C. or less. As described above, an example in which the heating amounts of the first heater 61 and the second heater 65 are set has been described. The present invention is not limited to this. Instead of or in addition to the above setting, for example, the first heater 61 and the resin so that the difference in melt viscosity between the resin flowing through the flow path G1 and the resin flowing through the flow path G3 is 1 g / 10 min to 50 g / 10 min. The heating amount of the second heater 65 may be set. The lower limit of the melt viscosity difference is more preferably 3 g / 10 min or more, and particularly preferably 5 g / 10 min or more. The upper limit of the difference in melt viscosity is more preferably 35 g / 10 min or less, and particularly preferably 20 g / 10 min or less. Even in this configuration, when manufacturing a tube having at least two flow paths, the flow path is separated from the flow path while maintaining the thickness of the resin layer between the outer surface of the tube and the flow path. The thickness of the resin layer can be increased.

<Other variations>
In the above embodiment, the first heater 61 disposed outside the flow path G1 in the main body 21 of the die box 20 in order to make the temperature of the resin flowing through the flow path G4 higher than the temperature of the resin flowing through the flow path G3. And the second heater 65 disposed outside the flow path G3 in the outer die 50, and the heating amount of the first heater 61 is set to be larger than the heating amount of the second heater 65. However, the present invention is not limited to this. For example, a third heater for increasing the temperature of the resin flowing in the flow path G4 may be arranged around the flow path G4 in addition to the second heater 65. In this case, the temperature of the third heater (the temperature at which the third heater heats the resin flowing through the flow path G4) is set to the temperature of the second heater 65 (the temperature at which the second heater heats the resin flowing through the flow path G3). The temperature difference between the temperature of the first heater 61 and the second heater 65 may be eliminated.

  In the above embodiment, the manufacturing method of the tube 1 having the two lumens of the first lumen 3 and the second lumen 4 has been described as an example. However, the method is applied to an extrusion molding apparatus that manufactures a tube having three or more lumens. You can also For example, as shown in FIG. 6, the present invention can be applied to an extrusion apparatus that manufactures a tube 201 having three lumens 203, 203, and 204.

  The first lumen 203 is formed by an inner peripheral surface 203a having a substantially circular shape when viewed from the flow path direction. When viewed from the flow path direction, the second lumen 204 has an inner peripheral surface 204a as a portion facing the inner peripheral surface 203a of the first lumen 203 and an inner peripheral surface 204b as a portion along the outer surface 201a of the tube 201. And have. The second lumen 204 has an inner peripheral surface formed from an arc-shaped portion and a linear portion when viewed from the flow path direction. The second lumen 204 may be formed in a so-called crescent shape as in the above embodiment. The first lumen 203 and the second lumen 204 are formed by being surrounded by the first resin layer 206 and the second resin layer 207.

  The first resin layer 206 forms the outer surface 201 a of the tube 201 and forms a resin layer between the outer surface 201 a and the inner peripheral surface 203 a of the first lumen 203 or the inner peripheral surface 204 b of the second lumen 204. The second resin layer 207 forms a resin layer between the first lumen 203 and the second lumen 204. In other words, the second resin layer 207 is a partition wall that separates the first lumen 203 and the first lumen 203 or separates the first lumen 203 and the second lumen 204. More specifically, the second resin layer 207 is formed between the inner peripheral surface 203a of the first lumen 203 and the inner peripheral surface 204a of the second lumen 204, and between the inner peripheral surface 203a of the first lumen 203 and the first lumen 203. The resin part between the inner peripheral surface 203a is formed. The first resin layer 206 and the second resin layer 207 can be formed of the same resin material as in the above embodiment.

  Various embodiments and modifications described above may be combined in various ways without departing from the spirit of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Resin tube, 1a ... External surface, 10 ... Extrusion molding apparatus, 90 ... Extruder, 11 ... Mold, 11a ... Tip part, 3,203 ... First lumen, 4,204 ... Second lumen, 6, 206 ... First resin layer, 7, 207 ... Second resin layer, 20 ... Die box, 30 ... Mandrel, 40 ... Point, 50 ... Outer die, 71 ... Fixing tool, 61 ... First heater, 65 ... Second heater , G1... Channel (third channel), G2... Channel, G3... Channel (first channel), G4.

Claims (14)

An extrusion apparatus for producing a resin tube having at least two flow paths,
The first resin layer in a cross section perpendicular to the direction in which the resin flows, and the first flow path through which the resin that forms the outer surface of the tube and forms the first resin layer between the outer surface and the flow path A mold having a second flow path through which a resin that forms a second resin layer between the flow path and the flow path is inside, and
One resin supply section for supplying the resin to the first flow path and the second flow path;
A resin adjusting section that adjusts a first temperature that is a temperature of the resin flowing in the first flow path at a downstream end of the mold and a second temperature that is a temperature of the resin flowing in the second flow path; ,
With
The resin adjusting unit is an extrusion molding apparatus that adjusts the temperature of the resin so that the second temperature is higher than the first temperature, the temperature being not lower than the melting temperature of the resin and not higher than the thermal decomposition temperature.   The extrusion molding apparatus according to claim 1, wherein the resin adjusting unit sets a temperature difference between the first temperature and the second temperature to 5 ° C. or more and 50 ° C. or less. An extrusion apparatus for producing a resin tube having at least two flow paths,
The first resin layer in a cross section perpendicular to the direction in which the resin flows, and the first flow path through which the resin that forms the outer surface of the tube and forms the first resin layer between the outer surface and the flow path A mold having a second flow path through which a resin that forms a second resin layer between the flow path and the flow path is inside, and
One resin supply section for supplying the resin to the first flow path and the second flow path;
Resin adjustment for adjusting the first viscosity, which is the melt viscosity of the resin flowing in the first flow path, and the second viscosity, which is the melt viscosity of the resin flowing in the second flow path, at the downstream end of the mold And comprising
The resin adjusting unit is an extrusion molding apparatus that adjusts the melt viscosity of the resin so that the second viscosity is lower than the first viscosity.   The extrusion molding apparatus according to claim 3, wherein the resin adjusting unit sets a difference in melt viscosity between the first viscosity and the second viscosity to 1 g / 10 min to 50 g / 10 min. The mold has a first mold portion having the first flow path and the second flow path, and a second mold having a third flow path for supplying the resin to the first flow path and the second flow path. And
The resin adjusting unit includes a first heater disposed outside the third flow path in the second mold part, and a second heater disposed outside the first flow path in the first mold part. Have
The extrusion apparatus according to any one of claims 1 to 4, wherein a heating amount of the first heater is larger than a heating amount of the second heater.   The temperature of the second mold part heated by the first heater is higher than the temperature of the first mold part heated by the second heater in a range of 5 ° C. or more and 50 ° C. or less. The extrusion apparatus according to claim 5, wherein the heating amounts of the first heater and the second heater are set.   The heating amount of the first heater and the second heater is such that the difference in melt viscosity between the resin flowing through the third flow path and the resin flowing through the first flow path is 1 g / 10 min to 50 g / 10 min. The extrusion molding apparatus according to claim 5 or 6, which is set.   The extrusion molding according to any one of claims 1 to 7, wherein the resin includes at least one selected from a polyamide resin, a polyamide elastomer, a polyurethane resin, a polyether resin, a polyester resin, a polyimide resin, and a polyethylene resin. apparatus.   The extrusion apparatus according to claim 8, wherein the resin includes any one of a polyamide resin and a polyamide elastomer.   The extrusion apparatus according to any one of claims 1 to 9, wherein the tube has two flow paths.   The extrusion apparatus according to any one of claims 1 to 10, wherein the tube is a medical tube.   The extrusion apparatus according to claim 11, wherein the tube is a catheter tube. A method for producing a resin tube having at least two flow paths,
The first resin layer in a cross section perpendicular to the direction in which the resin flows, and the first flow path through which the resin that forms the outer surface of the tube and forms the first resin layer between the outer surface and the flow path A step of supplying the resin from one resin supply unit to a mold having a second flow path through which a resin forming a second resin layer between the flow path and the flow path flows inside. When,
When the temperature of the resin flowing in the first flow path at the downstream end of the mold is the first temperature, and the temperature of the resin flowing in the second flow path is the second temperature, thermal decomposition is greater than the melting temperature of the resin. A step of adjusting the temperature of the resin so that the second temperature is higher than the first temperature, the temperature being equal to or lower than the temperature;
The manufacturing method of the tube containing this. A method for producing a resin tube having at least two flow paths,
The first resin layer in a cross section perpendicular to the direction in which the resin flows, and the first flow path through which the resin that forms the outer surface of the tube and forms the first resin layer between the outer surface and the flow path A step of supplying the resin from one resin supply unit to a mold having a second flow path through which a resin forming a second resin layer between the flow path and the flow path flows inside. When,
When the melt viscosity of the resin flowing in the first flow path at the downstream end of the mold is the first viscosity and the melt viscosity of the resin flowing in the second flow path is the second viscosity, it is more than the first viscosity. Adjusting the melt viscosity of the resin so that the second viscosity is low;
The manufacturing method of the tube containing this.

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