JP6771313B2 - Extrusion molding equipment and tube manufacturing method - Google Patents

Description

The present invention relates to an extrusion molding 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, and ureters or body tissues to 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 the other flow paths or reducing the cross-sectional area. There may be some problems. Such a defect makes it difficult to inject or suck a required amount of liquid and insert an instrument, for example. Therefore, there is a desire to thicken the resin layer separating the flow path and suppress deformation.

Japanese Unexamined Patent Publication No. 2008-92969

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

Therefore, an object of the present invention is to produce a tube having at least two flow paths, and to maintain the thickness of the resin layer between the outer surface of the tube and the flow path while maintaining the thickness between the flow paths. It is an object of the present invention to provide an extrusion molding apparatus and a method for manufacturing a tube, which can thicken the separating resin layer.

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 forms a first resin layer between the outer surface and the flow path. A second flow path through which the resin to be formed flows and a second flow path in 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. A mold having a flow path, a resin supply unit that supplies resin to the first flow path and the second flow path, and a first resin flowing in the first flow path at the downstream end of the mold. A resin adjusting unit for adjusting the temperature and the second temperature, which is the temperature of the resin flowing in the second flow path, is provided, and the resin adjusting unit has a temperature equal to or higher than the melting temperature of the resin and lower than the thermal decomposition temperature. The temperature of the resin is adjusted so that the second temperature is higher than the first temperature.

The method for manufacturing a tube of the present invention is a method for manufacturing 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. The first flow path through which the resin flows and the second flow path through which the resin that forms the second resin layer between the flow path and the flow path is inside the first resin layer in the cross section orthogonal to the direction in which the resin flows. The process of supplying resin from one resin supply unit to the mold having, and the temperature of the resin flowing in the first flow path at the downstream end of the mold are set to the first temperature and the temperature of the resin flowing in the second flow path. When the temperature is set to the second temperature, the step of adjusting the temperature of the resin so that the temperature is equal to or higher than the melting temperature of the resin and lower than the thermal decomposition temperature and the second temperature is higher than the first temperature is included.

In the above-mentioned extrusion molding apparatus and tube manufacturing method, the temperature of the resin flowing through the second flow path is higher than that of 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. As a result, the discharge amount (the amount of resin flowing through the cross section) of the mold portion forming the second flow path is larger than that of the mold portion forming the first flow path, so that the thickness of the second resin layer is larger than that of the first resin layer. It becomes easy to increase the amount. As a result, when manufacturing a tube having at least two flow paths, the thickness of the resin layer separating the flow paths is increased while maintaining the thickness of the resin layer between the outer surface of the tube and the flow path. can do. The upstream side and the downstream side referred to here indicate 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 higher and 50 ° C. or lower.

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 forms a first resin layer between the outer surface and the flow path. A second flow path through which the resin to be formed flows and a second flow path in 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. A mold having a flow path, a resin supply unit that supplies resin to the first flow path and the second flow path, and a melt viscosity of the resin flowing to the first flow path at the downstream end of the mold. A resin adjusting part for adjusting one viscosity and the second viscosity which is the melt viscosity of the resin flowing in the second flow path is provided, and the resin adjusting part has a second viscosity lower than the first viscosity. , Adjust the melt viscosity of the resin.

The method for manufacturing a tube of the present invention is a method for manufacturing 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. The first flow path through which the resin flows and the second flow path through which the resin that forms the second resin layer between the flow path and the flow path is inside the first resin layer in the cross section orthogonal to the direction in which the resin flows. The process of supplying resin from one resin supply unit to the mold having, and the melt viscosity of the resin flowing in the first flow path at the downstream end of the mold are the first viscosity and the resin flowing in the second flow path. This includes a step of adjusting the melt viscosity of the resin so that the second viscosity is lower than the first viscosity when the melt viscosity of the resin is the second viscosity.

In the above-mentioned extrusion molding apparatus and tube manufacturing method, the melt viscosity of the resin flowing through the second flow path is higher than that of 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. It gets lower. As a result, the discharge amount (the amount of resin flowing through the cross section) of the mold portion forming the second flow path is larger than that of the mold portion forming the first flow path, so that the thickness of the second resin layer is larger than that of the first resin layer. It becomes easy to increase the amount. As a result, when manufacturing a tube having at least two flow paths, the thickness of the resin layer separating the flow paths is increased while maintaining the thickness of the resin layer between the outer surface of the tube and the flow path. 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 portion 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 adjusting portion has a first heater arranged outside the third flow path in the second mold portion and a second heater arranged outside the first flow path in the first mold portion. , 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 by a simple configuration.

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

Even if the heating amounts of the first heater and the second heater are set so 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 or more and 50 g / 10 min or less. Good. In the extrusion molding apparatus, a sufficient melt viscosity difference can be generated between the melt viscosity of the resin flowing through the first flow path and the melt viscosity of the resin flowing through the second flow path, so that the outer surface of the tube and the flow path can be formed. While maintaining the thickness of the first resin layer between the two, the thickness of the resin layer separating the flow paths can be increased.

The resin may contain at least one selected from polyamide resins, polyamide elastomers, polyurethane resins, polyether resins, polyester resins, polyimide resins, and polyethylene resins.

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

The tube may have two channels. In the extrusion molding apparatus, the resin layer that separates the flow path and the flow path can be thickened 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 extrusion molding apparatus, it is possible to manufacture a medical tube in which the resin layer separating the flow path and the flow path is thickened 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 in which the resin layer separating the flow path and the flow path is thickened while maintaining the thickness of the resin layer between the outer surface of the tube and the flow path. ..

According to the present invention, the thickness of the resin layer separating the flow path and the flow path can be increased while maintaining the thickness of the resin layer between the outer surface of the tube and the flow path.

This is an example of a medical tube manufactured by the extrusion molding apparatus according to the present embodiment. It is sectional drawing at the time of cutting along the direction of flow of resin in the extrusion molding apparatus of one embodiment. It is a front view of the extrusion molding apparatus of FIG. 2 seen from the downstream end side in the direction of resin flow. (A) It is a perspective view which shows the point included in FIG. (B) It is a front view which looked at the end side of a point. It is a perspective view which showed disassembled a part part of the extrusion molding apparatus of FIG. This is an example of a medical tube manufactured by the extrusion molding apparatus according to the modified example. (A) It is a figure for demonstrating the cross section of the mold used in an Example and a comparative example. (B) It is a figure for demonstrating the dimension of the tube manufactured in Example and Comparative Example.

Hereinafter, a medical resin tube 1 having two lumens (flow path) manufactured by the extrusion molding apparatus 10 of one embodiment (hereinafter, simply referred to as “tube 1”) will be described with reference to the drawings. .. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicate description will be omitted. In the following description, in the flow path through which the resin flows, the side where the resin is supplied (extruder 90 side) is referred to as the upstream side, and the side where the resin is extruded (the tip portion 11a side of the mold 11) is the downstream side. That is.

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 includes 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 peripheral 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 when 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 peripheral surface 1a of the tube 1 and also forms a resin layer between the outer peripheral surface 1a and the inner peripheral surface 3a of the first lumen 3 or the inner peripheral surface 4b of the second lumen 4. The first resin layer 6 is made of a resin material. Examples of resin materials include at least one selected from polyamide resins, polyamide elastomers, polyurethane resins, polyether resins, polyester resins, polyimide resins, and polyethylene resins. 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 3a of the first lumen 3 and the inner peripheral surface 4a of the second lumen 4. The first resin layer 6 is made of a resin material. Examples of resin materials include at least one selected from polyamide resins, polyamide elastomers, polyurethane resins, polyether resins, polyester resins, polyimide resins, and polyethylene resins. 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 made of the same resin material.

Next, the extrusion molding apparatus 10 used when manufacturing the above-mentioned tube 1 will be described. The configuration and operation of the extrusion molding apparatus 10 will be described with reference to FIGS. 2 to 5. The extrusion molding apparatus 10 according to the present embodiment uses a resin continuously supplied from one extruder (resin supply unit) 90 to form a tube 1 having two lumens, a first lumen 3 and a second lumen 4. 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). A unit) 61 and a second heater (resin adjusting unit) 65.

The extruder 90 supplies the resin to the mold 11 described in detail later. The extruder 90 is a known uniaxial extruder having a screw or the like whose rotation can be controlled as an element component. The extruder 90 generally adjusts the amount of resin material supplied to the mold 11 by controlling the screw and / or valve.

The die box 20 is a rectangular parallelepiped mold component formed of a material having excellent thermal conductivity such as stainless steel, chrome molybdenum steel, and cemented carbide. As shown in FIG. 2, the die box 20 has a rectangular parallelepiped main body portion 21. A through hole 23, a front projecting portion 25, and a resin supply hole 27 are formed in the main body portion 21. The main body 21 has side surfaces 21a and side surfaces 21b facing each other. Hereinafter, for convenience of explanation, the direction in which the side surface 21a and the side surface 21b face each other is referred to as the front-rear direction A. Hereinafter, the side surface 21a will be referred to as a "rear surface 21a" and the side surface 21b will be referred to as a "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 to the front surface 21b. As shown in FIG. 5, the mandrel 30 is inserted into the through hole 23 from the rear surface 21a side. The front projecting portion 25 is an annular portion projecting forward from the front surface 21b. The inner diameter of the front protrusion 25 coincides with the inner diameter of the through hole 23. The resin supply hole 27 is a hole that communicates from the side surface 21c orthogonal to the rear surface 21a and the front surface 21b 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 (second mold portion) of the mold 11. The mandrel 30 is a mold component 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 in the front-rear direction A to the downstream side of the mold 11. Yes, it is made of a material with excellent thermal conductivity such as stainless steel, chrome molybdenum steel and cemented carbide. The mandrel 30 has a resin guiding portion 33, an insertion portion 37, and a fixing portion 39.

The resin guiding portion 33 is composed of an outer peripheral surface 33a that tapers toward the front surface 21b in the front-rear direction A. A groove for guiding the resin or the like may be formed on the outer peripheral surface 33a. The insertion portion 37 is an inner space portion into which the 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 larger dimensional shape as seen from the front-rear direction A 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 by, for example, a bolt (not shown) or the like.

As shown in FIG. 5, the mandrel 30 is inserted from the rear surface 21a side of 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 the resin flow path (third flow path) G1 supplied from the extruder 90 is provided. Is forming.

The point 40 is inserted into the interpolation portion 37 of the mandrel 30. Point 40 is a mold component that forms 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. There is. The point 40 has a detachable portion 43, a resin guiding portion 45, a tube forming portion 47, and a gas flow path 49.

The attachment / detachment portion 43 is a portion inserted into the insertion portion 37 of the mandrel 30. The detachable portion 43 has a protruding portion 43b that protrudes from the insertion portion 37 when the mandrel 30 is inserted into the insertion portion 37. A spiral groove is formed on the outer peripheral surface 43a of the protruding portion 43b of the detachable portion 43. The point 40 is fixed to the mandrel 30 by screwing the protruding portion 43b protruding rearward in the front-rear direction A from the insertion portion 37 of the mandrel 30 into a nut 35 or the like arranged outside the mandrel 30. The resin guiding portion 45 is composed of 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 guiding portion 45 of the point 40, and the extruder is operated. The flow path G2 of the resin supplied from 90 is formed. The resin guiding unit 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 portion 47 includes a first tube forming portion 48a, a first air flow path 48b, a second tube forming portion 48c, and a second air flow path 48d. Have. The first tube forming portion 48a and the second tube forming portion 48c project forward from the resin guiding portion 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 the flow path G4 forming 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 21b with respect to the mandrel 30 in the state of being inserted from the rear surface 21a of the die box 20.

The outer die 50 is inserted into the front protruding 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 component 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. There is. The outer die 50 has a large diameter portion 53, a small diameter portion 55 whose outer shape is smaller than that of the large diameter portion 53 when viewed from the front-rear direction A, and an insertion portion 57.

As shown in FIG. 5, it is extrapolated to a fixed point 40 so as to project from the die box 20. At this time, the position of the tip portion 40a of the point 40 and the position of the tip portion 50a of the outer die 50 coincide with each other. That is, the tip portion 40a of the point 40 and the tip portion 50a of the outer die 50 form the tip portion (downstream side end portion) 11a of the mold 11. The resin supplied from the extruder 90 to the mold 11 is extruded from the tip portion 11a of the mold 11.

As shown in FIG. 5, the outer die 50 is extrapolated to the point 40 from the front surface 21b side of the die box 20 to form a part (first mold portion) of the mold 11. 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 guiding 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 (outer peripheral surfaces 48e and 48f shown in FIG. 4B) of the tube forming portion 47, and the outer die 50 is extruded. It forms a flow path G3 of the resin supplied from the machine 90.

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. Spiral grooves that screw together are formed on 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. As a result, the fixture 71 can be easily attached to and detached from the die box 20.

The first heater 61 is arranged at the four corners of the die box 20 and extends in the axial direction, for example, a bar heater. The first heater 61 is arranged outside the through hole 23 of the die box 20. The first heater 61 heats the resin flowing through the flow path G1 by heating the main body 21 of the die box 20. The second heater 65 is, for example, a band heater arranged on the outer peripheral surface 71b 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 two to four 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 temperature (first temperature) of the main body 21 (a part of the second mold portion) in the die box 20 heated by the first heater 61 is the outer die 50 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 higher and 50 ° C. or lower than the temperature (second temperature) of (a part of the first mold portion). There is. That is, the heating amount of the first heater 61 and the second heater 65 has a temperature difference of 5 between the resin flowing through the flow path G1 inside the first heater 61 and the resin flowing through the flow path G2 inside the second heater 65. It is set to be ℃ or more and 50 ℃ or less. The lower limit of the temperature is preferably 5 ° C. or higher, more preferably 7 ° C. or higher, and particularly preferably 10 ° C. or higher. 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 when the heating amount is adjustable, or when a heater whose heating amount cannot be set is used. , A heater having a heating capacity that causes the above temperature difference may be selected and installed.

The operation of the extrusion molding apparatus 10 configured as described above will be described. When the tube 1 is molded using the extrusion molding device 10, the mold 11 is heated. The mold 11 is heated by the first heater 61 and the second heater 65. Specifically, the temperature of the main body 21 (a part of the second mold portion) in the die box 20 heated by the first heater 61 is the temperature of the outer die 50 (first mold) heated by the second heater 65. The mold 11 is heated so that the temperature is higher in the range of 5 ° C. or higher and 50 ° C. or lower than the temperature of the part). After that, the resin melt-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, and the flow path G1 between the die box 20 and the mandrel 30 and the outer die 50 and the point 40. It reaches the tube forming portion 47 at the point 40 described in detail in the upper part via the flow path G2 between the two. The resin that has reached 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 a cross section orthogonal to the front-rear direction A. It flows to the tip portion 40a of 40.

The resin supplied from the extruder 90 is heated by the first heater 61 as it passes 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 guiding portion 33 when viewed from the front-rear direction A) is, for example, about 2.0 mm, and is the entire mold 11. Since it is very small compared to the size, when the resin flows through the flow path G1 for a while, the temperature at which the first heater 61 heats the main body 21 of the die box 20, that is, the temperature substantially the same as the heat generation temperature of the first heater 61. Become. Similarly, the gap of the flow path G3 (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, for example, about 0.4 mm. Since it is very small compared to the size of the entire mold 11, when the resin flows through the flow path G3 for a while, the second heater 65 heats the fixture 71, the front protrusion 25 of the die box 20, and the outer die 50. That is, the temperature is almost 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 the range of 5 ° C. or higher and 50 ° C. or lower. 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 inside the flow path G3 (farther than the flow path G3) in the cross section viewed from the front-rear direction, it is not easily affected by the heat generated by the second heater 65. Therefore, the amount of reduction when the resin flows through the flow path G4 is smaller than that 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. It becomes smaller.

In the resin flowing through the flow paths G3 and the flow path G4 in such a state, compressed air is injected from the first air flow path 48b and the second air flow path 48d as shown in FIGS. 3 and 4 (b). It is extruded from the tip end portion 11a of the mold 11 in a closed state.

The tube 1 having a shape as shown in FIG. 1 can be used, for example, to adjust the amount of resin discharged from the tip portion 11a of the mold 11 or to take up the resin from the tip portion 11a of the mold 11 (extruder 90). The wall thickness of the tube 1 can be adjusted by adjusting the amount of compressed air injected from the first air flow path 48b and the second air flow path 48d). By adjusting, the inner space size of the first rumen 3 and the second rumen 4 can be adjusted.

As described above, the tube 1 having the shape shown in FIG. 1 is manufactured.
Such a tube 1 is a tube used inside the human body, and is, for example, 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, as well as a penetrating catheter. It is used in medical devices used for living lumens such as gastrointestinal catheters.

In the method for manufacturing the extrusion molding apparatus 10 and the tube, the temperature of the resin flowing through the flow path G4 is higher than that of 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 in the cross section of the flow path) of the mold portion forming the flow path G4 is larger than that of the mold portion forming the flow path G3, so that the second resin layer is compared with the first resin layer 6. It becomes easy to increase the thickness amount of 7. As a result, in manufacturing the tube 1 having two flow paths (first lumen 3 and 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 The second resin layer 7 that separates 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 arranged outside the flow path G1 in the main body 21 of the die box 20 and the second heater 65 arranged outside the flow path G3 in the outer die 50 are provided. 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 by a simple 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 with respect to 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 increase the temperature. Therefore, a difference in melt viscosity can be generated between the melt viscosity of the resin flowing through the flow path G3 and the melt viscosity of the resin flowing through the flow path G4, so that the outer surface 1a of the tube 1 and the first lumen 3 or the first lumen 3 or the first. The thickness of the second resin layer 7 that separates 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, the extrusion molding apparatus 10 of the above embodiment can suppress deformation of the second resin layer (flow path) 7 that separates the first lumen (flow path) 3 and the second lumen (flow path) 4. The point that the tube 1 can be manufactured will be described with reference to Example 1, Example 2 and Comparative Example 1 shown below. The present invention is not limited to the configuration of the mold 11 shown below and the manufacturing conditions of Examples 1 and 2.

In Example 1, Example 2 and Comparative Example 1 shown below, the double lumen mold 11 described in detail in the above embodiment and the extruder 90 which is a uniaxial extrusion molding machine are used as resin raw materials. A polyamide elastomer equivalent to Shore D72 was extruded from a resin under the following conditions (Example 1, Example 2 and Comparative Example 1) to prepare a double lumen tube 1 as shown in FIG.

The thickness of the three resin layers in the tube 1 manufactured in this manner, that is, the thickness between the outer surface 1a of the tube 1 and the inner peripheral surface 4b of the second lumen 4 shown in FIG. 7B. The thickness T11 of the first resin layer 6, the thickness T12 of the second resin layer 7 between the inner peripheral surface 3a of the first lumen 3 and the inner peripheral surface 4a of the second lumen 4, and the outer peripheral surfaces 1a and the first of the tube 1. The thickness T13 of the first resin layer 6 between the inner peripheral surface 3a of the lumen 3 was measured with a microhyscope, 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), and the temperature of the outer die 50 is changed. The MFR of the resin flowing through the flow path G3 when set to 200 ° C. was 4.1 (g / 10 min). The speed (extrusion speed or take-up speed) of the resin extruded from the tip portion 11a of the mold 11 was 15 m / min. The MFR referred to 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 it flows when the temperature of the outer die 50 is set to 260 ° C. The MFR of the resin flowing through the road G3 was 23.0 (g / 10min). The speed (extrusion speed or take-up 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 flows when the temperature of the outer die 50 is set to 210 ° C. The MFR of the resin flowing through the road G3 was 6.0 (g / 10 min). The speed (extrusion speed or take-up 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 peripheral surface 1a of the tube 1 and the inner peripheral surface 4b of the second lumen 4 are set. The thickness T11 of the first resin layer 6 between the two, 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 are not changed. 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 example 1>
In the above embodiment, the first heater 61 and the first heater 61 are set 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 at a temperature equal to or higher than the melting temperature of the resin and lower than the thermal decomposition temperature. Although the description has been given with an example in which the temperature of the resin is adjusted by the two heaters 65, the present invention is not limited thereto. For example, a resin adjusting unit that adjusts the first viscosity, which is the melt viscosity of the resin flowing in the flow path (first flow path) G1, and the second viscosity, which is the melt viscosity of the resin flowing 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 referred to here is an MFR value measured in accordance with 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 in the range of 5 ° C. or higher and 50 ° C. or lower than the temperature of the outer die 50 heated by the second heater 65. Therefore, 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. In place of or in addition to the above settings, for example, the first heater 61 and the first heater 61 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 or more and 50 g / 10 min or less. 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 melt viscosity difference is more preferably 35 g / 10 min or less, and particularly preferably 20 g / 10 min or less. Even with this configuration, when manufacturing a tube having at least two flow paths, the flow paths are separated from each other 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 variants>
In the above embodiment, 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, the first heater 61 arranged outside the flow path G1 in the main body 21 of the die box 20 An example in which the outer die 50 has a second heater 65 arranged outside the flow path G3, 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 raising the temperature of the resin flowing in the flow path G4 may be arranged separately from the second heater 65 around the flow path G4. 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 higher than 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 may be increased, and the temperature difference between the temperature of the first heater 61 and the temperature of the second heater 65 may not be required.

In the above embodiment, the method of manufacturing the tube 1 having two lumens of the first lumen 3 and the second lumen 4 has been described as an example, but it is applied to an extrusion molding apparatus for manufacturing a tube having three or more lumens. You can also do it. For example, as shown in FIG. 6, it can be applied to an extrusion molding apparatus for manufacturing a tube 201 having three lumens 203, 203, 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. 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 peripheral surface 201a of the tube 201 when viewed from the flow path direction. And have. The second lumen 204 has an inner peripheral surface formed of an arcuate portion and a linear portion in a shape 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 201a of the tube 201 and also forms a resin layer between the outer surface 201a and the inner peripheral surface 203a of the first lumen 203 or the inner peripheral surface 204b 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 the inner peripheral surface 203a and the first lumen 203 of the first lumen 203. A resin portion is formed between the inner peripheral surface 203a and the inner peripheral surface 203a. The first resin layer 206 and the second resin layer 207 can be formed of the same resin material as in the above embodiment.

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

1 ... resin tube, 1a ... outer surface, 10 ... extrusion molding device, 90 ... extruder, 11 ... mold, 11a ... tip, 3,203 ... first lumen, 4,204 ... second lumen, 6, 206 ... 1st resin layer, 7,207 ... 2nd resin layer, 20 ... Die box, 30 ... Mandrel, 40 ... Point, 50 ... Outer die, 71 ... Fixture, 61 ... 1st heater, 65 ... 2nd heater , G1 ... Flow path (third flow path), G2 ... Flow path, G3 ... Flow path (first flow path), G4 ... Flow path (second flow path).

Claims (14)

An extrusion molding device that manufactures a resin tube having at least two flow paths.
In the direction in which the resin that forms the outer surface of the resin tube and forms the first resin layer between the outer surface and the flow path flows, and the resin that forms the first resin layer flows. A mold having a second flow path inside the first resin layer in an orthogonal cross section and through which a resin flowing forming a second resin layer between the flow path and the flow path flows.
A resin supply unit that supplies the resin that forms the first resin layer to the first flow path and supplies the resin that forms the second resin layer to the second flow path.
The first temperature, which is the temperature of the resin forming the first resin layer flowing in the first flow path at the downstream end of the mold, and the resin forming the second resin layer flowing in the second flow path. A resin adjustment unit that adjusts the second temperature, which is the temperature,
With
The resin adjusting unit has a temperature equal to or higher than the melting temperature of the resin forming the first resin layer and the resin forming the second resin layer and lower than the thermal decomposition temperature, and the second temperature is higher than the first temperature. An extrusion molding apparatus that adjusts the temperature of the resin that forms the first resin layer and the resin that forms the second resin layer so as to be higher. The extrusion molding apparatus according to claim 1, wherein the resin adjusting unit sets the temperature difference between the first temperature and the second temperature to 5 ° C. or higher and 50 ° C. or lower. An extrusion molding device that manufactures a resin tube having at least two flow paths.
In the direction in which the resin that forms the outer surface of the resin tube and forms the first resin layer between the outer surface and the flow path flows, and the resin that forms the first resin layer flows. A mold having a second flow path inside the first resin layer in an orthogonal cross section and through which a resin flowing forming a second resin layer between the flow path and the flow path flows.
A resin supply unit that supplies the resin that forms the first resin layer to the first flow path and supplies the resin that forms the second resin layer to the second flow path.
The first viscosity, which is the melt viscosity of the resin forming the first resin layer flowing in the first flow path at the downstream end of the mold, and the resin forming the second resin layer flowing in the second flow path. It is provided with a resin adjusting unit for adjusting the second viscosity, which is the melt viscosity of the above.
The resin adjusting unit adjusts the melt viscosities of the resin forming the first resin layer and the resin forming the second resin layer so that the second viscosity is lower than the first viscosity. apparatus. The extrusion molding apparatus according to claim 3, wherein the resin adjusting unit has a melt viscosity difference between the first viscosity and the second viscosity of 1 g / 10 min or more and 50 g / 10 min or less. The mold supplies the first mold portion having the first flow path and the second flow path, and the resin forming the first resin layer to the first flow path, and the second flow path to the second flow path . ( Ii) A second mold portion having a third flow path for supplying a resin forming a resin layer , and
The resin adjusting portion includes a first heater arranged outside the third flow path in the second mold portion and a second heater arranged outside the first flow path in the first mold portion. Have,
The extrusion molding apparatus according to any one of claims 1 to 4, wherein the heating amount of the first heater is larger than the heating amount of the second heater. The temperature of the second mold portion heated by the first heater is set to be higher in the range of 5 ° C. or more and 50 ° C. or less than the temperature of the first mold portion heated by the second heater. The extrusion molding apparatus according to claim 5, wherein the heating amounts of the first heater and the second heater are set. The difference in melt viscosity between the resin forming the first resin layer flowing through the third flow path and the resin forming the second resin layer and the resin forming the first resin layer flowing through the first flow path is 1 g. The extrusion molding apparatus according to claim 5 or 6, wherein the heating amounts of the first heater and the second heater are set so as to be / 10 min or more and 50 g / 10 min or less. The resin forming the first resin layer and the resin forming the second resin layer are at least one selected from polyamide resin, polyamide elastomer, polyurethane resin, polyether resin, polyester resin, polyimide resin, and polyethylene resin. The extrusion molding apparatus according to any one of claims 1 to 7, further comprising. The extrusion molding apparatus according to claim 8, wherein the resin forming the first resin layer and the resin forming the second resin layer include either a polyamide resin or a polyamide elastomer. The extrusion molding apparatus according to any one of claims 1 to 9, wherein the resin tube has the two flow paths. The extrusion molding apparatus according to any one of claims 1 to 10, wherein the resin tube is a medical tube. The extrusion molding apparatus according to claim 11, wherein the resin tube is a tube for a catheter. A method for manufacturing a resin tube having at least two flow paths.
In the direction in which the resin that forms the outer surface of the resin tube and forms the first resin layer between the outer surface and the flow path flows, and the resin that forms the first resin layer flows. A mold having a second flow path inside the first resin layer and through which a resin forming a second resin layer between the flow path and the flow path flows in an orthogonal cross section. The process of supplying the resin forming the first resin layer and the resin forming the second resin layer from the resin supply unit, and
At the downstream end of the mold, the temperature of the resin forming the first resin layer flowing in the first flow path is the first temperature, and the temperature of the resin forming the second resin layer flowing in the second flow path is the temperature. When it is set to the second temperature, it is a temperature equal to or higher than the melting temperature of the resin forming the first resin layer and the resin forming the second resin layer and lower than the thermal decomposition temperature, and the second temperature is higher than the first temperature. The step of adjusting the temperature of the resin forming the first resin layer and the temperature of the resin forming the second resin layer so as to increase the temperature.
including,
How to make a tube. A method for manufacturing a resin tube having at least two flow paths.
In the direction in which the resin that forms the outer surface of the resin tube and forms the first resin layer between the outer surface and the flow path flows, and the resin that forms the first resin layer flows. A mold having a second flow path inside the first resin layer and through which a resin forming a second resin layer between the flow path and the flow path flows in an orthogonal cross section. The process of supplying the resin forming the first resin layer and the resin forming the second resin layer from the resin supply unit, and
The melt viscosity of the resin forming the first resin layer flowing in the first flow path at the downstream end of the mold is the first viscosity, and the melt of the resin forming the second resin layer flowing in the second flow path is melted. When the viscosity is the second viscosity, the melt viscosities of the resin forming the first resin layer and the resin forming the second resin layer are adjusted so that the second viscosity is lower than the first viscosity. Process and
How to make a tube, including.

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