JP2018171174A - Parison manufacturing method, and parison manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a parison capable of improving productivity in executing biaxially-oriented blow molding of a balloon.SOLUTION: A manufacturing method of a parison for manufacturing a balloon used for a balloon catheter, which has extension parts at both ends of the straight cylindrical part, includes: a heating step (B) for heating the parts to become the extension parts of one end side and the other end side of a tube 1 for a straight tubular parison; a first extension step (C) for applying tension to the tube 1 for the parison, and extending the parts heated in the heating step; and second extension steps (E) and (F) for applying tension to both ends of the part to become the straight cylindrical part of the tube 1 for the parison to extend the part, and then releasing the tension to shrink the part.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a parison manufacturing method for manufacturing a balloon provided in a balloon catheter used for IABP (intra-aortic balloon pumping) and the like, and a parison manufacturing apparatus suitable for carrying out the manufacturing method.

  IABP (intra-aortic balloon pumping) is performed as a treatment for lowering cardiac function, in which a balloon catheter is inserted into the aorta, and the balloon is expanded and contracted in accordance with the pulsation of the heart to assist the cardiac function. An IABP balloon catheter used for IABP is inserted from the femoral artery or the like, and is used in a state where the balloon is placed in the descending aorta of the chest.

  The balloon used for such an IABP balloon catheter has a cone portion (shoulder portion) formed in a tapered shape at both ends of the straight barrel portion, and a straight barrel neck portion at the tip of each cone portion. Each has an arranged shape. The balloon is mounted by attaching the neck portion to the outer surface of the catheter sheath.

  Such a balloon is manufactured by biaxial stretch blow molding of a parison (tube) formed into a tubular shape by extrusion molding. As a manufacturing technique of the parison for that purpose, although it relates to a balloon catheter for PTCA (angioplasty), not a balloon catheter for IABP, the one described in Patent Document 1 is known.

  In this technique, in order to improve the uniformity of the film thickness of the balloon, as a parison used for blow molding, a both-ends different diameter (thin diameter) tube whose both end parts are made thinner than the straight body part is used. . According to Patent Document 1, in the case of extrusion molding, both ends have different diameters by appropriately changing and controlling the extrusion conditions by the extruder, the take-up conditions by the take-up machine, and the like by alternately forming thin portions and thick portions. Manufactured.

  As another manufacturing method of such a both-end deformed tube, a method of heating and stretching the portions near both ends of a tube formed into a straight tube shape by extrusion molding has been practically used. In this method, a part of one end side of a tube formed in a straight tube shape is heated with a heating mold, tension is applied to both ends of the tube, the heated part on one end side is stretched, and then cooled. Subsequently, a part on the other end side of the tube is similarly heated with a heating mold, and tension is applied to both ends of the tube to extend the heated part on the other end side, and then the tube is cooled.

  Such a parison is set in a mold of a biaxial stretch blow molding machine, and axial stretching is performed in the non-heated state in the axial direction. In axial stretching, both ends of the parison are fixed, and both ends of the fixed portion are moved at a predetermined speed in a direction away from each other (or the other with respect to one), and the stretching is performed when a predetermined stretching length is reached. Stop. Next, the mold is heated, nitrogen gas is press-fitted into the inner cavity of the parison, and circumferential stretching is performed in the circumferential direction. The mold has a space that is substantially relative to the outer shape of the balloon to be manufactured. By appropriately changing and adjusting the heating temperature of the mold and the supply pressure of the nitrogen gas, the mold space is adjusted. A balloon stretched along the shape of the wall is produced. And in the biaxial stretch blow molding for manufacturing such a balloon, the parison which can shorten processing time and can improve productivity is desired.

JP 2001-321444 A

  The present invention has been made in view of such a situation, and an object thereof is a parison manufacturing method capable of improving productivity when a balloon is biaxially stretch blow-molded, and a parison suitable for carrying out the method. It is to provide a manufacturing apparatus.

The parison manufacturing method according to the first aspect of the present invention includes:
A method for producing a parison having stretched portions at both ends of a straight body portion for producing a balloon used for a balloon catheter,
A heating step of heating the part to be the extension part on one end side of the straight tubular parison tube and the part to be the extension part on the other end side;
Applying a tension to the parison tube and stretching a portion heated in the heating step;
Applying a tension to both ends of the portion to be the straight body portion of the parison tube, extending the portion to be the straight body portion, and then releasing and contracting the tension; Including.

  In the parison manufacturing method concerning the 1st viewpoint of the present invention, it has the process of releasing the tension and contracting, after extending the part which should become the straight body part of the tube for parison by tension. By performing such preliminary stretching and shrinkage, physical properties relating to stretchability change, and when this is stretched next, it becomes easy to stretch in the axial direction. Therefore, shortening the time required for the axial stretching (axial stretching described above) performed when producing a balloon by biaxial stretch blow molding using a parison that has undergone such preliminary stretching. And the productivity of the balloon can be improved.

The parison manufacturing apparatus according to the second aspect of the present invention is:
A device for manufacturing a parison having extended portions at both ends of a straight body portion for manufacturing a balloon used for a balloon catheter,
A pair of first fixing mechanisms for releasably fixing both ends of a straight tubular parison tube;
A pair of second fixing mechanisms for releasably fixing a part on one end side and a part on the other end side of the portion to be the straight body part of the parison tube;
A part of the part between the first fixing mechanism and the part fixed to the second fixing mechanism on one end side of the parison tube and the first fixing mechanism and the second fixing mechanism on the other end side are fixed. A pair of heating dies for heating a part of the part between the two parts in a non-contact manner,
A first stretching mechanism that urges the pair of first fixing mechanisms away from each other to stretch a portion heated by the heating mold of the parison tube;
And a second stretching mechanism that urges the pair of second fixing mechanisms so as to be separated from each other and stretches the portion of the parison tube that is to become the straight body portion.

  According to the parison manufacturing apparatus according to the second aspect of the present invention, a parison manufacturing apparatus capable of suitably carrying out the parison manufacturing method according to the first aspect of the present invention is provided.

FIG. 1 is a front view of a parison tube as a base material for producing a parison according to an embodiment of the present invention. FIG. 2 is a front view of a parison manufactured by heating and stretching the parison tube shown in FIG. FIG. 3 is a front view of an IABP balloon manufactured by biaxial stretch blow molding of the parison shown in FIG. FIG. 4 is a cross-sectional view of an IABP balloon catheter manufactured using the IABP balloon shown in FIG. FIG. 5 is a diagram showing a process for manufacturing a parison according to an embodiment of the present invention. FIG. 6A is a front view illustrating a schematic configuration of a parison manufacturing apparatus suitable for performing the parison manufacturing process illustrated in FIG. 5. FIG. 6B is a front view showing the parison manufacturing apparatus shown in FIG. 6A during heating and stretching. FIG. 7A is a diagram illustrating a configuration of a chuck mechanism that configures the parison manufacturing apparatus illustrated in FIG. 6A. FIG. 7B is a diagram showing a state in the middle of fixing one end of the parison tube to the chuck mechanism shown in FIG. 7A. FIG. 7C is a diagram showing a state where one end of the parison tube is fixed to the chuck mechanism shown in FIG. 7A. FIG. 7D is a view showing a modification of the chuck mechanism shown in FIG. 7A. FIG. 8A is a front view showing a configuration in a state where heating blocks of a heating mold constituting the parison manufacturing apparatus shown in FIG. 6A are separated. FIG. 8B is a side view of the heating mold shown in FIG. 8A. FIG. 8C is a bottom view of the heating block above the heating mold shown in FIG. 8A or a plan view of the lower heating block. FIG. 8D is a front view showing a state in which the heating block of the heating mold shown in FIG. 8A is brought into contact. FIG. 8E is a side view of the heating mold shown in FIG. 8D. FIG. 9A is a side view showing a configuration when the straight body fixing mechanism that constitutes the parison manufacturing apparatus shown in FIG. 6A is in the raised position (initial position). FIG. 9B is a side view showing a state where the fixing arm is separated at the lowered position of the straight body fixing mechanism shown in FIG. 9A. FIG. 9C is a side view showing a state in which the fixing arm of the straight body fixing mechanism shown in FIG. FIG. 10 is a block diagram showing a configuration of a control system of the parison manufacturing apparatus shown in FIG. 6A. FIG. 11 is a diagram illustrating a balloon manufacturing process using a biaxial stretch blow molding machine using a parison manufactured using the parison manufacturing apparatus shown in FIG. 6A.

  Hereinafter, as an embodiment of the present invention, a case where a balloon included in a balloon catheter used for IABP (intra-aortic balloon pumping) is manufactured will be described as an example with reference to the drawings.

  First, the parison tube 1 as a base material for manufacturing the parison according to the present embodiment will be described. As shown in FIG. 1, the parison tube 1 is a straight tube having a diameter that is substantially constant in the axial direction from one end to the other end.

  As the material of the tube 1 for parison, a thermoplastic resin is used, and it is preferable that it is a material excellent in the bending fatigue resistance of the IABP balloon finally produced using this, for example, polyurethane, polyethylene, polyamide Polyamide elastomers, polyesters, and the like can be used, and those made of polyurethane are particularly preferable because they have a high ability to inhibit thrombus generation and high wear resistance.

  Although the manufacturing method of the tube 1 for parison is not specifically limited, What was manufactured by extrusion molding can be used. The axial dimension of the parison tube 1 is about 50 to 400 mm, the outer diameter is about φ1 to 8 mm, and the wall thickness is about 0.1 to 1.0 mm.

  As shown in FIG. 2, the parison (balloon parison) 2 is manufactured by heating and stretching the vicinity of both ends of the above-described parison tube as a base material, and the diameter thereof is substantially constant in the axial direction. It is a double-end stretched tube in which stretched portions (stretch portions) are disposed at both ends of a large diameter straight body portion (unstretched portion) 2a. The extending portions at both ends respectively have a transition portion 2b whose diameter gradually decreases and a small-diameter straight body portion 2c whose diameter hardly changes.

  The dimension in the axial direction of the large diameter straight body portion 2a of the parison 2 is about 20 to 200 mm, and the dimension in the axial direction of the transition portion 2b is about 2 to 50 mm. The outer diameter of the large diameter straight body portion 2a is approximately the same as the outer diameter of the parison tube 1, and the outer diameter of the small diameter straight body portion 2c is approximately φ0.2 to 3.0 mm.

  As shown in FIG. 3, the balloon (IABP balloon) 3 manufactured using the above-described parison 2 gradually increases in diameter at both ends of the straight body portion 3a whose diameter is substantially constant in the axial direction. A cone portion (shoulder portion) 3b that decreases to a minimum and a neck portion 3c having a diameter that is substantially constant in the axial direction and smaller than that of the straight body portion 3a are arranged. The balloon 3 is manufactured by biaxial stretch blow molding. The straight barrel portion 3a of the balloon 3 is in the large diameter straight barrel portion 2a of the parison 2, the cone portion 3b of the balloon 3 is in the transition portion 2b of the parison 2, and the neck portion 3c of the balloon 3 is in the small diameter straight barrel portion 2c of the parison 2. It roughly corresponds.

  An IABP balloon catheter 4 as a final product manufactured using the above-described balloon 3 is configured as shown in FIG. The balloon 3 of the IABP balloon catheter 4 expands and contracts in accordance with the heart beat. The balloon 3 is composed of a cylindrical balloon film having a film thickness of about 20 to 200 μm. In the present embodiment, the shape of the balloon membrane in the expanded state is a cylindrical shape, but is not limited thereto, and may be a polygonal cylindrical shape.

  The outer diameter and length of the balloon 3 for IABP are set in accordance with the inner volume of the balloon 3 that greatly affects the assisting effect on the cardiac function, the inner diameter of the arterial blood vessel, and the like. The balloon 3 usually has an internal volume of 5 to 50 cc, an outer diameter of 8 to 20 mm when expanded, and a length of 80 to 270 mm.

  The distal end of the balloon 3 is attached to the outer periphery of the distal end of the inner tube 42 via a short tube 41 or directly by heat fusion or adhesion. The proximal end of the balloon 3 is joined to the distal end of the catheter tube 44 via a contrast marker 43 made of a metal tube or the like or directly. Through the first lumen formed inside the catheter tube 44, the pressure fluid is introduced into or extracted from the balloon 3, and the balloon 3 is expanded or contracted. The balloon 3 and the catheter tube 44 are joined by heat fusion or adhesion with an adhesive such as an ultraviolet curable resin.

  The distal end of the inner tube 42 projects farther from the distal end of the catheter tube 44. The inner tube 42 is inserted in the balloon 3 and the catheter tube 44 in the axial direction. The proximal end of the inner tube 42 is communicated with the second port 46 of the branch portion 45. A second lumen that does not communicate with the first lumen formed inside the balloon 3 and the catheter tube 44 is formed inside the inner tube 42.

  When the balloon catheter 4 is inserted into the artery, the second lumen of the inner tube 42 located in the balloon 3 is also used as a guide wire insertion lumen for conveniently inserting the balloon 3 into the artery. When the balloon catheter 4 is inserted into a body cavity such as a blood vessel, the balloon 3 is folded and wound around the outer periphery of the inner tube 42. The inner tube 42 is made of the same material as the catheter tube 44, for example.

  The inner diameter of the inner tube 42 may be a diameter that allows the guide wire to be inserted, and is, for example, 0.15 to 1.5 mm, preferably 0.5 to 1 mm. The wall thickness of the inner tube 42 is preferably 0.1 to 0.4 mm. The total length of the inner tube 42 is determined according to the axial length of the balloon catheter 4 inserted into the blood vessel and is not particularly limited, but is, for example, about 500 to 1200 mm, preferably about 700 to 1000 mm.

  The catheter tube 44 is preferably made of a material having a certain degree of flexibility. The inner diameter of the catheter tube 44 is preferably 1.5 to 4.0 mm, and the wall thickness of the catheter tube 44 is preferably 0.05 to 0.4 mm. The length of the catheter tube 44 is preferably about 300 to 800 mm.

  A branch portion 45 installed outside the patient's body is connected to the proximal end of the catheter tube 44. The branch portion 45 is formed separately from the catheter tube 44 and is fixed by means such as heat fusion or adhesion. The branch 45 includes a first port 48 for introducing or derivatizing pressure fluid to and from the first lumen in the catheter tube 44 and the balloon 3, and a second port 46 communicating with the second lumen of the inner tube 42. Is formed.

  The first port 48 is connected to an expansion / contraction drive device (not shown), and fluid pressure is supplied by the drive device so that the balloon 3 is expanded or contracted. The second port 46 is connected to a blood pressure fluctuation measuring device (not shown), and can measure a blood pressure fluctuation in the artery taken from the opening end 47 at the distal end of the balloon 3. Based on the blood pressure fluctuation measured by this blood pressure fluctuation measuring device, the driving device is controlled according to the heartbeat, and the balloon 3 is expanded and contracted in a short cycle of 0.4 to 1 second. .

  Next, the manufacturing process of the above-described parison 2 will be described with reference to FIG. First, as shown in FIG. 5 (A), two portions of one part on one end side and a part on the other end side of a portion to be a straight body part (see reference numeral 2a in FIG. 2) of the parison tube 1 are provided. The pair of straight body support mechanisms (second fixing mechanisms) 60 and 60 are fixed respectively.

  Thereafter, as shown in FIG. 5 (B), in the vicinity of each of the one end and the other end of the parison tube 1 (the portions on the end side corresponding to the straight body fixing mechanisms 60 and 60, respectively) The heating molds 51 and 51 are arranged, and the heating process of heating the corresponding part by the heating molds 51 and 51 is performed. The heating dies 51, 51 are not particularly limited, but non-contact type having a substantially cylindrical heating space (heating surface) having a larger diameter than the parison tube 1 can be used.

  The heating temperature in the heating step is about 180 to 200 ° C. and the heating time is about 20 to 150 seconds, for example, when polyurethane is used as the base material of the parison tube 1. The heating range (the dimension in the axial direction of the heating surface) b1 by the heating molds 51, 51 is set to about 5 to 100 mm so that the portion to be the straight body portion (large diameter straight body portion 2a) of the parison 2 is not heated as much as possible. In addition, it is desirable to perform heating locally.

  Next, as shown in FIG. 5C, by pulling both ends of the parison tube 1 as indicated by arrows a2 and a3 in the same figure, tension is applied to the parison tube 1, and the parison tube The extending process (1st extending process) which extends the part heated at the said 1 heating process is implemented. The tension in the first stretching step is about 2 to 20 N, and the stretching dimension b2 is about 5 to 200 mm.

  In the present embodiment, when the first stretching step is performed, heating by the heating molds 51 and 51 is stopped, but may be performed while heating is continued.

  When the stretching process is completed, a cooling process is then performed to fix (fix) the shape of the heated and stretched portion of the parison tube 1 as shown in FIG. The cooling step may be natural cooling in a state where heating by the heating dies 51, 51 is stopped or the heating dies 51, 51 and the parison tube 1 are separated from each other, or inside the parison tube 1. Alternatively, forced cooling may be performed by blowing a cooling gas to the outside. In the case of natural cooling, the cooling time is about 30 to 300 seconds when the internal temperature is 15 to 35 ° C.

  In the present embodiment, the fixing of the portion to be the straight body portion by the straight body fixing mechanisms 60, 60 is continued even during the cooling process. By continuing to fix the portion to be the straight body portion even during cooling, it is possible to suppress the deformation of the heated and stretched portion of the parison tube 1 due to the action of gravity during cooling. However, the fixing may be released after the stretching step and before the cooling step.

  Next, as shown in FIG. 5 (E), the straight body fixing mechanisms 60 and 60 are separated from each other (arrow a4 in FIG. 5 (E) under non-heating (for example, in an atmosphere of 15 to 35 ° C.). , A5) and applying tension to both ends of the portion to be the straight body portion of the parison tube 1 to preliminarily stretch the portion to be the straight body portion (second stretching) Step). The stretch length b3 in this step (b3 / 2 on the left and right respectively) is the length of the portion to be the straight body portion (fixed portion by the straight body portion fixing mechanisms 60, 60 in the initial position before stretching) (Between dimensions) b4, it can be about 1.5 to 4.0 times. The stretch length b3 is preferably equal to or greater than the stretch length of the axial stretch when performing biaxial stretch blow molding described later.

  Thereafter, as shown in FIG. 5 (F), the portion to be the straight body portion is released by the straight body portion fixing mechanisms 60, 60, the application of the tension is released, and the parison is left for a predetermined time. The tube 1 contracts by its own restoring force (elastic force) (see arrows a6 and a7 in FIG. 5F) and returns to the original length or a length close thereto. Here, it is described that the second stretching step (FIG. 5E) is started after the cooling step (FIG. 5D), but the second stretching step is performed simultaneously with the cooling step. Implementation in parallel is preferable from the viewpoint of productivity.

  Finally, the parison (balloon parison) 2 as a finished product shown in FIG. 2 is obtained by cutting at appropriate portions of the stretched portion (the position indicated by reference numeral c1 in FIG. 5G). Can be obtained.

  Next, a manufacturing apparatus for carrying out the above-described manufacturing process of the parison 2 will be described with reference to FIG. 6A. The parison manufacturing apparatus 5 includes a pair of chuck mechanisms (first fixing mechanism) 50, 50, a pair of heating dies 51, 51, and a pair of stretching mechanisms (first stretching mechanism) 53, 53. In addition, the parison manufacturing apparatus 5 includes a tension detection sensor (tension detection means) 54, a support base 55, a casing 56, a pair of fans 57 and 57, a temperature detection sensor 58 in the casing, a control device 59, and the like. Yes. Further, the parison manufacturing apparatus 5 includes a pair of straight body fixing mechanisms (second fixing mechanism) 60, 60 and a pair of straight body extending mechanisms (second extending mechanisms) 61, 61 (not shown in FIG. 6A, FIG. 9A).

  The pair of chuck mechanisms 50 and 50 are means for supporting and fixing both ends of the parison tube 1 so as to be releasable in a state in which the parison tube 1 extends substantially horizontally. Since the chuck mechanisms 50 are substantially the same except that they are arranged symmetrically, only one chuck mechanism 50 (left side in FIG. 6A) will be described.

  As shown in FIGS. 7A to 7C, the chuck mechanism 50 includes a substantially cylindrical positioning member having a positioning contact surface (contact portion) 50a, a substantially cylindrical pin member (pin portion) 50b, and a pair of pairs. A chuck member (chuck part) 50c is roughly provided.

  A pin member 50b is erected on the contact surface 50a of the positioning member so as to be substantially perpendicular to the corresponding contact surface 50a and substantially coaxial with the positioning member. The pin member 50b is a member that is inserted into the lumen 1a at the end of the parison tube 1, and is slightly larger in diameter as long as it is substantially equal to the inner diameter of the lumen 1a of the parison tube 1 or does not hinder insertion. Is formed. Although not shown in the figure, the distal end portion of the pin member 50b is tapered or rounded at a portion on the distal end side so that the insertion into the lumen 1a of the parison tube 1 can be performed smoothly. It is preferable to have a tinged shape.

  The abutting surface 50a of the positioning member is a surface with which the end surface of the parison tube 1 inserted into the inner cavity 1a of the pin member 50b abuts, and a stretching mechanism 53 described later is at a predetermined initial position. In the set state, the end surface of the parison tube 1 is brought into contact with the corresponding contact surface 50a, whereby the parison tube 1 can be positioned in the extending direction (left-right direction in FIG. 6A). ing.

  The chuck members 50c and 50c are portions in which the pin member 50b is inserted into the inner lumen 1a of the end portion thereof, and the pin member 50b of the parison tube 1 in which the end surface thereof is in contact with the contact surface 50a of the positioning member. It is a member for fixing the end part of the tube 1 for parison by being pressed and clamped from the outside.

  The chuck members 50c and 50c have a plurality of claw portions that are erected on the opposing portions in order to securely fix the parison tube 1. Further, in the present embodiment, the chuck members 50c and 50c are arranged at positions facing each other by 180 degrees, and although not illustrated, they are supported so as to be symmetrically close to and separated from each other, such as an air cylinder or the like. These driving means are configured to be close to or away from each other. The operation or stop of the chuck mechanisms 50, 50 (operation or stop of the driving means) is controlled by a control device 59, which will be described later, in accordance with an operator instruction.

  As shown in FIG. 7A, the operator places one end portion of the parison tube 1 in the vicinity of one chuck member 50c, and as shown in FIG. 7B, the operator inserts a pin member into the lumen 1a on one end side of the parison tube 1. 50b is inserted, and the one end surface of the parison tube 1 is brought into contact with the contact surface 50a of the positioning member. In this state, by operating the drive means of the chuck members 50c, 50c, one end of the parison tube 1 can be fixed as shown in FIG. 7C. By performing the same operation on the other end portion of the parison tube 1, the parison tube 1 extends between the pair of chuck mechanisms 50 and 50 in a substantially horizontal direction and is fixedly disposed. be able to.

  Since the parison tube 1 is sandwiched between the pin member 50b inserted into the lumen 1a and the chuck members 50c and 50c having a plurality of claws pressed against the pin member 50b, the lumen 1a of the parison tube 1 is crushed. Is difficult to occur, and it is possible to realize a strong fixation. For this reason, even when a high tensile load is applied, it is possible to withstand this. In addition, since the parison tube 1 can be accurately positioned, variation in quality between lots can be reduced.

  In the present embodiment, the number of chuck members 50c is two. However, the number of chuck members 50c may be three or more, and the chuck members 50c may be arranged radially at equal angular intervals. Although not essential, as shown in FIG. 7D, a gas passage 50d opened at the tip of the pin member 50b is formed, and nitrogen is introduced into the lumen 1a of the parison tube 1 through the gas passage 50d. It is preferable that an inert gas such as a gas can be supplied so as to suppress oxidation accompanying heating inside the parison tube 1.

  Returning to FIG. 6A, the chuck mechanisms 50 and 50 are supported and fixed to the stretching mechanisms 53 and 53, respectively. The stretching mechanisms 53, 53 move or urge one of the pair of chuck mechanisms 50, 50 so as to be separated from the other, respectively, to the parison tube 1 whose both ends are fixed to the chuck mechanisms 50, 50. Means for applying tension. Since the extending mechanisms 53 and 53 are substantially the same except that they are arranged symmetrically, only one extending mechanism 53 (left side in FIG. 6A) will be described.

  Although not shown in detail in the drawing mechanism 53, the movable member 53a and the movable member 53a are supported so as to be movable (slidable) in the left-right direction (see arrow a16) in the drawing, and the movable member 53a is linearly supported. The linear drive mechanism 53b etc. to be moved is provided.

  The above-described chuck mechanism 50 is supported and fixed on the movable member 53 a, and the linear drive mechanism 53 b of the stretching mechanism 53 is supported and fixed on the support base 55. The linear drive mechanism 53b includes a drive motor (such as a servo motor) and a ball screw mechanism that converts the rotational motion of the drive motor into linear motion. The linear drive mechanism 53b is not limited to such a configuration, and may be a rack and pinion mechanism, a linear motor, or the like. The linear drive mechanism 53b is controlled in its operation, stop, moving speed, moving direction, and the like by a control device 59 described later.

  With the stretching mechanisms 53 and 53 set to predetermined initial positions, both ends of the parison tube 1 are fixed to the chuck mechanisms 50 and 50, and the stretching mechanisms 53 and 53 are operated, whereby the movable members 53a and 53a are moved. Both move synchronously (or try to move) in directions away from each other, and a desired tension can be applied to the parison tube 1.

  Each of the stretching mechanisms 53 and 53 has a tension detection sensor (tension detection means) 54 that detects the tension generated in the parison tube 1. For example, a load cell can be used as the tension detection sensor 54. In the present embodiment, a power transmission member 53c is provided in parallel to be separated from the movable member 53a in the moving direction, and a coil spring (not shown) and a tension detection sensor 54 are provided between the movable member 53a and the power transmission member 53c. The driving force of the linear drive mechanism 53b is transmitted to the movable member 53a via the power transmission member 53c. The detection value of the tension detection sensor 54 is input to the control device 59, and the thrust by the linear drive mechanism 53b is controlled by the control device 59 so that an appropriate preset tension is applied.

  The heating dies 51, 51 include a part on one end side (a part to be an extension part) and a part on the other end side (an extension part) of the parison tube 1 whose both ends are supported and fixed to the chuck mechanisms 50, 50. This is a means for heating the portion to be formed without contact. The heating dies 51, 51 are disposed between the chuck mechanisms 50, 50 and spaced apart from each other in the left-right direction (the direction in which the parison tube 1 extends) in FIG. Since these heating molds 51 and 51 have substantially the same configuration, only one heating mold 51 (left side in FIG. 6A) will be described.

  As shown in FIGS. 8A to 8E, the heating mold 51 has a pair of heating blocks 51a and 51b which are respectively made of a metal material such as beryllium copper. The heating blocks 51a and 51b are moved up and down synchronously so as to be close to and away from each other in the vertical direction (see arrow a11 in FIG. 6A) by the lifting mechanism 51c.

  Although not shown in detail, the elevating mechanism 51c includes a slide mechanism that holds the heating blocks 51a and 51b so that the heating blocks 51a and 51b can be slid upward and downward, a servo motor for moving the heating blocks 51a and 51b up and down, a ball screw, and the like. Drive mechanism. In the present embodiment, the heating blocks 51a and 51b are configured so that both move symmetrically and are separated from each other, but one (for example, the lower heating block 51b) is fixed, Only the other (for example, the upper heating block 51a) may be configured to move up and down, or vice versa.

  A substantially semi-cylindrical inner wall surface (heating surface 51d) is formed on the lower surface of the upper heating block 51a and the upper surface of the lower heating block 51b, and the lower surface of the upper heating block 51a and the lower heating block 51b When the upper surface comes into contact, the semi-cylindrical heating surfaces 51d and 51d cause the left and right direction (the direction in which the parison tube 1 whose both ends are supported and fixed to the chuck mechanisms 50 and 50 extend). , The central axis extends, and a substantially cylindrical heating space opened at both ends thereof is defined.

  Although not shown in the drawings, each of the heating blocks 51a and 51b incorporates a heater that generates heat by energization and a mold temperature detection sensor (for example, a thermocouple) that detects the temperature of the heating blocks 51a and 51b. The control device 59 controls energization to the heater based on the detection value by the mold temperature detection sensor (see reference numeral 59c in FIG. 11), and is a substantially circle defined by the heating surfaces 51d and 51d of the heating blocks 51a and 51b. The columnar heating space is heated so as to have an appropriate temperature. The number of heaters and mold temperature detection sensors provided in each of the heating blocks 51a and 51b may be single or plural, but a plurality is more preferable because the temperature distribution on the heating surfaces 51d and 51d can be made more uniform. .

  The inner diameter of the substantially cylindrical heating space defined by the heating surfaces 51d and 51d of the heating blocks 51a and 51b is separated from the outer periphery of the parison tube 1 disposed through the inside by a predetermined dimension. The diameter is set larger than the outer diameter of the parison tube 1 so that it can be heated without contact. Specifically, the inner diameter of the substantially cylindrical heating space defined by the heating surfaces 51d and 51d of the heating blocks 51a and 51b is set to about 2 to 12 mm.

  When both ends of the parison tube 1 are supported and fixed to the pair of chuck mechanisms 50, 50, as shown in FIGS. 8A and 8B, the upper heating block 51a is set upward (see arrow a12) and the lower heating block is set. 51b is moved downward (see arrow a13) to be spaced apart from each other and open. When the portions near both ends of the parison tube 1 are heated, as shown in FIGS. 8D and 8E, the upper heating block 51a is downward (see arrow a13) and the lower heating block 51b is upward (arrow a12). And the lower surface of the upper heating block 51a and the upper surface of the lower heating block 51b are brought into contact with each other to be in a closed state. When removing the parison tube 1 from the chuck mechanisms 50, 50, as shown in FIGS. 8A and 8B, the upper heating block 51a is moved upward (see arrow a12) and the lower heating block 51b is moved downward (see This can be done by moving to the arrow a13) and making it open.

  Returning to FIG. 6A, the straight body fixing mechanisms 60, 60 are one ends of a portion (refer to reference numeral 2 a in FIG. 2) that should be the straight body of the parison tube 1 whose both ends are supported and fixed to the chuck mechanisms 50, 50. It is means for supporting and fixing a part on the side and a part on the other end side.

  The straight body fixing mechanisms 60, 60 are disposed between the heating dies 51, 51 and are spaced apart from each other in the left-right direction (the direction in which the parison tube 1 extends) in FIG. 6A. Since these straight body fixing mechanisms 60 and 60 have substantially the same configuration, only one of the straight body fixing mechanisms 60 (left side in FIG. 6A) will be described.

  As shown in FIGS. 9A to 9C, the straight body fixing mechanism 60 includes a pair of fixing arms 60a and 60a, a gripping mechanism 60c, and an elevating mechanism 60d. Fixing portions 60b and 60b, which are substantially half-shaped notches, are formed in the vicinity of the lower ends of the fixing arms 60a and 60a so as to face each other. The inner diameters of the fixing portions 60b and 60b are set to be slightly smaller than the outer diameter of the parison tube 1 so that the parison tube 1 can be securely fixed while suppressing deformation thereof. The shape of the fixing portions 60b, 60b is not limited to a substantially semicircular shape as long as the parison tube 1 can be reliably fixed while suppressing deformation and damage to the outer periphery as much as possible.

  The upper ends of the pair of fixed arms 60a, 60a are supported by the gripping mechanism 60c. Although not shown in detail in the gripping mechanism 60c, each of the fixed arms 60a and 60a is slidably held in the direction of the arrow a19 in FIG. 9A (the front-rear direction in FIG. 6A) and the fixed arms 60a and 60a. And a drive mechanism having a servo motor and a ball screw for movement. The fixed arms 60a and 60a are moved and opened synchronously in a direction away from each other as shown in FIG. 9A or 9B by the gripping mechanism 60c, and in a direction close to each other as shown in FIG. 9C ( Two states can be taken: a closed state by moving synchronously in the direction of arrow a20 in FIG. 9C.

  The gripping mechanism 60c is supported by the lifting mechanism 60d. Although not shown in detail, the elevating mechanism 60d includes a slide mechanism that slidably holds the gripping mechanism 60c up and down (see arrow a17 in FIG. 9A), a servo motor for driving the elevating mechanism 60c, a ball screw, and the like. And a drive mechanism having The gripping mechanism 60c is moved by the elevating mechanism 60d to the upper initial position as shown in FIG. 9A and downward (in the direction of arrow a18) as shown in FIG. The tube 1 can be in two states: a state where the tube 1 can be held and fixed.

  When the gripping mechanism 60c is set at the lower position by the elevating mechanism 60d, the pair of fixed arms 60a and 60a are brought close to each other by the gripping mechanism 60c, and as shown in FIG. The parison tube 1 is clamped and fixed by 60b.

  The straight body fixing mechanisms 60 and 60 are supported and fixed to the straight body extending mechanisms 61 and 61, respectively. The straight body part extending mechanisms 61 and 61 move or urge the pair of straight body part fixing mechanisms 60 and 60 so as to be separated from each other, and are fixed to the straight body part fixing mechanisms 60 and 60 (the straight body part). It is means for applying a tension to a portion to be a part and stretching. Since the straight body part extending mechanisms 61 and 61 are substantially the same except that they are arranged symmetrically, only one of the straight body part extending mechanisms 61 will be described.

  Although the detailed illustration of the straight body extending mechanism 61 is omitted, the movable member 61a and the movable member 61a are supported so as to be movable (slidable) in the left-right direction (see arrow a16) in 6A. The linear drive mechanism 61b etc. which move 61a linearly are provided.

  The lower end of the elevating mechanism 60d of the above-described straight body fixing mechanism 60 is supported and fixed to the movable member 61a, and the linear drive mechanism 61b of the straight body extending mechanism 61 is supported and fixed to the support base 55. The linear drive mechanism 61b includes a drive motor (such as a servo motor) and a ball screw mechanism that converts the rotational motion of the drive motor into linear motion. The linear drive mechanism 61b is not limited to such a configuration, and may be a rack and pinion mechanism, a linear motor, or the like. The linear drive mechanism 61b is configured such that its operation, stop, moving speed, moving direction, and the like are controlled by a control device 59 described later.

  In a state where the straight body part extending mechanisms 61 and 61 are set at predetermined initial positions, the straight body part fixing mechanisms 60 and 60 are fixed to the vicinity of both ends of the part to be the straight body part of the parison tube 1, A direction in which the movable member 61a of the left straight body stretching mechanism 61 and the movable member 61a of the right straight body stretching mechanism 61 are synchronously separated from each other by operating the straight body stretching mechanisms 61, 61. And the corresponding portion of the parison tube 1 is stretched. In addition, one or both of each straight body part extending | stretching mechanism 61 and 61 may be provided with the tension | tensile_strength detection sensor (tension detection means) which detects the tension | tensile_strength which has arisen in the part which should become a straight body part. As a tension detection sensor in this case, the same sensor as the tension detection sensor 54 according to the above-described stretching mechanism 53 can be used.

  Returning to FIG. 6A, a pair of stretching mechanisms 53, 53 (linear drive mechanisms 53b, 53b) holding the chuck mechanism 50, a pair of heating dies 51, 51 (elevating mechanisms 51c, 51c), and a pair of straight body stretching mechanisms. 61 and 61 (linear drive mechanisms 61 b and 61 b) are fixed on the support base 55, and the entirety thereof is accommodated in the housing 56. As the housing 56, a frame made of a metal or the like and a transparent panel (for example, an acrylic plate) attached thereto can be used. Although not shown, the casing 56 is provided with an openable / closable door for manually fixing or removing the parison tube 1 with respect to the chuck mechanisms 50, 50, or for other maintenance. Yes. A plurality of intake and exhaust (exhaust in this embodiment) fans 57 and 57 and an in-casing temperature detection sensor 58 for detecting the temperature in the casing 56 are attached to the casing 56.

  Next, a control system of the above-described parison manufacturing apparatus will be described with reference to FIG. The control device 59 includes input means 59a and display means 59b. The input means 59a includes buttons for operating or releasing the chuck mechanisms 50, 50, an emergency stop button, other buttons, a keyboard for selecting functions and inputting various setting values, and the like. The display means 59b includes a liquid crystal monitor and various indicators.

  At the time of manufacturing the parison, first, the operator manually sets the unstretched parison tube 1 to the chuck mechanisms 50 and 50 at both ends thereof. At this time, as shown in FIG. 6A, the stretching mechanisms 53 and 53 are set at predetermined initial positions, and the heating dies 51 and 51 are in a state where the heating blocks 51a and 51b are separated (open). It has become. At this time, as shown in FIGS. 6A and 9A, the straight body fixing mechanisms 60 and 60 are set at the upper initial position, and the fixing arms 60a and 60a are separated (open). It has become. Next, the operation buttons of the chuck mechanisms 50 and 50 are pressed to support and fix both ends of the parison tube 1.

  When it is confirmed that the ends of the parison tube 1 are fixed normally, the operator performs a predetermined operation (for example, presses a start button for heating and stretching), thereby performing a series of steps for manufacturing the parison. Operation starts. The control device 59 automatically controls each part in accordance with a control sequence previously selected by the operator. Note that this operation may be omitted, and a series of controls including the operation of fixing both ends of the above-described parison tube 1 may be started by pressing the operation buttons of the above-described chuck mechanisms 50 and 50.

  An example of a control sequence by the control device 59 will be described. First, the stretching mechanisms 53 and 53 are driven so as to be separated from each other so that both ends of the parison tube 1 are supported and fixed to the chuck mechanisms 50 and 50 in advance. The set tension (initial tension) is applied and the state is maintained. The tension generated in the parison tube 1 is detected by a tension detection sensor 54. Based on the detected value, the stretching mechanisms 53 and 53 are controlled so as to have a preset initial tension, and the initial tension is set. After reaching, the feedback control is performed so that the tension becomes constant.

  The initial tension is set to an appropriate value at which the slack of the parison tube 1 (the difference in height between the central portion in the axial direction of the tube and the fixed portions at both ends) is within an allowable range. If the initial tension is too small, the slack becomes large, and there are cases where the fixing by the straight body fixing mechanisms 60, 60 to be performed later cannot be performed properly. On the other hand, if the initial tension is too large, the slackness is reduced and the above problem can be solved. However, the heating portion of the parison tube 1 is unnecessarily stretched during the heating by the heating mold 51 and is manufactured. In addition, the unevenness of the transition part 2b of the parison 2 may not be uniform (the inclination becomes two steps), which may cause stretching unevenness. For this reason, the initial tension is set to an appropriate value that both of these allow. The initial tension can be about 1 to 10N. In this embodiment, since the tension generated in the parison tube 1 can be detected in real time by the tension detection sensor 54, the initial tension can be accurately maintained constant at a desired value, and the fluctuation of the initial tension can be maintained. It is possible to reduce the occurrence of stretching unevenness.

  If the initial tension is applied, the straight body part fixing mechanisms 60, 60 are operated in a state where the straight body part extending mechanisms 61, 61 are set to a predetermined initial position, and from the initial position shown in FIG. 9A, As shown in FIGS. 6B and 9B, the fixed arms 60a and 60a are lowered, and as shown in FIG. 9C, the fixed arms 60a and 60a are close to each other and closed, and the fixed portions 60b and 60b of the fixed arms 60 and 60 are closed. Thus, the portion to be the straight body portion of the parison tube 1 is clamped and fixed.

  Next, as shown in FIG. 6B, the elevating mechanisms 51c and 51c of the heating molds 51 and 51 are operated, the upper heating block 51a is lowered (see arrow a13 in the figure), and the lower heating block 51b is raised. Then (see arrow a12 in the figure), the portions to be stretched in the vicinity of both ends of the parison tube 1 are defined by the heating surfaces 51d and 51d of the heating blocks 51a and 51b. It arrange | positions in the heating space formed (refer also FIG. 8D and FIG. 8E).

  Next, energization of the heaters of the heating molds 51 and 51 is performed, and heat generation is started. The energization of the heaters of the heating molds 51 and 51 may be performed before the heating blocks 51a and 51b are closed. The temperatures of the heating molds 51 and 51 are detected by a mold temperature detection sensor 59c, and energization of the heater is controlled so as to be a predetermined temperature set in advance.

  When a predetermined time set in advance has elapsed from the start of heating (or after reaching a predetermined temperature), the heating is stopped and the stretching mechanisms 53 and 53 are moved away from each other (arrow a17). , A18), tension is applied to the portion between the chuck mechanism 50 and the straight barrel fixing mechanism 60 on one end side and the portion between the chuck mechanism 50 and the straight barrel fixing mechanism 60 on the other end side of the parison tube 1, respectively. Applied and stretched. The tension generated in the parison tube 1 is detected by a tension detection sensor 54, and the moving speed of the linear drive mechanisms 53b and 53b by the stretching mechanisms 53 and 53 is controlled based on the detected value. In addition, you may continue a heating during extending | stretching.

  When the preset stretching length (stretch length) is reached, the movement of the linear drive mechanisms 53b, 53b of the stretching mechanisms 53, 53 is stopped, and this state is maintained for a preset predetermined time. The parison tube 1 is cooled. Thereby, the shape of the tube 1 for parison by which the vicinity part of the both ends was extended is fixed.

  In parallel with this cooling or after the cooling is completed, the portion to be the straight body portion is stretched. That is, the straight body portion extending mechanism 61, 61 is moved in a direction away from each other (see arrows a17, a18 in FIG. 6B), and the straight body portion on one end side of the portion to be the straight body portion of the parison tube 1 Tension is applied to the portion between the fixing mechanism 60 and the straight body fixing mechanism 60 on the other end side to perform stretching. The tension generated in the portion that should become the straight body portion of the parison tube 1 is detected by a tension detection sensor (not shown), and based on the detected value, linear driving by the straight body stretching mechanisms 61 and 61 is performed. The moving speed of the mechanisms 61b and 61b is controlled.

  Next, a portion of the parison tube 1 to be the straight body portion is set to a predetermined stretch length (for example, the straight body portion fixing mechanism 60 of the parison tube 1 before the portion to be the straight body portion is stretched). , 60), the movement of the straight body extension mechanisms 61, 61 by the linear drive mechanisms 61b, 61b is stopped. During the stretching of the portion to be the straight body portion of the parison tube 1, the stretching mechanisms 53 and 53 related to the chuck mechanisms 50 and 50 are tensioned to the portions other than the portion to be the straight body portion of the parison tube 1. In order to prevent the compression force from acting, the straight body portion fixing mechanisms 60 and 60 are moved in directions away from each other in synchronization with the movement of the straight body fixing mechanisms 60 and 60.

  Thereafter, the urging force of the straight body extension mechanisms 61 and 61 to the movable members 61a and 61a by the linear drive mechanisms 61b and 61b is released, that is, the movable members 61a and 61a are movable, and the straight body of the parison tube 1 is moved. Due to its own elasticity (restoring force) of the part to be the part, the movable members 61a and 61a move in the proximity direction, and the part to be the straight body part is contracted. During contraction of the portion to be the straight body portion of the parison tube 1, the stretching mechanisms 53 and 53 related to the chuck mechanisms 50 and 50 are tensioned to portions other than the portion to be the straight body portion of the parison tube 1. In order to prevent the compression force from acting, the straight body portion fixing mechanisms 60 and 60 are moved in directions close to each other in synchronization with the movement of the straight body portion fixing mechanisms 60 and 60.

  Next, the fixing arms 60a, 60a of the straight body fixing mechanisms 60, 60 are opened by the gripping mechanism 60c so as to be separated from each other, and the straight body of the parison tube 1 by the fixing parts 60b, 60b of the fixing arms 60a, 60a The part to be fixed is released. Note that during the contraction of the portion to be the straight body portion after the fixing of the portion to be the straight body portion of the parison tube 1 is released, the stretching mechanisms 53 and 53 related to the chuck mechanisms 50 and 50 have the parison. The tubes 1 are moved in directions close to each other so that no tension or compressive force acts on the tube 1.

  If the portion to be the straight body portion of the parison tube 1 returns to its original length (length before stretching) or a predetermined length after a predetermined time has elapsed, it is determined that the series of operations has ended. To terminate the sequence. The end notification can be displayed on an indicator or the like of the display means 59b, or can be made with a buzzer or the like.

  When a series of sequences is completed, the operator depresses the release buttons of the chuck mechanisms 50 and 50 to release the fixing of both ends of the parison tube 1 in which the portions near the both ends are extended. Remove this at work. Note that during these series of operations, the temperature in the casing 56 is detected by the temperature detection sensor 58 in the casing, and the fans 57 and 57 are activated or stopped based on the detected value, whereby the casing 56 is detected. The temperature in the body 56 is controlled to be constant. Further, the releasing operation of the chuck mechanisms 50, 50 may be omitted, and this operation may be included in a series of sequences.

  Finally, the parison 2 as a completed body shown in FIG. 2 is obtained by manually cutting an appropriate portion of the stretched portion of the tube 1 for parison in which the vicinity of both ends is stretched and cutting off both ends. Can be obtained.

  A process of manufacturing a balloon using the parison 2 manufactured as described above and processing with a biaxial stretch blow molding machine will be outlined with reference to FIG. First, as shown in FIG. 11A, the parison 2 is set in a mold 70 of a biaxial stretch blow molding machine. The mold 70 has openings that are opened at both ends in the longitudinal direction (axial direction), and has a space substantially in the shape relative to the outer shape of the balloon to be manufactured. That is, the mold 70 has spaces 70a, 70b, 70b, 70c, 70c corresponding to the straight body portion 3a, the cone portions 3b, 3b and the neck portions 3c, 3c (see FIG. 3), respectively. The mold 70 is composed of a pair of split molds having a relative shape so that the spaces 70a, 70b, 70b, 70c, 70c are defined at the time of joining.

  The parison 2 is set as shown in FIG. 11A in a state where the mold 70 is opened (a state where the pair of split molds are separated from each other). Although not shown in the drawings, outside the both ends of the mold 70 in the axial direction, a pair of fixing mechanisms are arranged. By fixing both ends of the parison 2 to the fixing mechanism, the parison 2 Is set with its axis along the axis of the mold 70.

  Next, as shown in FIG. 11B, the pair of fixing mechanisms that fix both ends of the parison 2 are moved away from each other under non-heating (for example, in an atmosphere of 15 to 35 ° C.). Thus, tension is applied to the parison 2 and axial stretching is performed to stretch the parison 2 in the axial direction. The tension generated in the parison 2 is detected by a tension detection sensor, and the moving speed of the fixing mechanism is controlled in accordance with the detected tension. Stopped and maintained in that state.

  Next, heating of the mold 70 is started, and nitrogen gas is supplied into the inner cavity of the parison 2 at a predetermined supply (filling) pressure. Nitrogen gas is supplied from one end of the parison 2 and the other end is closed. However, it may be supplied from both ends. As the temperature of the mold 70 rises, the supply pressure of nitrogen gas is controlled to decrease. As a result, as shown in FIG. 11C, circumferential stretching is performed in which the large-diameter straight body portion 2a, the transition portions 2b and 2b, and the small-diameter straight body portions 2c and 2c of the parison 2 are stretched in the circumferential direction. It is formed into a shape corresponding to 70 corresponding spaces 70a, 70b, 70b, 70c, 70c. Thereby, the balloon which has the straight body part 3a, the cone parts 3b and 3b, and the neck parts 3c and 3c is manufactured.

  According to the embodiment described above, in the manufacturing process of the parison 2, the step of stretching the portion to be the straight body portion of the parison tube 1 once and then contracting it by its own elasticity is performed. By carrying out such preliminary stretching and contraction, the physical properties (stress-strain curve shape) relating to the stretchability of the straight body portion (large diameter straight body portion 2a) of the parison 2 are changed. When stretched, it becomes easy to stretch in the axial direction. For this reason, it is possible to reduce the time required for stretching in the axial direction (the above-mentioned axial stretching) performed when the balloon is manufactured by biaxial stretching blow molding using the parison 2, and the production of the balloon 3 can be shortened. Can be improved.

  Further, in the above-described embodiment, the preliminary stretching of the parison tube 1 is performed on the portion to be the straight body portion by fixing the vicinity portions of both ends of the portion to be the straight body portion. Therefore, this preliminary stretching does not affect the heated stretched portion (stretched portion) of the parison tube 1. Therefore, since this preliminary stretching can be performed in parallel with waiting for sufficient cooling of the stretched portion, the time required for manufacturing the parison 2 does not increase. In addition, in embodiment mentioned above, although the preliminary | backup extending | stretching of the part which should become a straight body part performed in the manufacturing process of the parison 2 is 1 time, you may make it perform 2 times or more.

  Examples of the present invention will be described below. As a base material of the test piece, a straight tube made of polyurethane is cut at 250 mm (a dimension between the contact surfaces 50a and 50a of the chuck mechanisms 50 and 50 when the stretching mechanisms 53 and 53 are set to the initial positions). A plurality of parison tubes 1 were manufactured. The outer diameter of the tube was 4.0 mm and the wall thickness was 0.5 mm.

  After the parison tube 1 was set in the parison manufacturing apparatus 5 shown in FIG. 6A and the portion to be the straight body portion was fixed, the parison tube 1 was heated and the heated portion was stretched. The mold temperature was 190 ° C., the heating time was 55 seconds, the stretching speed was 140 mm / second, and the stretching length (stretching length) b2 (see FIG. 5C) was 60 mm. The applied tension (initial tension) was 5N.

  Next, natural cooling was performed. The cooling time was 60 seconds. In parallel with this cooling, preliminary stretching of the portion to be the straight body portion was performed. The stretching distance was twice as much as that of the unstretched straight body portion (that is, 200 mm), and the stretching speed was 1000 mm / min. In addition, the temperature in the housing | casing 56 during manufacture was controlled to 30 degreeC. Then, the part which should become a straight body part was implemented. Ten test pieces were manufactured under the same conditions.

  As a comparative example, ten test pieces were similarly manufactured in the same manner as in the above-described example, except that the preliminary stretching of the portion to be the straight body portion was not performed.

  About each test piece (10 examples, 10 comparative examples), it sets to the metal mold | die of the blow molding machine shown in FIG. 11, implements extending | stretching to an axial direction (axial direction extending | stretching), and it complete | finishes from the start of extending | stretching ( The time until reaching the predetermined stretch length) was measured. The results are shown in Table 1.

  As shown in Table 1, in the example in which preliminary stretching of the portion to be the straight body portion was performed, the average value of the stretching time was 42 seconds and the standard deviation (σ) was 13.3 seconds. On the other hand, in the comparative example in which the preliminary stretching was not performed, the average value of the stretching time was 614 seconds, and the standard deviation (σ) was 546.7 seconds. It was confirmed that the example in which the preliminary stretching of the portion to be the straight body part was significantly shortened, the variation was small, and superior to the comparative example in which this was not performed. .

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above-described embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Tube for parison 2 ... Parison 2a ... Large diameter straight body part 2b ... Transition part 2c ... Small diameter straight body part 3 ... Balloon for IABP 3a ... Straight body part 3b ... Conical part 3c ... Neck part 4 ... Balloon catheter for IABP 5 ... Parison manufacturing equipment 50 ... Chuck mechanism (first fixing mechanism)
50a ... Contacting surface of positioning member 50b ... Pin member 50c ... Chuck member 51 ... Heating mold 51a, 51b ... Heating block 51c ... Lifting mechanism 51d ... Heating surface 53 ... Stretching mechanism (first stretching mechanism)
53a ... Moveable member 53b ... Linear drive mechanism 53c ... Power transmission member 54 ... Tension detection sensor 55 ... Support base 56 ... Case 57 ... Fan 58 ... In-case temperature detection sensor 59 ... Control device 59a ... Input means 59b ... Display means 59c ... Die temperature detection sensor 60 ... Straight barrel fixing mechanism (second fixing mechanism)
60a ... fixed arm 60b ... fixed part 60c ... gripping mechanism 60d ... lifting mechanism 61 ... straight body part extending mechanism (second extending mechanism)
61a ... movable member 61b ... linear drive mechanism

Claims (2)

A method for producing a parison having stretched portions at both ends of a straight body portion for producing a balloon used for a balloon catheter,
A heating step of heating the part to be the extension part on one end side of the straight tubular parison tube and the part to be the extension part on the other end side;
Applying a tension to the parison tube and stretching a portion heated in the heating step;
Applying a tension to both ends of the portion to be the straight body portion of the parison tube, extending the portion to be the straight body portion, and then releasing and contracting the tension; Including parison manufacturing method. A device for manufacturing a parison having extended portions at both ends of a straight body portion for manufacturing a balloon used for a balloon catheter,
A pair of first fixing mechanisms for releasably fixing both ends of a straight tubular parison tube;
A pair of second fixing mechanisms for releasably fixing a part on one end side and a part on the other end side of the portion to be the straight body part of the parison tube;
A part of the part between the first fixing mechanism and the part fixed to the second fixing mechanism on one end side of the parison tube and the first fixing mechanism and the second fixing mechanism on the other end side are fixed. A pair of heating dies for heating a part of the part between the two parts in a non-contact manner,
A first stretching mechanism that urges the pair of first fixing mechanisms away from each other to stretch a portion heated by the heating mold of the parison tube;
A parison manufacturing apparatus comprising: a second stretching mechanism that urges the pair of second fixing mechanisms so as to be separated from each other and stretches a portion to be the straight body portion of the parison tube.

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