JP6812884B2 - Parison manufacturing method and parison manufacturing equipment - Google Patents

Description

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

As a treatment for cardiac dysfunction, IABP (intra-aortic balloon pumping) is performed in which a balloon catheter is inserted into the aorta and the balloon is expanded and contracted in accordance with the heartbeat to assist the cardiac function. The 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 thoracic artery.

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

Such a balloon is manufactured by biaxially stretching blow molding a parison (tube) formed into a tubular shape by extrusion molding. As a parison manufacturing technique for that purpose, although it relates to a balloon catheter for PTCA (vasculoplasty) instead of 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 thickness of the balloon, tubes having different diameters (small diameters) at both ends are used as the parison used for blow molding, the diameters of both ends being smaller than those of the straight body. .. In Patent Document 1, this tube having different diameters at both ends is formed by alternately forming thin parts and thick parts by appropriately changing and controlling the extrusion conditions by an extruder, the take-up conditions by a take-up machine, and the like during extrusion molding. , Manufactured.

As another method for producing such a tube having a deformed shape at both ends, a method of heating and stretching the vicinity of both ends of a tube formed into a straight tube by extrusion molding is practically used. In this method, a part of a tube formed in a straight tube on one end side is heated by a heating mold, tension is applied to both ends of the tube to stretch the heated part on the one end side, and then the tube is cooled. Next, a part of 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 stretch the heated portion on the other end side and then cool the tube.

Such a parison is set in a mold of a biaxial stretching blow molding machine, and axial stretching is performed in which the parison is stretched in the axial direction in an unheated state. 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 one to the other), and the stretching is performed when the stretching length is reached. Stop. Next, the mold is heated, nitrogen gas is press-fitted into the cavity of the parison, and the circumferential stretching is performed. A space having a substantially relative shape to the outer shape of the balloon to be manufactured is formed in the mold, and the space of the mold can be adjusted by appropriately changing and adjusting the heating temperature and the supply pressure of nitrogen gas by the mold. A balloon stretched along the shape of the wall is manufactured. Then, in biaxial stretching blow molding for manufacturing such a balloon, there is a demand for a parison that can shorten the processing time and improve the productivity.

Japanese Unexamined Patent Publication No. 2001-321444

The present invention has been made in view of such circumstances, and an object of the present invention is a method for producing a parison capable of improving productivity in biaxial stretching blow molding of a balloon, and a parison suitable for carrying out the method. To provide manufacturing equipment.

The parison manufacturing method according to the first aspect of the present invention
A method for manufacturing a parison having extending portions at both ends of a straight body portion for manufacturing a balloon used for a balloon catheter.
A heating step of heating the portion to be the stretched portion on one end side of the straight tubular parison tube and the portion to be the stretched portion on the other end side, respectively.
A first stretching step of applying tension to the parison tube to stretch the portion heated in the heating step, and
A second stretching step of applying tension to both ends of the portion of the parison tube to be the straight body portion, stretching the portion to be the straight body portion, and then releasing the tension to contract the portion. Including.

The parison manufacturing method according to the first aspect of the present invention includes a step of stretching a portion of the parison tube to be a straight body portion by tension and then releasing the tension to contract the tube. By performing such preliminary stretching and contraction, the physical properties related to stretchability are changed, and when this is stretched next time, it becomes easy to stretch in the axial direction thereof. Therefore, it is possible to shorten the time required for the axial stretching (the above-mentioned axial stretching) performed when the balloon is manufactured by biaxial stretching blow molding using the parison subjected to such preliminary stretching. It is possible to improve the productivity of the balloon.

The parison manufacturing apparatus according to the second aspect of the present invention is
A parison manufacturing device having extension portions at both ends of a straight body portion for manufacturing a balloon used for a balloon catheter.
A pair of first fixing mechanisms that releaseably fix both ends of the 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 of the parison tube that should be the straight body portion.
A part of the portion between the first fixing mechanism on one end side of the parison tube and the portion fixed to the second fixing mechanism, and fixed to the first fixing mechanism and the second fixing mechanism on the other end side. A pair of heating dies that heat a part of the part between the parts in a non-contact manner,
A first stretching mechanism that urges the pair of first fixing mechanisms so as to be separated from each other to stretch a portion of the parison tube heated by the heating mold.
It has a second stretching mechanism that urges the pair of second fixing mechanisms so as to be separated from each other and stretches a portion of the parison tube that should be the straight body portion.

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

FIG. 1 is a front view of a parison tube as a base material for manufacturing 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 biaxially stretching blow molding the parison shown in FIG. 2. FIG. 4 is a cross-sectional view of an IABP balloon catheter manufactured by using the IABP balloon shown in FIG. FIG. 5 is a diagram showing a manufacturing process of a parison according to an embodiment of the present invention. FIG. 6A is a front view showing a schematic configuration of a parison manufacturing apparatus suitable for carrying out the parison manufacturing process shown in FIG. FIG. 6B is a front view showing the parison manufacturing apparatus shown in FIG. 6A during heating and stretching. FIG. 7A is a diagram showing a configuration of a chuck mechanism constituting the parison manufacturing apparatus shown in FIG. 6A. FIG. 7B is a diagram showing a state in which one end of the parison tube is being fixed to the chuck mechanism shown in FIG. 7A. FIG. 7C is a diagram showing a state in which one end of the parison tube is fixed to the chuck mechanism shown in FIG. 7A. FIG. 7D is a diagram showing a modified example of the chuck mechanism shown in FIG. 7A. FIG. 8A is a front view showing a configuration in which the heating blocks of the heating mold constituting the parison manufacturing apparatus shown in FIG. 6A are separated from each other. 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 heating block below. FIG. 8D is a front view showing a state in which the heating blocks of the heating mold shown in FIG. 8A are in contact with each other. 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 portion fixing mechanism constituting the parison manufacturing apparatus shown in FIG. 6A is in an ascending position (initial position). FIG. 9B is a side view showing a state in which the fixing arm is separated at the lowering position of the straight body portion fixing mechanism shown in FIG. 9A. FIG. 9C is a side view showing a state in which the fixing arm of the straight body portion fixing mechanism shown in FIG. 9B is brought close to each other and the parison tube is fixed. 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 showing a manufacturing process of a balloon by a biaxial stretching blow molding machine using a parison manufactured by using the parison manufacturing apparatus shown in FIG. 6A.

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

First, a 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 tubular tube whose diameter is substantially constant in the axial direction from one end to the other end.

As the material of the parison tube 1, a thermoplastic resin is used, and it is preferable that the material is excellent in bending fatigue resistance of the balloon for IABP finally produced by using the thermoplastic resin, for example, polyurethane, polyethylene, polyamide. , Polyamide elastomer, polyester and the like can be used, and those made of polyurethane are particularly suitable because they have a high ability to suppress the formation of blood clots and a high wear resistance.

The method for producing the parison tube 1 is not particularly limited, but those produced 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 manufactured by using the above-mentioned parison tube as a base material and heating and stretching the portions near both ends thereof has a substantially constant diameter in the axial direction. This is a double-ended stretch tube in which stretched portions (stretched portions) are arranged at both ends of the large-diameter straight body portion (unstretched portion) 2a. The stretched portions at both ends have a transition portion 2b whose diameter gradually decreases and a small diameter straight body portion 2c whose diameter hardly changes.

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

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

The balloon catheter 4 for IABP as a final product manufactured by using the balloon 3 described above is configured as shown in FIG. The balloon 3 of the IABP balloon catheter 4 expands and contracts in accordance with the beating of the heart. The balloon 3 is composed of a tubular balloon membrane 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 the shape is not limited to this, and a polygonal cylinder shape may be used.

The outer diameter and length of the balloon 3 for IABP are set according to the inner volume of the balloon 3, which greatly affects the auxiliary effect of 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 or directly through a contrast marker 43 made of a metal tube or the like. Through a first lumen formed inside the catheter tube 44, the pressure fluid is introduced or drawn into the balloon 3 so that the balloon 3 expands or contracts. 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 than the distal end of the catheter tube 44. The inner tube 42 is axially inserted into the balloon 3 and the catheter tube 44. The proximal end of the inner tube 42 communicates with the second port 46 of the branch 45. Inside the inner tube 42, a second lumen that does not communicate with the first lumen formed inside the balloon 3 and the catheter tube 44 is formed.

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 tube 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 circumference 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 pipe 42 may be any diameter as long as the guide wire can be inserted, 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 bifurcation 45 installed outside the patient's body is connected to the proximal end of the catheter tube 44. The bifurcation portion 45 is formed separately from the catheter tube 44 and is fixed by means such as heat fusion or adhesion. The bifurcation 45 has a first lumen in the catheter tube 44 and a first port 48 for introducing or deriving a pressure fluid to the balloon 3 and a second port 46 communicating in 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 the drive device supplies fluid pressure so that the balloon 3 expands or contracts. The second port 46 is connected to a blood pressure fluctuation measuring device (not shown), and can measure the fluctuation of blood pressure in the artery taken from the open end 47 at the distal end of the balloon 3. Based on the fluctuation of blood pressure 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 parison 2 described above will be described with reference to FIG. First, as shown in FIG. 5 (A), two places, a part on one end side and a part on the other end side of the portion to be the straight body portion (see reference numeral 2a in FIG. 2) of the parison tube 1. It is fixed by a pair of straight body support mechanisms (second fixing mechanism) 60, 60, respectively.

After that, as shown in FIG. 5 (B), in the vicinity of one end and the other end of the parison tube 1 (parts on the end side corresponding to the straight body fixing mechanisms 60 and 60, respectively). The heating dies 51, 51 are arranged, and the heating step of heating the corresponding portion by the heating dies 51, 51 is carried out. The heating dies 51 and 51 are not particularly limited, but non-contact types having a substantially columnar heating space (heating surface) having a diameter larger than that of the parison tube 1 can be used.

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

Next, as shown in FIG. 5 (C), tension is applied to the parison tube 1 by pulling both ends of the parison tube 1 as shown by arrows a2 and a3 in the figure to apply tension to the parison tube 1. A stretching step (first stretching step) for stretching the portion heated in the heating step of 1 is carried out. 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 carried out, it is assumed that the heating by the heating dies 51 and 51 is stopped, but the heating may be continued.

After the stretching step is completed, a cooling step is then carried out in order to fix (fix) the shape of the heat-stretched portion of the parison tube 1 as shown in FIG. 5 (D). In the cooling step, heating by the heating dies 51, 51 may be stopped, or the heating dies 51, 51 and the parison tube 1 may be separated from each other by natural cooling, or the inside of the parison tube 1 may be cooled. Alternatively, a cooling gas may be blown to the outside for forced cooling. The cooling time is about 30 to 300 seconds in the case of natural cooling when the temperature inside the housing is 15 to 35 ° C.

In the present embodiment, the straight body portion fixing mechanisms 60 and 60 continue to fix the portion to be the straight body portion even during the cooling process. By continuing to fix the portion that should be the straight body portion even during cooling, it is possible to suppress deformation of the particularly heated / 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), under unheated conditions (for example, in an atmosphere of 15 to 35 ° C.), the straight body portion fixing mechanisms 60 and 60 are separated from each other (arrow a4 in FIG. 5 (E)). , A5), tension is applied to both ends of the portion of the parison tube 1 that should be the straight body, and the part that should be the straight body is preliminarily stretched (second stretching). Step) is carried out. The stretch length b3 (b3 / 2 on the left and right) in this step 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 state set at the initial position before stretching). Dimension between) b4 can be about 1.5 to 4.0 times. The stretch length b3 is preferably equal to or longer than the stretch length of axial stretching when biaxial stretching blow molding described later is performed.

After that, as shown in FIG. 5 (F), the straight body portion fixing mechanisms 60 and 60 release the fixing of the portion to be the straight body portion, release the application of tension, and leave the parison for a predetermined time. The tube 1 contracts due to its own restoring force (elastic force) (see arrows a6 and a7 in FIG. 5 (F)), and returns to the original length or a length close thereto. Although it is described here that the second stretching step (FIG. 5 (E)) is started after the cooling step (FIG. 5 (D)) is performed, the second stretching step is performed at the same time as the cooling step. It is preferable to carry out in parallel from the viewpoint of productivity.

Finally, the parison (balloon parison) 2 as a completed product shown in FIG. 2 is obtained by cutting each of the stretched portions at appropriate locations (positions indicated by reference numerals c1 in FIG. 5 (G)). Obtainable.

Next, a manufacturing apparatus for carrying out the manufacturing process of the parison 2 described above 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 to this, the parison manufacturing apparatus 5 includes a tension detection sensor (tension detection means) 54, a support 55, a housing 56, a pair of fans 57, 57, a temperature detection sensor 58 inside the housing, a control device 59, and the like. There is. Further, the parison manufacturing apparatus 5 includes a pair of straight body portion fixing mechanisms (second fixing mechanism) 60, 60 and a pair of straight body portion stretching mechanisms (second stretching mechanism) 61, 61 (not shown in FIG. 6A). 9A) is provided.

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

As shown in FIGS. 7A to 7C, the chuck mechanism 50 includes a substantially columnar positioning member having a contact surface (contact portion) 50a for positioning, a substantially columnar pin member (pin portion) 50b, and a pair. The chuck member (chuck portion) 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 contact surface 50a and substantially coaxial with the positioning member. The pin member 50b is a member to be inserted into the lumen 1a at the end of the parison tube 1, and has a diameter substantially equal to the inner diameter of the lumen 1a of the parison tube 1 or a slightly larger diameter within a range that does not interfere with the insertion. Is formed in. Although not shown in the figure, the tip of the pin member 50b has a tapered tip or a rounded tip so that the parison tube 1 can be smoothly inserted into the cavity 1a. It is preferable that the shape is tinged with.

The contact surface 50a of the positioning member is a surface on which the end surface of the parison tube 1 in which the pin member 50b is inserted into the cavity 1a at the end thereof is contacted, and the stretching mechanism 53 described later is placed at a predetermined initial position. By bringing the end surface of the parison tube 1 into contact with the corresponding contact surface 50a in the set state, 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 cavity 1a at the end thereof and the pin member 50b of the parison tube 1 whose end surface is in contact with the contact surface 50a of the positioning member is inserted. It is a member for fixing the end portion of the parison tube 1 by pressing and sandwiching the parison tube 1 from the outside.

The chuck members 50c and 50c have a plurality of claws erected on opposite 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 shown, they are supported so as to be symmetrically close to each other, such as an air cylinder. It is configured to be close to or separated from each other by the driving means of the above. The operation or stop of the chuck mechanisms 50 and 50 (operation or stop of the drive means) is controlled by a control device 59 described later in response to an operator's instruction.

As shown in FIG. 7A, the operator arranges one end of the parison tube 1 in the vicinity of one chuck member 50c, and as shown in FIG. 7B, a pin member is inserted into the cavity 1a on one end side of the parison tube 1. 50b is inserted, and 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 driving means of the chuck members 50c and 50c, one end of the parison tube 1 can be fixed as shown in FIG. 7C. By performing the same work on the other end of the parison tube 1, the parison tube 1 is substantially horizontally extended and fixedly arranged between the pair of chuck mechanisms 50 and 50. be able to.

Since the parison tube 1 is sandwiched between the pin member 50b inserted into the cavity 1a and the chuck members 50c and 50c having a plurality of claws pressed against the outside thereof, the cavity 1a of the parison tube 1 is crushed. Is unlikely to occur, and strong fixing can be realized. Therefore, even when a high tensile load is applied, it is possible to withstand this. Further, since the parison tube 1 can be accurately positioned, it is possible to reduce the variation in quality between lots.

In the present embodiment, the number of chuck members 50c is two, but three or more may be used, and the chuck members 50c may be arranged radially at equal angular intervals. Further, although not essential, as shown in FIG. 7D, a gas passage 50d that opens at the tip of the pin member 50b is formed, and nitrogen is formed in the cavity 1a of the parison tube 1 through the gas passage 50d. It is preferable to make it possible to supply an inert gas such as gas so as to suppress oxidation due to 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 and 53 move or urge one of the pair of chuck mechanisms 50 and 50 so as to be separated from the other, and the stretching mechanisms 53 and 53 are attached to the parison tube 1 having both ends fixed to the chuck mechanisms 50 and 50. It is a means for applying tension. Since the stretching mechanisms 53 and 53 have substantially the same configuration except that they are arranged symmetrically, only one stretching mechanism 53 (on the left side in FIG. 6A) will be described.

Although detailed illustration is omitted, the stretching mechanism 53 supports the movable member 53a and the movable member 53a in the left-right direction (see arrow a16) in the figure so as to be movable (sliding), and supports the movable member 53a in a straight line. It is configured to include a linear drive mechanism 53b or the like for moving the object.

The chuck mechanism 50 described above is supported and fixed to the movable member 53a, and the linear drive mechanism 53b of the stretching mechanism 53 is supported and fixed to the support base 55. The linear drive mechanism 53b includes a drive motor (servo motor or the like) and a ball screw mechanism or the like that converts the rotational motion of the drive motor into a 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 operation, stop, movement speed, movement direction, and the like of the linear drive mechanism 53b are controlled by a control device 59 described later.

With the stretching mechanisms 53 and 53 set at 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 to operate the movable members 53a and 53a. Both move (or try to move) synchronously in a direction away from each other so that a desired tension can be applied to the parison tube 1.

Each of the stretching mechanisms 53 and 53 has a tension detecting sensor (tension detecting means) 54 for detecting the tension generated in the parison tube 1. As the tension detection sensor 54, for example, a load cell can be used. In the present embodiment, the power transmission member 53c is arranged side by side with the movable member 53a separated from the movable member 53a in the moving direction, and a coil spring (not shown) and a tension detection sensor 54 are inserted 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 control device 59 controls the thrust by the linear drive mechanism 53b so that an appropriate preset tension is applied.

The heating dies 51 and 51 have a part on one end side (a part to be a stretched part) and a part on the other end side (a stretched part) of the parison tube 1 whose both ends are supported and fixed to the chuck mechanisms 50 and 50. It is a means to heat the part to be non-contact. The heating dies 51 and 51 are arranged between the chuck mechanisms 50 and 50 so as to be separated from each other in the left-right direction (the direction in which the parison tube 1 extends) in the figure. Since these heating dies 51 and 51 have substantially the same configuration, only one of the heating dies 51 (on the left side in FIG. 6A) will be described.

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

Although detailed illustration is omitted, the elevating mechanism 51c has a slide mechanism for holding the heating blocks 51a and 51b so as to be slidable up and down, and a servomotor and a ball screw for elevating and driving the heating blocks 51a and 51b. It is equipped with a drive mechanism. In the present embodiment, the heating blocks 51a and 51b are configured so that they both move symmetrically and are close to each other, but one of them (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 is in contact with the surface, the semi-cylindrical heating surfaces 51d and 51d are used in the left-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 along the outline of the above, and a substantially columnar heating space opened at both ends thereof is defined.

Although not shown, each heating block 51a and 51b has a built-in heater that generates heat when energized 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 of the heater based on the value detected by the mold temperature detection sensor (see reference numeral 59c in FIG. 11), and is defined by the heating surfaces 51d and 51d of the heating blocks 51a and 51b. Heat so that the columnar heating space has 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 of heaters and mold temperature detection sensors are preferable because the temperature distribution of 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 by a predetermined dimension from the outer circumference of the parison tube 1 arranged so as to penetrate the inside of the heating space. The diameter is set to be larger than the outer diameter of the parison tube 1 so that it can be heated in a non-contact manner. 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 moved upward (see arrow a12) and the lower heating block is moved upward. The 51b is moved downward (see arrow a13) so that it is separated from each other and opened. When heating the vicinity of both ends of the parison tube 1, 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). (See), 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 bring them into a closed state. When removing the parison tube 1 from the chuck mechanisms 50 and 50, again, 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 arrow a12). This can be done by moving it to (see arrow a13) to open it.

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

The straight body portion fixing mechanisms 60, 60 are arranged between the heating dies 51, 51 and are separated 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 (on the left side in FIG. 6A) will be described.

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

The upper end sides of the pair of fixed arms 60a, 60a are supported by the gripping mechanism 60c. Although detailed illustration is omitted, the gripping mechanism 60c includes a slide mechanism that slides the fixed arms 60a and 60a in the direction of arrow a19 in FIG. 9A (front-back direction in FIG. 6A), and fixed arms 60a and 60a, respectively. It is equipped with a servomotor for moving and a drive mechanism having a ball screw or the like. The fixed arms 60a and 60a are moved and opened synchronously in the directions away from each other by the gripping mechanism 60c as shown in FIGS. 9A or 9B, and the fixed arms 60a and 60a are moved in the directions close to each other as shown in FIG. 9C. In FIG. 9C, it can move synchronously in the direction of arrow a20) and take two states, that is, a closed state.

The gripping mechanism 60c is supported by the elevating 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 servomotor for driving the gripping mechanism 60c up and down, a ball screw, and the like. It is equipped with a drive mechanism having. The gripping mechanism 60c is moved downward (in the direction of arrow a18 in the same figure) by the elevating mechanism 60d in a state of being set to the upper initial position as shown in FIG. 9A and as shown in FIG. 9B, and is a parison. It is possible to take two states, that is, a state in which the tube 1 is set at a position where it can be gripped and fixed.

With the gripping mechanism 60c set to a 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, so that the fixing portions 60b, as shown in FIG. 9C, The parison tube 1 is sandwiched and fixed by the 60b.

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

Although detailed illustration is omitted, the straight body extension mechanism 61 supports the movable member 61a and the movable member 61a in the left-right direction (see arrow a16) in the same 6A so as to be movable (sliding) and the movable member. It is configured to include a linear drive mechanism 61b or the like that linearly moves the 61a.

The lower end of the elevating mechanism 60d of the straight body portion fixing mechanism 60 described above is supported and fixed to the movable member 61a, and the linear drive mechanism 61b of the straight body portion extending mechanism 61 is supported and fixed to the support base 55. The linear drive mechanism 61b includes a drive motor (servo motor or the like) and a ball screw mechanism or the like that converts the rotational motion of the drive motor into a 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 operation, stop, movement speed, movement direction, and the like of the linear drive mechanism 61b are controlled by a control device 59 described later.

With the straight body extension mechanisms 61 and 61 set at predetermined initial positions, the straight body fixing mechanisms 60 and 60 are fixed to the parts near both ends of the part of the parison tube 1 that should be the straight body. By operating the straight body extension mechanisms 61 and 61, the movable member 61a of the straight body extension mechanism 61 on the left side and the movable member 61a of the straight body extension mechanism 61 on the right side are synchronously separated from each other. The corresponding portion of the parison tube 1 is stretched. One or both of the straight body portion stretching mechanisms 61 and 61 may be provided with a tension detecting sensor (tension detecting means) for detecting the tension generated in the portion to be the straight body portion. As the tension detection sensor in this case, the same tension detection sensor 54 as described above for the 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. The 61, 61 (linear drive mechanisms 61b, 61b) are fixed on the support base 55, and all of them are housed in the housing 56. As the housing 56, a frame made of metal or the like to which a transparent panel (for example, an acrylic plate) is attached can be used. Although not shown, the housing 56 is provided with a door that can be opened and closed in order to manually fix or remove the parison tube 1 to the chuck mechanisms 50 and 50, or for other maintenance and the like. There is. A plurality of intake / exhaust (in this embodiment, exhaust) fans 57 and 57 and a temperature detection sensor 58 inside the housing that detects the temperature inside the housing 56 are attached to the housing 56.

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

At the time of manufacturing the parison, the operator first manually sets both ends of the unstretched parison tube 1 on the chuck mechanisms 50 and 50. At this point, 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 (opened). It has become. Further, at this point, as shown in FIGS. 6A and 9A, the straight body portion fixing mechanisms 60 and 60 are in a state where the fixing arms 60a and 60a are separated (opened) in a state where they are set at the upper initial positions. 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.

After confirming that both ends of the parison tube 1 have been normally fixed, the operator performs a predetermined operation (for example, pressing the start button for heating and stretching) to perform a series of steps for manufacturing the parison. The operation is started. The control device 59 automatically controls each unit according to a control sequence selected in advance by the operator. It should be noted that this operation may be omitted, and a series of controls including the operation of fixing both ends of the parison tube 1 described above may be started by pressing the operation buttons of the chuck mechanisms 50 and 50 described above.

An example of the 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, and both ends thereof are previously supported and fixed to the chuck mechanisms 50 and 50 in the parison tube 1. The set tension (initial tension) is applied and the state is maintained. The tension generated in the parison tube 1 is detected by the tension detection sensor 54, and based on the detected value, the stretching mechanisms 53 and 53 are controlled so as to have a preset initial tension to obtain the initial tension. After reaching the point, feedback control is performed so that the tension becomes constant.

The initial tension is set to an appropriate value so that 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 it may not be possible to properly fix the straight body portion fixing mechanisms 60 and 60 to be performed later. On the other hand, if the initial tension is too large, the slack is reduced and the above problem can be solved, but the heated portion of the parison tube 1 is unnecessarily stretched during heating by the heating die 51, and the product is manufactured. The inclination of the transition portion 2b of the parison 2 is not uniform (the inclination becomes two steps), and stretching unevenness may occur. Therefore, the initial tension is set to an appropriate value that both of them can tolerate. The initial tension can be about 1 to 10 N. In the present embodiment, the tension detection sensor 54 can detect the tension generated in the parison tube 1 in real time, so that the initial tension can be accurately maintained at a desired value, and the initial tension fluctuates. It is possible to reduce the occurrence of stretching unevenness due to the above.

When the initial tension is applied, the straight body portion fixing mechanisms 60 and 60 are operated in a state where the straight body portion extending mechanisms 61 and 61 are set to predetermined initial positions, 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 closed close to each other and the fixed portions 60b and 60b of the fixed arms 60 and 60b. As a result, the portion of the parison tube 1 that should be the straight body portion is sandwiched and fixed.

Next, as shown in FIG. 6B, the elevating mechanisms 51c and 51c of the heating dies 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 drawn by the heating surfaces 51d and 51d of the heating blocks 51a and 51b by abutting (closing) each other. It is placed in the heated space formed (see also FIGS. 8D and 8E).

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

When a predetermined predetermined time elapses from the start of heating (or after reaching a predetermined temperature), heating is stopped and the stretching mechanisms 53 and 53 are moved in a direction away from each other (arrow a17). , A18), tension is applied to the portion between the chuck mechanism 50 and the straight body fixing mechanism 60 on one end side of the parison tube 1 and the portion between the chuck mechanism 50 and the straight body fixing mechanism 60 on the other end side, respectively. It is applied and stretching is performed. The tension generated in the parison tube 1 is detected by the tension detection sensor 54, and the moving speeds of the linear drive mechanisms 53b and 53b by the stretching mechanisms 53 and 53 are controlled based on the detected values. In addition, heating may be continued during stretching.

When the preset stretching length (stretch length) is reached, the linear drive mechanisms 53b and 53b of the stretching mechanisms 53 and 53 are stopped from moving, and this state is maintained for a predetermined time set in advance. , The parison tube 1 is cooled. As a result, the shape of the parison tube 1 in which the portions near both ends thereof are stretched 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 mechanisms 61 and 61 are moved in a direction away from each other (see arrows a17 and 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 portion fixing mechanism 60 on the other end side to perform stretching. The tension generated in the portion of the parison tube 1 that should be the straight body portion is detected by a tension detection sensor (not shown), and based on the detected value, linear drive is performed by the straight body portion stretching mechanisms 61 and 61. The moving speed of the mechanisms 61b and 61b is controlled.

Next, the straight body portion fixing mechanism 60 of the parison tube 1 before the portion to be the straight body portion of the parison tube 1 is stretched to a predetermined predetermined stretching length (for example, the portion to be the straight body portion is stretched). , 60), the movement of the straight body extension mechanisms 61 and 61 by the linear drive mechanisms 61b and 61b is stopped. During stretching of the portion of the parison tube 1 that should be the straight body portion, the stretching mechanisms 53 and 53 related to the chuck mechanisms 50 and 50 tension the portion other than the portion that should be the straight body portion of the parison tube 1. It is moved in a direction away from each other in synchronization with the movement of the straight body portion fixing mechanisms 60 and 60 so that the compression force does not act.

After that, the urging force of the straight body extension mechanisms 61, 61 against the movable members 61a, 61a by the linear drive mechanisms 61b, 61b is released, that is, the movable members 61a, 61a become movable, and the straight body of the parison tube 1 Due to the self-elasticity (restoring force) of the portion to be a portion, the movable members 61a and 61a move in a direction close to each other, and the portion to be a straight body portion is contracted. During the contraction of the portion of the parison tube 1 that should be the straight body portion, the stretching mechanisms 53 and 53 related to the chuck mechanisms 50 and 50 tension the portion other than the portion that should be the straight body portion of the parison tube 1. And, so that the compressive force does not act, they are moved in the 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 and 60a of the straight body portion fixing mechanisms 60 and 60 are opened so as to be separated from each other by the gripping mechanism 60c, and the straight body portions of the parison tube 1 are formed by the fixing portions 60b and 60b of the fixing arms 60a and 60a. The part that should be fixed is released. During the contraction of the portion of the parison tube 1 that should be the straight body portion after the fixing of the portion that should be the straight body portion is released, the stretching mechanisms 53 and 53 related to the chuck mechanisms 50 and 50 are used for the parison. The tubes 1 are moved in directions close to each other so that tension or compressive force does not act on the tubes 1.

When the portion of the parison tube 1 that should be the straight body portion returns to the original length (length before stretching) or the predetermined length after a lapse of a predetermined time, the operator indicates that the series of operations is completed. To terminate this sequence. The end notification can be displayed on an indicator or the like of the display means 59b, or can be performed by a buzzer or the like.

When the series of sequences is completed, the operator presses the release buttons of the chuck mechanisms 50 and 50 to release the fixation of both ends of the parison tube 1 in which the portions near both ends thereof are extended. Remove this at work. During these series of operations, the temperature inside the housing 56 is detected by the temperature detection sensor 58 inside the housing, and the fans 57 and 57 are operated or stopped based on the detected values, so that the housing The temperature inside the body 56 is controlled to be constant. Further, the release operation of the chuck mechanisms 50 and 50 may be omitted, and this operation may be included in the series of sequences.

Finally, the parison 2 as a completed product shown in FIG. 2 is obtained by manually cutting an appropriate portion of the stretched portion of the parison tube 1 in which the portions near both ends are stretched and cutting off both ends. Obtainable.

The process of manufacturing a balloon by processing the parison 2 thus manufactured by a biaxial stretching blow molding machine will be outlined with reference to FIG. First, as shown in FIG. 11A, the parison 2 is set in the mold 70 of the biaxial stretching blow molding machine. The mold 70 has openings at both ends in the longitudinal direction (axial direction), and has a space inside the mold 70 that is substantially 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 shapes relative to each other so that the spaces 70a, 70b, 70b, 70c, and 70c are defined at the time of coupling.

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

Next, as shown in FIG. 11 (B), under unheated conditions (for example, in an atmosphere of 15 to 35 ° C.), the pair of fixing mechanisms fixing both ends of the parison 2 are moved in a direction away from each other. As a result, tension is applied to the parison 2 to carry out axial stretching that stretches the parison 2 in the axial direction. The tension generated in the parison 2 is detected by the tension detection sensor, and the moving speed of the fixing mechanism is controlled according to the detected tension, and when the predetermined stretching length is reached, the fixing mechanism moves. It is stopped and its state is maintained.

Next, heating of the mold 70 is started, and nitrogen gas is supplied into the lumen of the parison 2 at a predetermined supply (filling) pressure. Nitrogen gas is supplied from one end side of the parison 2 and the other end side 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, the large-diameter straight body portions 2a, transition portions 2b, 2b and the small-diameter straight body portions 2c, 2c of the parison 2 are stretched in the circumferential direction, and the mold is stretched. It is formed into a shape corresponding to the corresponding spaces 70a, 70b, 70b, 70c, 70c of 70. As a result, a balloon having a straight body portion 3a, cone portions 3b, 3b, and neck portions 3c, 3c is manufactured.

According to the above-described embodiment, in the manufacturing process of the parison 2, a step of stretching a portion of the parison tube 1 that should be a straight body portion 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) related to the stretchability of the straight body portion (large diameter straight body portion 2a) of the parison 2 are changed, and the parison 2 is next. When stretched, it tends to stretch in the axial direction. Therefore, the time required for the axial stretching (the above-mentioned axial stretching) performed when the balloon is manufactured by biaxial stretching blow molding using the parison 2 can be shortened, and the balloon 3 can be produced. The sex can be improved.

Further, in the above-described embodiment, the preliminary stretching of the parison tube 1 is performed for the portion to be the straight body portion by fixing the portions near both ends of the portion to be the straight body portion. Therefore, this preliminary stretching does not affect the heat-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 the above-described embodiment, the preliminary stretching of the portion to be the straight body portion performed in the manufacturing process of the parison 2 is performed once, but it may be performed twice or more.

Hereinafter, examples of the present invention will be described. As the base material of the test piece, a straight tubular tube made of polyurethane is cut at 250 mm (dimension between the contact surfaces 50a and 50a of the chuck mechanisms 50 and 50 when the stretching mechanisms 53 and 53 are set at 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 setting the parison tube 1 in the parison manufacturing apparatus 5 shown in FIG. 6A and fixing the portion to be the straight body portion, 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 / sec, and the stretching length (stretch length) b2 (see FIG. 5 (C)) was 60 mm. The applied tension (initial tension) was 5N.

Then, natural cooling was carried out. The cooling time was 60 seconds. In parallel with this cooling, preliminary stretching of the part to be the straight body part was carried out. The stretching distance was twice that of the unstretched straight body portion (that is, 200 mm), and the stretching speed was 1000 mm / min. The temperature inside the housing 56 during manufacturing was controlled to 30 ° C. After that, the portion to be the straight body was stretched. Ten test pieces were produced under the same conditions.

As a comparative example, 10 test pieces were also produced in the same manner as in the above-mentioned example, except that the portion to be the straight body portion was not preliminarily stretched.

Each test piece (10 examples, 10 comparative examples) was set in the mold of the blow molding machine shown in FIG. 11, axial stretching (axial stretching) was performed, and stretching started and ended (10 examples). The time until the predetermined stretching length was reached) was measured. The results are shown in Table 1.

As shown in Table 1, in the example in which the portion to be the straight body was preliminarily stretched, the average 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 portion to be the straight body was preliminarily stretched was significantly shorter in the stretching time than the comparative example in which this was not performed, and the variation was small, which was superior. ..

The embodiments described above are described for facilitating the understanding of the present invention, and are 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.

1 ... Parison tube 2 ... Parison 2a ... Large diameter straight body 2b ... Transition part 2c ... Small diameter straight body 3 ... Balloon for IABP 3a ... Straight body 3b ... Cone part 3c ... Neck part 4 ... Balloon catheter for IABP 5 ... Parison manufacturing equipment 50 ... Chuck mechanism (first fixing mechanism)
50a ... Contact surface of positioning member 50b ... Pin member 50c ... Chuck member 51 ... Heating mold 51a, 51b ... Heating block 51c ... Elevating mechanism 51d ... Heating surface 53 ... Stretching mechanism (first stretching mechanism)
53a ... Movable member 53b ... Linear drive mechanism 53c ... Power transmission member 54 ... Tension detection sensor 55 ... Support stand 56 ... Housing 57 ... Fan 58 ... Housing temperature detection sensor 59 ... Control device 59a ... Input means 59b ... Display means 59c … Mold temperature detection sensor 60… Straight body fixing mechanism (second fixing mechanism)
60a ... Fixed arm 60b ... Fixed part 60c ... Gripping mechanism 60d ... Elevating mechanism 61 ... Straight body extension mechanism (second extension mechanism)
61a ... Movable member 61b ... Linear drive mechanism

Claims (2)

A method for manufacturing a parison having extending portions at both ends of a straight body portion for manufacturing a balloon used for a balloon catheter.
A heating step of heating the portion to be the stretched portion on one end side of the straight tubular parison tube and the portion to be the stretched portion on the other end side, respectively.
A first stretching step of applying tension to the parison tube to stretch the portion heated in the heating step, and
A second stretching step of applying tension to both ends of the portion of the parison tube to be the straight body portion, stretching the portion to be the straight body portion, and then releasing the tension to contract the portion. Parison manufacturing method including. A parison manufacturing device having extension portions at both ends of a straight body portion for manufacturing a balloon used for a balloon catheter.
A pair of first fixing mechanisms that releaseably fix both ends of the 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 of the parison tube that should be the straight body portion.
A part of the portion between the first fixing mechanism on one end side of the parison tube and the portion fixed to the second fixing mechanism, and fixed to the first fixing mechanism and the second fixing mechanism on the other end side. A pair of heating dies that heat a part of the part between the parts in a non-contact manner,
A first stretching mechanism that urges the pair of first fixing mechanisms so as to be separated from each other to stretch a portion of the parison tube heated by the heating mold.
A parison manufacturing apparatus having a second stretching mechanism for urging the pair of second fixing mechanisms so as to be separated from each other to stretch a portion of the parison tube to be a straight body portion.

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