JPH04174663A - Manufacture of medical tube - Google Patents

Abstract

PURPOSE:To manufacture simply a tube body having a reinforcement embedded therein such that the inner and outer diameters are constant and further improve an operational environment by loading liquefied material in a cavity, locating and setting a bore forming core pin having a thin wall tube covered with the reinforcement in a cavity of a lower die to set an upper die to the lower die for press molding. CONSTITUTION:After a fixed amount of about 50 hardness liquefied silicone rubber is evenly discharged and loaded in a cavity 31 of a lower die 30 having a trachea pin 28 set therein by a fixed amount discharger, a prepared core pin 33 is set in the lower die 30. A fixed amount of liquefied silicone rubber is discharged into a cavity of an upper die by the constant amount discharger. Then, the upper die is quickly set to the lower die 30 for press molding with fixed pressure at about 130 deg.C for several minutes. Thereafter, the dies are opened to take out the core pin 33 and a tube body 21 with the trachea pin 28. First, the trachea pin 28 is drawn out of the other end side of the tube body 21 by pincers having pointed tips or the like to ensure the cough trachea 27, and then the core pin 33 is drawn out by air pressure or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a method for manufacturing medical tubes embedded with reinforcements for securing airways, such as tracheostomy tubes and endotracheal tubes.

A conventional method for manufacturing this type of tube will be described with reference to FIGS. 8 to 13. First, as shown in Fig. 8, a thin two-piece tube with a cuff airway 5, which has an inner diameter slightly smaller than the outer diameter of a cylindrical stainless steel reinforcing body 3, is made in a spiral shape based on predetermined specifications. The main body 1 is produced by extrusion (Fig. 9) 9. Next, the tube main body 1 is cut to a predetermined length longer than the reinforcing body 3, and then it is swollen with an appropriate solvent, air pressure is applied, etc. Expanding the lumen 2 by a means,
The reinforcing member 3 is inserted into the tube main body 1 so that the lengths of both ends of the reinforcing member 3 and each end of the tube main body 1 are approximately equal, and the reinforcing member 3 is inserted uniformly over the entire length (FIG. 10). The inner peripheral surface of the tube body 1 into which the tube is inserted is coated with silicone rubber dispersion. The silicone rubber used for this dispersion may be a one-component RTV silicone rubber or a two-component liquid silicone rubber. After making these suitable silicone rubbers with a solvent such as xylene or hexane to an appropriate viscosity that makes it easy to coat, hang one end of the tube body 1 from a hook, and then hang it from the other end facing downward. The inner peripheral surface is coated. After several ten minutes, when the solvent has dispersed considerably and the coating liquid has dried, turn the tube body 1 upside down and coat the inner circumferential surface with the coating liquid in the same way from the other end. do. The reinforcing body 3 thus inserted is filled with the coating liquid and coating is repeated several times until it reaches a predetermined inner diameter.

When the coating layer 4 has been formed to a predetermined thickness, in order to completely cure the coating layer 4, if the coating liquid is a room temperature curing type, leave it sufficiently at room temperature, or if it is a heat curing type, heat it in an oven. This tube body 1 is hardened. As a result, a tube body 1 with a cuff airway 5 in which the reinforcing body 3 is embedded concentrically within the wall thickness is obtained (FIG. 11.12).

After filling the openings of the cuff airways 5 at both ends with RTV silicone rubber 6, one end of the tube body 1 is cut diagonally as shown in FIG. 13, and markings (not shown) are made on the surface of the tube body 1. . The reinforcing tube 7 is then inserted into the rear end of the tube body 1 and adhered in the same manner to prevent kinking when the slip joint 8 is inserted. Next, the branch tube 10 with the pilot balloon 9 attached,
A side hole 11 is opened above the cuff airway 5 at the rear end of the tube body 1 using forceps, and then connected and bonded. 12 is a one-way valve. Then, use forceps to similarly open a side hole 14 at the approximately central position on the airway 5 where the cuff 13 is to be attached at one end of the tube body 1. is adhered to the tube body 1 with RTV silicone rubber 15. A medical tube made of silicone rubber in which the reinforcing body 3 is embedded concentrically is manufactured using the two-lumen tube body 1 extruded in this manner.

However, there are several problems in manufacturing a medical tube in which the reinforcing body 3 is embedded by extrusion as in the conventional method as described below.

■ It is quite difficult to uniformly extrude the thin two-piece tube body 2, which has an inner diameter several millimeters smaller than the outer diameter of the reinforcing body 3. This is because the inner and outer diameters of this reinforcing body 3 vary somewhat depending on the production lot, and the tube body l has a constant small inner diameter for such reinforcing body 3.
This is because it is difficult to make. If the reinforcing body 3 is not properly fixed to the inner circumferential surface of the tube body 1, a good product cannot be obtained even if the inner circumferential surface of the tube body 1 is coated. In other words, if this fixation is loose, the tube body 1 will swell when the inner peripheral surface of the tube body 1 into which the suspended reinforcing body 3 is inserted is coated with dispersion of silicone rubber diluted with a solvent. The reinforcing body 3 fixed inside the main body 1 tends to slip down, and air bubbles tend to form between the reinforcing body 3 and the tube main body l. In addition, if it is hooked too tightly, there will be a considerable difference in the inner and outer diameters between the part where the reinforcing body 3 is inserted and the parts at both ends where it is not inserted, and in extreme cases, as shown in Fig. 14. The unevenness of the reinforcing body 3 appears on the outer circumferential surface of the tube body l.

■ It is difficult to uniformly coat the inner circumferential surface of the tube body l with silicone rubber diluted with a solvent so that the inner diameter is constant. The viscosity of silicone rubber varies considerably from lot to lot, and is also subtly influenced by coating speed and workplace environment (temperature, humidity).

- Since a solvent is used for dispersion of the coating liquid, it takes time for the solvent to be dispersed, and the tube body 1 has to be turned over several times for coating, resulting in poor production efficiency. And sometimes, if this solvent is not sufficiently diffused, small air bubbles are likely to form in the product.

(2) As mentioned above, since a solvent is used, it is not favorable in terms of the working environment.

Therefore, the present invention solves the problems of the conventional manufacturing method, and makes it possible to easily manufacture a tube body in which a reinforcing body is embedded so that the inner and outer diameters are constant, and to improve the working environment. The purpose of this invention is to provide a method for manufacturing tubes for

In order to achieve the above object, the present invention has a lumen extending in the axial direction, and a cylindrical reinforcing body for preventing kink in the wall thickness between the lumen and the outer peripheral surface. A method for manufacturing a medical tube comprising a tube body in which are embedded substantially concentrically, the method comprising:
A liquid material is charged into the cavities of the lower and upper molds of a pair of mating molds, and a core pin for forming the inner cavity, which is a thin tube covered with a reinforcing body, is inserted into the cavity of the lower mold. After positioning and setting, the upper mold is matched with the lower mold and press-molded.

After setting the core pin instead of press forming as described above,
It is also possible to use injection molding in which the upper mold is fitted to the lower mold and liquid material is supplied into both cavities. Furthermore, before supplying the liquid material to the lower mold, a cuff airway forming pin covered with a thin tube may be positioned and set in the cavity of the lower mold. Preferably, the thin-walled tube and liquid material are silicone rubber.

FIG. 1 is an enlarged side cross-sectional view of a two-lumen tube body 21 manufactured according to the present invention, and a spiral cylindrical stainless steel reinforcing body 23 is embedded concentrically in the tube body 21. has been done. The cross-sectional shape of the reinforcing body 23 can be any shape such as rectangular or round. 24 is a thin silicone rubber tube forming an inner cavity 25, and is integrally fixed to the tube body 1 so as to sandwich the reinforcing body 23 therebetween. Further, 26 is a thin silicone rubber tube forming a cuff airway 27, and is embedded within the thickness of the tube body 21 on the outside of the reinforcing body 23.

To make the tube body 21 as described above, as in the conventional method shown in FIG. 13, first, as shown in FIG. In order to provide a cuff airway 27 for inflating the cuff to the length of the cuff within the wall thickness of the tube body 21 on the outside of the reinforcing body 23, the airway pin 28 covered with the silicone rubber tube 26 is inserted during pressing. It is positioned and set in the cavity 31 of the lower mold 30 so that it does not move due to pressure.

This positioning can be solved by erecting several small knobs in the cavity 31 of the lower die 30 so as to sandwich the silicone rubber tube 26 so that it does not move.

The outer diameter of the silicone rubber tube 26 may be approximately the same as the wall thickness between the outer diameter of the reinforcing body 23 and the outer diameter of the tube body 21.

After setting the airway pin 28 as in step 2, the silicone rubber tube 24 is placed over the core pin 33 so that the outer diameter of the core pin 33 is approximately the same as the inner diameter as shown in FIG. 3(A). Then, a reinforcing body 23 made in advance to a certain standard is placed and set on the silicone rubber tube 24 as shown in FIG. 3(B). At this time, it is preferable that the gap between the outer diameter of the silicone rubber tube 24 and the inner diameter of the reinforcing body 23 be as small as possible. This is because if this gap is large, the reinforcing bodies 23 will move due to pressure during pressing, resulting in a tube body 21 containing reinforcing bodies with uneven pitches. Note that the tube 24 does not necessarily need to be made of silicone rubber.

That is, during press molding, the tube 24 is filled with liquid liquid, which will be described later.
It can be bonded to silicone rubber, has heat resistance that can withstand molding temperatures, has low surface friction resistance that makes it easy for the suction tube inserted into the inner lumen of the manufactured tube to slip when suctioning secretions, and is suitable for medical use. The material does not matter as long as it is suitable. ``First, prepare the core pin 33 set in this way. Then, a fixed amount of liquid silicone rubber having a hardness of about 50 is uniformly dispensed into the cavity 31 of the lower mold 30 in which the airway pin 28 is set using a quantitative dispensing machine (not shown), and then the prepared medium is filled. The child pin 33 is set on the lower mold 30 as shown in FIG. Similarly, a fixed amount of liquid silicone rubber is discharged into the cavity of the upper mold (not shown) using a metering discharge machine.

After that, quickly align this upper mold with the lower mold 30, and make about 13
Press molding at 0°C for several minutes under low pressure. After press molding, the mold is opened and the tube body 21 with the core pin 33 and the airway pin 28 attached is taken out as shown in FIG. The cuff airway 27 is secured by pulling it out using thin pliers or the like, and then the core pin 33 is pulled out using air pressure or the like. As a result, as shown in FIG. 6, a tube body 21 with a cuff airway 27 in which the reinforcing body 23 is concentrically embedded within the wall thickness is obtained. Moreover, in this case, there is no need to cut one end of the tube body as in the conventional case, and the reinforcing tube portion is also formed integrally.

After the tube body 21 in which the reinforcing body 23 is embedded is made as described above, the work of attaching the cuff etc. is the same as the conventional method. In this way, a medical tube including the tube body 21 in which the reinforcing body 23 is embedded is manufactured by press molding.

In this example, manufacturing by press molding has been described, but the present invention can be similarly manufactured by injection molding using a liquid injection machine at a low pressure such that the pitch of the reinforcing body 23 does not become non-uniform. That is, in this case, the silicone rubber tube 26 is placed inside the cavity 3 of the lower mold 30.
After setting the airway pin 28 covered with For example, a certain amount of liquid silicone rubber is injected from a nozzle provided in an upper mold to form the mold.

In this case, care must be taken because if injection molding is performed at too low a pressure and it takes too long for the silicone rubber to be injected into the cavity, scorch will occur and the molding will not be successful.

When performing injection molding, unlike press molding, it is not necessary to use a quantitative dispensing machine to discharge liquid silicone rubber into the cavities of the lower and upper molds, so products of constant quality can be produced efficiently.

If press molding or injection molding as described above is used, it is possible to create a straight or J-shaped endotracheal tube in which the reinforcing body 23 is embedded, or a tracheostomy in which the tube body 21 is curved by nearly 90 degrees and the reinforcing body 23 is embedded in it. Even shapes that are difficult to make by extrusion molding, such as tubes, can be easily manufactured.

By increasing the number of airway pins, it is possible to attach that many cuffs. Furthermore, in order to make a tube body 41 having another small lumen 48 within the wall thickness as shown in FIG. Cuff airway 2 using
Mold in the same manner as when forming 7. As a result, the tube main body 41 has a partial convex portion on the outside, and a small lumen (for example, a cuff airway 47 and a small lumen having another purpose) near this convex portion (
For example, a three-lumen tube body 41 having a small lumen 48 for a smooth kink formed in a small kink type tracheostomy tube can be made.

In each of the above embodiments, the method of making the tube body 21.41 with a cuffed airway has been described, but the present invention is not limited to those with a cuffed airway.

Since the method for manufacturing a medical tube according to the invention of claim 1 or 2 is as described above, there is no need for any troublesome work as in the conventional extrusion method, and it is possible to produce a tube body with constant inner and outer diameters. Easy to manufacture. Furthermore, since no solvent is used, the working environment is significantly improved.

In the case of the invention of claim 3, a tube body with a cuff airway can be manufactured at the same time. In the case of the invention of claim 4, a tube body made of silicone rubber that is suitable for living organisms can be manufactured.

[Brief explanation of the drawing]

Fig. 1 is an enlarged side sectional view taken along line XX in Fig. 6 of a tube body manufactured according to an embodiment of the present invention, and Fig. 2 shows a cuff airway pin set in the cavity of the lower mold. A plan view of the state, FIG. 3 shows a state in which the core pin for forming the inner cavity is partially omitted, (A) shows a state in which the core is covered with a thin tube, and (B) shows a state in which the core is covered with a spiral tube. Fig. 4 is a plan view of the core pin shown in Fig. 3 (B) set in the cavity of the lower mold, and Fig. 5 shows the core pin and tube after molding. FIG. 6 is a plan view with the airway pin and core pin removed from FIG. 5, partially omitted, and FIG. Enlarged side sectional views corresponding to figures 8 to 1
Fig. 4 shows a conventional example, Fig. 8 is a front cross-sectional view with a part of the reinforcing body omitted, Fig. 9 is a perspective view showing one end of the tube body, and Fig. 10 shows a reinforcing body in the inner cavity of the tube body. 11 is a partially omitted front sectional view of the inserted state, and FIG. 11 is a front sectional view of the main part along the line Y-Y of FIG. Fig. 13 is a partially omitted front sectional view of the tube body with a cuff etc. further attached, and Fig. 14 is a front sectional view of the tube body with the unevenness of the reinforcing body appearing on the outer circumferential surface. It is a diagram. 21.41...Tube body 23...Reinforcement body 24
．． 26...Thin-walled tube 25.42...Inner lumen 2
7.47...Cuff airway 28 River airway pin 30...
Lower mold 31... Cavity 33... Core pin 1st
Figure 3 Figure 4 Sun Figure 5 ψ Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] 1. A medical tube comprising a tube body having an axially extending lumen and in which a cylindrical reinforcing body for kink prevention is embedded approximately concentrically within the wall thickness between the lumen and an outer peripheral surface. This is a manufacturing method in which a liquid material is charged into the cavities of the lower and upper molds of a pair of mating molds, and a core pin for forming the inner cavity is placed on a thin-walled tube covered with a reinforcing material. A method for manufacturing a medical tube, which comprises positioning and setting the tube in a cavity of a lower mold, and then press-molding the upper mold by aligning the lower mold with the upper mold. 2. 3. In the manufacturing method according to claim 1, instead of press molding, after setting a core pin, aligning the upper mold with the lower mold, and supplying liquid material into both cavities for injection molding. The manufacturing method of a medical tube according to claim 1 or 2, wherein the cuff airway forming pin covered with a thin tube is positioned and set in the cavity of the lower mold before supplying the liquid material to the lower mold. . 4. 4. The method of manufacturing a medical tube according to claim 1, wherein the thin walled tube and the liquid material are silicone rubber.