JPS6115699B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a disposable medical tube part.

The blood circuit used in artificial kidneys etc. is equipped with branch lines (heparin lines, monitor lines, level adjustment lines, etc.) for connecting to external devices such as venous pressure monitors, syringes, infusion sets, etc. It is well known that in many cases JIS standard connectors are attached.

Conventionally, this type of connector, as shown in Figure 3, connects a connector 2 made of hard plastic such as PC (polycarbonate) to the end of a tube 1, and the opening is designed to prevent bacteria and dirt from entering. To prevent this, a cap 3 made of plastic such as P/P (polypropylene) is fitted.

However, with such conventional connectors, when the entire blood circuit is sterilized under high pressure and high temperature conditions during the sterilization process, and these conditions fluctuate rapidly several times, the pressure inside tube 1 fluctuates. When pressure is applied to the cap at the end of the tube, the looser the fit between connector 2 and cap 3, the looser the cap 3 becomes, and the more pressure is applied to the cap at the end of the tube.
If the materials of the cap 3 and the cap 3 are different, the degrees of expansion of the two will be different, which will cause the cap 3 to become loose due to the above-mentioned conditions.

As a result, when the sterilized blood circuit is used for, for example, hemodialysis, the tube 1 of the blood circuit is filled with physiological saline using a pump and air is removed from the tube (so-called priming). Physiological saline will leak from the gap between connector 2 and cap 3. For this reason, it is generally necessary to clamp the vicinity of the connector of each line using forceps, which requires time to prepare.

On the other hand, if the connector 2 described above is molded from hard plastic, if there is even the slightest distortion when fitting the cap 3 during the manufacturing process or in the convex connector of the external device to which the connector 2 is to be fitted, When this was connected, cracks were generated on the side surface of the connector 2, which caused leakage of air and liquid.

The present invention has been proposed as a result of studies to improve these conventional disadvantages.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. First, in FIG. 1, 10 is a tube mainly made of a soft thermoplastic material such as vinyl chloride. The diameter of the end opening 10a is expanded into a tapered shape, and a cap 12 is fitted into the expanded diameter portion 11. The cap 12 has a convex portion 13 formed in a tapered shape corresponding to the enlarged diameter portion 11, and the tip end 13a of this convex portion 13 extends deep into the enlarged diameter portion 11, thereby causing the enlarged diameter portion to expand. The entire inside of the diameter portion 11 is sealed.

Further, in the embodiment shown in FIG. 2, a connector 14 made of a soft thermoplastic material such as vinyl chloride is connected to the opening 10a of the tube 10, and an enlarged diameter portion 15 similar to that described above is connected to the opening 14a of the connector 14. , into which the cap 12 is inserted.

Tube end opening 10a and connector opening 14a in the embodiment of FIGS. 1 and 2
is a soft thermoplastic material, so by simply inserting the convex part 13 of the cap 12 and heating the convex part 13 as a mold, the enlarged diameter part 11 or 15 is formed, and the opening part 10a or 14a is formed. The inner surface of the cap is in close contact with the cap protrusion 13.

In the present invention, the material of the cap 12 is not particularly limited, but a material with heat resistance and pressure resistance is desirable. Further, the difference between the outer diameter of the cap protrusion 13 and the inner diameter of the tube 10 can be determined by, for example, the sterilization temperature,
It is adjusted according to conditions such as pressure.

When manufacturing such a connector, first the opening 10a of the tube 10 or this opening 1 is
Opening 14a of connector 14 connected to 0a
A cap 12 having a tapered convex portion 13 having a diameter larger than the inner diameter of the tube as described above is press-fitted into the tube.
It is then sterilized by a sterilization method that involves heating, such as an autoclave. As a result, the tapered enlarged diameter portion 11 or 15 is formed in the tube opening 10a or the connector opening 14a, and the outer circumferential surface of the cap convex portion 13 and the inner circumferential surface of the enlarged diameter portion 11 or 15 are brought into close contact. become.

In addition, in the present invention, when the cap 12 is to be removed when using the line, it is easy to remove the cap 12 by pushing the cap 12 in the length direction of the tube to introduce air into the close contact area between the enlarged diameter part 11 or 15 and the cap convex part 13. can be removed.

According to the present invention described above, the tapered convex portion 13 of the cap 12 is deeply and reliably inserted into the tube end opening 10a or the connector opening 14a due to its wedge action, and the openings 10a, 14a are Since the cap 12 is made of a soft thermoplastic material, even if the cap 12 is made of a different material, the inner surface of the opening and the outer surface of the convex portion will be in complete contact with each other when heated during sterilization, etc. It will not loosen, and therefore, even when priming the blood circuit for dialysis, saline and the like will not leak out from the line openings 10a, 14a. Moreover, according to the present invention, the molding of the enlarged diameter portions 11 and 15 is performed simultaneously with the sterilization process in the heat sterilization process, so manufacturing efficiency is improved.
It can be implemented at low cost. Furthermore, openings 10a, 1
Since 4a is soft, its elasticity allows it to be tightly connected even if the connector on the external device side has variations or distortions depending on the manufacturer, and it also does not break like conventional connectors. Therefore, various excellent effects can be obtained, such as being able to prevent leakage of air and liquid caused by this.

[Brief explanation of the drawing]

1 and 2 are both schematic diagrams for explaining an embodiment of the present invention, and FIG. 3 is a schematic diagram showing a conventional connector. In the figure, 10 is a tube, 11 and 15 are enlarged diameter parts,
12 is a cap, 13 is a cap protrusion, and 14 is a connector.

Claims (1)

[Claims] 1. In medical disposable tubes,
In a sterilization process in which the connector part of the tube is made of a soft thermoplastic material, a cap having a tapered convex part with a larger diameter than the opening is press-fitted into the opening of the connector part, and heating is performed in this state. A method of manufacturing a connector part in a medical disposable tube, comprising expanding the diameter of the connector part in a tapered manner by heating.