JPS63165128A - Method for forming tubular body stretchedly provided with partition membrane - Google Patents

Abstract

PURPOSE:To make it possible to completely eliminate the weldline or crack developed during injection molding on a partition membrane by a method wherein the partition membrane after the injection molding of a tubular body is fabricated by utilizing jigs so as to re-melt the partition membrane part. CONSTITUTION:The interior of the cavity of a mold assembly 11 corresponds to the external shape of a tubular body equipped with a partition membrane. In addition, the thickness of a partition membrane 2 part is made thicker than that of the partition membrane of a final product. Molten resin to mold a tubular body 1 is simultaneously forces in the cavity from a pair of injection ports 12. After cooling, the primarily processed tubular body 1 is removed from the mold assembly 11 so as to melt the partition membrane 2 by heating under the condition that a pair of jigs 14 and 15, a part of the outer diameter of each of which is nearly equal to each of the inner diameter of the tubular body 1, are urged on both the upper and the lower surfaces of the partition membrane 2. By the above-mentioned fabricating operation, weldline 13 or crack in membrane disappears and at the same time the thickness of the partition membrane 2 can be made thinner to the desired thickness in the final product.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for forming a plastic tubular body by extending a septum membrane that can be penetrated by a puncture needle into an internal passage, such as the outlet of a blood bag. .

(Prior Art) Conventionally, the outlet of blood bags and the like has been made of thermoplastic synthetic resin such as vinyl chloride by injection molding. However, as shown in FIG. 5, the blood bag outlet is easily penetrated by a puncture needle in the currently used injection molding, and the septum membrane 2 stretched over the internal passage of the tubular body 1 can be easily penetrated by a puncture needle, resulting in poor molding. It is impossible to prevent this from happening.

For example, if the injection port for the n7'h resin provided in the injection mold is opened at two or more locations on the side circumference of the partition membrane 2, the molten resin will flow from the injection port onto the partition membrane 2 portion. It is difficult for the resin to flow smoothly and the membrane does not close completely, resulting in molding defects called membrane cracking, or the resin flows along the confluence point of a pair of opposed mold injection ports. There is a problem that a weld line is formed and this weld line breaks during heat sterilization in an autoclave, etc. Please note that if the injection port is opened almost at the center of the septum membrane 2, and the thickness of the septum membrane 2 is set to a value that allows the puncture needle to penetrate the product, the molded product will be damaged after injection molding. When the mold is removed from the mold, the partition membrane 2 sticks to the mold and breaks. In FIG. 5, numeral 3 is the main body of the plug, 4 is a ninth cover for protecting the tubular body 1, and 5 is a tongue piece for exposing the opening of the tubular body 1.

(Problems to be Solved by the Invention) This invention provides a barrier membrane that can prevent the occurrence of defective products due to membrane cracks, weld lines, or membrane breaks in the membrane as described above. The purpose is to provide a molding method.

(Means for Solving the Problems) As a means for solving the above-mentioned problems, the present invention provides a method in which a partition membrane is stretched, a companion tubular body is injection molded in the conventional manner, and then this partition membrane portion is subjected to secondary processing. method was adopted.

That is, the present invention comprises a tubular part and a partition membrane which can be penetrated to block an internal passage of the tubular part, and then the tubular body is integrally molded by injection molding. The above-mentioned problems can be solved by providing a method for forming a tubular body having a partition membrane stretched thereon, which is characterized in that the partition membrane portion is heated and melted while being pressed against both upper and lower surfaces using a jig, and then cooled. It is intended to be In the above-described solution, at least one of the distal ends of the jig may be notched in a tapered shape, heated and melted, and then a part of the partition membrane may escape into this tapered notch. Further, as the heating means, a method using high frequency heating or the like may be appropriately adopted.

(Function) In the method of the present invention, after injection molding in the first step, the upper and lower surfaces of the partition membrane are heated and melted again using a jig, and secondary processing is performed into a membrane having a uniform plane, and the membrane is divided. , which eliminates weld lines.

(Example) FIG. 1 shows the next mold assembly 11 (closed state) for injection molding a tubular body with a partition membrane stretched thereon, and at the same time,
The next state is shown in which molten resin is introduced into the cavity formed by this mold assembly 11. In this mold 1, a pair of injection ports 12 for introducing molten resin into the cavity are arranged right next to the partition membrane 2 of the tubular body 1. Note that the inside of this cavity corresponds to the external shape of the intended tubular body with a partition membrane.
The thickness of the portion becomes thicker (for example, approximately twice as thick) than the desired thickness in the final product.

Since the dense molten resin forming the tubular body 1 is simultaneously press-fitted into the cavity from the pair of injection ports 12, a weld 2-in 13 is formed along the confluence of the resin flows, as shown in FIG. In extreme cases, membrane cracking (pores) may occur.

Next, after cooling the molded tubular body 1, it is taken out from the mold assembly 11, and a pair of jigs 14 and 15 each having an outer diameter approximately equal to the inner diameter of the tubular body 1, as shown in FIG. As shown, it is inserted from the upper and lower sides of the partition membrane 2, and is brought into pressure contact with both the upper and lower surfaces of the partition membrane 2 by these jigs 14 and 15, and in this state, the partition wall M2 is heated and melted by a heating means such as high frequency. Through this secondary processing operation, the runil dry line 13 (or membrane cracks) disappears, and the thickness of the partition membrane 2 can be reduced to the desired thickness in the final product (fourth
(see figure).

In addition, jigs 14 and 15 used in this secondary processing
As shown in FIG. 3, air vent holes 14h and 15g may be provided in the center of the jigs 14 and 15 to allow internal air to escape when the jigs 14 and 15 are inserted. in this case,
There are also some protrusions 2a in the center of the partition membrane 2 after this secondary processing.
will be formed, but there is no practical problem. Man,
Each of the jigs 14 and 15 may have a tapered cutout at its tip end peripheral edge. In particular, the jig 15 for shaping the partition wall membrane surface on the side of the main body 3 is designed so that the tapered surface 15b at the peripheral edge of the tip is made large as shown in FIG. - A part of the partition membrane 2 melted on the surface 11b is
It is preferable to let it escape as J 2 b. Accordingly, when a camera is introduced into the tubular body 1, it is possible to prevent the occurrence of a lump on the cannula introduction side that would hinder puncturing of the camera.

In the above embodiment, the thickness of the partition membrane 2 is formed to be thicker than the desired thickness in the final product during injection molding of the tubular body 1, and the thickness is thinned to the desired thickness by applying pressure in secondary processing using the jigs 14 and 15. Although an example has been described in which the partition membrane 2 is formed into a desired thickness in the final product during injection molding, the jigs 14 and 15 are not limited to this.
In the secondary processing, the weld line 13 may be simply remelted by heating to eliminate the weld line 13.

(Effects of the Invention) As described in detail above, according to the method of the present invention, after injection molding of the tubular body, the partition membrane is again subjected to secondary processing using a jig,
Since this partition membrane portion is remelted, weld lines or film cracks on the partition membrane that occur during injection molding can be completely eliminated. Furthermore, during injection molding of the tubular body, the thickness of the partition membrane portion is made relatively thick,
Injection molding of the partition membrane is made easier, and in secondary processing,
It is also possible to simultaneously reduce the thickness to a desired thickness.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the main parts of an injection mold used in the method of the present invention, Figure 2 is a plan view of a tubular body obtained by the injection molding of Figure 1, and Figure 3 is a method of the present invention. 1... Tubular body, 2... Partition membrane, 2 &... Protrusion, 2b... Paris, 3... Pa,
main body, 4... cover, 5... tongue piece, 11... mold 7 assembly, 12... injection port, 13... weld line, 14.15-... jig, 14m, 15m...
・Air vent hole. Applicant's agent Patent attorney Takeshi Suzue 2 Figure 1
Figure 2 Figure 3

Claims (5)

[Claims] (1) After integrally molding a tubular body with a partition membrane, which includes a tubular part and a penetrable partition membrane that blocks an internal passage of the tubular part, by injection molding, the partition membrane part is A method for forming a tubular body having a partition membrane stretched thereon, which is characterized by heating and melting the body while pressing it again with a jig from the top and bottom sides, and then cooling it. (2) The partition membrane portion is formed thicker than the desired thickness in the final product by the injection molding, and is thinned to the desired thickness by a subsequent heating and melting process using the jig. The method for forming a tubular body according to item 1. (3) The tubular body according to claim 1, wherein at least one of the distal ends of the jig has a tapered notch so that a part of the heated and melted partition membrane escapes into the tapered notch. molding method. (4) The method for forming a tubular body according to claim 1, wherein the partition membrane portion is heated by high-frequency heating. (5) An air vent hole is drilled almost in the center of the jig,
2. The method of forming a tubular body according to claim 1, wherein a part of the air remaining in the heating and melting process using the jig is thereby released.