JPH0729336B2 - Molding method of infusion stopper - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for molding an infusion stopper capable of forming an extremely thin film of the infusion stopper.

(Prior Art) Generally, a conventional infusion plug is fitted with a synthetic resin ring 22 on an upper inner peripheral surface of a cylindrical wall 21 having a welding flange 20 on a lower portion, as shown in FIGS. 4 and 5. An annular protrusion 23 is formed to support the outer peripheral portion of the rubber stopper 25, and a thin film 24 for completely blocking the portion where the rubber stopper is located and the inside of the infusion bottle is provided inside the annular protrusion 23. It is integrally molded with synthetic resin.

On the other hand, the conventional molding die for the infusion plug has a resin filling port at the central position of the thin film molding portion of the upper core type, and a lower pool has a basin formed at a position facing the filling port. It is assembled so as to form a thin film molding part that has the same gap as the thin film thickness, and when molding the infusion stopper, the resin is filled from the central part of the thin film molding part, and through the narrow gap of the thin film molding part, the annular protrusion molding And the cylindrical wall molding portion are filled and integrally molded. The plug formed by the above-mentioned conventional molding method cannot make the thin film extremely thin due to the restriction on molding, and even the thinnest one is 0.
It has a thickness of 3 to 0.32 mm, and a projection is formed on the lower surface of the central part of the thin film by the pool. As a result, when the conventional infusion plug is pierced with the needle 30 during use, as shown in FIG. 5, a coring phenomenon occurs in which the thin film in that portion is punched out, and the punching piece 31 enters the infusion fluid and floats. There is a problem that it may get stuck or get into the needle hole. The coring phenomenon is caused by the fact that the thin film is so thick that the needle sticks out completely without breaking the film.

(Problems to be Solved by the Invention) In order to prevent the coring phenomenon from occurring, it is desirable to make the thickness of the thin film that the needle sticks as thin as possible. However, in the above-mentioned conventional molding method, if the thickness of the membrane portion of the infusion stopper is made thinner than the conventional one, the gap between the membrane molded portions becomes very narrow, and the flow of resin to the annular protrusion and the cylindrical wall molded portion is reduced. It gets very bad. Therefore, molding failure occurs due to insufficient resin filling, and it is difficult to reduce the thickness of the thin film as compared to the current situation, and the coring phenomenon cannot be avoided. Further, in the conventional plug body, since the protrusion of the pool is formed on the lower surface of the central portion of the thin film as described above, there is a problem that the needle cannot be stuck when hitting this portion.

The present invention was devised in view of the above circumstances, and the thickness of the thin film portion is dramatically reduced as compared with the conventional one without forming a liquid reservoir portion, and the occurrence of coring phenomenon is completely eliminated during use. It is an object of the present invention to provide an infusion solution molding method and a mold thereof that can easily mold an infusion solution body that can be manufactured.

(Means for Solving the Problems) A method for molding an infusion plug according to the present invention that solves the above problems is a cylindrical wall, an annular protrusion protruding from an inner peripheral surface of the cylindrical wall, and an inside of the annular protrusion. In a method for molding an infusion solution plug made of a synthetic resin composed of a thin film formed on a cylindrical wall molding part, an annular projection molding part communicating from the inner peripheral surface of the cylindrical wall molding part, and the annular shape. There is a molding chamber composed of a thin film molding portion that communicates with the inner periphery of the protrusion molding portion, and a part of the mold member that constitutes the thin film molding portion is movable in the thickness direction of the thin film molding portion, and By using a mold having a resin filling port provided near the boundary between the thin film molding portion and the annular protrusion molding portion, the gap of the thin film molding portion is expanded to be larger than the finally obtained thin film thickness, and at least a thin film is formed. The gap between the two parts, but the unfilled part remains in the gap of the cylindrical wall forming part. The step of filling with oil, the movable die member is displaced so that the gap of the thin film molding portion becomes equal to the finally obtained thin film thickness, and excess resin is removed from the gap of the thin film molding portion by the annular projection molding portion and the cylinder. The infusion plug body comprises a step of extruding into a wall forming part to form a thin film having a desired thickness, and a step of filling a resin so as to completely fill the gap between the annular projection forming part and the cylindrical wall forming part from the filling port. It is characterized by molding.

(Function) At the start of molding, the movable core mold is moved downward so that the gap in the thin film molding part is wider than the film thickness that is finally obtained, and in that state, the resin is filled through the filling port, and at least the resin is thin film molded. When the gap is completely filled, the movable core mold is moved upward so that the gap of the thin film forming portion becomes equal to the desired film thickness. As a result, the resin filled in the thin film forming portion is extruded to the periphery and escapes to the cylindrical wall forming portion to form an extremely thin film. After that, if you fill the resin from the filling port,
Since the resin filling port is located at the boundary between the annular projection forming part and the thin film forming part, the resin fills the cylindrical wall forming part through the annular protruding part with a large gap regardless of the film formation. Then, the entire chabber is completely filled with the resin. Therefore,
Even if the film thickness is extremely thin, insufficient filling does not occur in the cylindrical wall portion as in the conventional case. As a result, according to the method of the present application,
It is possible to form an ultra-thin film of 2 mm or less. Also,
Since the resin filling port is arranged at the boundary between the annular protrusion and the film portion, a protrusion for forming a molten metal is not formed on the lower surface of the central portion of the film, and an ultrathin film having a uniform thickness is formed, and the needle is easily pierced. It is possible to obtain an infusion plug that does not cause the coring phenomenon.

(Example) Hereinafter, the Example of this invention is described in detail based on drawing.

FIG. 1 shows a mold for molding an infusion plug of the present invention, in which 1 is a molding chamber in which a plug is molded by being filled with resin, a cylindrical wall molding part 1 ₁ , an annular protrusion. Molding part 1 ₂ ,
Consists film forming unit 1 _3, first the molding chamber outer mold 2,
The second outer mold 3, the upper core mold 4, the lower core mold 5, and the movable core mold 6 are formed by molds. The first outer mold 2 has a molding surface on the outer peripheral portion of the cylindrical wall of the infusion plug, and the second outer mold 3 has a molding surface on the lower surface of the plug flange. The upper core mold 4 has an outer surface of the annular protrusion and the thin film, and a molding die surface of the inner peripheral surface of the cylindrical wall above the annular protrusion,
A resin filling port 7 is formed at the boundary between the annular projection molding portion and the film molding portion. The lower core mold 5 has a lower surface of the annular projection and a molding die surface of the inner peripheral surface of the cylinder below the annular projection, and is hollow inside. The movable core die 6 has a molding die surface on the lower surface of the thin film portion at the top, and is fitted in the core portion of the lower core die so as to be vertically movable. A cam follower 9 having an inclined groove 8 is fixed to the lower end of the movable core, and is vertically moved by a cam 11 driven in the left and right direction by a cylinder 10 fixed to a frame. In addition, 12 is a bearing.

The mold of the present embodiment is configured as described above, and has an appropriate jig.
Assembled by 15. Next, a method for forming an infusion plug body using the mold will be described with reference to FIGS.

At the start of forming, and is moved downward the movable core die 6, leave spread than the film thickness to obtain a gap film forming unit 1 ₃ Finally, the resin is filled from the resin filling port 7 in this state. As the resin shown in FIG. 2, when it is completely filled at least in the film forming section clearance, so moved rightward cam 11 by the cylinder 10, becomes equal to the film thickness gap film forming unit 1 ₃ is desired Thus, the movable core mold 6 is moved upward. By moving the core die 6 moves upward, the resin filled in the film forming section 1 _3, as shown in Figure 3, is filled therein escapes pushed around by the cylindrical wall forming portion 1 ₁ It Further, by filling the resin from the filling opening, the resin passes through the annular projection forming portion 1 ₂ is filled in the cylindrical wall forming portion 1 _1, completely resin is filled in the entire Chaba. At that time, since the resin filling opening is arranged in the boundary between the annular projection forming portion 1 ₂ and the thin film forming section 1 _3, the resin is directly cylindrical wall forming portion through the gap is large annular projection forming portion 1 ₁
In the conventional method, even if the film thickness is extremely thin, insufficient filling does not occur unlike the conventional case. As a result, according to the method of the present application,
It became possible to form ultra-thin films of 0.2 mm or less.

According to this method, an infusion stopper having an ultrathin film having a thickness of 0.2 mm was molded and used in the same manner as the conventional one as shown in FIG. 5, resulting in easy needle sticking and punching piece There was no occurrence.

(Effects) The method for molding an infusion plug according to the present invention has the above-described structure and has the following remarkable effects.

The film thickness can be formed extremely thinner than before, and even if the film thickness is extremely thin, there is no lack of filling in the cylindrical wall portion as in the conventional case, so a high quality infusion plug can be obtained. . In addition, since the resin filling port of the mold is arranged at the boundary between the annular projection molding portion and the thin film molding portion, a projection for the pool is not formed on the lower surface of the central portion of the film, and an ultrathin film of uniform thickness is formed. It is possible to obtain an infusion solution plug that is molded, is easy to pierce with a needle, and does not cause the coring phenomenon.

Further, since the mold is configured such that one of the molds having the thin film forming mold surface can be moved and driven with respect to the molding part, an infusion solution plug having an extremely thin film can be molded very easily. Furthermore, since the resin is filled in two stages before thin film molding and after thin film molding, there is no generation of excess resin, and there is no need to provide a cavity for letting excess resin escape in the mold, and the structure of the mold is constructed. In addition to simplification, waste of resin is small and cost can be reduced.

[Brief description of drawings]

FIG. 1 is a side sectional view of an embodiment of a mold for molding an infusion stopper according to the present invention, FIGS. 2 and 3 are explanatory views of a method for forming an infusion stopper, and FIG. 4 is a conventional infusion stopper. FIG. 5 is a side sectional view of the body, and FIG. 5 is a side sectional view in the use state. 1: molding chamber, 1 _3: film forming unit, 1 _2: annular projection forming portion,
1 ₁ : Cylindrical wall molding part, 2: First outer mold, 3: Second outer mold, 4: Upper core mold, 5: Lower core mold, 6: Movable core mold, 7: Resin filling port, 9:
Cam follower, 10: Cylinder, 11: Cam

Claims (1)

[Claims] 1. Molding of an infusion plug body for molding a synthetic resin infusion plug body comprising a cylindrical wall, an annular protrusion protruding from the inner peripheral surface of the cylindrical wall, and a thin film formed inside the annular protrusion. In the method, a molding chamber comprising a cylindrical wall molding portion, an annular projection molding portion communicating from the inner peripheral surface of the cylindrical wall molding portion, and a thin film molding portion communicating with the inner circumference of the annular projection molding portion, A part of the mold member forming the thin film molding portion is movable in the thickness direction of the thin film molding portion, and a resin filling port is provided near the boundary between the thin film molding portion and the annular projection molding portion. Using a mold that is made, the gap of the thin film forming portion is expanded more than the thin film thickness to be finally obtained, and at least the gap of the thin film forming portion is filled, but the unfilled portion remains in the gap of the cylindrical wall forming portion. The step of filling the resin, the thickness of the thin film that finally obtains the gap of the thin film molding part, etc. Displacing the movable mold member so as to form a thin film having a desired thickness by extruding excess resin from the gap of the thin film molding part to the annular protrusion molding part and the cylindrical wall molding part, the filling port The step of filling the resin so as to completely fill the gap between the annular projection molding portion and the cylindrical wall molding portion, and molding the infusion plug body.