JPS6113296Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a mold for molding a nipple used for a baby bottle etc. using a silicone resin molding material.
This mold does not require any processing after cutting the gate or drilling the mouthpiece hole, and can produce molded products without defects such as discoloration due to air inside the mold.

Conventional nipples are made of synthetic rubber such as silicone rubber by compression molding, transfer molding, or the like. It was thought that the gate of the mold normally used for this purpose needed a cross-sectional area of 1 to 15 ^mm2 , so the gate was placed somewhere other than the crown of the nipple from the viewpoint of aesthetics and texture during suckling. The hole for the mouthpiece at the top was processed after molding. However, when the gate position is restricted in this way, the air inside the mold becomes an inhibiting factor during the molding process, which tends to cause shape defects and the phenomenon of discoloration due to adiabatic compression of the air. In addition, post-processing of the mouthpiece hole remained a major problem in terms of cost reduction.

The present invention skillfully utilizes the shape of the nipple, which has a hole at the top of the head, eliminating the need for post-drilling processing.
Furthermore, the present invention aims to provide a mold that can effectively exhaust all the air inside the mold from the mating surfaces of the male and female molds during material injection, thereby producing a nipple that is good in use and aesthetically.

That is, the present invention uses a mold for molding a nipple having a mouth opening at the top of the head using a silicone resin molding material, and the outer circumferential surface of a pin-shaped protrusion erected on the top of the male mold and the gate wall of the female mold. This nipple forming mold is characterized by having a gate with a gap of 0.15 mm or less.

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an example of the product shape of the nipple, and there is a mouth hole 2 in the crown 1 of the head. The diameter of the suction hole 2 is, for example, 2.
Thicknesses in the range of 0.3 to 0.9 mm are used depending on the age, such as for babies up to 3 months old or babies over 7 months old.
The silicone rubber nipple is highly praised for not releasing harmful substances such as formalin, and for being resistant to boiling water sterilization.

FIG. 2 is a conceptual diagram of the nipple molding die of the present invention. 3 is a female mold, 4 is a male mold, and the gap 5 between them is the part that will become the nipple molded product. Figure 3 shows an enlarged view of the area around the top of the nipple (inside the circle in Figure 2). A pin-like protrusion 6 is erected on the top of the male mold 4, and the lower part 7 of the protrusion corresponding to the wall thickness of the top of the nipple has a diameter such that, for example, the diameter of the suction hole is 0.6 mm after molding. do it like this. The tip 8 of the protrusion is made to protrude into the female gate hole to form a cylindrical gate or a modified gate therebetween with the inner wall (gate wall) 9 of the hole. The silicone resin molding material is applied to the nozzle of the injection molding machine (as shown) at the nozzle contact part 10 in Fig. 2.
are brought into contact with each other and are injected through the gate 11.
The material is poured into a mold heated to about 80-150°C.

The cross-sectional area of such a gate can be made into a mold with a cross-sectional area of about 0.3 mm ² , and compared to conventionally used gates of 1 to 15 mm ² , a gate with a microscopic size of less than 1/3 is sufficient. 0.3
If a gate with a cross-sectional area of mm ² is made with a uniform wall thickness around the outer circumference of a pin-shaped protrusion with a diameter of 0.6 mm, the wall thickness will be only 0.15 mm, and there will be a slight difference in thickness, especially at the tip of the pin-shaped protrusion. By applying a taper, the molded part can be separated from the gate and removed, leaving almost no trace of the gate. The molded product can then be obtained with a mouthpiece hole passing through it.

Since the gate position of the present invention is at the top of the head, the air inside the mold is evenly discharged from the mold mating surface 12 during molding, and defects in shape and appearance such as discoloration do not occur.

Figure 3 shows a runnerless structure. This structure has less scrap and can help save resources. The ability of the mold of the present invention to have a minute gate cross-sectional area is not limited to such runnerless molds. Even in the case of a six-cavity mold with a runner and a runner cross-sectional area of 1 mm ² , it was possible to mold with a gate cross-sectional area of 0.3 mm ² or less.

For such a mold, a material such as silicone rubber for injection molding, such as YE-5626 manufactured by Toshiba Silicone Corporation, may be used.

[Brief explanation of the drawing]

Figure 1 is an elevational view of the silicone rubber nipple, Figure 2
The figure is a sectional view of the nipple molding die of the present invention, and FIG. 3 is an enlarged detailed view of the inside of the circle in FIG. 2. 2... Sucking hole, 3... Female type, 4... Male type, 6
... Pin-shaped protrusion, 7... Lower part of pin-shaped protrusion,
8...Tip of pin-shaped protrusion, 9...Gate wall.

Claims (1)

[Scope of utility model registration request] In a mold for molding a nipple with a sucking hole on the top of the head using a silicone resin molding material, the gap between the outer peripheral surface of the pin-shaped protrusion erected on the top of the male mold's head and the gate wall of the male mold is 0.15 mm. A nipple molding mold characterized by having a gate formed as follows.