JP5746581B2 - Injection molding dropper and method for producing the same - Google Patents

Description

  The present invention relates to an injection molded plastic dropper and a method for manufacturing the same.

  Conventional syringes are blow-molded (also referred to as hollow molding) as shown in FIG. Blow molding is a kind of plastic processing method and is a molding method used when molding hollow products such as plastic bottles.

  In blow molding of a hollow product, a plastic material in the form of pellets is melted by a blow molding machine, and is first molded into a shape called a pipe-shaped parison 16. The parison 16 discharged from above is sandwiched between blow molds 15 including front and rear molds 15a and 15b in which only the outside of the product (cavity of product mold 15c, dropper-shaped dotted line part) is carved. Thereafter, air is blown into the cavity of the product mold 15c, and the parison 16 is inflated to form the product shape. The product cooled in the blow mold 15 becomes a blow molded product.

  A dropper formed by blow molding is shown in FIG. The blow molding dropper 11 is formed by sandwiching a plastic resin with the blow mold 15 as described above, inflating it with air, forming a pipe part 12 having one end 12a for sucking and discharging a liquid, It comprises an operation portion 13 of an internal cavity that is connected to the other end and is pressed and self-recovers. The rear end 13a of the operation unit 13 is sealed during blow molding. For example, although the shape is special, a dropper that is blow-molded in Patent Document 1 is disclosed.

JP 2006-271747 A

  However, in the case of blow molding, since the parison 16 is used, a large number of products cannot be molded with one mold due to the limitation, and productivity is poor. Furthermore, an unnecessary portion called burr 14 is always attached, and a process of removing it is necessary. Further, the thickness of the blow mold 15 is not constant because of molding by air.

  Therefore, the blow molding dropper 11 has a high product cost and the quality is not constant. In particular, when measuring a reagent or the like, the wall thickness is not constant, a burr 14 is generated at the tip, and the discharge amount is not stable unless a step of cutting the burr 14 is performed. It was a problem that could be taken.

  Accordingly, an object of the present invention is to provide an injection molding syringe having a stable quality at low cost and without burrs.

In order to solve the above problems, the present invention
(1)
An injection-molded plastic dropper comprising a pipe part having a mouth for sucking and discharging a liquid at one end and an operation part of an internal cavity that is connected to the other end of the pipe part and is self-recovered by being pressed. The injection forming dropper is characterized by including a seal portion in which the other end of the operation portion is welded and sealed.
(2)
The structure of the injection molding dropper according to (1), wherein the seal portion includes a first seal that intermittently seals the operation portion side and a second seal that tightly seals the counter operation portion side. It was.
(3)
The injection molding dropper according to (1) or (2), wherein the seal part is heat-sealed by a press once with a mold engraved with the shapes of the first seal and the second seal. It was.
(4)
The heat sealing is ultrasonic welding, and the injection molding dropper according to any one of (1) to (3) is used.
(5)
A manufacturing method by injection molding of a dropper comprising a pipe part having a mouth for sucking and discharging a liquid at one end and an operation part of an internal cavity that is connected to the other end of the pipe part and is self-recovered and pressed. An injection molding comprising: a step of forming a seal portion by welding the end portion of an injection-molded product that has been injection-molded into a shape having an open end portion; and a step of cutting back from the seal portion. It was set as the structure of the manufacturing method of a dropper.

  Since the present invention is injection molding, there is no generation of burrs, the wall thickness is constant, and many pieces can be produced with one mold. Therefore, the product cost can be kept low, and a syringe with high quality and stability can be provided.

It is a schematic diagram of the injection molding step of the injection molding syringe according to the present invention. It is a flow of the processing process after an injection molding process. It is a cross-sectional schematic diagram of the injection molding dropper which is this invention. It is a schematic diagram of the blow molding process of the conventional blow molding dropper. It is a front schematic diagram of conventional blow molding.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1 and 2, a plastic injection molding dropper 1 is a step of first performing injection molding using an injection mold 5 comprising an inner mold 5a and an outer mold 5b. An injection molded product 1a composed of a cylindrical portion 3a having an open end connected to the tube portion 2 is formed.

  Here, the injection molding is also called injection molding, and is a molding technique in which the injection-molded product 1a is molded by injecting and injecting a heat-melted resin material into the injection mold 5, and cooling and solidifying it. is there.

  In the present invention, it is possible to employ a general injection method that has been conventionally performed. In general, in injection molding, mold clamping, injection, holding pressure, cooling, mold opening, and product removal are sequentially performed. By repeating this cycle, the injection molded product 1a is continuously produced.

  The injection device is composed of a mold clamping unit and an injection unit 9, and the mold clamping unit is an apparatus for opening / closing and ejecting (ejecting) the injection mold 5. The injection unit 9 heats and melts the resin and injects it into the injection mold 5. It is a device to do.

  The injection mold 5 is a metal mold in which molten resin is injected and injected in order to make the material resin into a desired shape, and has several holes (not shown). Temperature controlled. The molten resin enters the injection mold 5 from the sprue 8 and is filled into the mold body 5c (cavity) through the runner 7 (branch) and the gate 6.

  Thereafter, through a cooling process, the mold body 5c is opened, and the ejector plate of the mold is pushed onto the ejector rod of the molding machine, thereby ejecting the injection molded product 1a. In such injection molding, a plurality of mold main bodies 5c are connected by the runner 7, and a plurality of injection molded products 1a can be molded simultaneously, and the productivity is high.

  In the mold body 5c of the present invention, the groove is formed in the shape in which the end portion of the dropper is opened. Therefore, the mold body 5c is inserted into the outer mold 5b in which the cavity of the dropper is carved, and the cavity. And an inner mold 5a having an inner shape. The resin is filled in the gap between the inner and outer molds 5a and 5b, and an injection molded product 1a having an open end is formed.

  In the injection molding, the sprue 8 into which the molten resin flows, the runner 7 that leads to the mold body 5c, and the injection molded product 1a (product part) are formed in a row. Therefore, in order to obtain the injection molded product 1a, the sprue 8 and the runner 7 are cut off. The obtained injection molded product 1a is shown in FIG.

  As shown in FIG. 2 (A), the injection molded product 1a has an opening 3b at the end of the tube portion 3a on the side opposite to the tube 2 side. Therefore, as shown in FIG. 2 (B), in order to seal the tube portion 3a, a step of forming the seal portion 4 by welding the tube portion 3a with heat or the like is performed to obtain a sealed seal product 1b.

  By forming the seal part 4, the cylinder part 3 a is sealed and the operation part 3 is formed. Subsequently, as shown in FIG. 2 (C), the rear portion (removal portion 3c) from the seal portion 4 is not necessary, and thus the injection molding dropper 1 is obtained through a cutting step. FIG. 3 shows a schematic sectional view of the injection molding dropper 1.

  As shown in FIGS. 2 and 3, the injection molding dropper 1 includes a tube portion 2 having a mouth 2 a for sucking and discharging a liquid at one end, and an operation portion 3 that is connected to the other end of the tube portion 2 and is an internal cavity. Become. And the seal | sticker part 4 which welded and sealed the rear-end part 3d which is the other end of the operation part 3 is provided.

  As a material of the injection molding dropper 1, a plastic resin such as polyethylene is suitable. The thickness should just be the range which the operation part 3 can press and self-recover. For example, it may be 0.4 mm to 0.8 mm.

  The operation unit 3 is an internal cavity. When the operation unit 3 is pressed, the internal air is discharged from the mouth 2a, and the operation unit 3 is restored to its original shape (self-healing) by releasing the pressure by putting the port 2a into the liquid. At the same time, the liquid is sucked into the tube portion 2 and the operation portion 3. By pressing the operation unit 3 again, the liquid sucked inside is discharged.

  As shown in FIG. 3, the seal unit 4 is provided with a first seal 4 a that is intermittently sealed with a gap 4 c on the operation unit 3 side, and the second side in which the counter-operation unit 3 side is tightly sealed without a gap. It is desirable to arrange the seal 4b. By applying such two seals having different adhesion degrees, burrs are hardly generated in the welded portion inside the operation unit 3.

  On the other hand, if only the close seal as the second seal 4b is applied, burrs are generated inside, the inner volume of the operation unit 3 is not constant, and burrs are removed during use, and may be discharged when the operation unit 3 is pressed. . Naturally, the intermittent seal as the first seal 4a alone does not keep the suction, and even if the suction can be performed, the content sucked into the operation unit 3 leaks and does not function as a dropper.

  The form of the 1st seal | sticker 4a is not limited to what provided the some seal | sticker part and the clearance gap 4c in the oblique line shape illustrated here, A dot shape and other shapes may be sufficient. What is necessary is just to give the loose seal which does not generate | occur | produce a burr | flash between the 2nd seal | sticker 4b and the internal cavity of the operation part 3. FIG.

  When the first and second seals 4a and 4b are heat-sealed with a single press using a mold engraved with the shapes of the first seal 4a and the second seal 4b, the productivity is improved and further burrs are generated. It is desirable because it is suppressed.

  Further, it is more preferable to perform heat sealing by ultrasonic welding. Ultrasonic welding is a welding method in which ultrasonic vibration of about 15 to 50 kilohertz is applied to the seal portion 4 together with pressure and the resulting frictional heat is used for joining.

  By ultrasonically welding the seal portion 4, it is not necessary to control the temperature of the mold that forms the seal portion 4, and the formed seal portion 4 is stably hermetically sealed.

  In addition, when adopting vinyl chloride as a material, high frequency welding can also be used. This is a method in which the resin member itself generates heat from the inside by the electric field action of high-frequency energy and is welded. Since it is sandwiched between molds without physical vibration, the surface finish is beautiful.

DESCRIPTION OF SYMBOLS 1 Injection molding dropper 1a Injection molded product 1b Seal sealed product 2 Pipe part 2a Port 3 Operation part 3a Tube part 3b Opening 3c Removal part 3d Rear end part 4 Seal part 4a First seal 4b Second seal 5 Injection mold 5a Inner metal mold Mold 5b Outer mold 6 Gate 7 Runner 8 Spru 9 Injection unit 11 Blow molding dropper 12 Pipe part 12a Port 13 Operation part 13a Rear end part
14 Burr 15 Blow mold 15a Front mold 15b Rear mold 15c Product mold 16 Parison

Claims (5)

Injection molded plastic dropper,
It consists of a pipe part having a mouth for sucking and discharging liquid at one end, and an operation part of an internal cavity that is connected to the other end of the pipe part and is self-recovered and pressed.
An injection-forming dropper comprising a seal portion that is welded and sealed at the other end of the operation portion. 2. The injection molding dropper according to claim 1, wherein the seal part includes a first seal that intermittently seals the operation part side and a second seal that tightly seals the counter-operation part side. The injection molding dropper according to claim 1 or 2, wherein the seal portion is heat-sealed by a press once with a mold engraved with the shapes of the first seal and the second seal. The injection molding dropper according to any one of claims 1 to 3, wherein the heat seal is ultrasonic welding. A manufacturing method by injection molding of a syringe comprising a pipe part having a mouth for sucking and discharging a liquid at one end, and an operation part of an internal cavity continuously connected to the other end of the pipe part and self-recovered,
An injection comprising: a step of forming a seal portion by welding the end portion of an injection-molded product that has been injection-molded into a shape in which the end portion of the dropper is opened; and a step of cutting back from the seal portion. A manufacturing method of a molding dropper.

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