JP3362904B2 - Injection molding method - Google Patents

Injection molding method

Info

Publication number
JP3362904B2
JP3362904B2 JP5562293A JP5562293A JP3362904B2 JP 3362904 B2 JP3362904 B2 JP 3362904B2 JP 5562293 A JP5562293 A JP 5562293A JP 5562293 A JP5562293 A JP 5562293A JP 3362904 B2 JP3362904 B2 JP 3362904B2
Authority
JP
Japan
Prior art keywords
shaped
resin
injection molding
pipe
product
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP5562293A
Other languages
Japanese (ja)
Other versions
JPH06262636A (en
Inventor
賢一 成田
憲治 河野
Original Assignee
三菱エンジニアリングプラスチックス株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 三菱エンジニアリングプラスチックス株式会社 filed Critical 三菱エンジニアリングプラスチックス株式会社
Priority to JP5562293A priority Critical patent/JP3362904B2/en
Publication of JPH06262636A publication Critical patent/JPH06262636A/en
Application granted granted Critical
Publication of JP3362904B2 publication Critical patent/JP3362904B2/en
Anticipated expiration legal-status Critical
Application status is Expired - Fee Related legal-status Critical

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17Component parts, details or accessories; Auxiliary operations
    • B29C45/1703Introducing an auxiliary fluid into the mould
    • B29C45/1704Introducing an auxiliary fluid into the mould the fluid being introduced into the interior of the injected material which is still in a molten state, e.g. for producing hollow articles
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17Component parts, details or accessories; Auxiliary operations
    • B29C45/1703Introducing an auxiliary fluid into the mould
    • B29C45/1704Introducing an auxiliary fluid into the mould the fluid being introduced into the interior of the injected material which is still in a molten state, e.g. for producing hollow articles
    • B29C2045/1719Introducing an auxiliary fluid into the mould the fluid being introduced into the interior of the injected material which is still in a molten state, e.g. for producing hollow articles making tubular articles

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of injection molding a hollow pipe-shaped molded product branched into a plurality. The above molded product is
For example, it can be widely used for a connector for branching a fluid used for passing a fluid for heat dissipation or heating. 2. Description of the Related Art In a conventional injection molding, when a pipe-shaped molded product is injection-molded, there is known a method of molding by inserting a piece into a mold or incorporating a core. However, in order to form a complicated hollow portion, the mold structure becomes complicated, and there is a practical limit. Also, using a molten metal or a water-soluble resin, the shape of the hollow part is created in advance and inserted into the mold at the time of molding, and after molding, the molten metal inside is melted or the water-soluble resin is melted to form a hollow. Although there are methods for forming a structure, these methods have a problem that the number of manufacturing steps increases, for example, it is necessary to previously shape a hollow portion. [0003] An object of the present invention is to form a pipe-shaped molded product branched into a plurality of pipes by using a mold portion corresponding to one end of one of the branched pipes. Inject gas and do not need complicated mold structure,
An object of the present invention is to provide a method for injection molding a branched pipe-shaped molded product. The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have made each end of a pipe portion branched into a plurality of shapes longer than the product shape, A resin injection portion and a gas injection port are provided at one extension, and after the molten resin is injected into the cavity, the molten resin is injected in an amount sufficient to form the molded article, and a pressurized gas is injected during the injection process. As a result, the present inventors have found that a pipe-shaped molded product having a complicatedly branched interior and continuous inside can be formed, and the present invention has been completed. That is, the present invention relates to an injection molding method of a branched pipe-like molded product, wherein a pressurized gas is injected from a pipe-shaped end portion during injection injection of a molten resin into a mold cavity for a branched pipe. The present invention relates to an injection molding method for a pipe-shaped molded product, which comprises producing a pipe-shaped product branched into a plurality by injection. In the present invention, the resin forming the hollow pipe portion is not limited to general thermoplastic resins such as general-purpose thermoplastic resins such as polyolefin, polystyrene, ABS resin, AS resin, methacryl resin, and fluorine-containing resin. Polyamide, saturated polyester, polycarbonate
So-called engineering plastics exemplified by bone, polyacrylate, polyacetal, polysulfone, modified polyrenylene ether and the like can be used. The preferred molding method of the present invention is described below. As the mold to be used, one having a structure capable of injecting a resin and a gas from a portion corresponding to an end of a pipe-shaped molded product branched into a plurality is used. The one with the smallest outer diameter is preferred, but the location of resin and gas injection is not particularly limited. Also, the end of each pipe section is 10m longer than the size required for the product to cut and form a continuous pipe.
It is desirable to design the product so that it is longer than m. Using a mold as described above, a predetermined amount of thermoplastic resin melted in a cylinder of an injection molding machine is measured and then injected into a cavity. However, the amount of the molten resin is insufficient to completely fill the mold cavity, and is sufficient to fill the cavity when the pressurized gas is injected. The molten thermoplastic resin is all injected into the cavity, and before the injection is completed, a pressurized gas is supplied to a gas gate provided in the mold cavity via a gas nozzle provided in the mold. And into the product cavity. Normally, it is preferable to use nitrogen gas as the pressurized gas. The molten thermoplastic resin flows along the flow path of the cavity provided in the mold while being stretched by the pressurized gas. The molten resin is pushed to the end of the flow path by the pressurized gas, and a continuous hollow portion is formed inside the product. In the cooling step, the pressure inside the hollow portion is maintained by a pressurized gas, and after the molten resin is cooled and solidified,
The product is taken out by opening the mold with the pressure in the hollow part at atmospheric pressure. Next, the end portion of the branched pipe portion is cut by machining to obtain a continuous hollow pipe-shaped product.
By the above-mentioned injection molding method, it is possible to mold a molded product having a T-shape, a cross shape, a star shape, and the like. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. Example 1 Each end of a T-shaped cylinder having an outer diameter of 15 mmφ and a length of 100 mm is extended 15 mm from the center of a cylinder having an outer diameter of 20 mmφ and a length of 200 mm. 1
Using a cavity-shaped mold having a resin gate and a gas gate at the end of 5 mmφ, a polycarbonate resin (Mitsubishi Gas Chemical Co., Ltd., trade name: Iupilon S30)
00) was injected to fill 60% of the cavity volume. The temperature of the molten resin in the cylinder at the time of injection is 29
At 0 ° C., the injection pressure was 75 MPa. Before the end of injection of the molten resin, nitrogen gas was injected from a gas gate at the same end as the resin gate. The molten resin was extruded by nitrogen gas, filled up to the end of the cylindrical portion of 20 mmφ inside the cavity, and then cooled while maintaining the nitrogen gas pressure at 3.5 MPa. After releasing the mold by lowering the nitrogen gas pressure in the hollow part of the molded article to atmospheric pressure, the molded article shown in FIG. 1 was taken out.
Each end of the molded product was cut by 15 mm to obtain a T-shaped product having a continuous hollow portion. Embodiment 2 Each end of a cross-shaped cylinder having an outer diameter of 20 mm and a length of 150 mm is extended by 15 mm from the center of a cylinder having an outer diameter of 15 mm and a length of 150 mm, and an outer diameter of 15 mm.
Using a cavity-shaped mold provided with a resin gate and a gas gate at the end of the cylinder, a polycarbonate resin (Mitsubishi Gas Chemical Co., Ltd., trade name: Iupilon S300)
0) was injected to fill 60% of the cavity volume. The temperature of the molten resin in the cylinder at the time of injection is 290
° C and the injection pressure were 75 MPa. Before the end of injection of the molten resin, nitrogen gas was injected from a gas gate at the same end as the resin gate. The molten resin was extruded by a nitrogen gas, filled up to the end of a cylindrical portion having a diameter of 20 mm inside the cavity, and then cooled while maintaining the nitrogen gas pressure at 4 MPa. After lowering the nitrogen gas pressure in the hollow part of the molded article to atmospheric pressure and releasing the mold, the molded article shown in FIG. 2 was taken out. Each end of the molded product was cut by 15 mm to obtain a cross-shaped product having a continuous hollow portion. Example 3 Each end of a star-shaped cylinder having an outer diameter of 15 mmφ and a length of 100 mm is extended by 15 mm, and a resin gate and a gas gate are provided at one end. Using a cavity-shaped mold provided, polycarbonate resin (trade name: Iupilon S3000, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was injected so as to fill 70% of the cavity volume. The temperature of the molten resin in the cylinder at the time of injection was 290 ° C., and the injection pressure was 75 MPa. Before the end of molten resin injection,
Nitrogen gas was injected under pressure from the gas gate at the same end as the gas. The molten resin is extruded by nitrogen gas and after filling up to the end of each cylindrical portion of 15 mmφ inside the cavity,
The resin was cooled while maintaining the pressure of nitrogen gas at 4 MPa. After releasing the mold by lowering the nitrogen gas pressure in the hollow part of the molded article to the atmospheric pressure, the molded article shown in FIG. 3 was taken out. Each end of the molded product was cut by 15 mm to obtain a star-shaped product having a continuous hollow portion. According to the present invention, a structural part having a shape which has conventionally required a molten core method or a mold having a complicated structure,
Since molding can be performed by injection molding with a normal mold structure, a large number of identical products can be obtained in a short time, and productivity can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a T-shaped product formed in Example 1. FIG. 2 is a plan view of a cross-shaped product formed in Example 2. FIG. 3 is a plan view of a star-shaped product formed in Example 3. [Description of Signs] 1: Resin gate position 2: Gas gate position 3: Cutting point

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-68920 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) B29C 45/00-45/84

Claims (1)

  1. (57) [Claim 1] An injection molding method for a branched pipe-like molded product, wherein a molten resin is injected and injected into a mold cavity for a branched pipe. An injection molding method for a pipe-shaped molded product, wherein a pipe-shaped product branched into a plurality of shapes is molded by injecting more pressurized gas. 2. The injection molding method according to claim 1, wherein the branched pipe-shaped product is T-shaped. 3. The injection molding method according to claim 1, wherein the branched pipe-shaped product has a cross shape. 4. The injection molding method according to claim 1, wherein the branched pipe-shaped product has a star shape.
JP5562293A 1993-03-16 1993-03-16 Injection molding method Expired - Fee Related JP3362904B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP5562293A JP3362904B2 (en) 1993-03-16 1993-03-16 Injection molding method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5562293A JP3362904B2 (en) 1993-03-16 1993-03-16 Injection molding method

Publications (2)

Publication Number Publication Date
JPH06262636A JPH06262636A (en) 1994-09-20
JP3362904B2 true JP3362904B2 (en) 2003-01-07

Family

ID=13003886

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5562293A Expired - Fee Related JP3362904B2 (en) 1993-03-16 1993-03-16 Injection molding method

Country Status (1)

Country Link
JP (1) JP3362904B2 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5639417A (en) 1994-07-15 1997-06-17 Mitsubishi Gas Chemical Company, Inc. Mold apparatus for process for injection molding
JP5242519B2 (en) * 2009-01-30 2013-07-24 アァルピィ東プラ株式会社 Manufacturing method of pipe with branch
JP4947083B2 (en) * 2009-03-31 2012-06-06 株式会社デンソー Injector connector manufacturing method

Also Published As

Publication number Publication date
JPH06262636A (en) 1994-09-20

Similar Documents

Publication Publication Date Title
EP0688652B1 (en) Opposed gating injection method
JP5249181B2 (en) Injection molding of microporous materials
US3461197A (en) Method for producing composite articles
DE60037449T2 (en) Improved mixing device and method for injection molding machines
US3475530A (en) Process for molding plastic articles having decorative panels thereon
US4035466A (en) Method for central injection molding
US5443378A (en) Apparatus for the sandwich method of injection molding
US4944909A (en) Method for manufacturing multilayer molded articles
US5204051A (en) Process for the injection molding of fluid-filled plastic bodies
JP3440289B2 (en) Valve gate injection molding method and apparatus
EP0739705A1 (en) Process for manufacturing foam-filled extruded products
US5139724A (en) Method and apparatus for injection moulding blanks
Goodship ARBURG practical guide to injection moulding
EP0625089B1 (en) Injection molding of plastic article having hollow rib
US4636347A (en) Method of making a fastener
US4422995A (en) Method and apparatus for molding hollow, slender workpieces
EP0057547B1 (en) Stabilized core injection molding of plastic
AU714434B2 (en) Valve-gate bushing for gas-assisted injection molding
US4508676A (en) Core stabilization by sequential injections
DE69932924T2 (en) Extrusion forming of optical objects
EP0567926A1 (en) Plastic system for injection molding and extruding a hollow tube for forming a plastic container by blowing
CA2157568C (en) Method of manufacturing needles
EP0640460B1 (en) Method for producing a thin film
US4255367A (en) Method for injection molding articles wherein additives are added in selective portions
US4498860A (en) Injection molding apparatus having a sprue holder with an inclined retractable ram

Legal Events

Date Code Title Description
R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

FPAY Renewal fee payment (prs date is renewal date of database)

Free format text: PAYMENT UNTIL: 20071025

Year of fee payment: 5

FPAY Renewal fee payment (prs date is renewal date of database)

Free format text: PAYMENT UNTIL: 20081025

Year of fee payment: 6

FPAY Renewal fee payment (prs date is renewal date of database)

Free format text: PAYMENT UNTIL: 20091025

Year of fee payment: 7

LAPS Cancellation because of no payment of annual fees