JPH0735058B2 - Hollow molding method - Google Patents
Hollow molding methodInfo
- Publication number
- JPH0735058B2 JPH0735058B2 JP1142057A JP14205789A JPH0735058B2 JP H0735058 B2 JPH0735058 B2 JP H0735058B2 JP 1142057 A JP1142057 A JP 1142057A JP 14205789 A JP14205789 A JP 14205789A JP H0735058 B2 JPH0735058 B2 JP H0735058B2
- Authority
- JP
- Japan
- Prior art keywords
- fluid
- mold
- pressure
- hollow
- injection
- 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 - Lifetime
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/1703—Introducing an auxiliary fluid into the mould
- B29C45/1704—Introducing 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
- B29C45/1705—Introducing 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 using movable mould parts
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
- Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、溶融樹脂の他に加圧流体を型キャビティ内に
注入して中空型物を成形する方法に関する。The present invention relates to a method for molding a hollow mold by injecting a pressurized fluid into a mold cavity in addition to a molten resin.
［従来の技術］ 従来、中空型物の射出成形方法として、金型の型キャビ
ティを満たすに不十分な量の溶融合成樹脂を型キャビテ
ィに注入した後、引続き同じ入口よりガス体を単独で或
は溶融合成樹脂を注入しつつ圧入して型キャビティを満
たす方法が知られている（特公昭57−14968号、米国特
許第4,101,617号など）。[Prior Art] Conventionally, as a method of injection molding a hollow mold, after injecting an amount of molten synthetic resin insufficient to fill a mold cavity of a mold into the mold cavity, a gas body alone or from the same inlet is continuously used. Is known to fill a mold cavity by injecting a molten synthetic resin while injecting it (Japanese Patent Publication No. 57-14968, US Pat. No. 4,101,617, etc.).
上記の方法は、いわゆるブロー成型に比べ、表面の型再
現が良く、またバリ（はみ出し部）の発生も少ないとい
われている。It is said that the above-mentioned method has better reproduction of the mold on the surface and less burrs (protruding portions) than so-called blow molding.
［発明が解決しようとする課題］ しかしながら、加圧（高圧）ガスの注入によって金型間
にバリが発生することがあり、バリの切断加工や研磨処
理を要することがある。[Problems to be Solved by the Invention] However, burrs may be generated between the dies due to injection of a pressurized (high-pressure) gas, which may require cutting and polishing of the burrs.
バリの発生を防止するには、課題な型縮力の成形機を必
要とし、金型も耐圧の構造及び材質の使用が必要にな
る。In order to prevent the occurrence of burrs, a molding machine having a problematic mold contraction force is required, and the mold is also required to use a pressure resistant structure and material.
また、形成する中空部の容積が大の場合は、多量の高圧
流体が必要になり、大型の高圧流体製造設備を必要とす
る。In addition, when the volume of the hollow portion to be formed is large, a large amount of high-pressure fluid is required, and a large-scale high-pressure fluid manufacturing facility is required.
本発明は従来の中空型物の射出成型方法の改良を行っ
て、バリの発生がなく、後加工・後仕上げを必要としな
いで、より中空部の大きな中空型物を成形できる射出成
形方法を提供することを目的とする。The present invention improves the conventional injection molding method of a hollow molded article, and an injection molding method capable of molding a hollow molded article having a larger hollow portion without generating burr and requiring no post-processing / finishing. The purpose is to provide.
［課題を解決するための手段（及び作用）］ 本発明は、 射出ノズルから型キャビティ内に溶融樹脂を圧入
し、 キャビティ内に向けて高圧流体を圧入して該溶融樹
脂内に流体道を形成し、 次いで、低圧流体を圧入しながら、型キャビティを
拡大して、キャビティ内の溶融樹脂を中空型物状に成形
し、 中空型物内の流体を排出した後に、成形された中空
型物を取り出すことを特徴とする中空型物の成形法であ
る。[Means (and Action) for Solving the Problems] The present invention is to form a fluid path in a molten resin by injecting a molten resin from an injection nozzle into a mold cavity and a high-pressure fluid into the cavity. Then, while pressurizing the low-pressure fluid, the mold cavity is expanded, the molten resin in the cavity is molded into a hollow mold, and the fluid in the hollow mold is discharged, and then the molded hollow mold is removed. This is a method for molding a hollow molded article, which is characterized by taking out.
以下、工程毎に説明する。Hereinafter, each step will be described.
（１）射出工程［第１図（ａ）］ 本発明に用いる合成樹脂は、射出成形できる熱可塑性樹
脂、熱可塑性エラストマー、熱硬化性樹脂のいずれでも
よく、またこれらと従来公知の添加剤やフィラーとの配
合物が使用できるが、熱可塑性樹脂、熱可塑性エラスト
マー及びその配合物が好ましい。(1) Injection Step [FIG. 1 (a)] The synthetic resin used in the present invention may be any of injection-moldable thermoplastic resins, thermoplastic elastomers, and thermosetting resins. Blends with fillers can be used, but thermoplastics, thermoplastic elastomers and blends thereof are preferred.
本射出工程は、単一樹脂あるいは公知の多成分射出のい
ずれでもよい。This injection step may be either single resin injection or known multi-component injection.
金型２内への溶融合成樹脂３の射出量は、金型２の型キ
ャビティ８を満たすに不十分な量あるいは、型キャビテ
ィ８内容積と同一量又は型キャビティ８内容積以上（所
謂過充填）であってもよい。The injection amount of the molten synthetic resin 3 into the mold 2 is insufficient to fill the mold cavity 8 of the mold 2, the same as the inner volume of the mold cavity 8 or more than the inner volume of the mold cavity 8 (so-called overfilling). ) May be sufficient.
（２）高圧流体注入工程［第２図（ｂ）］ 本発明に用いる高圧流体としては、例えば窒素、炭酸ガ
ス、空気等のように、無害で成形温度及び射出圧力下で
液化しないガスが一般的であるが、溶融合成樹脂と相溶
性のない液体やオリゴマーを用いることもできる。流体
圧は、通常10Kg/cm2Ｇ以上とし、好ましくは50Kg/cm2Ｇ
以上である。高圧流体の流体圧が10Kg/cm2Ｇ未満では、
使用合成樹脂の種類や射出圧力によっては後述するガス
道10を形成しにくくなる。(2) High-pressure fluid injection step [FIG. 2 (b)] As the high-pressure fluid used in the present invention, a gas that is harmless and does not liquefy at the molding temperature and injection pressure, such as nitrogen, carbon dioxide, and air, is generally used. However, it is also possible to use a liquid or oligomer which is incompatible with the molten synthetic resin. The fluid pressure is usually 10 kg / cm 2 G or more, preferably 50 kg / cm 2 G
That is all. When the fluid pressure of high pressure fluid is less than 10 kg / cm 2 G,
Depending on the type of synthetic resin used and the injection pressure, it becomes difficult to form the gas passage 10 described later.
高圧流体の注入は、第１図に示されるように、射出ノズ
ル１内に流体ノズル４を内蔵させ、射出ノズル１をスプ
ルー９に密着させて、樹脂注入口６を介して金型のスプ
ルー９内へと行うことができる。As shown in FIG. 1, the injection of the high-pressure fluid is performed by incorporating the fluid nozzle 4 into the injection nozzle 1, bringing the injection nozzle 1 into close contact with the sprue 9, and then inserting the sprue 9 of the mold through the resin injection port 6. It can be done inward.
高圧流体の注入は、必要な溶融合成樹脂３の一部の射
出に続いて残りの溶融合成樹脂３の射出と共に、必要
な全溶融合成樹脂３の射出に続いて、必要な全溶融合
成樹脂３を射出してから一定時間経過後、のいずれかの
時期に行われる。The high-pressure fluid is injected by injecting a part of the necessary molten synthetic resin 3 and then the remaining molten synthetic resin 3, and then by injecting the necessary total molten synthetic resin 3 and then the necessary total molten synthetic resin 3. After a certain period of time has elapsed from the injection of, is performed at any time of.
この高圧流体の注入によって、ガス道10を形成する。高
圧流体による流体道10は、後述する低圧流体の注入を助
けるもので、樹脂注入口６付近に形成されていれば十分
である。The injection of the high-pressure fluid forms the gas passage 10. The fluid passage 10 for the high-pressure fluid assists the injection of the low-pressure fluid, which will be described later, and is sufficient if it is formed near the resin injection port 6.
なお、高圧流体の注入は、図示されるものでは一箇所か
ら行うものとなっているが、二箇所以上から行うものと
してもよい。It should be noted that the injection of the high-pressure fluid is performed from one place in the illustrated one, but may be performed from two or more places.
（３）低圧流体注入・型キャビティ拡大工程［第１図
（ｃ）］ 低圧流体を注入しながら、型キャビティ８の拡大を行っ
て、中空型物５を形成する。(3) Low Pressure Fluid Injection / Mold Cavity Expansion Step [FIG. 1 (c)] The mold cavity 8 is expanded while injecting the low pressure fluid to form the hollow mold 5.
低圧流体の注入は、高圧流体による流体道10の形成と共
に、又は形成後直ちに行っても良いが、低圧流体の圧力
よりも低いレベルにて高圧流体を一旦回収した後に行う
ことが好ましい。低圧流体の流体圧は、通常10Kg/cm2Ｇ
未満である。低圧流体の流体圧が10Kg/cm2Ｇ以上になる
と、金型2a,2b間にバリが発生しやすくなる。また、後
述するように、金型2bをスライドさせることで型キャビ
ティ８の拡大を行う場合、低圧流体の流体圧が10Kg/cm2
Ｇ以上になると、低圧流体の注入によって金型2bがスラ
イドしてしまうのを抑制するのに大きな力を要し、金型
2bのスライド制御がしにくくなる。The injection of the low-pressure fluid may be performed at the same time as the formation of the fluid passage 10 of the high-pressure fluid or immediately after the formation, but it is preferable to perform the injection of the high-pressure fluid at a level lower than the pressure of the low-pressure fluid once. Fluid pressure of low-pressure fluid is usually 10 kg / cm 2 G
Is less than. When the fluid pressure of the low-pressure fluid is 10 kg / cm 2 G or more, burrs are easily generated between the molds 2a and 2b. Also, as will be described later, when the mold cavity 8 is expanded by sliding the mold 2b, the fluid pressure of the low-pressure fluid is 10 kg / cm 2
Above G, a large force is required to prevent the mold 2b from sliding due to the injection of the low pressure fluid.
2b slide control becomes difficult.
高圧流体による流体道10の形成と共に、又は形成後直ち
に行う場合は、型キャビティ８の拡大により形成された
流体道10の拡大により、高圧流体の圧力が低圧流体の圧
力以下まで低下すると同時に、低圧流体の注入を行う。When the fluid passage 10 is formed by the high-pressure fluid or immediately after the formation, the expansion of the fluid passage 10 formed by the expansion of the mold cavity 8 causes the pressure of the high-pressure fluid to drop below the pressure of the low-pressure fluid, and at the same time, lower the pressure. Inject fluid.
型キャビティ８の拡大は、例えば金型2bを徐々にスライ
ドさせることによって行い、より中空部の大きな中空型
物５を成形することができる。なお、型キャビティ拡大
の段階で、低圧ガスによらず高圧ガスを注入するのは、
金型間にバリが発生しやすくなったり、スライド抑制力
が大きくなり制御が困難になる等の問題を避けられな
い。The mold cavity 8 can be enlarged, for example, by gradually sliding the mold 2b to mold the hollow mold 5 having a larger hollow portion. In addition, at the stage of expanding the mold cavity, injecting high pressure gas regardless of low pressure gas is
Problems such as easy occurrence of burrs between molds and difficulty in control due to increased slide restraining force cannot be avoided.
（４）冷却固化工程［第１図（ｄ）］ 冷却固化は、上記低圧流体の注入による金型２内の圧力
を維持した状態で行われる。即ち、射出ノズル１はスプ
ルー９に密着させた状態で行われる。(4) Cooling and solidifying step [FIG. 1 (d)] Cooling and solidifying is performed in a state where the pressure in the mold 2 is maintained by the injection of the low-pressure fluid. That is, the injection nozzle 1 is carried out in a state of being in close contact with the sprue 9.
上記金型２内の圧力維持は、中空型物５の外面を型キャ
ビティ８の内面に押圧し、型形状の再現性を向上するた
めである。The pressure in the mold 2 is maintained because the outer surface of the hollow mold 5 is pressed against the inner surface of the mold cavity 8 to improve the reproducibility of the mold shape.
（５）流体排出工程［第１図（ｅ）］ 流体の排出は、射出ノズル１の樹脂注入口６と金型２と
の間及び流体ノズル４の流体注入口７と金型２との間の
シール状態を維持したまま流体注入口７を介して金型内
２の加圧流体を排出することによって行うことが好まし
い。(5) Fluid discharging step [FIG. 1 (e)] Fluid is discharged between the resin injection port 6 of the injection nozzle 1 and the mold 2 and between the fluid injection port 7 of the fluid nozzle 4 and the mold 2. It is preferable to discharge the pressurized fluid in the mold 2 through the fluid injection port 7 while maintaining the sealed state of.
即ち、流体ノズル４を内蔵する射出ノズル１とスプルー
９は、前記ガス注入工程及び冷却固化工程と同様な状態
を維持しているもので、射出ノズル１がスプルー９から
離れることによって金型２から直接加圧ガスが大気中に
放出されるのを防止しつつ、流体注入口７を介して行わ
れるものである。That is, the injection nozzle 1 including the fluid nozzle 4 and the sprue 9 maintain the same state as in the gas injection step and the cooling and solidification step, and the injection nozzle 1 is separated from the sprue 9 so that it is separated from the mold 2. This is performed through the fluid inlet 7 while directly preventing the pressurized gas from being released into the atmosphere.
本排出工程は、流体注入口７を介して排出されてくる加
圧流体を、大気に放出することによって行っても、また
適宜の回収容器等に回収して再利用することによって行
ってもよい。This discharge step may be performed by discharging the pressurized fluid discharged through the fluid inlet 7 into the atmosphere, or by collecting it in an appropriate collecting container or the like and reusing it. .
（６）取出し工程［第１図（ｆ）］ 上記流体排出工程の後、金型２を開いて中空型物５を取
出すが、この取出しは、射出ノズル１や流体ノズル４を
金型２に対して圧接させたままで行っても、両者を金型
２から離してから行ってもよい。両者を金型２に圧接さ
せたまま取出しを行った場合、金型２を閉じて再び射出
工程へと戻り、両者を金型２から離して取出しを行った
場合、金型２を閉じ、その前又は後に両者を金型２に圧
接させてから再び射出工程へと戻ることになる。(6) Extracting Step [FIG. 1 (f)] After the fluid discharging step, the mold 2 is opened and the hollow mold 5 is taken out. In this taking out, the injection nozzle 1 and the fluid nozzle 4 are moved to the mold 2. It may be carried out while being pressed against each other, or may be carried out after separating both from the mold 2. When the two are taken out while being pressed against the mold 2, the mold 2 is closed and the process returns to the injection step again. When the two are separated from the mold 2 and taken out, the mold 2 is closed. Before or after the both are pressed against the mold 2, the process returns to the injection step.
［実施例］ まず、実施例に用いた装置を第２図で説明する。Example First, the apparatus used in the example will be described with reference to FIG.
金型２は、2aとスライド可能な2bとから構成されてい
る。The mold 2 is composed of 2a and a slidable 2b.
１は、スクリュー11によって溶融合成樹脂３を射出する
射出ノズルで、先端に樹脂注入口６を有し、かつその内
方に流体ノズル４を内蔵している。この射出ノズル１
は、金型２に対して進退可能なもので、前進して先端が
金型２のスプルー９に圧接されると、樹脂注入口６と金
型２間及び金型２と流体ノズル４のガス注入口７間が同
時にシールされるものとなっている。Reference numeral 1 denotes an injection nozzle for injecting the molten synthetic resin 3 with a screw 11, which has a resin injection port 6 at its tip and a fluid nozzle 4 inside thereof. This injection nozzle 1
Is capable of advancing and retreating with respect to the mold 2, and when the tip moves forward and comes into pressure contact with the sprue 9 of the mold 2, the gas between the resin injection port 6 and the mold 2 and between the mold 2 and the fluid nozzle 4 is The space between the inlets 7 is sealed at the same time.
射出ノズル１に内蔵されている流体ノズル４は、その周
囲に溶融合成樹脂３を通す隙間をもって配置されてお
り、前述した流体注入工程時に、その先端に設けられて
いる流体注入口７から樹脂注入口６を介して金型２に流
体を注入するものである。The fluid nozzle 4 built in the injection nozzle 1 is arranged with a gap around it to allow the molten synthetic resin 3 to pass therethrough, and at the time of the above-mentioned fluid injection step, resin injection is performed from the fluid injection port 7 provided at the tip thereof. A fluid is injected into the mold 2 through the inlet 6.
流体ノズル４は、高圧流体及び低圧流体供給経路に接続
されている。高圧流体の注入は、高圧流体源13より昇圧
装置12により昇圧され開閉バルブ14を介して行われる。
流体道（第１図中の10）形成後、高圧流体を排気バルブ
15を介して排気し、金型2bをスライドさせながら、低圧
流体を低圧流体源16より開閉バルブ17を介して注入す
る。The fluid nozzle 4 is connected to the high pressure fluid and low pressure fluid supply paths. The high-pressure fluid is injected from the high-pressure fluid source 13 by the pressure increasing device 12 through the opening / closing valve 14.
After forming the fluid passage (10 in Fig. 1), exhaust the high pressure fluid.
The low pressure fluid is injected from the low pressure fluid source 16 through the opening / closing valve 17 while exhausting through 15 and sliding the mold 2b.
また、別の態様では、開閉バルブ14を開き、流体道（第
１図中の10）の少なくとも一部が形成された後、開閉バ
ルブ14を閉じ、金型2bをスライドさせながら流体道（第
１図中の10）の内容積を拡大させ、流体道内の流体圧
が、低圧流体の圧力未満に低下した時、開閉バルブ17を
開き、低圧流体源16から開閉バルブ17を介して低圧流体
を注入しつつ、金型2bのスライドを継続し、金型2bのス
ライド源に達したら低圧流体圧で金型２内の圧力を維持
する。In another embodiment, after the opening / closing valve 14 is opened and at least a part of the fluid passage (10 in FIG. 1) is formed, the opening / closing valve 14 is closed and the fluid passage (first When the internal pressure of 10) in Fig. 1 is expanded and the fluid pressure in the fluid passage drops below the pressure of the low-pressure fluid, the on-off valve 17 is opened and low-pressure fluid is supplied from the low-pressure fluid source 16 via the on-off valve 17 While pouring, the slide of the mold 2b is continued, and when the slide source of the mold 2b is reached, the pressure in the mold 2 is maintained by the low pressure fluid pressure.
更に、別の態様では、第３図の装置を使用し、開閉バル
ブ14を開き、流体道（第１図中の10）の少なくとも１部
が形成された後、開閉バルブ14を閉じ、次いで開閉バル
ブ17を開き、金型2bをスライドさせながら流体道（第１
図中の10）の内容積を拡大する。流体道内の高圧流体
が、流体道の内容積の拡大と共に圧力が低下し、低圧流
体の圧力と均衡した後は、低圧流体源16から低圧流体が
供給され、低圧流体圧の下で、金型2bのスライドによる
型キャビティ８の拡大が進行し、低圧流体圧の圧力下
で、中空型物５の外面が型キャビティ８の内面に押圧さ
れ、型形状の再現が達成される。In yet another embodiment, the apparatus of FIG. 3 is used to open the on-off valve 14 and after at least a portion of the fluid path (10 in FIG. 1) is formed, the on-off valve 14 is closed and then opened and closed. Open the valve 17 and slide the mold 2b while
Expand the inner volume of 10) in the figure. After the pressure of the high-pressure fluid in the fluid passage decreases with the expansion of the inner volume of the fluid passage and balances with the pressure of the low-pressure fluid, the low-pressure fluid is supplied from the low-pressure fluid source 16 and the mold is The expansion of the mold cavity 8 by the slide of 2b progresses, the outer surface of the hollow mold 5 is pressed against the inner surface of the mold cavity 8 under the pressure of the low pressure fluid pressure, and the reproduction of the mold shape is achieved.
また、金型２のスライド部2bは、金型２の型キャビティ
８の全面、一部のいづれでも良く、一部の場合は、複数
個でもよい。この場合、設定された場所に複数の中空部
を有する中空型物が得られる。Further, the slide portion 2b of the mold 2 may be on the entire surface or a part of the mold cavity 8 of the mold 2, and in the case of a part, it may be plural. In this case, a hollow product having a plurality of hollow portions at the set place can be obtained.
実施例１ 第２図に示した装置を用い、直径200mm、厚さ14mmの円
盤状の中空型物５を射出成形した。Example 1 A disk-shaped hollow mold 5 having a diameter of 200 mm and a thickness of 14 mm was injection-molded by using the apparatus shown in FIG.
合成樹脂としては、ポリスチレン［「スタイロン＃47
0」旭化成工業（株）製］を200℃に加熱可塑化し、射出
ノズル１の先端を、初期のキャビティ８の間隔7mmの金
型２のスプルー９に密着させて、上記溶融合成樹脂３を
220g金型２内に注入し、次いで80Kg/cm2Ｇの圧力で、高
圧ガスとして窒素を金型２に注入した。As a synthetic resin, polystyrene [“Stylon # 47
0 "made by Asahi Kasei Kogyo Co., Ltd.] is plasticized by heating to 200 ° C., the tip of the injection nozzle 1 is brought into close contact with the sprue 9 of the mold 2 having the initial cavity 8 spacing of 7 mm, and the molten synthetic resin 3 is obtained.
220 g was injected into the mold 2, and then nitrogen was injected into the mold 2 as a high pressure gas at a pressure of 80 Kg / cm 2 G.
次に、金型2bを、7mmスライドさせ型キャビティ８を拡
大させながら、高圧ガスを排気後に8Kg/cm2Ｇの圧力の
低圧ガス（窒素）を注入した。Then, the mold 2b was slid by 7 mm to expand the mold cavity 8, and after discharging the high pressure gas, a low pressure gas (nitrogen) having a pressure of 8 kg / cm 2 G was injected.
射出ノズル１をそのままの状態に維持して、金型２内の
溶融合成樹脂３を冷却固化した後、金型２内の加圧ガス
の排出を行った。その後金型２を開き、中空型物５を取
出した。While maintaining the injection nozzle 1 as it is, the molten synthetic resin 3 in the mold 2 was cooled and solidified, and then the pressurized gas in the mold 2 was discharged. After that, the mold 2 was opened and the hollow mold 5 was taken out.
上述の結果、54％の中空部を持つ中空型物を得た。この
中空型物はバリがなく表面性に優れたものであった。As a result of the above, a hollow product having a hollow portion of 54% was obtained. This hollow product had no burrs and had excellent surface properties.
実施例２ 第３図に示した装置を用い、直径200mm、厚さ14mmの円
盤状の中空型物５を射出成形した。Example 2 A disk-shaped hollow mold 5 having a diameter of 200 mm and a thickness of 14 mm was injection-molded by using the apparatus shown in FIG.
合成樹脂としては、ポリスチレン［「スタイロン＃47
0」旭化成工業（株）製］を200℃に加熱可塑化し、射出
ノズル１の先端を、初期のキャビティ８の間隔7mmの金
型２のスプルー９に密着させて、上記溶融合成樹脂３を
220g金型２内に注入し、次いで60Kg/cm2Ｇの圧力で、高
圧ガスとして窒素を開閉バルブ14を開いて６秒間金型２
に注入した。As a synthetic resin, polystyrene [“Stylon # 47
0 "made by Asahi Kasei Kogyo Co., Ltd.] is plasticized by heating to 200 ° C., the tip of the injection nozzle 1 is brought into close contact with the sprue 9 of the mold 2 having the initial cavity 8 spacing of 7 mm, and the molten synthetic resin 3 is obtained.
220 g is injected into the mold 2, and then nitrogen is used as a high pressure gas at a pressure of 60 kg / cm 2 G for 6 seconds by opening the open / close valve 14.
Injected.
次に、開閉バルブ14を閉じ、開閉バルブ17を開き、金型
2bを、7mmスライドさせ、型キャビティ８を拡大させな
がら、8Kg/cm2Ｇの圧力の低圧圧縮空気を注入した。Next, the open / close valve 14 is closed, the open / close valve 17 is opened, and the mold
2b was slid by 7 mm, and low pressure compressed air having a pressure of 8 kg / cm 2 G was injected while expanding the mold cavity 8.
射出ノズル１をそのままの状態に維持して、金型２内の
溶融合成樹脂３を冷却固化した後、金型２内の加圧ガス
の排出を行った。その後金型２を開き、中空型物５を取
出した。While maintaining the injection nozzle 1 as it is, the molten synthetic resin 3 in the mold 2 was cooled and solidified, and then the pressurized gas in the mold 2 was discharged. After that, the mold 2 was opened and the hollow mold 5 was taken out.
上述の結果、54％の中空部を持つ中空型物を得た。この
中空型物はバリがなく表面性に優れたものであり、窒素
ガスの消費量を減らすことが出来た。また、中空部内面
を押圧するガス圧を連続的に低下させ、中空型物の冷却
は、8Kg/cm2Ｇの低圧のガス圧下で保持することが出
来、非中空部のヒケを防止することが出来た。As a result of the above, a hollow product having a hollow portion of 54% was obtained. This hollow product was free of burrs and had excellent surface properties, and the consumption of nitrogen gas could be reduced. In addition, the gas pressure that presses the inner surface of the hollow part can be continuously reduced, and cooling of the hollow mold can be maintained under a low gas pressure of 8 Kg / cm 2 G to prevent sink marks in the non-hollow part. Was completed.
［発明の効果］ 本発明は、以上説明した通りのものであり、次の効果を
奏するものである。[Effects of the Invention] The present invention is as described above and has the following effects.
（１）型キャビティの拡大を行って中空型物を作るた
め、15〜70％のより大きな中空部をもつ成形品を得るこ
とができる。(1) Since the mold cavity is expanded to make a hollow mold, a molded product having a larger hollow portion of 15 to 70% can be obtained.
（２）高圧流体の注入後、型キャビティの拡大の際は低
圧流体による注入を行うため、成形品はバリの発生はな
く、表面の型再現に優れ、鏡面塗装ができる。(2) After the injection of the high-pressure fluid, the injection of the low-pressure fluid is performed when the mold cavity is expanded, so that the molded product does not have burrs, the surface has excellent mold reproduction, and mirror surface coating is possible.
第１図（ａ）〜（ｆ）は本発明の方法の説明図、第２図
及び第３図は実施例に用いた装置の説明図である。 1:射出ノズル、2:金型、3:溶融合成樹脂、4:流体ノズ
ル、5:中空型物、6:樹脂注入口、7:流体注入口、8:型キ
ャビティ、10:流体道、1 (a) to 1 (f) are explanatory views of the method of the present invention, and FIGS. 2 and 3 are explanatory views of the apparatus used in the examples. 1: Injection nozzle, 2: Mold, 3: Molten synthetic resin, 4: Fluid nozzle, 5: Hollow object, 6: Resin injection port, 7: Fluid injection port, 8: Mold cavity, 10: Fluid passage,
Claims (5)
樹脂を圧入し、 キャビティ内に向けて高圧流体を圧入して該溶融樹
脂内に流体道を形成し、 次いで、低圧流体を圧入しながら型キャビティを拡
大して、キャビティ内の溶融樹脂を中空型物状に成形
し、 中空型物内の流体圧を維持しながら、溶融樹脂を冷
却固化し、 中空型物内の流体を排出した後に、成形された中空
型物を取り出す、 ことを特徴とする中空型物の成形法。1. A mold cavity in which a molten resin is press-fitted from an injection nozzle into a mold cavity, a high-pressure fluid is pressed into the cavity to form a fluid passage in the molten resin, and then a low-pressure fluid is press-fitted into the mold cavity. Expand the mold to mold the molten resin in the cavity into the shape of a hollow mold, and while maintaining the fluid pressure in the hollow mold, cool and solidify the molten resin, discharge the fluid in the hollow mold, and then mold A method for molding a hollow mold product, comprising removing the hollow mold product.
で、前記低圧流体の流体圧が10Kg/cm2Ｇ未満であること
を特徴とする請求項（１）記載の成形法。2. The molding method according to claim 1, wherein the fluid pressure of the high-pressure fluid is 10 kg / cm 2 G or more and the fluid pressure of the low-pressure fluid is less than 10 kg / cm 2 G.
りも低いレベルにて高圧流体を一旦回収した後に行うこ
とを特徴とする請求項（２）記載の成形法。3. The molding method according to claim 2, wherein the low pressure fluid is press-fitted after the high pressure fluid is once recovered at a level lower than the pressure of the low pressure fluid.
樹脂を圧入し、 キャビティ内に向けて高圧流体を圧入して該溶融樹
脂内に流体道を形成し、高圧流体の圧入を停止し、型キ
ャビティを拡大して、キャビティ内の溶融樹脂を中空型
物状に成形し、 次いで、中空型物の中空部の流体圧が低圧流体の圧
力と均衡したら、低圧流体を圧入し、 中空型物内の流体圧を低圧流体圧に維持しながら、
溶融樹脂を冷却固化し、 中空型物内の流体を排出した後に、成形された中空
型物を取り出す、 ことを特徴とする中空型物の成形法。4. A molten resin is press-fitted from an injection nozzle into a mold cavity, a high-pressure fluid is pressed into the cavity to form a fluid passage in the molten resin, and the press-fitting of the high-pressure fluid is stopped. To enlarge the molten resin in the cavity into a hollow mold, then when the fluid pressure in the hollow part of the hollow mold is balanced with the pressure of the low pressure fluid, press the low pressure fluid into the hollow mold. While maintaining the fluid pressure at low pressure,
A method for molding a hollow mold, wherein the molten resin is cooled and solidified, the fluid in the hollow mold is discharged, and then the molded hollow mold is taken out.
で、前記低圧流体の流体圧が10Kg/cm2Ｇ未満であること
を特徴とする請求項（４）記載の成形法。5. The molding method according to claim 4, wherein the fluid pressure of the high-pressure fluid is 10 kg / cm 2 G or more and the fluid pressure of the low-pressure fluid is less than 10 kg / cm 2 G.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1142057A JPH0735058B2 (en) | 1989-06-06 | 1989-06-06 | Hollow molding method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1142057A JPH0735058B2 (en) | 1989-06-06 | 1989-06-06 | Hollow molding method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH039820A JPH039820A (en) | 1991-01-17 |
| JPH0735058B2 true JPH0735058B2 (en) | 1995-04-19 |
Family
ID=15306414
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1142057A Expired - Lifetime JPH0735058B2 (en) | 1989-06-06 | 1989-06-06 | Hollow molding method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0735058B2 (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1992013699A1 (en) * | 1991-01-30 | 1992-08-20 | Asahi Kasei Kogyo Kabushiki Kaisha | Mold for injection blow molding, method of blow molding, and metallic mold |
| JP2976059B2 (en) * | 1991-02-08 | 1999-11-10 | 住友化学工業株式会社 | Manufacturing method of hollow molded products |
| US5284429A (en) * | 1992-05-07 | 1994-02-08 | Cascade Engineering, Inc. | Gas-assisted injection molding apparatus |
| DE4319381C2 (en) * | 1993-06-11 | 1996-07-11 | Battenfeld Gmbh | Process for the injection molding of molded parts made of thermoplastic material and molding tool for carrying out the same |
| US5639417A (en) * | 1994-07-15 | 1997-06-17 | Mitsubishi Gas Chemical Company, Inc. | Mold apparatus for process for injection molding |
| US5656234A (en) * | 1994-08-12 | 1997-08-12 | Mitsubishi Gas Chemical Company, Inc. | Mold apparatus and injection molding method for producing hollow-structured article by injection molding |
| US5885518A (en) * | 1995-06-21 | 1999-03-23 | Melea Limited | Method for injection molding utilizing a variable volume spill area within an article-defining mold cavity and article produced thereby |
| US6284171B1 (en) * | 1997-02-25 | 2001-09-04 | Kao Corporation | Blow molding process |
| CN1064894C (en) * | 1997-02-25 | 2001-04-25 | 花王株式会社 | Blow molding method |
| US6767487B2 (en) | 2001-07-10 | 2004-07-27 | Cinpres Gas Injection Ltd. | Plastic expulsion process |
| US7426078B2 (en) | 2002-11-26 | 2008-09-16 | Hitachi Maxell, Ltd. | Plastic lens, manufacturing method thereof, production tracing management method thereof, and optical pickup device |
| US6890477B2 (en) | 2003-03-25 | 2005-05-10 | Lear Corporation | Plastic injection molded articles with hollow rib members |
| US6899843B2 (en) | 2003-03-25 | 2005-05-31 | Lear Corporation | Plastic injection molding with moveable mold members forming speaker grill |
| DE102004025842A1 (en) * | 2004-05-24 | 2005-12-15 | Universität Paderborn | Method and device for producing plastic components |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2501314A1 (en) * | 1975-01-15 | 1976-07-22 | Roehm Gmbh | INJECTION MOLDING OF HOLLOW MOLDED PARTS MADE OF THERMOPLASTIC PLASTICS, IN PARTICULAR FOR THE CONSTRUCTION SECTOR |
| US4136220A (en) * | 1976-07-14 | 1979-01-23 | Union Carbide Corporation | Process for the molding of plastic structural web and the resulting articles |
| JPS5434378A (en) * | 1977-08-22 | 1979-03-13 | Riyuuji Uematsu | Method of manufacturing buffering synthetic resin moldings |
| JPS5714968A (en) * | 1980-07-02 | 1982-01-26 | Hitachi Ltd | Process and control system for information at point of sales time |
| JPS6378714A (en) * | 1986-05-19 | 1988-04-08 | 旭化成株式会社 | Method and device for manufacturing injection molding of plastic material |
| DE3734164C3 (en) * | 1987-10-09 | 1999-09-09 | Battenfeld Gmbh | Process for injection molding molded parts from thermoplastic materials and device for carrying out the process |
-
1989
- 1989-06-06 JP JP1142057A patent/JPH0735058B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH039820A (en) | 1991-01-17 |
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