JP2003041037A - Method for producing resin molded article - Google Patents
Method for producing resin molded articleInfo
- Publication number
- JP2003041037A JP2003041037A JP2001232001A JP2001232001A JP2003041037A JP 2003041037 A JP2003041037 A JP 2003041037A JP 2001232001 A JP2001232001 A JP 2001232001A JP 2001232001 A JP2001232001 A JP 2001232001A JP 2003041037 A JP2003041037 A JP 2003041037A
- Authority
- JP
- Japan
- Prior art keywords
- resin molded
- foaming agent
- molded article
- resin material
- resin
- 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.)
- Pending
Links
Landscapes
- Injection Moulding Of Plastics Or The Like (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本願発明は、発泡成形による
樹脂成形品の製造方法に関するものである。TECHNICAL FIELD The present invention relates to a method for producing a resin molded product by foam molding.
【０００２】[0002]
【従来の技術】従来より、例えば送風機の羽根車におい
ては、その軽量化による性能向上を図るべく、これを軽
量素材である樹脂材の発泡成形によって製造することが
行われていた。2. Description of the Related Art Conventionally, in an impeller of a blower, for example, in order to improve performance by reducing the weight, it has been manufactured by foam molding a resin material which is a lightweight material.
【０００３】[0003]
【発明が解決しようとする課題】ところが、従来の樹脂
発泡成形に使用されていた発泡剤は、樹脂材の内部にお
いて発泡により生成される気泡の大きさが不揃いで、且
つ樹脂材内部に不均一に分布するという気泡の形状・分
布に係わる欠点、及び発泡剤の発泡圧力が比較的高いと
いう性状的な欠点を有していた。このため、従来の発泡
剤を用いた発泡成形によって、例えば送風機の羽根車を
製造する場合、次のような問題があった。However, in the foaming agent used in the conventional resin foam molding, the sizes of the bubbles generated by foaming in the resin material are not uniform and the foaming agent is not uniform in the resin material. It had a defect related to the shape and distribution of bubbles, and a characteristic defect that the foaming pressure of the foaming agent was relatively high. Therefore, for example, when an impeller of a blower is manufactured by foam molding using a conventional foaming agent, there are the following problems.
【０００４】即ち、（ａ）樹脂材内部における気泡の分
布が不均一であることから、羽根車の各部位間において
比重が異なり、これを羽根車として使用して良好な回転
特性を確保しようとすれば、成形後における回転バラン
スの調整が不可欠となり、それだけ製造コストが高くつ
く、（ｂ）樹脂材内部における気泡の大きさが不揃いで
あることから、羽根車の各部位間においてその強度性能
が異なり、場合によっては、部分的な強度不足を生じ、
羽根車としての信頼性が確保できない、（ｃ）発泡圧力
が比較的高いことから、金型内のみでは十分に発泡が完
了せず、成形品を金型から取り出した後に二次発泡が生
じ、膨張変形を起こし形状精度が損なわれる、等の問題
が生じるものであった。That is, (a) since the distribution of air bubbles inside the resin material is non-uniform, the specific gravities are different among the parts of the impeller, and it is intended to use this as an impeller to ensure good rotation characteristics. If so, the adjustment of the rotational balance after molding becomes indispensable, and the manufacturing cost increases accordingly. (B) Since the sizes of the bubbles inside the resin material are not uniform, the strength performance between the parts of the impeller is high. Different, in some cases, a partial lack of strength,
The reliability as an impeller cannot be ensured. (C) Since the foaming pressure is relatively high, the foaming is not completed sufficiently in the mold alone, and secondary foaming occurs after the molded product is taken out of the mold, There are problems such as expansion and deformation, which impairs the shape accuracy.
【０００５】そこで本願発明は、新規な性状を有する発
泡剤を用いて射出成形を行うことで、形状精度及び強度
性能に優れた樹脂成形品を製造する方法を提案すること
を目的としてなされたものである。Therefore, the present invention was made for the purpose of proposing a method for producing a resin molded product excellent in shape accuracy and strength performance by performing injection molding using a foaming agent having a novel property. Is.
【０００６】[0006]
【課題を解決するための手段】本願発明ではかかる課題
を解決するための具体的手段として次のような構成を採
用している。In the present invention, the following constitution is adopted as a concrete means for solving such a problem.
【０００７】本願の第１の発明では、発泡剤が添加され
た溶融樹脂材を、金型４のキャビティ５内に射出し、該
キャビティ５内での発泡成形により樹脂成形品を得る樹
脂成形品の製造方法において、上記発泡剤として、吸熱
により化学分解して上記溶融樹脂材中に可及的に均一で
緻密な微細気泡６，６，・・を生成する性状を有するも
のを用いることを特徴としている。In the first invention of the present application, a resin molded product is obtained by injecting a molten resin material to which a foaming agent is added into the cavity 5 of the mold 4 and performing foam molding in the cavity 5 to obtain a resin molded product. In the manufacturing method of the above, the foaming agent having a property of chemically decomposing by heat absorption to generate fine and uniform fine bubbles 6, 6, ... In the molten resin material is used. I am trying.
【０００８】本願の第２の発明では、上記第１の発明に
かかる樹脂成形品の製造方法において、上記発泡剤を、
クエン酸と重曹とを主成分とした組成のものとしたこと
を特徴としている。According to a second invention of the present application, in the method for producing a resin molded product according to the first invention, the foaming agent is added to
It is characterized by having a composition mainly composed of citric acid and baking soda.
【０００９】本願の第３の発明では、上記第１又は第２
の発明にかかる樹脂成形品の製造方法において、上記発
泡剤の溶融樹脂材に対する発泡剤混入比率を０．１％〜
１．０％の範囲に設定したことを特徴としている。In the third invention of the present application, the above-mentioned first or second
In the method for producing a resin molded product according to the invention, the mixing ratio of the foaming agent to the molten resin material is 0.1% to
The feature is that it is set in the range of 1.0%.
【００１０】本願の第４の発明では、上記第１，第２又
は第３の発明にかかる樹脂成形品の製造方法において、
上記樹脂成形品が送風機の羽根車１であることを特徴と
している。According to a fourth invention of the present application, in the method for producing a resin molded product according to the first, second or third invention,
The resin molded product is an impeller 1 of a blower.
【００１１】[0011]
【発明の効果】本願発明ではかかる構成とすることによ
り次のような効果が得られる。According to the present invention, the following effects can be obtained by adopting such a configuration.
【００１２】 本願の第１の発明にかかる樹脂成形品
の製造方法によれば、発泡剤が添加された溶融樹脂材
を、金型４のキャビティ５内に射出し、該キャビティ５
内での発泡成形により樹脂成形品を得る樹脂成形品の製
造方法において、上記発泡剤として、吸熱により化学分
解して上記溶融樹脂材中に可及的に均一で緻密な微細気
泡６，６，・・を生成する性状を有するものを用いるよ
うにしている。According to the method for producing a resin molded product according to the first invention of the present application, the molten resin material to which the foaming agent is added is injected into the cavity 5 of the mold 4, and the cavity 5
In the method for producing a resin molded product by foam molding inside, in the method for producing a resin molded product, the foaming agent is chemically decomposed by endothermic heat, and fine bubbles 6, 6, which are as uniform and dense as possible in the molten resin material. ··············
【００１３】従って、この発明の製造方法によれば、溶
融樹脂材中に生成される気泡６，６，・・が可及的に均
一で且つ緻密な微細気泡であることから、例え樹脂成形
品が薄肉品であっても重量バランスが良好で、且つ強度
性能に優れた樹脂成形品を製造することができる。Therefore, according to the production method of the present invention, since the bubbles 6, 6, ... Generated in the molten resin material are fine bubbles as uniform and dense as possible, for example, a resin molded product. Even if the product is a thin product, it is possible to produce a resin molded product having a good weight balance and excellent strength performance.
【００１４】また、溶融樹脂材の射出に伴って発泡剤が
化学分解しガスを発生して気泡３を生じるが、この場
合、この発生ガスの分子がその分子運動によって樹脂分
子相互間に介入してこれらを引き離し分子結合を緩和さ
せるとともに、樹脂分子の流動に伴う樹脂分子相互間の
摩擦抵抗を低減させるように作用し、溶融樹脂材の流動
性が高められる。この結果、金型４のキャビティ５内へ
の溶融樹脂材の射出圧力を低圧に設定しても、溶融樹脂
材の流動性が高いことから上記キャビティ５の隅々まで
十分に溶融樹脂材を充填させて形状精度の高い樹脂成形
品を得ることができる。Further, as the molten resin material is injected, the foaming agent is chemically decomposed to generate gas and generate bubbles 3. In this case, the molecules of the generated gas intervene between the resin molecules due to their molecular motion. These are separated from each other to relax the molecular bond and to reduce the frictional resistance between the resin molecules associated with the flow of the resin molecules, thereby enhancing the fluidity of the molten resin material. As a result, even if the injection pressure of the molten resin material into the cavity 5 of the mold 4 is set to a low pressure, the fluidity of the molten resin material is high, so that every corner of the cavity 5 is sufficiently filled with the molten resin material. As a result, a resin molded product having a high shape accuracy can be obtained.
【００１５】さらに、溶融樹脂材の流動性が良好である
分だけ、キャビティ５内への溶融樹脂材の押し込み抵抗
に対応する型内圧を低く抑えることができ、この結果、
溶融樹脂材の低圧射出が可能となり、延いては射出成形
機の小型軽量化を図ることができる。Further, since the fluidity of the molten resin material is good, the mold internal pressure corresponding to the pushing resistance of the molten resin material into the cavity 5 can be suppressed to a low level.
Low-pressure injection of the molten resin material becomes possible, which in turn makes it possible to reduce the size and weight of the injection molding machine.
【００１６】また、型内圧が低圧であることから、発泡
剤の発泡作用が促進され、キャビティ５内での溶融樹脂
材の充填成形時点でほとんど発泡作用が完了し、離型後
の二次発泡による膨張変形の発生が可及的に防止され、
高い形状精度をもった樹脂成形品の製造が可能となると
ともに、型内圧を低く抑えられる分だけ金型４の強度を
低く設定して金型費用の低減、延いては樹脂成形品の製
造コストの低減を図ることができる。Further, since the internal pressure of the mold is low, the foaming action of the foaming agent is promoted, the foaming action is almost completed at the time of filling and molding the molten resin material in the cavity 5, and the secondary foaming after the mold release. The occurrence of expansion deformation due to
It is possible to manufacture resin molded products with high shape accuracy, and reduce the mold cost by setting the strength of the mold 4 as low as possible to keep the mold internal pressure low, and in turn the resin molded product manufacturing cost. Can be reduced.
【００１７】 本願の第２の発明にかかる樹脂成形品
の製造方法によれば、上記に記載の効果に加えて次の
ような特有の効果が得られる。即ち、この発明では、上
記発泡剤を、クエン酸と重曹とを主成分とした組成のも
のとしているので、これらクエン酸と重曹とが共に人体
に無害の物質であることからして、製造作業中における
環境汚染という問題がなく、作業上における安全性が確
保される。According to the method for producing a resin molded product according to the second invention of the present application, in addition to the effects described above, the following unique effects can be obtained. That is, in the present invention, since the foaming agent has a composition containing citric acid and baking soda as the main components, since these citric acid and baking soda are both substances that are harmless to the human body, the manufacturing work There is no problem of environmental pollution inside, and work safety is secured.
【００１８】 本願の第３の発明にかかる樹脂成形品
の製造方法によれば、上記又はに記載の効果に加え
て次のような特有の効果が得られる。即ち、この発明で
は、上記発泡剤の溶融樹脂材に対する発泡剤混入比率を
０．１％〜１．０％の範囲に設定しているので、この発
泡剤混入比率が低い分だけ製造される樹脂成形品の製造
コストを低く抑えることができる。According to the method for producing a resin molded product according to the third invention of the present application, the following peculiar effect is obtained in addition to the above-mentioned effects. That is, in the present invention, since the foaming agent mixing ratio of the foaming agent to the molten resin material is set in the range of 0.1% to 1.0%, the resin produced only by the low foaming agent mixing ratio. The manufacturing cost of the molded product can be kept low.
【００１９】 本願の第４の発明にかかる樹脂成形品
の製造方法によれば、上記，又はに記載の効果に
加えて次のような特有の効果が得られる。即ち、この発
明では、上記樹脂成形品として送風機の羽根車１を採用
しているので、該羽根車１においては、樹脂材中に可及
的に均一で且つ緻密な微細気泡６，６，・・が分布した
組織をもつことから、該羽根車１の各部位間における重
量のバラツキがほとんどなく、例えば事後的な回転バラ
ンスの調整作業の省略あるいは簡易化によってコストダ
ウンが図れるとともに、各部位間における強度のバラツ
キがなく、肉厚を過度に厚くするような必要がないこと
から、強度性能と軽量化との両立が可能になる、等の効
果が得られる。According to the method for producing a resin molded product according to the fourth invention of the present application, in addition to the effects described above or, the following unique effects can be obtained. That is, in the present invention, since the impeller 1 of the blower is adopted as the resin molded product, in the impeller 1, fine bubbles 6, 6, ... Since there is a distributed tissue, there is almost no variation in weight among the parts of the impeller 1, and for example, cost reduction can be achieved by omitting or simplifying the subsequent work of adjusting the rotational balance, and between the parts. Since there is no variation in strength and it is not necessary to make the wall thickness excessively thick, it is possible to achieve both strength performance and weight reduction.
【００２０】また、上記羽根車１は、低い型内圧の下で
の発泡成形によって得られるものであって、成形後の二
次発泡による変形がないことから、設計形状に可及的に
合致した適正な形状をもち、その高性能化が図れる。Further, the impeller 1 is obtained by foam molding under a low mold pressure, and since it is not deformed by secondary foaming after molding, it matches the design shape as much as possible. It has a proper shape, and its performance can be improved.
【００２１】[0021]
【発明の実施の形態】以下、本願発明にかかる樹脂成形
品の製造方法を、プロペラファンの羽根車１の製造を例
にとって説明する。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for manufacturing a resin molded product according to the present invention will be described by taking an example of manufacturing an impeller 1 of a propeller fan.
【００２２】図１には、例えば空気調和機に用いられる
プロペラファンの羽根車１を示している。この羽根車１
は、本願発明にかかる製造方法によって射出成形される
ものであって、ハブ２の外周面に薄肉翼構造（図２を参
照）をもつ複数枚（この実施形態では三枚）の羽根３，
３，・・を備えて構成される。FIG. 1 shows an impeller 1 of a propeller fan used in, for example, an air conditioner. This impeller 1
Is injection-molded by the manufacturing method according to the present invention, and has a plurality of blades 3 (three in this embodiment) having a thin blade structure (see FIG. 2) on the outer peripheral surface of the hub 2.
3, ...
【００２３】上記羽根車１は、樹脂材の発泡射出成形に
よって製造される。即ち、上記羽根車１は、図４に示す
ように、金型４と射出成形機１０とを用いて製造され
る。The impeller 1 is manufactured by foam injection molding of a resin material. That is, the impeller 1 is manufactured using the mold 4 and the injection molding machine 10, as shown in FIG.
【００２４】上記金型４は、複数分割型の金型であっ
て、その型閉じ状態でその内部にキャビティ５を形成す
るとともに、該キャビティ５はゲート７を介して該金型
４の表面側に連通している。また、上記射出成形機１０
は、素材樹脂１５に発泡剤を適量混入しこれを溶融させ
て押し出す溶融押出部１１と該溶融押出部１１からの溶
融樹脂材を所定の射出圧力で射出する射出ノズル１２と
を備えている。The die 4 is a multi-divided die, and in the closed state of the die 4, a cavity 5 is formed therein, and the cavity 5 is provided on the surface side of the die 4 via a gate 7. Is in communication with. In addition, the injection molding machine 10
Is provided with a melt extruding section 11 that mixes an appropriate amount of a foaming agent into a material resin 15 and melts and extrudes the foaming agent, and an injection nozzle 12 that injects a molten resin material from the melt extruding section 11 at a predetermined injection pressure.
【００２５】そして、上記羽根車１の製造に際しては、
上記射出成形機１０の射出ノズル１２から押し出された
溶融樹脂材を、上記ゲート７から上記キャビティ５内に
射出してここに充填し、且つ所定の圧力（即ち、保圧）
を上記ゲート７にかけたまま、上記キャビティ５内で溶
融樹脂材を冷却固化させることで上記羽根車１が得られ
る。When the impeller 1 is manufactured,
The molten resin material extruded from the injection nozzle 12 of the injection molding machine 10 is injected from the gate 7 into the cavity 5 and filled therein, and a predetermined pressure (that is, holding pressure).
The impeller 1 can be obtained by cooling and solidifying the molten resin material in the cavity 5 while keeping the gate 7 applied to the gate 7.
【００２６】ところで、キャビティ５内への溶融樹脂材
の射出に伴って、該溶融樹脂材中に混入されていた発泡
剤が吸熱により分解反応してガスを発生し、該溶融樹脂
材中に６，６，・・（図３を参照）を生成させる。かか
る発泡成形は、第１には樹脂成形品としての羽根車１の
軽量化を促進させ、第２には発泡圧によって溶融樹脂材
をキャビティ５の外面に押し付けて溶融樹脂材の冷却収
縮に起因する「引け」の発生を防止する（保圧による
「引け」抑制をさらに補強する）ことを目的とするもの
であるが、この実施形態の製造方法においては上記発泡
剤として従来に無い新規な性状をもつものを採用するこ
とで、上記第１及び第２の目的の外に、（ａ）溶融樹脂
材の流動性を高めて充填時の型内圧の低下を図る、
（ｂ）樹脂成形品としての羽根車１の重量バランスと強
度性能の向上を図る、という目的をもっている。By the way, with the injection of the molten resin material into the cavity 5, the foaming agent mixed in the molten resin material undergoes a decomposition reaction due to endothermic reaction to generate gas, and 6 gas is generated in the molten resin material. , 6, ... (See FIG. 3) are generated. Such foam molding firstly promotes the weight reduction of the impeller 1 as a resin molded product, and secondly, the molten resin material is pressed against the outer surface of the cavity 5 by the foaming pressure to cause cooling shrinkage of the molten resin material. The purpose is to prevent the occurrence of "shrinkage" (further reinforce the suppression of "shrinkage" by holding pressure), but in the manufacturing method of this embodiment, the foaming agent has a novel property that has never been achieved. In addition to the above-mentioned first and second purposes, by adopting a resin having (a), (a) the fluidity of the molten resin material is enhanced to reduce the mold internal pressure during filling,
(B) The purpose is to improve the weight balance and strength performance of the impeller 1 as a resin molded product.
【００２７】即ち、この実施形態の製造方法では、発泡
剤として、従来に無い新規な性状、具体的には、吸熱に
より化学分解して溶融樹脂材中に可及的に均一で緻密な
微細気泡６，６，・・を生成する性状を有するもの、例
えば日本ベーリンガーインゲルハイム株式会社製で、ク
エン酸と重曹を主成分とする吸熱反応型の商品名「ハイ
ドロセロール」という発泡剤を採用している。尚、溶融
樹脂材としては、例えばＰＰ，ＰＰＧ，ＰＰＧＭ，ＡＳ
Ｇ，ＡＢＳが上記発泡剤との相性からして好適である。That is, in the manufacturing method of this embodiment, the foaming agent has a novel property which has not existed in the past, specifically, it is chemically decomposed by endothermic and is as uniform and dense as possible in the molten resin material. Those that have the property of producing 6,6, ..., for example, manufactured by Nippon Boehringer Ingelheim Co., Ltd., and employ an endothermic reaction type trade name "hydrocerol" foaming agent containing citric acid and baking soda as main components. ing. As the molten resin material, for example, PP, PPG, PPGM, AS
G and ABS are preferable in view of compatibility with the foaming agent.
【００２８】この発泡剤は、上述のように、可及的に均
一で緻密な微細気泡６，６，・・を生成する性状を有す
ることを最大の特徴とするものであり、この気泡６，
６，・・の生成によって以下のような特有の作用効果が
奏せられる。As mentioned above, this foaming agent is most characterized by having a property of forming fine and uniform fine bubbles 6, 6, ... As much as possible.
By generating 6, ..., The following peculiar operational effects are achieved.
【００２９】即ち、溶融樹脂材の射出に伴って発泡剤が
化学分解しガスを発生して気泡３を生じるが、この場
合、この発生ガスの分子がその分子運動によって樹脂分
子相互間に介入してこれらを引き離し分子結合を緩和さ
せるとともに、樹脂分子の流動に伴う樹脂分子相互間の
摩擦抵抗を低減させるように作用し、溶融樹脂材の流動
性が高められる。また、気泡６，６，・・が可及的に均
一で緻密な微細気泡であることから、上記の如き溶融樹
脂材の流動性の向上作用が該溶融樹脂材の全域において
均一的に得られ、流動性向上効果がさらに促進されるこ
とになる。That is, with the injection of the molten resin material, the foaming agent chemically decomposes to generate gas and generate bubbles 3. In this case, the molecules of the generated gas intervene between the resin molecules due to their molecular motion. These are separated from each other to relax the molecular bond and to reduce the frictional resistance between the resin molecules associated with the flow of the resin molecules, thereby enhancing the fluidity of the molten resin material. Further, since the bubbles 6, 6, ... Are fine and uniform and as fine as possible, the effect of improving the fluidity of the molten resin material as described above can be uniformly obtained in the entire area of the molten resin material. Therefore, the liquidity improving effect is further promoted.
【００３０】このように、溶融樹脂材の流動性が高めら
れれば、後述のように、キャビティ５内への溶融樹脂材
の押し込み抵抗に対応する型内圧を低く抑えることがで
きる。この結果、溶融樹脂材の低圧射出が可能となり、
延いては射出成形機の小型化を図ることができる。ま
た、型内圧が低圧であることから、発泡剤の発泡作用が
促進され、キャビティ５内での溶融樹脂材の充填成形時
点でほとんど発泡作用が完了し、離型後の二次発泡によ
る膨張変形の発生が可及的に防止され、高い形状精度を
もった樹脂成形品の製造が可能となるとともに、型内圧
を低く抑えられる分だけ金型４の強度を低く設定して金
型費用の低減、延いては樹脂成形品の製造コストの低減
を図ることができることにもなる。If the fluidity of the molten resin material is improved in this way, the mold internal pressure corresponding to the pushing resistance of the molten resin material into the cavity 5 can be suppressed to a low level, as will be described later. As a result, low-pressure injection of molten resin material is possible,
As a result, the size of the injection molding machine can be reduced. Further, since the mold internal pressure is low, the foaming action of the foaming agent is promoted, the foaming action is almost completed at the time of filling and molding the molten resin material in the cavity 5, and the expansion deformation due to the secondary foaming after the mold release. It is possible to manufacture resin molded products with high shape accuracy as much as possible and to reduce the mold cost by setting the strength of the mold 4 low enough to keep the mold internal pressure low. As a result, the manufacturing cost of the resin molded product can be reduced.
【００３１】ところで、上述のように、発泡剤の混入に
よって溶融樹脂材の流動性を高めることができるが、か
かる流動性向上効果は溶融樹脂材に対する発泡剤の混入
比率によって左右されるものである。そこで、本願発明
者は、実用上有効な流動性向上効果を得ることのできる
発泡剤の混入比率を実験等によって確認した。By the way, as described above, the fluidity of the molten resin material can be increased by mixing the foaming agent, and the effect of improving the fluidity depends on the mixing ratio of the foaming agent to the molten resin material. . Then, the inventor of the present application confirmed the mixing ratio of the foaming agent that can obtain the practically effective fluidity improving effect by experiments and the like.
【００３２】即ち、図５に示すように、板厚２．０ｍ
ｍ、樹脂の流動方向の長さ（流動長）１００ｍｍの樹脂
成形品２１を発泡射出成形によって成形し、その成形時
の型内圧を射出ゲート２２の近傍に配置した圧力センサ
２３によって検出し、この型内圧と発泡剤の混入比率と
の関係を図６に示した。That is, as shown in FIG. 5, the plate thickness is 2.0 m.
m, a resin molded product 21 having a length of 100 m in the flow direction of the resin (flow length) is molded by foam injection molding, and the mold pressure at the time of molding is detected by a pressure sensor 23 arranged near the injection gate 22. The relationship between the mold internal pressure and the mixing ratio of the foaming agent is shown in FIG.
【００３３】尚、型内圧は、キャビティ内に溶融樹脂材
を射出してこれを強制的に押し込んでキャビティ奥側へ
移動させて充填する場合において、該溶融樹脂材の流動
抵抗によって生じるキャビティ内の圧力であり、従っ
て、溶融樹脂材の流動性が高いほど型内圧は低くなり、
流動性が低いほど型内圧は高くなる。Incidentally, the mold internal pressure is such that when the molten resin material is injected into the cavity and forcedly pushed and moved to the inner side of the cavity to be filled, the internal pressure of the cavity is caused by the flow resistance of the molten resin material. Pressure, therefore, the higher the fluidity of the molten resin material, the lower the mold internal pressure,
The lower the fluidity, the higher the mold internal pressure.
【００３４】この図６によれば、混入比率０％時、即
ち、発泡剤を用いない通常の射出成形においては、溶融
樹脂材の流動性が低いために型内圧が２３０Kg/cm2と高
圧であるのに対して、混入比率１．０％時には型内圧が
１０６Kg/cm2、混入比率２．０％時には型内圧が９２Kg
/cm2、混入比率３．０％時には型内圧が８８Kg/cm2と、
それぞれ低下する。即ち、発泡剤が少量添加されること
で溶融樹脂材の流動性が大きく向上すること、しかし混
入比率が１．０％以上（即ち、２．０％とか３．０％
等）においては、発泡剤の混入量の増加に対する型内圧
の低下割合が小さい（換言すれば、発泡剤の添加量の増
加の割りには流動性の向上効果が低い）ことが判る。According to FIG. 6, when the mixing ratio is 0%, that is, in normal injection molding without using a foaming agent, the internal pressure of the mold is as high as 230 Kg / cm 2 because the fluidity of the molten resin material is low. On the other hand, when the mixing ratio is 1.0%, the mold internal pressure is 106 kg / cm 2 , and when the mixing ratio is 2.0%, the mold internal pressure is 92 kg.
/ cm 2 , when the mixture ratio is 3.0%, the mold pressure is 88 kg / cm 2 ,
Each decreases. That is, the fluidity of the molten resin material is greatly improved by adding a small amount of the foaming agent, but the mixing ratio is 1.0% or more (that is, 2.0% or 3.0%).
And the like), the decrease rate of the in-mold pressure with respect to the increase of the mixing amount of the foaming agent is small (in other words, the fluidity improving effect is low for the increase of the foaming agent addition amount).
【００３５】さらに、発泡剤の混入比率１．０％以下の
領域については、上記発泡剤の製造者である「日本ベー
リンガーインゲルハイム株式会社」の技術資料「化学発
泡射出成形技術」によれば、発泡剤は０．１％〜０．２
％の混入比率で効果を発揮する、旨の記載がされてお
り、かかる記載は上掲製造者における製品試験の結果に
基づくもので、上記発泡剤（商品名：ハイドロセロー
ル）を用いる限り、同等の効果が得られるものと考えら
れる。Further, regarding the region where the mixing ratio of the foaming agent is 1.0% or less, according to the technical data "Chemical foam injection molding technology" of "Nippon Boehringer Ingelheim Co., Ltd." The foaming agent is 0.1% to 0.2
There is a statement that the effect is exhibited at a mixing ratio of%, and such description is based on the result of the product test by the above-mentioned manufacturer, so long as the above-mentioned foaming agent (trade name: hydrocerol) is used, It is considered that the same effect can be obtained.
【００３６】以上の検討により、本願発明者は、この発
明の製造方法に用いる発泡剤の溶融樹脂材に対する混入
比率を「０．１％〜１．０％」の範囲に特定している。
かかる範囲の混入比率で上記発泡剤を用いることで、最
小の発泡剤の添加量で最大に近い効果が得られ、実用上
極めて有効である。From the above examination, the inventor of the present application specifies the mixing ratio of the foaming agent used in the manufacturing method of the present invention to the molten resin material in the range of "0.1% to 1.0%".
By using the foaming agent in such a mixing ratio in such a range, an effect close to the maximum can be obtained with the minimum amount of the foaming agent added, which is extremely effective in practice.
【００３７】一方、図３には、上記発泡剤を「０．１％
〜１．０％」の混入比率で溶融樹脂材に添加して射出成
形により製造した上記羽根車１の羽根３の断面を拡大図
示している。この図３からも判るように、この羽根車１
においては、上記発泡剤を上記混入比率で用いること
で、可及的に均一で緻密な微細気泡６，６，・・がその
全域に均一的に分布した発泡組織が得られるものであ
る。このような発泡組織をもつことで上記羽根車１にお
いては、上記羽根３が薄翼構造であっても該羽根３の各
部位間での重量のバラツキがほとんど無く、該羽根車１
全体としての重量バランスが極めて良好であり、この結
果、事後的な回転バランス調整が不要に、あるいは簡略
され、それだけ羽根車１の製造コストの低廉化が図れ
る。また、上記気泡６，６，・・が均一的に分布した発
泡組織をもつことから、上記羽根車１においては、例え
ば上記羽根３の部位間での強度のバラツキがほとんど無
く、強度性能に優れたものとなる。On the other hand, in FIG.
FIG. 3 is an enlarged view of a cross section of the blade 3 of the impeller 1 manufactured by injection molding by adding the molten resin material at a mixing ratio of “˜1.0%”. As can be seen from FIG. 3, this impeller 1
In the above, by using the above-mentioned foaming agent in the above-mentioned mixing ratio, a foamed structure in which the finest and finest microscopic cells 6, 6 ,. With such a foamed structure, in the impeller 1, even if the impeller 3 has a thin blade structure, there is almost no variation in the weight between the parts of the impeller 3, and the impeller 1
The weight balance as a whole is extremely good, and as a result, subsequent rotational balance adjustment is unnecessary or simplified, and the manufacturing cost of the impeller 1 can be reduced accordingly. Further, since the cells 6, 6, ... Have a foaming structure in which the cells 6, 6, ... Are evenly distributed, in the impeller 1, for example, there is almost no variation in the strength between the parts of the impeller 3 and the strength performance is excellent. It becomes a thing.
【００３８】尚、上記実施形態においては、上記羽根車
１の羽根３を薄肉翼構造としているが、本願発明の製造
方法は厚肉翼構造の羽根３を備えた羽根車１にも同様に
適用して同様の効果を得ることができることは勿論であ
る。In the above embodiment, the blades 3 of the impeller 1 have a thin-walled blade structure, but the manufacturing method of the present invention is similarly applied to the impeller 1 having the blades 3 of thick-walled blade structure. Of course, the same effect can be obtained.
【図面の簡単な説明】[Brief description of drawings]
【図１】本願発明にかかる製造方法により製造される樹
脂成形品の実施形態としてのプロペラファンの羽根車の
正面図である。FIG. 1 is a front view of an impeller of a propeller fan as an embodiment of a resin molded product manufactured by a manufacturing method according to the present invention.
【図２】図１のＩＩ−ＩＩ断面図である。FIG. 2 is a sectional view taken along line II-II of FIG.
【図３】図３に示す断面の要部拡大図である。FIG. 3 is an enlarged view of a main part of the cross section shown in FIG.
【図４】射出成形状態の説明図である。FIG. 4 is an explanatory diagram of an injection molding state.
【図５】射出成形性の試験条件を示す概念図である。FIG. 5 is a conceptual diagram showing test conditions for injection moldability.
【図６】射出成形における発泡剤混入比率と型内圧との
対応図である。FIG. 6 is a diagram showing the correspondence between the foaming agent mixing ratio and the mold internal pressure in injection molding.
１は羽根車、２はハブ、３は羽根、４は金型、５はキャ
ビティ、６は気泡、７はゲート、１０は射出成形機、１
１は溶融押出部、１２は射出ノズル、１５は素材樹脂、
１６は溶融樹脂、２１は樹脂成形品、２２は射出ゲー
ト、２３は圧力センサである。1 is an impeller, 2 is a hub, 3 is a blade, 4 is a mold, 5 is a cavity, 6 is a bubble, 7 is a gate, 10 is an injection molding machine, 1
1 is a melt extrusion part, 12 is an injection nozzle, 15 is a material resin,
Reference numeral 16 is a molten resin, 21 is a resin molded product, 22 is an injection gate, and 23 is a pressure sensor.
フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｃ０８Ｌ 101:00 Ｃ０８Ｌ 101:00 Ｆターム(参考） 3H033 AA02 AA18 BB02 BB08 CC01 DD01 DD25 DD26 EE10 EE11 4F074 BA03 BA20 CA23 CC61 4F206 AB02 AG20 AH04 JA04 JF04 JL02 JN01 Front page continuation (51) Int.Cl. 7 Identification code FI theme code (reference) C08L 101: 00 C08L 101: 00 F term (reference) 3H033 AA02 AA18 BB02 BB08 CC01 DD01 DD25 DD26 EE10 EE11 4F074 BA03 BA20 CA23 CC61 4F206 AB02 AG20 AH04 JA04 JF04 JL02 JN01
Claims (4)
（４）のキャビティ（５）内に射出し、該キャビティ
（５）内での発泡成形により樹脂成形品を得る樹脂成形
品の製造方法であって、 上記発泡剤が、吸熱により化学分解して上記溶融樹脂材
中に可及的に均一で緻密な微細気泡（６），（６），・
・を生成する性状を有するものであることを特徴とする
樹脂成形品の製造方法。1. A resin-molded article for injecting a molten resin material to which a foaming agent has been added, into a cavity (5) of a mold (4) to obtain a resin-molded article by foam molding in the cavity (5). In the method for producing, the foaming agent is chemically decomposed by heat absorption, and fine bubbles (6), (6), ...
A method for producing a resin molded product, which has a property of generating.
もつものであることを特徴とする樹脂成形品の製造方
法。2. The method for producing a resin molded article according to claim 1, wherein the foaming agent has a composition containing citric acid and sodium bicarbonate as main components.
１％〜１．０％の範囲に設定したことを特徴とする樹脂
成形品の製造方法。3. The mixing ratio of the foaming agent to the molten resin material according to claim 1 or 2, wherein
A method for producing a resin molded product, wherein the resin molded product is set in a range of 1% to 1.0%.
徴とする樹脂成形品の製造方法。4. The method for manufacturing a resin molded product according to claim 1, wherein the resin molded product is an impeller (1) of a blower.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001232001A JP2003041037A (en) | 2001-07-31 | 2001-07-31 | Method for producing resin molded article |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001232001A JP2003041037A (en) | 2001-07-31 | 2001-07-31 | Method for producing resin molded article |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2003041037A true JP2003041037A (en) | 2003-02-13 |
Family
ID=19063980
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001232001A Pending JP2003041037A (en) | 2001-07-31 | 2001-07-31 | Method for producing resin molded article |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2003041037A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010094999A (en) * | 2008-10-17 | 2010-04-30 | Sulzer Mixpac Ag | Static mixer |
-
2001
- 2001-07-31 JP JP2001232001A patent/JP2003041037A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010094999A (en) * | 2008-10-17 | 2010-04-30 | Sulzer Mixpac Ag | Static mixer |
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