JPH11115013A - Plastic injection molding method - Google Patents
Plastic injection molding methodInfo
- Publication number
- JPH11115013A JPH11115013A JP28481797A JP28481797A JPH11115013A JP H11115013 A JPH11115013 A JP H11115013A JP 28481797 A JP28481797 A JP 28481797A JP 28481797 A JP28481797 A JP 28481797A JP H11115013 A JPH11115013 A JP H11115013A
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- JP
- Japan
- Prior art keywords
- mold
- temperature
- resin
- product
- temp
- Prior art date
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、プラスチック樹脂
を材料とし、プラスチック製品の射出成形において、製
品に接する金型表面を材料樹脂が非結晶性の場合は、ガ
ラス転移温度以上、結晶性樹脂の場合は融点温度以上ま
で急速に加熱し、樹脂充填時間中この温度を保持した
後、充填完了後は金型表面を短時間で急速に冷却する金
型温度制御を行い、高転写なプラスチック製品を低圧で
得るプラスチック製品の射出成形方法に関する。BACKGROUND OF THE INVENTION The present invention relates to a method for injection molding a plastic product using a plastic resin as a material. In this case, heat quickly to the melting point temperature or higher, hold this temperature during the resin filling time, and after filling is completed, perform mold temperature control to rapidly cool the mold surface in a short time to produce high-transfer plastic products. The present invention relates to an injection molding method for a plastic product obtained at a low pressure.
【０００２】[0002]
【従来の技術】金型表面を低温かつ一定温度に制御して
行う従来のプラスチック射出成形では、溶融した熱可塑
性樹脂等の材料樹脂が金型に接する表面から急速に冷却
され厚い固化層を形成または熱収縮するに起因して、金
型表面と製品表面の転写が十分に行われず、転写不良が
生じる。これは樹脂表面の固い固化層が、樹脂の内圧に
よる変形を阻害して、金型表面に樹脂表面が密着し、転
写するのを妨げるためである。また、樹脂の機械的強度
補強のためガラス繊維やビーズといったフィラー、ブタ
ジエン等のゴム粒子を樹脂内に含有する場合、これらと
樹脂の熱収縮差によりガラス等フィラー、ブタジエン等
ゴム粒子が樹脂表面に残され、微細な凹凸を形成して転
写性を悪くして製品外観が損なわれる。2. Description of the Related Art In conventional plastic injection molding in which a mold surface is controlled at a low temperature and a constant temperature, a material resin such as a molten thermoplastic resin is rapidly cooled from a surface in contact with the mold to form a thick solidified layer. Alternatively, due to the heat shrinkage, the transfer between the mold surface and the product surface is not sufficiently performed, resulting in poor transfer. This is because the hard solidified layer on the resin surface inhibits deformation due to the internal pressure of the resin, and prevents the resin surface from closely contacting the mold surface and preventing transfer. In addition, when rubber particles such as fillers such as glass fibers and beads and butadiene are contained in the resin for reinforcing the mechanical strength of the resin, fillers such as glass and rubber particles such as butadiene are formed on the resin surface due to a difference in thermal shrinkage between these and the resin. It is left and fine irregularities are formed to deteriorate the transferability and impair the appearance of the product.
【０００３】このような製品の転写不良は、製品の見栄
えを損なって製品価値を低下させると共に、製品表面に
塗装を施す場合にも均質な塗装を阻害して美観を損ね、
補修のための費用が高くなる問題もある。また、極端な
場合、製品に要求される表面平滑精度或いは外観を満足
できず、製品を無価値なものとする。[0003] Such poor transfer of the product impairs the appearance of the product and lowers the product value, and also impairs the uniform appearance when coating the product surface, impairing the appearance.
There is also a problem that the cost for repair is high. In an extreme case, the surface smoothness or appearance required for the product cannot be satisfied, and the product is rendered worthless.
【０００４】このような転写不良は、金型内の樹脂圧力
を高圧として樹脂の金型表面への押し付けを強くした
り、材料樹脂に含入されるフィラー、ゴム粒子等の量の
低減、粒径の小型化等材料樹脂自体の改良によってもあ
る程度は改善できる。しかし、金型内圧を高圧にするこ
とは、より高強度な金型や高圧を発生できる大型の成形
機を必要とし費用が高くなるほか、製品自体も内部歪
み、変形の発生等新たな問題を生じる。また、樹脂自体
の改善は、外観面を重視することで、必要な強度等の性
能が満足できなくなる問題も発生する。[0004] Such poor transfer may be caused by increasing the pressure of the resin in the mold to a high pressure to intensify the pressing of the resin against the surface of the mold, reducing the amount of fillers, rubber particles, etc. contained in the material resin, Improvement can be made to some extent by improving the material resin itself, such as reducing the diameter. However, increasing the internal pressure of the mold to a high pressure requires a higher-strength mold and a large-sized molding machine capable of generating a high pressure, which increases the cost and raises new problems such as internal distortion and deformation of the product itself. Occurs. In addition, when the appearance of the resin is emphasized in improving the resin itself, there arises a problem that performance such as required strength cannot be satisfied.
【０００５】最も転写不良に対し効果が高いのは、金型
の製品に接する表面において材料樹脂が非結晶性の場合
はガラス転移温度以上、結晶性樹脂の場合は融点温度以
上の高温に加熱することである。これは、金型表面を高
温にすることで、金型表面に接する樹脂の固化層が薄
く、変形しやすくなり、金型表面を忠実に転写しやすく
なるためである。しかし、単に高温に加熱するだけで
は、製品に反り、変形が生じるなど、新たな問題を生じ
る他、成形サイクルが延びて製品コストが高くなる弊害
が生じる。The most effective against transfer failure is that the material resin is heated to a temperature higher than the glass transition temperature if the material resin is non-crystalline on the surface in contact with the product of the mold, and to a temperature higher than the melting point temperature if the material resin is a crystalline resin. That is. This is because when the mold surface is heated to a high temperature, the solidified layer of the resin in contact with the mold surface is thin and easily deformed, and the mold surface is easily transferred faithfully. However, simply heating to a high temperature causes new problems such as warpage and deformation of the product, and also causes a problem that the molding cycle is extended and the product cost is increased.
【０００６】従来、金型温度応答性を良くし、金型加熱
時間短縮を図った装置として、以下の各種のものが提案
されている。 金型の外周に誘導コイルを設けたもの（実開昭６２−
１１１８３２号）。 金型に銅パイプからなる高周波誘導コイルを設け、パ
イプ内に冷却水を流すようにしたもの（特開昭６３−１
５７０７号）。 電熱ヒータを設けた可動入子を金型に出し入れ可能と
したもの（特開昭６３−１５７１９号）。 金型外部に金型温度調節用媒体を急速に加熱、冷却或
いは加熱、冷却した媒体を切り替えて金型に供給する装
置を設け、供給される加熱、冷却媒体を金型内の温度調
節用媒体循環路に通して金型を加熱、冷却できるように
したもの（特開昭６２−１５７０７号、同６２−２０８
９１８号、特公平７−２５１１５号）。Conventionally, the following various devices have been proposed as devices which improve the mold temperature response and shorten the mold heating time. Induction coil provided on the outer periphery of the mold (Jpn.
No. 111832). A high-frequency induction coil made of a copper pipe is provided in a mold so that cooling water flows in the pipe (Japanese Patent Laid-Open No. 63-1).
No. 5707). One in which a movable insert provided with an electric heater can be inserted into and removed from a mold (JP-A-63-15719). A device for rapidly heating, cooling or switching between heated and cooled media for the mold temperature adjusting medium is provided outside the mold and supplied to the mold, and the supplied heating and cooling medium is the temperature adjusting medium in the mold. A mold that can be heated and cooled by passing through a circulation path (Japanese Patent Application Laid-Open Nos. 62-15707 and 62-208).
No. 918, Tokuhei 7-25115).
【０００７】[0007]
【発明が解決しようとする課題】前述のように、製品の
転写不良は、金型の材料樹脂が流れる表面を高温に加熱
することによって改善できるが、加熱、冷却に時間をか
ければ成形サイクルが延びて生産性が低下し、製品コス
トの高騰を招くほか、製品自体反り等の新たな不良が生
じる。また、金型表面温度が高温になりすぎたり、長時
間高温にさらされる場合、材料樹脂の収縮量がさらに大
きくなり、後収縮等によりガラス等のフィラー、ブタジ
エン等のゴム粒子が樹脂表面に残され転写不良が再度発
生する問題もある。また、金型表面を加熱する方法につ
いても、上記従来法には以下のような問題がある。As described above, the improper transfer of a product can be improved by heating the surface of the mold through which the resin material flows to a high temperature. However, if the heating and cooling take time, the molding cycle can be improved. This leads to a decrease in productivity, resulting in an increase in product cost and a new defect such as warpage of the product itself. Also, when the mold surface temperature becomes too high or is exposed to the high temperature for a long time, the amount of shrinkage of the material resin further increases, and fillers such as glass and rubber particles such as butadiene remain on the resin surface due to post-shrinkage and the like. There is also a problem that transfer failure occurs again. Also, the method of heating the mold surface has the following problems in the conventional method.
【０００８】、の誘導コイルを設けるものは、金型
内組込に制約が多く金型が大型化する。の電熱ヒータ
を有する可動入子を設けたものは、金型に可動入子の挿
入部を設けなくてはならず、金型構造が複雑となる。ま
た、加熱手段の汎用性がない。冷却については、自然冷
却によるため、成形サイクルが長くなる。の外部装置
より加熱、冷却媒体を金型内の温度調節用媒体循環路に
通して金型表面を加熱、冷却するものは、汎用性があ
り、かつ金型構造も特殊な加工を要さない。しかし、通
常設けられている範疇の金型内の温度調節用媒体循環路
を使用した場合、加熱、冷却する金型部分の熱容量が大
きいため熱のロスが生じ、加熱、冷却に時間がかかる。
また、最終的には金型表面温度の応答が遅いために、温
度の制御精度が悪くなる問題がある。本発明は、上記事
情に鑑みて発明されたものであり、高転写な製品を低圧
で得るプラスチック製品の射出成形方法を提供すること
が目的である。[0008] In the case where the induction coil is provided, there are many restrictions on assembling in the mold, and the mold becomes large. When the movable insert having the electric heater is provided, the mold must be provided with an insertion portion for the movable insert, and the mold structure becomes complicated. Further, there is no versatility of the heating means. Cooling is performed by natural cooling, so that the molding cycle becomes longer. Heating and cooling the mold surface by passing the heating and cooling medium from the external device through the temperature control medium circulation path in the mold is versatile, and the mold structure does not require special processing. . However, when a temperature control medium circulation path in a mold in a normally provided category is used, heat loss occurs due to a large heat capacity of a mold portion to be heated and cooled, and it takes time to heat and cool.
In addition, since the response of the mold surface temperature is finally slow, there is a problem that the temperature control accuracy is deteriorated. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an injection molding method for a plastic product which can obtain a high-transfer product at a low pressure.
【０００９】[0009]
【課題を解決するための手段】本発明者らは上記問題解
決のため、製品に接する金型表面を高温にして行う成形
法及び温度応答性の良い金型構造、製造法について鋭意
研究した。その結果、射出成形において、製品に接する
金型面を短時間で材料樹脂が非結晶性の場合はガラス転
移温度以上、結晶性樹脂の場合は融点温度以上まで毎秒
２℃以上の昇温速度で急速に加熱して樹脂充填時間中こ
の温度を保持し、充填完了後に金型表面を毎秒２℃以上
の降温速度で短時間で急速に冷却する金型温度のサイク
ルを行うことで、成形サイクルを延ばさずに高転写な製
品を低圧で得るプラスチック製品の射出成形方法を完成
した。Means for Solving the Problems In order to solve the above problems, the present inventors have intensively studied a molding method in which a mold surface in contact with a product is heated to a high temperature, a mold structure having good temperature response, and a manufacturing method. As a result, in injection molding, the surface of the mold in contact with the product is heated in a short time to a temperature higher than the glass transition temperature if the material resin is non-crystalline and to a temperature higher than the melting point if the material resin is a crystalline resin at a rate of 2 ° C. or higher per second. The molding cycle is performed by rapidly heating and maintaining this temperature during the resin filling time, and by performing a mold temperature cycle of rapidly cooling the mold surface at a temperature decreasing rate of 2 ° C. or more per second in a short time after filling is completed. We have completed an injection molding method for plastic products that can obtain high-transfer products at low pressure without stretching.
【００１０】このように急速な金型面の加熱、冷却を可
能とする金型の構造及び製造方法は、過去において、本
発明者らの特許出願（特願平８−１８４４４１号 １９
９６年７月１５日付出願）に詳しく述べられている。ま
た、この成形方法は、一般的な射出成形法のみならず、
ガスアシスト成形、圧縮成形法等にも適用可能である。In the past, the structure and manufacturing method of a mold which enables rapid heating and cooling of the mold surface have been disclosed in the past by the present inventors (Japanese Patent Application No. 8-184441).
(Filed on July 15, 1996). In addition, this molding method is not only a general injection molding method,
It is also applicable to gas assist molding, compression molding and the like.
【００１１】本発明の金型による成形の適用できる樹脂
は、ポリオレフィン樹脂、ポリスチレン樹脂、ＡＢＳ樹
脂などの汎用性樹脂やポリカーボネート樹脂、ポリアミ
ド樹脂などの工業用樹脂だけでなく、各種の樹脂を混合
したものや補強材或いは意匠性としてメタリック、石目
調の感じを出すための有機、無機充填材、さらには発泡
剤を混入したものも使用できる。The resin applicable to the molding by the mold of the present invention is not only a general-purpose resin such as polyolefin resin, polystyrene resin and ABS resin, but also an industrial resin such as polycarbonate resin and polyamide resin, and a mixture of various resins. An organic or inorganic filler for giving a metallic or stone-like feeling as a material, a reinforcing material or a design property, and a material mixed with a foaming agent can also be used.
【００１２】[0012]
【作用】上記のように、射出成形において、製品に接す
る金型面を短時間で、材料樹脂が非結晶性の場合はガラ
ス転移温度以上、結晶性樹脂の場合は融点温度以上まで
急速に加熱して樹脂充填時間中この温度を保持し、充填
完了後に短時間で急速に冷却する成形法を用いた場合、
充填時高温に加熱されている金型表面に接する樹脂表面
の固化層は、従来の低温な金型表面温度での成形に較
べ、発達しにくく、薄く変形しやすい。このため、樹脂
の内圧で容易に樹脂表面が金型表面に密着して転写が良
くなる。かつ、密着により、樹脂及び金型表面間に、高
い物理的接合強度が得られて樹脂の離型が遅れ、この間
に充分な強度まで固化層が発達するために、樹脂の熱収
縮による影響が少ない。このため、材料樹脂中収縮の小
さいガラス等のフィラー、ブタジエン等のゴム粒子の樹
脂表面への残存に起因する転写不良が発生せず、高転写
な製品を得ることができる。As described above, in the injection molding, the mold surface in contact with the product is rapidly heated to a temperature higher than the glass transition temperature when the material resin is non-crystalline and higher than the melting point temperature when the material resin is crystalline. When using a molding method that maintains this temperature during the resin filling time and cools quickly in a short time after completion of filling,
The solidified layer on the resin surface that is in contact with the mold surface heated to a high temperature during filling is less likely to develop and is thinner and more deformable than conventional molding at a low mold surface temperature. For this reason, the resin surface easily adheres to the mold surface by the internal pressure of the resin, and the transfer is improved. In addition, due to the close contact, a high physical bonding strength is obtained between the resin and the mold surface, and the release of the resin is delayed. During this time, the solidified layer develops to a sufficient strength, so that the influence of the heat shrinkage of the resin is reduced. Few. For this reason, a transfer failure due to the residual resin particles such as filler such as glass, butadiene or the like having a small shrinkage in the resin material does not occur on the resin surface, and a high-transfer product can be obtained.
【００１３】しかも、樹脂表面が変形しやすいために、
金型面に樹脂表面を押し付けて転写させるのに必要な樹
脂内圧は低くてすみ、樹脂の固化層が薄いことから、樹
脂の圧力損失が小さく、従来の成形法より低い金型内圧
での成形が可能である。また、特に本発明の特徴である
金型面を急速に加熱、冷却して樹脂が高温な型面にさら
される時間を必要最小限に抑えることが肝要である理由
を、以下に詳細に述べる。Moreover, since the resin surface is easily deformed,
The resin internal pressure required for transferring the resin surface by pressing it against the mold surface is low, and the resin solidified layer is thin, so the resin pressure loss is small and molding with a lower mold internal pressure than conventional molding methods Is possible. In addition, the reason why it is essential to rapidly heat and cool the mold surface, which is a feature of the present invention, to minimize the time required for the resin to be exposed to the high-temperature mold surface is described below in detail.
【００１４】材料樹脂が高温な金型面に必要以上の時間
さらされた場合、材料樹脂の収縮量がさらに大きくな
り、後収縮等によりガラス等のフィラー、ブタジエン等
のゴム粒子等樹脂に混入されているものが樹脂表面に残
され、転写性不良が再発する。更に、金型表面を高温に
して成形する場合、冷却が遅いと製品に反り等の変形も
生じやすい。しかも、金型表面の加熱、冷却が短時間で
達成できないと、成形サイクルが延びて量産性を損な
い、コストの増加を招く。If the material resin is exposed to the high-temperature mold surface for an unnecessarily long time, the amount of shrinkage of the material resin further increases, and the material resin is mixed into the resin such as filler such as glass and rubber particles such as butadiene by post-shrinkage. Is left on the resin surface, and poor transferability recurs. Furthermore, when molding is performed at a high temperature on the mold surface, if the cooling is slow, the product is likely to be deformed such as warping. Moreover, if heating and cooling of the mold surface cannot be achieved in a short time, the molding cycle is extended, mass productivity is impaired, and the cost is increased.
【００１５】[0015]
【実施例１】本発明を実施例に基づいて説明する。図１
は、本発明の成形法を行う場合のプラスチック射出成形
用金型の一実施例を示す概略図である。図１に示すプラ
スチック射出成形用金型１は大きく分けてコア２（製品
非可視面側）とキャビティー３（製品可視面側）とから
成り、共に図外の射出成形機に連結されており、コア２
とキャビティー３とが開閉可能にされている。コア２と
キャビティー３には製品４の外形状に対応した凹部５が
形成されており、キャビティー３の所定箇所に設けられ
たスプルー６を介して図外の射出成形機から溶融プラス
チックが凹部５に流し込まれ、製品４が成形されるよう
になっている。この製品４の製品可視面側は、金型表面
高速加熱、冷却用入れ駒７内の金型温度調節用媒体循環
路８内を流れる媒体により成形時高速に高温に加熱、冷
却され、固化後にプラスチック射出成形用金型１から取
り出される。なお、金型温度調節用媒体循環路８内を流
れる媒体は、図外の高周波加熱機及び冷却機を備え高速
加熱冷却が可能な媒体温度調節機より媒体入口１１を経
由して金型温度調節用媒体循環路８に供給され、媒体出
口１２を経由して媒体温度調節機に還る。Embodiment 1 The present invention will be described based on an embodiment. FIG.
FIG. 1 is a schematic view showing one embodiment of a plastic injection mold for performing the molding method of the present invention. The plastic injection mold 1 shown in FIG. 1 is roughly divided into a core 2 (product invisible surface side) and a cavity 3 (product visible surface side), and both are connected to an injection molding machine (not shown). , Core 2
And the cavity 3 can be opened and closed. A recess 5 corresponding to the outer shape of the product 4 is formed in the core 2 and the cavity 3, and the molten plastic is recessed from an injection molding machine (not shown) through a sprue 6 provided at a predetermined position in the cavity 3. 5, and the product 4 is formed. The product visible surface side of the product 4 is heated and cooled to a high temperature at a high speed during molding by a medium flowing in a mold temperature adjusting medium circulation path 8 in a mold surface high-speed heating / cooling insert 7 and solidified. It is taken out of the plastic injection mold 1. The medium flowing in the mold temperature adjusting medium circulation path 8 is supplied from a medium temperature adjuster, which is provided with a high-frequency heater and a cooler (not shown) and capable of high-speed heating and cooling, via a medium inlet 11 through a mold inlet. And is returned to the medium temperature controller via the medium outlet 12.
【００１６】図２、図３及び図４は、図１の金型表面高
速加熱、冷却用入れ駒７の説明図である。製品可視面に
接する金型表面電鋳層９はＮｉ−Ｃｒで形成されてお
り、内部には金型温度調節用媒体循環路８が形成されて
いる。この金型温度調節用媒体循環路８は、金型表面電
鋳層９の金型内部面にロストワックスで管路を形成後に
電鋳層９で表面を被覆し、その後ロストワックスを溶出
させ空洞として、金型表面電鋳層９と一体構成とした。
金型温度調節用媒体循環路８の断面形状は、５ｍｍ×５
ｍｍの正方形で、ピッチは１２ｍｍである。この金型温
度調節用媒体循環路８と製品４に接する金型表面高速加
熱、冷却用入れ駒７の表面間距離は２ｍｍとした。ま
た、金型温度調節用媒体循環路８の裏面には、２ｍｍ程
度厚のエポキシ及び補強材で構成される断熱層１０を設
け、急加熱、冷却を行う金型部位を熱的に隔離すること
で熱容量を小さく構成した。図中符号の１４は鋼材であ
る。FIGS. 2, 3 and 4 are illustrations of the insert 7 for high-speed heating and cooling of the mold surface shown in FIG. The mold surface electroformed layer 9 that is in contact with the visible surface of the product is formed of Ni—Cr, and a mold temperature adjusting medium circulation path 8 is formed inside. The mold temperature adjusting medium circulating path 8 forms a conduit with lost wax on the inner surface of the mold of the mold surface electroformed layer 9, coats the surface with the electroformed layer 9, and then elutes the lost wax to form a cavity. To form an integral structure with the mold surface electroformed layer 9.
The cross-sectional shape of the mold temperature control medium circulation path 8 is 5 mm × 5
mm square with a pitch of 12 mm. The distance between the surfaces of the mold surface high-speed heating / cooling insert 7 in contact with the mold temperature adjusting medium circulation path 8 and the product 4 was 2 mm. In addition, a heat insulating layer 10 made of epoxy and a reinforcing material having a thickness of about 2 mm is provided on the back surface of the mold temperature control medium circulation path 8 to thermally isolate a mold portion for rapid heating and cooling. To reduce the heat capacity. Reference numeral 14 in the drawing denotes a steel material.
【００１７】図１の装置とガラスフィラー２０％含入の
ＡＢＳ樹脂（１５Ｇ２０ ガラス転移温度９８℃ 日本
合成ゴム）を用い、製品可視面側金型表面温度を樹脂ガ
ラス転移温度前後に変化させて射出成形を行った。この
時、金型表面温度は、樹脂充填完了まで加熱後、短時間
で冷却する条件（実験１）とした。また、この時の成形
サイクル（型閉〜射出〜保圧〜冷却〜型開〜取出し）は
６０秒、加熱に要した時間は１８秒、冷却に要した時間
は２５秒で、金型表面温度の昇温速度毎秒２℃、降温速
度毎秒２℃とした。得られた製品の可視面光沢度測定結
果を、図８に示す。Using the apparatus shown in FIG. 1 and an ABS resin (15G20, glass transition temperature 98 ° C., Japan synthetic rubber) containing 20% of glass filler, the mold surface temperature on the visible side of the product is changed around the resin glass transition temperature, and injection is performed. Molding was performed. At this time, the mold surface temperature was set to a condition (experiment 1) in which heating was performed until resin filling was completed, followed by cooling in a short time. At this time, the molding cycle (mold closing-injection-holding pressure-cooling-mold opening-removal) was 60 seconds, the time required for heating was 18 seconds, the time required for cooling was 25 seconds, and the mold surface temperature was The temperature was raised at a rate of 2 ° C./sec and the temperature was lowered at a rate of 2 ° C./sec. FIG. 8 shows the measurement results of the glossiness of the visible surface of the obtained product.
【００１８】上記実験１では、樹脂充填時の金型表面温
度を樹脂のガラス転移温度以上かつ昇温・冷却速度毎秒
２℃で、製品面光沢度９２の最大値となり、ガラスフィ
ラー入りにもかかわらず高光沢な製品が得られた。光沢
は、転写性の指標であり、型面を樹脂のガラス転移温度
以上に加熱後、高速に冷却することで高い転写性を得る
ことができた。また、製品の取出し時点において、製品
は充分に固化しており、製品の反り等変形、離型の問題
は生じなかった。In Experiment 1, the surface temperature of the mold at the time of filling the resin was equal to or higher than the glass transition temperature of the resin and the temperature was raised and cooled at 2 ° C. per second. A high gloss product was obtained. Gloss is an index of transferability, and high transferability was obtained by heating the mold surface to a temperature equal to or higher than the glass transition temperature of the resin and then cooling it at high speed. Further, at the time of taking out the product, the product was sufficiently solidified, and there was no problem of deformation such as warpage of the product and release.
【００１９】[0019]
【実施例２】実施例１と同じ装置と耐衝撃性ポリスチレ
ン（ＨＴ５６０ ガラス転移温度９７℃ 出光石油化
学）を用い、製品可視面側金型表面温度を樹脂充填時１
２０℃、冷却時６０℃に高速に加熱、冷却して射出成形
を行った（実験３）。また、この時の成形サイクル（型
閉〜射出〜保圧〜冷却〜型開〜取出し）は６０秒、加熱
に要した時間は１８秒、冷却に要した時間は２５秒で、
金型表面温度の昇温速度毎秒３℃、降温速度毎秒２℃と
した。なお、金型表面にはダイヤモンドチップで大きさ
の異なる四角錐状の圧痕を予めつけておき、金型表面と
樹脂表面の圧痕の幅を計測し、この幅の割合（樹脂表面
圧痕幅／金型表面圧痕幅）を転写率として転写性を評価
した。得られた製品、金型の圧痕転写率の測定結果を、
図９に示す。上記実験３では、１０ミクロンから１００
ミクロンまでの大きさの異なる四角錐状圧痕のいずれに
おいても、転写率は、ほぼ１００％と高い値を示した。
また、保圧有無のいずれの条件でも、ほぼ同じ転写率で
あり、保圧を要さず低圧で高い転写性を得ることができ
た。Example 2 Using the same apparatus as in Example 1 and impact-resistant polystyrene (HT560 glass transition temperature 97 ° C, Idemitsu Petrochemical), the surface temperature of the mold on the visible side of the product was set at 1
Injection molding was performed by heating and cooling at a high speed of 20 ° C. and 60 ° C. during cooling (Experiment 3). The molding cycle (mold closing-injection-holding pressure-cooling-mold opening-unloading) at this time is 60 seconds, the time required for heating is 18 seconds, and the time required for cooling is 25 seconds.
The mold surface temperature was raised at a rate of 3 ° C. per second and a rate of temperature decrease was set at 2 ° C. per second. In addition, square pyramid-shaped indentations of different sizes were previously formed on the mold surface with a diamond chip, the width of the indentations on the mold surface and the resin surface was measured, and the ratio of this width (resin surface indentation width / metal mold) was measured. The transferability was evaluated with the transfer rate of the mold surface impression width). The obtained product, the measurement results of the impression transfer rate of the mold,
As shown in FIG. In Experiment 3 above, 10 microns to 100
The transfer rate showed a high value of almost 100% in any of the pyramidal indentations having different sizes down to microns.
In addition, the transfer rate was almost the same under both the conditions with and without the pressure holding, and high transferability could be obtained at a low pressure without the need for the pressure holding.
【００２０】[0020]
【比較例１】実施例１と同じ実験装置、樹脂を用い、製
品可視面側金型表面温度を樹脂ガラス転移温度前後に変
化させて射出成形を行った。この時、金型表面温度は、
樹脂の充填から冷却まで定温に制御する条件とした（実
験２）。また、この時の成形サイクル（型閉〜射出〜保
圧〜冷却〜型開〜取出し）は６０秒、加熱に要した時間
は１８秒、冷却（加熱温度定温保持）時間は２５秒で、
金型表面温度の昇温速度毎秒２℃、降温速度は加熱温度
定温保持のため毎秒０℃とした。得られた製品の可視面
光沢度測定結果を、図８に示す。Comparative Example 1 Using the same experimental apparatus and resin as in Example 1, injection molding was performed by changing the surface temperature of the mold on the visible side of the product to around the glass transition temperature of the resin. At this time, the mold surface temperature is
Conditions were set to control the temperature to be constant from resin filling to cooling (Experiment 2). The molding cycle (mold closing-injection-holding pressure-cooling-mold opening-removal) at this time is 60 seconds, the time required for heating is 18 seconds, and the cooling (heating temperature constant temperature holding) time is 25 seconds.
The temperature rise rate of the mold surface temperature was set at 2 ° C./sec, and the temperature decrease rate was set at 0 ° C./sec for keeping the heating temperature constant. FIG. 8 shows the measurement results of the glossiness of the visible surface of the obtained product.
【００２１】上記実験２でも、金型表面温度が、樹脂の
ガラス転移温度付近では、製品可視面の光沢度は約９０
と、ガラスフィラー入りにもかかわらず高光沢な製品が
得られたが、実施例１に較べ光沢度は低下した。また、
金型表面温度を樹脂のガラス転移温度以上とすると、製
品可視面の光沢度は著しく低下し、更に製品の取出し時
点において、製品は充分に固化しておらず、製品の反り
等変形、離型の問題が生じた。In Experiment 2 above, when the mold surface temperature is near the glass transition temperature of the resin, the glossiness of the visible surface of the product is about 90.
Thus, a product with high gloss was obtained despite containing glass filler, but the glossiness was lower than that of Example 1. Also,
If the mold surface temperature is equal to or higher than the glass transition temperature of the resin, the glossiness of the visible surface of the product is significantly reduced, and the product is not sufficiently solidified at the time of removal of the product. The problem arose.
【００２２】[0022]
【比較例２】実施例１の金型表面高速加熱、冷却用入れ
駒７を鋼材Ｓ５５Ｃ製で金型温度調節用媒体循環路８が
横穴状に２本機械加工してある通常の金型構造を模擬し
た鋼材入れ駒１３（図５〜図７）に交換した以外は、実
施例１と同じ装置、樹脂を用い、樹脂充填時の製品可視
面側金型表面温度をガラス転移温度前後に加熱し、冷却
時には６０℃まで冷却する温度制御条件で成形を行っ
た。製品面の光沢が最大値を示したのは金型面を１００
℃に加熱したときで、これ以上低くても高くても、光沢
度すなわち転写性は低下する傾向を示した。また、金型
面を１００℃に加熱したときの成形サイクル（型閉〜射
出〜保圧〜冷却〜型開〜取出し）は８４秒、加熱に要し
た時間は３９秒、冷却に要した時間は４０秒で、金型表
面温度の昇温速度毎秒１℃、降温速度毎秒１℃であっ
た。成形サイクルも、実施例１に較べ４０％長くなっ
た。製品可視面の光沢度測定結果も、光沢度８８と実施
例１の製品光沢度９２に較べ低下した。また、逆に成形
サイクルを実施例１と同じ６０秒にした場合、金型表面
の到達温度が低く製品光沢も著しく低下し、また、金型
表面の冷却も遅く、取出し時点の製品温度が高いために
製品が変形しやすかった。COMPARATIVE EXAMPLE 2 An ordinary mold structure in which a mold surface high-speed heating / cooling insert 7 of Example 1 is made of steel material S55C and a mold temperature adjusting medium circulation path 8 is machined into two lateral holes. Using the same apparatus and resin as in Example 1 except that the steel material insert 13 (FIG. 5 to FIG. 7) was replaced with a simulated steel material, the surface temperature of the mold on the visible side of the product when the resin was filled was heated to around the glass transition temperature. Then, at the time of cooling, molding was performed under temperature control conditions of cooling to 60 ° C. The maximum value of the gloss on the product surface was 100
When heated to ° C, the glossiness, that is, the transferability, tended to decrease, whether it was lower or higher. The molding cycle (mold closing-injection-holding pressure-cooling-mold opening-removal) when the mold surface was heated to 100 ° C. was 84 seconds, the time required for heating was 39 seconds, and the time required for cooling was 84 seconds. At 40 seconds, the mold surface temperature was raised at a rate of 1 ° C./sec and a rate of temperature decrease was 1 ° C./sec. The molding cycle was also 40% longer than in Example 1. The gloss measurement result of the visible surface of the product was also lower than the gloss 88 and the product gloss 92 of Example 1. Conversely, when the molding cycle is set to 60 seconds, which is the same as that in Example 1, the temperature reached on the mold surface is low and the product gloss is significantly reduced, and the cooling of the mold surface is slow and the product temperature at the time of removal is high. The product was easy to deform because of it.
【００２３】[0023]
【比較例３】実施例２と同じ装置、樹脂を用い、製品可
視面側金型表面温度を６０℃一定として射出成形を行っ
た（実験４）。得られた製品、金型の圧痕転写率を測定
した結果を、図９に示す。上記実験４では、３０ミクロ
ン以下の四角錐状圧痕では、転写率は０％となった。ま
た、保圧有の条件では、保圧無しの条件に較べ、転写率
が若干良化するものの、実施例２のような高い転写率は
得られなかった。COMPARATIVE EXAMPLE 3 Using the same apparatus and resin as in Example 2, injection molding was performed while keeping the surface temperature of the mold on the product visible side constant at 60 ° C. (Experiment 4). FIG. 9 shows the results of measuring the indentation transfer rate of the obtained product and mold. In Experiment 4, the transfer rate was 0% for the pyramid-shaped indentations of 30 microns or less. Further, under the condition with the pressure holding, the transfer rate was slightly improved as compared with the condition without the pressure holding, but the high transfer rate as in Example 2 was not obtained.
【００２４】[0024]
【発明の効果】上記成形法によれば、高転写な製品を低
圧かつ成形サイクルを延ばすことなく得ることができ、
品質並びにコストの面からもメリットが大きく、製品不
良を低減する上での効果は極めて大きい。According to the above-mentioned molding method, a high-transfer product can be obtained at a low pressure without extending the molding cycle.
The advantages are great in terms of quality and cost, and the effect in reducing product defects is extremely large.
【図１】本発明の成形法の実施例に係る射出成形用金型
の一例を示す断面図。FIG. 1 is a cross-sectional view showing an example of an injection mold according to an embodiment of the molding method of the present invention.
【図２】金型表面高速加熱、冷却用入れ駒を裏面側（反
製品面側）から見た断面図。FIG. 2 is a cross-sectional view of the insert for high-speed heating and cooling of the mold surface as viewed from the back side (non-product side).
【図３】Ａ−Ａ′線断面図。FIG. 3 is a sectional view taken along line AA ′.
【図４】Ｂ−Ｂ′線断面図。FIG. 4 is a sectional view taken along line BB ′.
【図５】比較例２で用いた鋼材入れ駒を裏面側（反製品
面側）から見た断面図。FIG. 5 is a cross-sectional view of the steel insert used in Comparative Example 2 as viewed from the back side (non-product side).
【図６】Ｃ−Ｃ′線断面図。FIG. 6 is a sectional view taken along line CC ′.
【図７】Ｄ−Ｄ′線断面図。FIG. 7 is a sectional view taken along line DD ′.
【図８】光沢度の比較例の説明図。FIG. 8 is an explanatory diagram of a comparative example of glossiness.
【図９】転写率の比較例の説明図。FIG. 9 is an explanatory diagram of a comparative example of a transfer rate.
１ プラスチック射出成形用金型 ２ コア ３ キャビティー ４ 製品 ５ 凹部 ６ スプルー ７ 金型表面高速加熱、冷却用入れ駒 ８ 金型温度調節用媒体循環路 ９ 金型表面電鋳層 １０ 断熱層 １１ 金型温度調節用媒体入口 １２ 金型温度調節用媒体出口 １３ 鋼材入れ駒 １４ 鋼材 DESCRIPTION OF SYMBOLS 1 Mold for plastic injection molding 2 Core 3 Cavity 4 Product 5 Concave part 6 Sprue 7 Insert for high speed heating and cooling of mold surface 8 Medium circulation path for mold temperature control 9 Mold electroforming layer 10 Heat insulation layer 11 Gold Mold temperature control medium inlet 12 Mold temperature control medium outlet 13 Steel material holder 14 Steel material
Claims (4)
製品に接する金型表面温度を、材料樹脂が非結晶性の場
合は樹脂のガラス転移温度以上まで、毎秒２℃以上の昇
温速度で短時間に高速に加熱し、樹脂充填時間中この温
度を保持した後、充填完了後は金型表面温度を毎秒２℃
以上の降温速度で短時間に高速に冷却する金型温度制御
を行い、高転写なプラスチック製品を低圧で得る射出成
形方法。1. In injection molding of a plastic product,
The surface temperature of the mold in contact with the product, if the material resin is non-crystalline, is heated to a temperature higher than the glass transition temperature of the resin at a rate of 2 ° C./sec. After holding, after filling is completed, the mold surface temperature is set to 2 ° C per second.
An injection molding method in which a high-transfer plastic product is obtained at a low pressure by controlling a mold temperature for rapidly cooling at a high speed in the above-mentioned temperature decreasing rate.
製品に接する金型表面温度を、材料樹脂が結晶性の場合
は樹脂の融点温度以上まで、毎秒２℃以上の昇温速度で
短時間に高速に加熱し、樹脂充填時間中この温度を保持
した後、充填完了後は金型表面温度を毎秒２℃以上の降
温速度で短時間に高速に冷却する金型温度制御を行い、
高転写なプラスチック製品を低圧で得る射出成形方法。2. In the injection molding of a plastic product,
The surface temperature of the mold in contact with the product, if the material resin is crystalline, was heated to a temperature higher than the melting point of the resin at a rate of 2 ° C. or higher per second in a short time, and this temperature was maintained during the resin filling time. Then, after filling is completed, mold temperature control is performed to rapidly cool the mold surface temperature at a rate of 2 ° C./sec or more per second in a short time,
Injection molding method to obtain high transfer plastic products at low pressure.
部位を、製品に接する金型表面の一部もしくは製品可視
面側に接する金型表面にのみ限定してなる請求項１又は
２記載のプラスチック製品の射出成形法。3. The mold surface portion for controlling the heating and cooling temperature at high speed is limited to only a part of the mold surface in contact with the product or the mold surface in contact with the visible side of the product. Injection molding method for plastic products.
る際に、温度制御する金型表面範囲を複数に分割し、異
なる加熱温度、冷却温度或いは温度制御時間で成形する
ことを特徴とする請求項１又は２又は３記載のプラスチ
ック製品の射出成形法。4. The method according to claim 1, wherein, when rapidly controlling the heating and cooling temperatures of the mold surface, the mold surface area to be temperature-controlled is divided into a plurality of sections and molded at different heating temperatures, cooling temperatures or temperature control times. The injection molding method for a plastic product according to claim 1, 2 or 3.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28481797A JPH11115013A (en) | 1997-10-17 | 1997-10-17 | Plastic injection molding method |
| US09/174,262 US6203731B1 (en) | 1997-10-17 | 1998-10-16 | Method for injection molding of plastic products having excellent transcription properties |
| EP98308470A EP0909626A3 (en) | 1997-10-17 | 1998-10-16 | Method and apparatus for injection moulding plastics |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28481797A JPH11115013A (en) | 1997-10-17 | 1997-10-17 | Plastic injection molding method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH11115013A true JPH11115013A (en) | 1999-04-27 |
Family
ID=17683399
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28481797A Pending JPH11115013A (en) | 1997-10-17 | 1997-10-17 | Plastic injection molding method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH11115013A (en) |
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| JP2006103202A (en) * | 2004-10-06 | 2006-04-20 | Unitika Ltd | Method of molding polylactic acid resin composition and its molding |
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| CN102689395A (en) * | 2012-06-28 | 2012-09-26 | 金发科技股份有限公司 | Molding technology combining PA11 with metal embedding pieces |
| CN102729401A (en) * | 2012-06-28 | 2012-10-17 | 金发科技股份有限公司 | Molding process for combination of PA6/PA66/PA10T alloy and metal insert |
| JP2018094814A (en) * | 2016-12-14 | 2018-06-21 | 三井化学株式会社 | Resin molding with metal coating and process for producing resin molding with metal coating |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005514224A (en) * | 2001-10-26 | 2005-05-19 | アクララ バイオサイエンシーズ， インコーポレイテッド | Systems and methods for injection micro-replication of microfluidic substrates |
| JP2006103202A (en) * | 2004-10-06 | 2006-04-20 | Unitika Ltd | Method of molding polylactic acid resin composition and its molding |
| JP4645971B2 (en) * | 2004-10-06 | 2011-03-09 | ユニチカ株式会社 | Method for molding polylactic acid resin composition and molded body thereof |
| CN102639310A (en) * | 2010-03-18 | 2012-08-15 | 三菱重工塑胶科技股份有限公司 | Injection molding method, method for manufacturing molded product, and injection molding device |
| US8741193B2 (en) | 2010-03-18 | 2014-06-03 | Mitsubishi Heavy Industries Plastic Technology Co., Ltd. | Injection molding method, molded-article producing method, and injection molding apparatus |
| CN102689395A (en) * | 2012-06-28 | 2012-09-26 | 金发科技股份有限公司 | Molding technology combining PA11 with metal embedding pieces |
| CN102729401A (en) * | 2012-06-28 | 2012-10-17 | 金发科技股份有限公司 | Molding process for combination of PA6/PA66/PA10T alloy and metal insert |
| CN102689395B (en) * | 2012-06-28 | 2015-06-03 | 金发科技股份有限公司 | Molding technology combining PA11 with metal embedding pieces |
| CN102729401B (en) * | 2012-06-28 | 2015-06-03 | 金发科技股份有限公司 | Molding process for combination of PA6/PA66/PA10T alloy and metal insert |
| JP2018094814A (en) * | 2016-12-14 | 2018-06-21 | 三井化学株式会社 | Resin molding with metal coating and process for producing resin molding with metal coating |
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