JPH09174631A - Injection molding method - Google Patents

Injection molding method

Info

Publication number
JPH09174631A
JPH09174631A JP33377595A JP33377595A JPH09174631A JP H09174631 A JPH09174631 A JP H09174631A JP 33377595 A JP33377595 A JP 33377595A JP 33377595 A JP33377595 A JP 33377595A JP H09174631 A JPH09174631 A JP H09174631A
Authority
JP
Japan
Prior art keywords
mold
pressure
resin
clamping force
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.)
Granted
Application number
JP33377595A
Other languages
Japanese (ja)
Other versions
JP3237496B2 (en
Inventor
Yoshinobu Takeda
与志信 武田
Kunio Yamamoto
国雄 山本
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Materials Corp
Original Assignee
Mitsubishi Materials Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Materials Corp filed Critical Mitsubishi Materials Corp
Priority to JP33377595A priority Critical patent/JP3237496B2/en
Publication of JPH09174631A publication Critical patent/JPH09174631A/en
Application granted granted Critical
Publication of JP3237496B2 publication Critical patent/JP3237496B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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
    • B29C45/46—Means for plasticising or homogenising the moulding material or forcing it into the mould
    • B29C45/57—Exerting after-pressure on the moulding material
    • 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
    • B29C45/46—Means for plasticising or homogenising the moulding material or forcing it into the mould
    • B29C45/56—Means for plasticising or homogenising the moulding material or forcing it into the mould using mould parts movable during or after injection, e.g. injection-compression moulding
    • B29C45/561—Injection-compression moulding
    • 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
    • B29C45/46—Means for plasticising or homogenising the moulding material or forcing it into the mould
    • B29C45/56—Means for plasticising or homogenising the moulding material or forcing it into the mould using mould parts movable during or after injection, e.g. injection-compression moulding
    • B29C45/561—Injection-compression moulding
    • B29C2045/563—Enlarging the mould cavity during injection

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)
  • Injection Moulding Of Plastics Or The Like (AREA)

Abstract

PROBLEM TO BE SOLVED: To make high density molding possible and improve dimensional precision by forming a skin curing layer by injecting with low pressure clamping force, inbreasing resin pressure after pressure is removed, cutting a gate after a dwelling process for opening a split face of a mold, and thereafter clamping with high clamping force so as to reduce an opening quantity. SOLUTION: After a mold clamping by a first clamping force of low pressure, a melting resin 41 is injected into a cavity 16 so as to form a skin curing layer 42. During a short time immediately before an inside of a mold is filled with the melting resin 41, an injecting pressure is made to be zero and the mold is filled with the melting resin 41. Thereafter, the resin pressure is heightened to be higher than the highest resin pressure in the mold at the time of injection, and made to exceed the first clamping force and dwelling is done. The skin curing layer 42 is expanded with pressure, a gap between the layer and the inside face of the mold is bridged, and shrinkage in thickness is removed. Also, split faces 1a and 2a of the mold are actively opened. When the opening quantity reaches the highest value, a gate 17 is cut. For reducing the opening quantity, the clamping is performed by a second clamping force higher than the first clamping force.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【発明の属する技術分野】本発明は、射出工程と保圧工
程の後に、型締め力増加による圧縮工程を加えた射出成
形方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding method in which a compression process by increasing a mold clamping force is added after an injection process and a pressure holding process.

【０００２】[0002]

【従来の技術】従来、特公平４−７８０９３号公報に示
されるような射出成形方法が知られている。図４は同公
報に示された線図であり、溶融樹脂の射出開始から冷却
固化に至るまでの型内樹脂圧の変化を示している。この
射出成形方法は、型締めした金型のキャビティ内へ溶融
樹脂を射出し（射出工程）、キャビティ内が溶融樹脂で
満たされる直前に射出圧力を下げ（圧抜工程）、次に型
内樹脂圧を徐々に増加させて射出時の最大型内樹脂圧よ
りも大きな型内樹脂圧で保圧を行う（保圧工程）という
ものである。2. Description of the Related Art Conventionally, an injection molding method as disclosed in Japanese Patent Publication No. 4-78093 is known. FIG. 4 is a diagram shown in the publication and shows changes in the resin pressure in the mold from the start of injection of the molten resin to the cooling and solidification. In this injection molding method, the molten resin is injected into the mold cavity that has been clamped (injection step), the injection pressure is reduced immediately before the cavity is filled with the molten resin (pressurization step), and then the in-mold resin The pressure is gradually increased to hold the resin with a resin pressure in the mold that is larger than the maximum resin pressure in the mold at the time of injection (pressure holding step).

【０００３】この方法によれば、キャビティが溶融樹脂
で満たされる直前に射出圧力を下げるから、樹脂が固化
していない時点での型開きを防止することができる。ま
た、保圧工程では型内樹脂圧の増加に伴い型開きするこ
とになるが、溶融樹脂の表面が漸次冷却固定するので、
溶融樹脂が型の分割面の隙間に入り込むことがなく、バ
リの発生を防止することができる。According to this method, the injection pressure is lowered immediately before the cavity is filled with the molten resin, so that the mold opening at the time when the resin is not solidified can be prevented. Also, in the pressure-holding step, the mold will open as the resin pressure in the mold increases, but since the surface of the molten resin is gradually cooled and fixed,
The molten resin does not enter the gap between the divided surfaces of the mold, and it is possible to prevent the occurrence of burrs.

【０００４】一方、キャビティへの溶融樹脂の充填後
に、金型を微駆動して溶融樹脂に圧縮力を作用させなが
ら成形を行う射出圧縮成形という方法が知られている。
従来のこの方法は、図５（ａ）に示すように、雌型５１
と雄型５２とでできるキャビティ５３内に溶融樹脂５４
を充填した後、雄型５２を雌型５１に対して押圧摺動さ
せることにより、余剰樹脂をゲート５５から外部に流出
させると共に、図５（ｂ）に示すように雄型５２でゲー
ト５５をカットし、ゲートカットと同時あるいはその後
さらに雄型５２を微駆動することにより、型内樹脂に圧
縮力を与えて成形するというものである。On the other hand, there is known a method called injection compression molding in which after the molten resin is filled in the cavity, the mold is finely driven to perform the molding while applying a compressive force to the molten resin.
In this conventional method, as shown in FIG.
A molten resin 54 in the cavity 53 formed by the male mold 52
Then, the male mold 52 is pushed and slid with respect to the female mold 51 to allow excess resin to flow out from the gate 55, and as shown in FIG. By cutting, and simultaneously with or after gate cutting, the male die 52 is finely driven to give a compressive force to the resin in the die for molding.

【０００５】[0005]

【発明が解決しようとする課題】ところで、従来の射出
成形方法は、キャビティへの樹脂の充填後、射出成形機
側からの圧力により保圧をかけているが、肉ひけ、転写
性、樹脂歪み等の改善のために、更に高密度成形を行い
たいという要請があった。By the way, in the conventional injection molding method, after the cavity is filled with the resin, the holding pressure is applied by the pressure from the injection molding machine side. There has been a demand for higher density molding to improve the above.

【０００６】また、従来の射出圧縮成形方法は、高密度
成形が可能であるため、肉ひけや転写性といった点では
良好な成果が得られるものの、圧縮工程時にゲートから
の樹脂流れを伴うのでフローマークや樹脂歪みが発生す
る可能性があり、また金型の摺動部５６（図５参照）の
摩耗によりバリが出やすいという問題があった。In addition, since the conventional injection compression molding method can achieve high density molding, good results can be obtained in terms of shrinkage and transferability, but the resin flow from the gate during the compression process causes a flow. There is a problem that marks and resin distortion may occur, and burr is likely to occur due to abrasion of the sliding portion 56 (see FIG. 5) of the mold.

【０００７】本発明は、上記事情を考慮し、高密度成形
が可能であり、しかも圧縮工程時の樹脂流れの問題や摺
動部の摩耗の問題を回避することができて、製品の寸法
精度を大幅に向上させることのできる射出成形方法を提
供することを目的とする。In consideration of the above circumstances, the present invention enables high-density molding and avoids the problem of resin flow during the compression process and the problem of wear of the sliding portion, thus improving the dimensional accuracy of the product. It is an object of the present invention to provide an injection molding method capable of significantly improving the molding temperature.

【０００８】[0008]

【課題を解決するための手段】本発明の射出成形方法
は、低圧の第１の型締め力で型締めを行った後、キャビ
ティ内へ溶融樹脂を射出して、スキン硬化層を形成させ
つつ溶融樹脂の充填を行う射出工程と、キャビティ内が
溶融樹脂で満たされる直前に射出圧力を下げる圧抜工程
と、圧抜工程後に、型内樹脂圧を徐々に増加させて射出
時の最大型内樹脂圧よりも大きく、且つ前記第１の型締
め力を越える型内樹脂圧で保圧を行うことにより、金型
の分割面を開く保圧工程と、保圧工程後にゲートカット
し、ゲートカット後、保圧工程で生じた分割面の開き量
を減少させるべく、前記第１の型締め力よりも高圧の第
２の型締め力で型締めを行う圧縮工程とを備えたことを
特徴としている。その際、第１の型締め力は、第２の型
締め力の略１／２程度するのが好ましい。According to the injection molding method of the present invention, after the mold is clamped by the first mold clamping force of low pressure, the molten resin is injected into the cavity to form the hardened skin layer. The injection process of filling the molten resin, the depressurization process of decreasing the injection pressure immediately before the cavity is filled with the molten resin, and the post-pressurization process by gradually increasing the resin pressure in the mold By holding pressure with a resin pressure in the mold that is larger than the resin pressure and exceeds the first mold clamping force, a pressure holding step of opening the split surface of the mold, and gate cutting after the pressure holding step, and gate cutting And a compression step of performing mold clamping with a second mold clamping force, which is higher than the first mold clamping force, in order to reduce the amount of opening of the divided surfaces generated in the pressure holding step. There is. At that time, it is preferable that the first mold clamping force is approximately ½ of the second mold clamping force.

【０００９】[0009]

【発明の実施の形態】以下、本発明の一実施形態を図面
に基づいて説明する。図１は射出成形方法の工程説明
図、図２は溶融樹脂の射出開始から冷却固化に至るまで
のラム圧と型内樹脂圧の変化および型開き量の変化を示
す線図、図３はこの射出成形方法を実施するのに用いる
金型と射出成形機の一例を示す構成図である。DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a process explanatory view of the injection molding method, FIG. 2 is a diagram showing changes in the ram pressure and the resin pressure in the mold and changes in the mold opening amount from the start of injection of the molten resin to the cooling and solidification, and FIG. It is a block diagram which shows an example of the metal mold | die used for implementing the injection molding method, and an injection molding machine.

【００１０】まず、金型Ａおよび射出成形機Ｂについて
説明するが、こられは一般的なものであるから簡単に説
明する。金型Ａの詳細を説明すると、１は可動型、２は
固定型、４は固定側取付板、５は固定側スペーサ、６は
可動側スペーサ、７は可動側取付板、８、９は突出板、
１０はロケートリング、１１はマニホールド、１２はト
ーピード、１３はランナーブッシュ、１４は突出ピン、
１５はランナー、１６は可動型１と固定型２との間に形
成されるキャビティ、１７はゲートである。１ａ、２ａ
は可動型１と固定型２の分割面である。この金型Ａに
は、油圧シリンダ式あるいはトグル機構式などの型締め
機構Ｃが付設されている。ただし、この型締め機構Ｃ
は、少なくとも２段階（低圧と高圧）に型締め力を調節
できる機能を持つものである。First, the mold A and the injection molding machine B will be explained, but since these are general ones, they will be briefly explained. Explaining the details of the mold A, 1 is a movable type, 2 is a fixed type, 4 is a fixed side mounting plate, 5 is a fixed side spacer, 6 is a movable side spacer, 7 is a movable side mounting plate, and 8 and 9 are protrusions. Board,
10 is a locate ring, 11 is a manifold, 12 is a torpedo, 13 is a runner bush, 14 is a protruding pin,
Reference numeral 15 is a runner, 16 is a cavity formed between the movable mold 1 and the fixed mold 2, and 17 is a gate. 1a, 2a
Is a dividing surface of the movable die 1 and the fixed die 2. A mold clamping mechanism C such as a hydraulic cylinder type or a toggle mechanism type is attached to the mold A. However, this mold clamping mechanism C
Has a function of adjusting the mold clamping force in at least two stages (low pressure and high pressure).

【００１１】成形機Ｂについて説明すると、油圧シリン
ダ１８により往復駆動されるラム１９が、ヒータ２０で
加熱される加熱筒２１内に摺動自在に収容され、加熱筒
２１の後方上部にホッパー２２が備わり、先端にノズル
２３が備わっている。Explaining the molding machine B, a ram 19 which is reciprocally driven by a hydraulic cylinder 18 is slidably accommodated in a heating cylinder 21 heated by a heater 20, and a hopper 22 is provided at an upper rear portion of the heating cylinder 21. It is equipped with a nozzle 23 at the tip.

【００１２】次に、上述の金型Ａ、射出成形機Ｂ、型締
め機構Ｃを用いて行う射出成形方法について、図１、図
２を参照しながら説明する。なお、図１は金型Ａの構成
と動きを模式化して示している。Next, an injection molding method using the mold A, the injection molding machine B, and the mold clamping mechanism C will be described with reference to FIGS. 1 and 2. Note that FIG. 1 schematically shows the structure and movement of the mold A.

【００１３】この射出成形方法では、まず、図１（ａ）
のように、低圧の第１の型締め力（小）で型締めを行っ
た後、キャビティ１６内に溶融樹脂４１を射出する（射
出工程）。このとき、キャビティ１６内に溶融樹脂４１
が行き渡るのに伴い、溶融樹脂の表面には、冷却固化し
たスキン硬化層４２ができる。また、型内樹脂圧は徐々
に上昇して行く。In this injection molding method, first, as shown in FIG.
As described above, after the mold is clamped with the first mold clamping force (small) of low pressure, the molten resin 41 is injected into the cavity 16 (injection step). At this time, the molten resin 41 is filled in the cavity 16.
As a result, the skin-hardened layer 42 solidified by cooling is formed on the surface of the molten resin. Further, the resin pressure in the mold gradually rises.

【００１４】そして、型内が溶融樹脂４１で満たされる
直前に射出圧力をゼロにし（圧抜工程）、その状態を短
時間維持する。これにより、低圧で型締めしてあるもの
の、金型の分割面１ａ、２ａが開かない状態で、溶融樹
脂４１がキャビティ１６内に充填される。Immediately before the inside of the mold is filled with the molten resin 41, the injection pressure is set to zero (depressurizing step) and the state is maintained for a short time. As a result, the molten resin 41 is filled in the cavity 16 in a state where the mold is clamped at a low pressure but the split surfaces 1a, 2a of the mold are not opened.

【００１５】その後、ラム圧上昇により型内樹脂圧を高
めて行き、射出時の最大型内樹脂圧よりも大きく、且つ
第１の型締め力を越える型内樹脂圧となるよう保圧をか
けて行き（保圧工程）、それにより溶融樹脂４１の表面
に形成されたスキン硬化層４２を押し広げて、スキン硬
化層４２と型の内面との間に生じている隙間を埋め、肉
ひけを除去する。また、保圧の上昇により、図１（ｂ）
に示すように、低い型締め力で型締めした金型の分割面
１ａ、２ａを積極的に開かせる。このとき、溶融樹脂４
１の表面にはスキン硬化層が存在するので、樹脂が分割
面１ａ、２ａの隙間にはみ出すことはない。After that, the resin pressure in the mold is increased by increasing the ram pressure, and a holding pressure is applied so that the resin pressure in the mold is larger than the maximum resin pressure in the mold at the time of injection and exceeds the first mold clamping force. (The pressure-holding step), by which the skin-cured layer 42 formed on the surface of the molten resin 41 is spread out to fill the gap between the skin-cured layer 42 and the inner surface of the mold to reduce the shrinkage. Remove. In addition, as the holding pressure increases,
As shown in (1), the split surfaces 1a, 2a of the mold clamped with a low mold clamping force are positively opened. At this time, the molten resin 4
Since the skin hardened layer exists on the surface of No. 1, the resin does not overflow into the gap between the divided surfaces 1a and 2a.

【００１６】所定時間の保圧を行って、分割面１ａ、２
ａの開き量が最大値（例えば０．１５ｍｍ）に達したと
ころで、次に図１（ｃ）に示すように、ゲート１７をカ
ットする（閉じる）。そして、ゲートカット後、図１
（ｄ）に示すように、保圧工程で生じた分割面１ａ、２
ａの開き量を減少させるべく、第１の型締め力よりも高
圧の第２の型締め力で型締めを行う（圧縮工程）。これ
により、内部の樹脂が高圧縮された状態で成形されるこ
とになる。The pressure is maintained for a predetermined time to divide the divided surfaces 1a, 2
When the opening amount of a reaches the maximum value (for example, 0.15 mm), the gate 17 is cut (closed) as shown in FIG. And after the gate cut,
As shown in (d), the divided surfaces 1a, 2 generated in the pressure holding step.
In order to reduce the opening amount of a, mold clamping is performed with a second mold clamping force that is higher than the first mold clamping force (compression step). As a result, the resin inside is molded in a highly compressed state.

【００１７】従って、保圧工程までで終わっていた従来
の射出成形方法と比べて、肉ひけ、転写性、樹脂歪み等
の改善が図れる。また、保圧時に積極的に金型が開くよ
うにし、その後、型締め力の増大によって樹脂に圧縮力
を作用させるようにしているので、樹脂流れ等を伴わ
ず、キャビティ内の樹脂の均一化が図れる。また、圧縮
工程の際に金型を摺動させるわけではないから、摺動部
の摩耗によるバリの発生の可能性もない。Therefore, as compared with the conventional injection molding method which has been completed up to the pressure holding step, shrinkage, transferability, resin distortion and the like can be improved. In addition, the mold is positively opened at the time of pressure holding, and then the compression force is applied to the resin by increasing the mold clamping force, so that the resin in the cavity is made uniform without the resin flowing. Can be achieved. Further, since the mold is not slid during the compression process, there is no possibility of burrs due to wear of the sliding portion.

【００１８】なお、型締め力は、第１の型締め力が第２
の型締め力の約１／２程度であるのが望ましい。また、
第２の型締め力で型締めを行った際、型開き量を必ずし
もゼロにしなくてもよい。Regarding the mold clamping force, the first mold clamping force is the second.
It is desirable that the mold clamping force is about 1/2. Also,
When performing mold clamping with the second mold clamping force, the mold opening amount does not necessarily have to be zero.

【００１９】[0019]

【発明の効果】以上説明したように、本発明によれば、
保圧工程の後に圧縮工程を付加し、高密度成形を可能に
したので、肉ひけや転写性、樹脂歪み等の成形性の改善
が図れる。また、圧縮工程では、型締め力を増大させる
ことにより、型開き量を減少させて、樹脂に圧縮力を作
用させるので、樹脂流れ等を伴わず、キャビティ内の樹
脂分布の均一化が図れる。また、圧縮工程で摺動させる
部分がないので、摩耗によるバリの発生もない。その結
果、製品の寸法精度を大幅に向上させることができる。As described above, according to the present invention,
Since the compression process is added after the pressure-holding process to enable high-density molding, it is possible to improve moldability such as sink marks, transferability, and resin distortion. Further, in the compression step, by increasing the mold clamping force, the mold opening amount is reduced and the compression force is applied to the resin, so that the resin distribution in the cavity can be made uniform without the resin flow. Further, since there is no sliding portion in the compression process, burrs due to abrasion do not occur. As a result, the dimensional accuracy of the product can be significantly improved.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本発明の射出成形方法の工程説明図である。FIG. 1 is a process explanatory view of an injection molding method of the present invention.

【図２】本発明の射出成形方法におけるラム圧、型内樹
脂圧、型開き量の時間変化を示す線図である。FIG. 2 is a diagram showing changes over time in a ram pressure, a resin pressure inside a mold, and a mold opening amount in the injection molding method of the present invention.

【図３】本発明の射出成形方法の実施に用いる金型およ
び射出成形機の一例を示す断面図である。FIG. 3 is a cross-sectional view showing an example of a mold and an injection molding machine used for carrying out the injection molding method of the present invention.

【図４】従来の射出成形方法における型内樹脂圧の変化
を示す線図である。FIG. 4 is a diagram showing a change in in-mold resin pressure in a conventional injection molding method.

【図５】従来の射出圧縮成形方法の説明図である。FIG. 5 is an explanatory diagram of a conventional injection compression molding method.

【符号の説明】[Explanation of symbols]

Ｃ 型締め機構 １ 可動型 ２ 固定型 １ａ，２ａ 分割面 １６ キャビティ １７ ゲート ４１ 溶融樹脂 ４２ スキン硬化層 C Mold clamping mechanism 1 Movable mold 2 Fixed mold 1a, 2a Dividing surface 16 Cavity 17 Gate 41 Molten resin 42 Skin hardening layer

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】 低圧の第１の型締め力で型締めを行った
後、キャビティ内へ溶融樹脂を射出して、スキン硬化層
を形成させつつ溶融樹脂の充填を行う射出工程と、 キャビティ内が溶融樹脂で満たされる直前に射出圧力を
下げる圧抜工程と、 圧抜工程後に、型内樹脂圧を徐々に増加させて射出時の
最大型内樹脂圧よりも大きく、且つ前記第１の型締め力
を越える型内樹脂圧で保圧を行うことにより、金型の分
割面を開く保圧工程と、 保圧工程後にゲートカットし、ゲートカット後、保圧工
程で生じた分割面の開き量を減少させるべく、前記第１
の型締め力よりも高圧の第２の型締め力で型締めを行う
圧縮工程とを備えたことを特徴する射出成形方法。1. An injection step of injecting a molten resin into a cavity after performing mold clamping with a low-pressure first mold clamping force to fill the molten resin while forming a skin-hardened layer, and an inside cavity Of the first mold with a depressurizing step of lowering the injection pressure immediately before being filled with molten resin, and gradually increasing the resin pressure in the mold after the depressurizing step to be larger than the maximum resin pressure in the mold at the time of injection. By holding pressure with resin pressure inside the mold that exceeds the clamping force, a pressure-holding process that opens the dividing surface of the mold, gate cutting after the pressure-holding step, and opening of the dividing surface that occurred in the pressure-holding step after gate cutting In order to reduce the amount, the first
And a compression step of performing mold clamping with a second mold clamping force that is higher in pressure than the mold clamping force. 【請求項２】 第１の型締め力は第２の型締め力の略１
／２とすることを特徴とする請求項１記載の射出成形方
法。2. The first mold clamping force is approximately 1 of the second mold clamping force.
The injection molding method according to claim 1, wherein the injection rate is set to / 2.
JP33377595A 1995-12-21 1995-12-21 Injection molding method Expired - Fee Related JP3237496B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP33377595A JP3237496B2 (en) 1995-12-21 1995-12-21 Injection molding method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP33377595A JP3237496B2 (en) 1995-12-21 1995-12-21 Injection molding method

Publications (2)

Publication Number Publication Date
JPH09174631A true JPH09174631A (en) 1997-07-08
JP3237496B2 JP3237496B2 (en) 2001-12-10

Family

ID=18269824

Family Applications (1)

Application Number Title Priority Date Filing Date
JP33377595A Expired - Fee Related JP3237496B2 (en) 1995-12-21 1995-12-21 Injection molding method

Country Status (1)

Country Link
JP (1) JP3237496B2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2289686A1 (en) 2001-08-27 2011-03-02 KraussMaffei Technologies GmbH Method and device for producing planar plastic moulded parts, in particular plastic panes
CN109278260A (en) * 2017-07-20 2019-01-29 恩格尔奥地利有限公司 Method for being manufactured part

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2289686A1 (en) 2001-08-27 2011-03-02 KraussMaffei Technologies GmbH Method and device for producing planar plastic moulded parts, in particular plastic panes
CN109278260A (en) * 2017-07-20 2019-01-29 恩格尔奥地利有限公司 Method for being manufactured part
CN109278260B (en) * 2017-07-20 2021-08-10 恩格尔奥地利有限公司 Method for producing a molded part, molding tool and molding machine
US11312052B2 (en) 2017-07-20 2022-04-26 Engel Austria Gmbh Process for producing a molded part

Also Published As

Publication number Publication date
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