JPS583815B2 - Hatsupou Kouzou Tainoseikeihou - Google Patents
Hatsupou Kouzou TainoseikeihouInfo
- Publication number
- JPS583815B2 JPS583815B2 JP50089153A JP8915375A JPS583815B2 JP S583815 B2 JPS583815 B2 JP S583815B2 JP 50089153 A JP50089153 A JP 50089153A JP 8915375 A JP8915375 A JP 8915375A JP S583815 B2 JPS583815 B2 JP S583815B2
- Authority
- JP
- Japan
- Prior art keywords
- resin
- mold cavity
- foaming
- molding
- injected
- 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
Links
- 229920005989 resin Polymers 0.000 claims description 124
- 239000011347 resin Substances 0.000 claims description 124
- 238000000034 method Methods 0.000 claims description 39
- 239000004604 Blowing Agent Substances 0.000 claims description 26
- 238000000465 moulding Methods 0.000 claims description 25
- 238000005187 foaming Methods 0.000 claims description 23
- 239000004088 foaming agent Substances 0.000 claims description 20
- 238000002347 injection Methods 0.000 claims description 20
- 239000007924 injection Substances 0.000 claims description 20
- 229920005992 thermoplastic resin Polymers 0.000 claims description 5
- 239000007789 gas Substances 0.000 description 23
- 239000006260 foam Substances 0.000 description 17
- 239000002344 surface layer Substances 0.000 description 16
- 238000010097 foam moulding Methods 0.000 description 7
- 239000004793 Polystyrene Substances 0.000 description 5
- 229920002223 polystyrene Polymers 0.000 description 5
- 239000000203 mixture Substances 0.000 description 4
- 239000002666 chemical blowing agent Substances 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- 230000002265 prevention Effects 0.000 description 3
- USVVENVKYJZFMW-ONEGZZNKSA-N (e)-carboxyiminocarbamic acid Chemical compound OC(=O)\N=N\C(O)=O USVVENVKYJZFMW-ONEGZZNKSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- OFBQJSOFQDEBGM-UHFFFAOYSA-N Pentane Chemical compound CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 238000009472 formulation Methods 0.000 description 2
- 238000001746 injection moulding Methods 0.000 description 2
- -1 polyethylene Polymers 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000000454 talc Substances 0.000 description 2
- 229910052623 talc Inorganic materials 0.000 description 2
- 239000004952 Polyamide Substances 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 229920000122 acrylonitrile butadiene styrene Polymers 0.000 description 1
- 239000003570 air Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 1
- 229920002285 poly(styrene-co-acrylonitrile) Polymers 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 239000004926 polymethyl methacrylate Substances 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
Landscapes
- Injection Moulding Of Plastics Or The Like (AREA)
Description
【発明の詳細な説明】
この発明は、平滑な表面を有する発泡構造体の成形方法
に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of molding a foamed structure having a smooth surface.
さらに詳しくは発泡剤を含有する熱可塑性樹脂を加熱可
塑化した後、型キャビテイに注入して平滑な表面を有す
る発泡構造型物を成形する方法に関する。More specifically, the present invention relates to a method of molding a foamed structural molded article having a smooth surface by heating and plasticizing a thermoplastic resin containing a foaming agent and then injecting it into a mold cavity.
従来から各種の発泡射出成形方法が知られている。Various foam injection molding methods have been known in the past.
最も一般的に行なわれている方法は、いわゆるショート
ショット法である。The most commonly used method is the so-called short shot method.
この方法は、型キャビテイ内にその容積に満たない量の
未発泡の発泡性樹脂を注入し、ついで樹脂自体の発泡力
で型キャビテイを充満させるものである。This method involves injecting an amount of unfoamed foamable resin into a mold cavity that is less than the volume of the mold cavity, and then filling the mold cavity with the foaming power of the resin itself.
このショートショット法は最も容易に行うことができる
が、この方法の最犬の欠点は成形品表面に発泡ガスの走
った跡、いわゆるスワールマークが生じ、成形品の価値
を低下させていることである。This short shot method is the easiest to perform, but the biggest drawback of this method is that traces of foaming gas, so-called swirl marks, occur on the surface of the molded product, reducing the value of the molded product. be.
このショートショット法の欠点を改良するため多くの成
形方法が考案されているが、それぞれまだ問題が残され
ている。Although many molding methods have been devised to improve the drawbacks of the short shot method, problems still remain with each method.
発泡成形品の外観を平滑にする発泡成形法にいわゆるフ
ルショット法がある。A so-called full shot method is a foam molding method for smoothing the appearance of foam molded products.
この方法は、未発泡の発泡性樹脂を型キャビテイに満し
た後、型キャビテイを拡大させるかまたはこの発泡性樹
脂の一部を型キャビテイ外に放出させて発泡させる方法
である。In this method, a mold cavity is filled with unfoamed foamable resin, and then the mold cavity is expanded or a portion of the foamable resin is discharged outside the mold cavity to cause foaming.
しかし、フルショット法は成形装置、特に金型が複雑に
なり、高価になる欠点がある。However, the full shot method has the disadvantage that the molding equipment, especially the mold, becomes complicated and expensive.
ショートショット法の改良の一つに、サンドイツチ成形
によるショートショット法がある。One of the improvements to the short shot method is the short shot method using sandwich molding.
この方法は、型キャビテイにまず発泡剤を含有しない樹
脂を注入し、ついで発泡剤を含有する樹脂を注入して発
泡成形を行ない、発泡成形品の表層を発泡剤を含有しな
い樹脂で覆う方法である。In this method, a resin that does not contain a blowing agent is first injected into the mold cavity, then a resin that contains a blowing agent is injected to perform foam molding, and the surface layer of the foam molded product is covered with a resin that does not contain a blowing agent. be.
しかし、この方法も均一な発泡体ができないとか発泡倍
率があがりにくいなどの欠点を有する。However, this method also has drawbacks such as not being able to produce a uniform foam and difficulty in increasing the foaming ratio.
この発明は、サンドイツチ成形によるショートショット
法をさらに改良したものである。This invention is a further improvement of the short shot method using sanderch molding.
すなわち、この発明は、平滑な表面、均一な発泡構造、
発泡倍率の増大などを目的とするものでありこの発明の
要旨は、加熱可塑化した熱可塑性樹脂を型キャビテイに
注入して発泡構造体を成形する成形法において、型キャ
ビテイをガス体により加圧状態に保持し、好ましくは発
泡性樹脂の発泡を防止するに充分な加圧状態に保持し、
この型キャビテイに発泡剤を含有する第１の樹脂、発泡
剤を含有しない第２の樹脂および発泡剤を含有する第３
の樹脂を、第１の樹脂、第２の樹脂および第３の樹脂の
合計が型キャビテイを満すに不充分な量となるように９
順次注入し、ついであるいは注入しつつ型キャビテイの
ガス体を放出して発泡剤を含有する樹脂番発泡させるこ
とを特徴とする発泡構造体の成形法である。That is, this invention has a smooth surface, a uniform foam structure,
The purpose of this invention is to increase the expansion ratio, etc., and the gist of this invention is to pressurize the mold cavity with a gas in a molding method in which a thermoplastic resin that has been thermoplasticized is injected into a mold cavity to mold a foamed structure. and preferably under sufficient pressure to prevent foaming of the foamable resin;
A first resin containing a blowing agent, a second resin not containing a blowing agent, and a third resin containing a blowing agent are placed in this mold cavity.
of resin such that the total of the first resin, second resin, and third resin is insufficient to fill the mold cavity.
This method of molding a foamed structure is characterized by sequentially injecting the resin and then or while injecting it, releasing a gas in a mold cavity to foam a resin containing a foaming agent.
この発明の方法を従来の発泡成形法と比較しながら図面
により説明する。The method of the present invention will be explained with reference to the drawings while comparing it with a conventional foam molding method.
第１〜９図は、型キャビテイへの樹脂の入り方を示した
ものであり、第１０図および第１１図は、この発明を実
施するだめの成形装置を例示するものである。1 to 9 show how the resin enters the mold cavity, and FIGS. 10 and 11 illustrate a final molding apparatus for carrying out the present invention.
第１〜３図は、ゲート２が型キャビテイ１の端部にある
場合を示している。1 to 3 show the case where the gate 2 is located at the end of the mold cavity 1.
第１図のイおよびロは、通常のショートショット法によ
る発泡成形を示したものであり、第２図のイ，ロおよび
ハが通常のサンドイツチ発泡成形によるもの、第３図の
イ，ロ，ハおよびニは、この発明の方法を示したもので
ある。A and B in Fig. 1 show foam molding using the normal short shot method, A, B and C in Fig. 2 show those using normal sandwich foam molding, and A, B and B in Fig. C and D illustrate the method of this invention.
通常のショートショット法では、第１図のイおよびロに
示すように、型キャビテイ１に発泡性樹脂３を注入し、
この樹脂の発泡力で型キャビテイを満し、発泡倍率の高
い内核５と発泡倍率の低い表層４，６よりなる発泡型物
が成形される。In the normal short shot method, as shown in Figure 1 A and B, foamable resin 3 is injected into the mold cavity 1,
The foaming power of this resin fills the mold cavity, and a foam molded article consisting of an inner core 5 with a high expansion ratio and surface layers 4 and 6 with a low expansion ratio is molded.
この発泡成型物の表層４，６には、発泡ガスの走ったス
ワールマークが生ずる。Swirl marks caused by the foaming gas are formed on the surface layers 4 and 6 of the foamed molded product.
発泡性樹脂３の注入に先立ち、型キャビテイを発泡性樹
脂の発泡を防正するに充分なガス圧をかけた後、発泡性
樹脂を注入し、ついで型キャビテイのガス体を放出して
発泡性樹脂を発泡させると、ガス体を放出した後に型キ
ャビテイを発泡力で満した部分の表層６にスワールマー
クが発生する。Prior to injecting the foamable resin 3, sufficient gas pressure is applied to the mold cavity to prevent foaming of the foamable resin, the foamable resin is injected, and then the gas in the mold cavity is released to prevent foaming. When the resin is foamed, swirl marks are generated on the surface layer 6 at the portion where the mold cavity is filled with foaming force after the gas is released.
通常のサンドイツチ成形によるショートショット法を第
２図のイ，ロおよびハに示す。A, B, and C in Fig. 2 show the short shot method using conventional sanderch molding.
まず発泡剤を含有しない樹脂７を型キャビテイに注入し
、ついで発泡剤を含有する樹脂８を注入し、発泡剤を含
有する樹脂８の発泡力で型キャビテイを充満させ、表層
が発泡剤を含有しない樹脂７、内核が発泡剤を含有する
樹脂８を発泡させた発泡体９より成る発泡成形品を得る
。First, resin 7 that does not contain a blowing agent is injected into the mold cavity, then resin 8 that contains a blowing agent is injected, and the mold cavity is filled with the foaming power of the resin 8 that contains a blowing agent, so that the surface layer contains the blowing agent. A foamed molded article is obtained, which is made of a foamed body 9 made by foaming a resin 7 containing a foaming agent and a resin 8 whose inner core contains a foaming agent.
しかし、第２図のハに示すように、発泡構造が不均一と
なり、また発泡倍率も低いものしか得られない。However, as shown in FIG. 2C, the foamed structure becomes non-uniform and only a low foaming ratio can be obtained.
この発明は、上記第２図のハに示すような不均一な発泡
構造を均一化するものであり、かつ発泡倍率も増大させ
るものである。This invention is intended to make the non-uniform foamed structure as shown in FIG. 2C above uniform, and also to increase the foaming ratio.
この発明による型キャビテイへの樹脂の入り方を第３図
のイ，ロ，ハおよびニに示す。How the resin enters the mold cavity according to the present invention is shown in FIG. 3, A, B, C, and D.
まず型キャビテイを発泡性樹脂の発泡を防止するガス圧
に保持し、発泡剤を含有する第１の樹脂１０を型キャビ
テイに注入し、ついで発泡剤を含有しない第２の樹脂１
１を注入し、ついで再び発泡剤を含有する第３の樹脂１
２を注入する。First, the mold cavity is held at a gas pressure that prevents foaming of the foamable resin, and a first resin 10 containing a foaming agent is injected into the mold cavity, and then a second resin 1 containing no foaming agent is injected into the mold cavity.
1 and then again a third resin 1 containing a blowing agent.
Inject 2.
この際第１の樹脂、第２の樹脂および第３の樹脂の合計
は型キャビテイを満すに不充分な量である。At this time, the total amount of the first resin, second resin, and third resin is insufficient to fill the mold cavity.
これらの樹脂を注入した後、型キャビテイのガス体を放
出して、発泡剤を含有する樹脂１０，１２を発泡させる
ことにより、表層が樹脂１０，１１より成り、内核が発
泡体１３よりなる成形品表面にスワールマークのない、
均一な発泡構造体が得られる。After injecting these resins, the gas in the mold cavity is released and the resins 10 and 12 containing the foaming agent are foamed, resulting in molding in which the surface layer is made of the resins 10 and 11 and the inner core is made of the foam 13. No swirl marks on the product surface.
A uniform foamed structure is obtained.
第４〜５図は、ゲートの近くに厚肉部分がある下駄の様
な型物を成形する場合を示す。Figures 4 and 5 show the case of molding a clog-like molded article having a thick portion near the gate.
第４図のイおよびロが通常のサンドイツチ成形によるシ
ョートショット法であり、第５図のイ，ロおよびハがこ
の発明の方法である。4A and 4B are the conventional short shot method using sandwich molding, and FIG. 5A, 5B and 5B are the methods of the present invention.
通常のサンドイツチ成形によるショートショット法では
、まず発泡剤を含有しない樹脂１４を型キャビテイに注
入し、ついて発泡剤を含有する樹脂１５を注入し、発泡
剤を含有する樹脂１５０発泡力で型キャビテイを充満さ
せ、表層が発泡剤を含有しない樹脂１４、内核が発泡剤
を含有する樹脂１５を発泡させた発泡体１６よりなる発
泡成形品を得る。In the short shot method using normal sandwich molding, resin 14 that does not contain a blowing agent is first injected into the mold cavity, then resin 15 that contains a blowing agent is injected, and the mold cavity is closed with the foaming power of the resin 150 that contains a blowing agent. A foamed molded article is obtained by filling the resin 14 with a foamed body 16 in which the surface layer is foamed with a resin 14 that does not contain a foaming agent and the inner core is foamed with a resin 15 that contains a foaming agent.
しかし、第４図のロに示すように、ゲート近くの厚肉部
分では発泡が起らず、不均一な発泡成形品となる。However, as shown in FIG. 4B, foaming does not occur in the thick portion near the gate, resulting in a non-uniform foamed molded product.
一方、この発明の方法は、まず型キャビテイをガス体で
加圧状態に保持し、発泡剤を含有する第１の樹脂１７を
型キャビテイに注入し、ついで発泡剤を含・有しない第
２の樹脂１８を注入し、ついで再び発泡剤を含有する第
３の樹脂１９を注入する。On the other hand, in the method of the present invention, the mold cavity is first kept in a pressurized state with a gas, a first resin 17 containing a foaming agent is injected into the mold cavity, and then a second resin 17 containing or not containing a foaming agent is injected into the mold cavity. A resin 18 is injected, and then a third resin 19 containing a blowing agent is injected again.
この際第１の樹脂、第２の樹脂および第３の樹脂の合計
は型キャビテイを満すに不充分な量である。At this time, the total amount of the first resin, second resin, and third resin is insufficient to fill the mold cavity.
そしてこの樹脂の注入後、型キャビテイのガス体を放出
して、発泡剤を含有する樹脂１７，１９を発泡させるこ
とにより、表層が樹脂１７，１８より成り、内核が発泡
体２０上りなる成形品表面にスワールマークのない均一
な発泡構造体が得られる。After injecting this resin, the gas in the mold cavity is released to foam the resins 17 and 19 containing the foaming agent, resulting in a molded product whose surface layer is made of the resins 17 and 18 and whose inner core is made of foam 20. A uniform foamed structure without swirl marks on the surface is obtained.
第６〜７図は非常に厚肉な成形品を成形する場合を示す
。Figures 6 and 7 show the case of molding a very thick molded product.
第６図が通常のサンドイツチ成形によるショートショッ
ト法であり、第７図のイおよびロがこの発明の方法であ
る。FIG. 6 shows the short shot method using normal sanderch molding, and A and B in FIG. 7 show the method of the present invention.
前記したと同様のサンドイツチ成形のショートショット
法で厚肉成形品を成形すると、第６図に示すように、厚
い表層、２１と発泡体の薄い内核２２が得られ、成形品
全体の発泡倍率を上げることは困難である。When a thick-walled molded product is molded using the short-shot method of sandwich molding similar to that described above, a thick surface layer 21 and a thin inner core 22 of foam are obtained, and the foaming ratio of the entire molded product is increased. It is difficult to raise it.
これに対し、この発明の方法では、第７図のロに示すよ
うに、薄い表層２３，２４と発泡体の厚い内核２６より
なり、成形品表面にはスワールマークのない発泡倍率の
高い成形品が得られる。On the other hand, in the method of the present invention, as shown in FIG. is obtained.
この第７図の場合は、前記と同様、第１の樹脂２３、第
２の樹脂２４および第３の樹脂２５の順に型キャビテイ
に注入し、発泡成形を行ない、第７図のロに示す発泡構
造体を得るものである。In the case of FIG. 7, the first resin 23, second resin 24, and third resin 25 are injected into the mold cavity in this order in the same manner as described above, and foam molding is performed. This is what gets the structure.
第８〜９図は厚肉スピーカーボックスを成形したもので
、第８図が通常のサンドイツチ成形、第９図がこの発明
の方法により成形したものである３この発明の方法を実
施する成形装置には、種々の装置がある。Figures 8 and 9 show thick-walled speaker boxes that have been molded, with Figure 8 showing normal sandwich molding, and Figure 9 showing molding using the method of the present invention. There are various devices.
代表例を第１０図および第１１図に示す。Representative examples are shown in FIGS. 10 and 11.
第１０図において、第１の樹脂および第３の樹脂は、加
熱可塑化され射出シリンダー２７とスクリュー２８によ
って、逆流防止弁３１、ノズル３３を経て、型３４，３
５でつくられた型キャビテイ３６へ射出される。In FIG. 10, the first resin and the third resin are heated and plasticized, and are passed through the injection cylinder 27 and screw 28 to the molds 34 and 3 through the check valve 31 and the nozzle 33.
It is injected into the mold cavity 36 made in step 5.
第２の樹脂は、射出シリンダー２９とスクリュー３０に
よって加熱可塑化され蓄積され、逆流防止弁３２を経て
、ノズル３３から型キャビテイ３６に射出される。The second resin is heated and plasticized and accumulated by the injection cylinder 29 and screw 30, passes through the check valve 32, and is injected from the nozzle 33 into the mold cavity 36.
型キャビテイにはあらかじめ細孔３７、加圧ガス注入排
出用導管３８より加圧ガスが注入されており、加圧状態
に保たれている。Pressurized gas is injected into the mold cavity in advance through the pores 37 and the pressurized gas injection/discharge conduit 38, and is maintained in a pressurized state.
第１、第２および第３の樹脂が順に型キャビテイに注入
された後、型キャビテイの加圧ガスは細孔３７、導管３
８より放出され発泡成形が行なわれる。After the first, second and third resins are sequentially injected into the mold cavity, the pressurized gas in the mold cavity flows through the pores 37 and into the conduit 3.
8 and foam molding is performed.
この装置では、第１の樹脂と第３の樹脂とは全く同一の
樹脂となる６第１１図は１つの射出シリンダーで３種の
樹脂を射出する装置を示したものである。In this device, the first resin and the third resin are exactly the same resin.6 Figure 11 shows a device that injects three types of resins with one injection cylinder.
第１１図において、射出シリンダー３９には、射出ピス
トン４０、射出シリンダーを前室と後室に分離する可動
マンドレル４７のほか、蓄積する押出機４１，４３，４
５を有している。In FIG. 11, the injection cylinder 39 includes an injection piston 40, a movable mandrel 47 that separates the injection cylinder into a front chamber and a rear chamber, and extruders 41, 43, and 4 that accumulate.
5.
まず第２の樹脂は、押出機４１でスクリュー４２の回転
により加熱可塑化され、逆流防止弁４８を経て、射出シ
リンダー３９の前室に注入される。First, the second resin is heated and plasticized by the rotation of the screw 42 in the extruder 41, and is injected into the front chamber of the injection cylinder 39 through the check valve 48.
ついで、第１の樹脂を押出機４３でスクリュー４４の回
転により加熱可塑化し、逆流防止弁４９を経て、射出シ
リンダー３９の先端部に注入する。Next, the first resin is heated and plasticized by the rotation of the screw 44 in the extruder 43, and is injected into the tip of the injection cylinder 39 through the check valve 49.
また、第３の樹脂は、第１の樹脂または第２の樹脂と同
時に、押出機４５、スクリュー４６により、逆流防止弁
５０を経て、射出シリンダー３９の後室に注入される。Further, the third resin is injected into the rear chamber of the injection cylinder 39 through the non-return valve 50 by the extruder 45 and the screw 46 at the same time as the first resin or the second resin.
このようにして射出シリンダー３９中に蓄積された第１
の樹脂５２、第２の樹脂５３および第３の樹脂５４は、
射出ピストン４０の前進によって、順にノズル５１を経
て、型キャビテイ３６に注入されることになる。The first accumulated in the injection cylinder 39 in this way
The resin 52, the second resin 53, and the third resin 54 are
The advancement of the injection piston 40 causes injection into the mold cavity 36 through the nozzle 51 in turn.
この発明においてガス体とは、常温・大気圧で気体のも
のをいい、たとえば空気、窒素、炭酸ガスなどがある。In this invention, a gas body refers to a gas at room temperature and atmospheric pressure, such as air, nitrogen, carbon dioxide, and the like.
この発明において熱可塑性樹脂とノしては、一般に射出
成形に使用し得る熱可塑性樹脂が全て使用できる。As the thermoplastic resin in this invention, all thermoplastic resins that can generally be used for injection molding can be used.
たとえば、ポリエチレン、ポリプロピレンなどのポリオ
レフイン、ポリスチレン、スチレンーアクリロニトリル
共重合体、ＡＢＳ樹脂などのスチレン系樹脂、ポリ塩化
ビニｉル、ポリアミド、ポリメチルメタクリレートなど
である。Examples include polyolefins such as polyethylene and polypropylene, polystyrene, styrene-based resins such as styrene-acrylonitrile copolymers, and ABS resins, polyvinyl chloride, polyamide, and polymethyl methacrylate.
−この発明で使用される発泡剤としては、一般に使用さ
れる公知の物理発泡剤、化学発泡剤が全て使用できるが
、発泡剤を含有する第１の樹脂に使用される発泡剤とし
ては、常圧における沸２点が４℃〜６０℃の範囲の加熱
気化性物質と有機化学発泡剤との混合物が好適である。- As the blowing agent used in this invention, all commonly used physical blowing agents and chemical blowing agents can be used, but as the blowing agent used in the first resin containing a blowing agent, A mixture of an organic chemical blowing agent and a heat-vaporizable substance having a boiling point in the range of 4° C. to 60° C. at pressure is suitable.
このような発泡剤の例としては樹脂１００重量部、常温
における沸点が４℃〜６０℃の範囲の加熱気化性物質０
．５〜１０重量部および有機化学発泡剤０．０３〜１０
．６重量部より基本的に成るものがある。An example of such a blowing agent is 100 parts by weight of a resin, 0 parts by weight of a vaporizable substance with a boiling point in the range of 4°C to 60°C at room temperature.
．． 5 to 10 parts by weight and 0.03 to 10 parts by weight of an organic chemical blowing agent
．． Some basically consist of more than 6 parts by weight.
この発明においては、発泡性樹脂の注入に先立ち、型キ
ャビテイはガス体により発泡性樹脂の発泡を防止するに
充分な加圧状態に保持することが好ましい。In the present invention, it is preferable that the mold cavity is maintained under sufficient pressure to prevent foaming of the foamable resin by means of a gas prior to injection of the foamable resin.
しかし、若干の発泡が起っても発泡ガスが樹脂層を喰い
破って逃げなければ、成形品表面にスワールマークは発
生しないので、このようなガス体による加圧状態に保つ
ことは必要である。However, even if some foaming occurs, if the foaming gas does not eat away at the resin layer and escape, swirl marks will not occur on the surface of the molded product, so it is necessary to maintain this pressurized state with gas. .
また、型キャビテイのガス体の放出は、第１，第２，第
３の樹脂の注入後放出することが好まし；いが、場合に
よっては樹脂を注入しつつ放出することができる。Furthermore, it is preferable to release the gas from the mold cavity after the first, second, and third resins are injected; however, in some cases, the gas may be released while the resins are being injected.
例えば、第３の樹脂の半分を注入したところでガス体の
放出を開始することは良好に行なわれる。For example, it may work well to start releasing the gas when half of the third resin has been injected.
また発泡剤を含有する第１の樹脂と第３の樹脂とは同一
でもよく、異っていてもよνい。Further, the first resin and the third resin containing a foaming agent may be the same or different.
そして、第１の樹脂にくらべ第３の樹脂に多量の発泡剤
が含まれるようにするのがより好ましい。It is more preferable that the third resin contains a larger amount of blowing agent than the first resin.
実施例 １
第１０図に示す成形装置を用い、第３図ニに示す表面平
滑でスワールマークのない発泡構造体を成形した。Example 1 Using the molding apparatus shown in FIG. 10, a foamed structure with a smooth surface and no swirl marks as shown in FIG. 3D was molded.
発泡剤を含有する第１の樹脂および第３の樹脂として、
ポリスチレン１００重量部、ｎ一ペンタン２重量部、ア
ゾジカルボン酸アミド０．２重量部、タルク１重量部か
らなる配合物を使用し、第２の樹脂としてポリスチレン
を使用した第１、第２、第３の樹脂を１５０℃に加熱し
た後あらかじめ空気で９ｋｇ／ｃｍに加圧した型キャビ
テイへ、第３図イ，ロ，ハ，ニの順に成形し、スワール
マークのない表層を有し、均一に発泡した内核を有する
発泡構造体を得だ。As a first resin and a third resin containing a blowing agent,
The first, second, and second resins were prepared using a blend consisting of 100 parts by weight of polystyrene, 2 parts by weight of n-pentane, 0.2 parts by weight of azodicarboxylic acid amide, and 1 part by weight of talc, and using polystyrene as the second resin. After heating the resin in Step 3 to 150°C, it was molded in the order of A, B, C, and D in Figure 3 into a mold cavity that had been pressurized with air to 9 kg/cm in advance to form a uniform surface layer with no swirl marks. A foamed structure with a foamed inner core is obtained.
実施例 ２
実施例１に示したと同様の樹脂処方、および成形法を用
い、第５図、ハに示した表面平滑でスワールマークのな
い発泡構造体を成形した。Example 2 Using the same resin formulation and molding method as shown in Example 1, a foamed structure with a smooth surface and no swirl marks as shown in FIG. 5, C, was molded.
実施例 ３
第１１図に示す成形装置を用い、第７図ロに示す表面平
滑でスワールマークのない厚肉の発泡構造体を成形した
。Example 3 Using the molding apparatus shown in FIG. 11, a thick foamed structure with a smooth surface and no swirl marks as shown in FIG. 7B was molded.
発泡剤を含有する第１の樹脂として実施例１に示した配
合物を用い、第２の樹脂としてポリスチレンを用い、発
泡剤を含有する第３の樹脂として、ポリスチレ７１００
重量部、アゾジカルボン酸アミド１．０重量部、タルク
１．０重量部の配合物を使用した。The formulation shown in Example 1 was used as the first resin containing a blowing agent, polystyrene was used as the second resin, and polystyrene 7100 was used as the third resin containing a blowing agent.
Parts by weight, 1.0 parts by weight of azodicarboxylic acid amide, and 1.0 parts by weight of talc were used.
第１、第２、第３の樹脂を１６０℃に加熱した後、あら
かじめ空気１０ｋｇ ／ｃｍ２に加圧した型キャビテイ
に、第７図イ，ロの順で成形し、スワールマークのない
平滑な表面をもち、薄い均一な表層と、均一に発泡した
内核を有する厚肉の発泡構造体を得た。After heating the first, second, and third resins to 160°C, they were molded in the order of A and B in Figure 7 into a mold cavity that had been pressurized to 10 kg/cm2 of air in advance, and a smooth surface with no swirl marks was obtained. A thick foamed structure having a thin uniform surface layer and a uniformly foamed inner core was obtained.
【図面の簡単な説明】
第１図〜第９図は、この発明の方法を説明するため、型
キャビテイへの樹脂の入り方を示す型キャビテイ内の樹
脂の断面図であり、第１０図、第１１図は、この発明の
方法を実施するための成形装置の断面図である。
１・・・型キャビテイ、２・・・ゲート、３・・・発泡
性樹脂、４・・・表層、５・・・内核、６・・・表層、
７・・・発泡剤を含有しない樹脂、８・・・発泡剤を含
有する樹脂、９・・・発泡体、１０・・・第１の樹脂、
１１・・・第２の樹脂、１２・・・第３の樹脂、１３・
・・発泡体、１４・・・発泡剤を含有しない樹脂、１５
・・・発泡剤を含有する樹脂、１６・・・発泡体、１７
・・・第１の樹脂、１８・・・第２の樹脂、１９・・・
第３の樹脂、２０・・・発泡体、２０・・・厚い表層、
２２・・・発泡体の薄い内核、２３・・・薄い表層、第
１の樹脂、２４・・・薄い表層、第２の樹脂、２５・・
・第３の樹脂、２６・・・発泡体の厚い内核、２７・・
・射出シリンダー、２８・・・スクリュー、２９・・・
射出シリンダー、３０・・・スクリュー、３１・・・逆
流防止弁、３２・・・逆流防止弁、３３・・・ノズル、
３４・・・型、３５・・・型、３６・・・型キャビテイ
、３７・・・細孔、３８・・・加圧ガス注入排出用導管
、３９・・・射出シリンダー、４０・・・射出ピストン
、４１・・・押出機、４２・・・スクリュー、４３・・
・押出機、４４・・・スクリュー、４５・・・押出機、
４６・・・スクリュー、４７・・・可動マンドレル、４
８・・・逆流防止弁、４９・・・逆流防止弁、５０・・
・逆流防止弁、５１・・・ノズル、５２・・・第１の樹
脂、５３・・・第２の樹脂、５４・・・第３の樹脂。[BRIEF DESCRIPTION OF THE DRAWINGS] FIGS. 1 to 9 are cross-sectional views of the resin in the mold cavity, showing how the resin enters the mold cavity, in order to explain the method of the present invention, and FIGS. FIG. 11 is a sectional view of a molding apparatus for carrying out the method of the present invention. DESCRIPTION OF SYMBOLS 1... Mold cavity, 2... Gate, 3... Foaming resin, 4... Surface layer, 5... Inner core, 6... Surface layer,
7... Resin not containing a foaming agent, 8... Resin containing a foaming agent, 9... Foam, 10... First resin,
11...Second resin, 12...Third resin, 13.
... Foam, 14... Resin containing no foaming agent, 15
... Resin containing a foaming agent, 16... Foam, 17
...first resin, 18...second resin, 19...
Third resin, 20... Foam, 20... Thick surface layer,
22... Thin inner core of foam, 23... Thin surface layer, first resin, 24... Thin surface layer, second resin, 25...
・Third resin, 26... Thick inner core of foam, 27...
・Injection cylinder, 28...Screw, 29...
Injection cylinder, 30... Screw, 31... Non-return valve, 32... Non-return valve, 33... Nozzle,
34... Mold, 35... Mold, 36... Mold cavity, 37... Pore, 38... Pressurized gas injection and discharge conduit, 39... Injection cylinder, 40... Injection Piston, 41... Extruder, 42... Screw, 43...
・Extruder, 44...screw, 45...extruder,
46...Screw, 47...Movable mandrel, 4
8... Backflow prevention valve, 49... Backflow prevention valve, 50...
- Backflow prevention valve, 51... nozzle, 52... first resin, 53... second resin, 54... third resin.
Claims (1)
して発泡構造体を成形する成形法において、型キャビテ
イをガス体により加圧状態に保持し、この型キャビテイ
に発泡剤を含有する第１の樹脂発泡剤を含有しない第２
の樹脂および発泡剤を含有する第３の樹脂を、第１の樹
脂、第２の樹脂および第３の樹脂の合計が型キャビテイ
を満すに不充分な量となるように、順次注入し、ついで
あるいは注入しつつ型キャビテイのガス体を放出して発
泡剤を含有する樹脂を発泡させることを特徴とする発泡
構造体の成形法。1 In a molding method in which a foamed structure is formed by injecting a thermoplasticized thermoplastic resin into a mold cavity, the mold cavity is held under pressure by a gas body, and a first foaming agent containing a foaming agent is injected into the mold cavity. The second layer does not contain a resin blowing agent.
sequentially injecting a third resin containing a resin and a blowing agent such that the sum of the first resin, second resin, and third resin is insufficient to fill the mold cavity; A method for molding a foamed structure, which comprises foaming a resin containing a foaming agent by ejecting a gas in a mold cavity either subsequently or during injection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP50089153A JPS583815B2 (en) | 1975-07-23 | 1975-07-23 | Hatsupou Kouzou Tainoseikeihou |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP50089153A JPS583815B2 (en) | 1975-07-23 | 1975-07-23 | Hatsupou Kouzou Tainoseikeihou |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5213561A JPS5213561A (en) | 1977-02-01 |
| JPS583815B2 true JPS583815B2 (en) | 1983-01-22 |
Family
ID=13962894
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP50089153A Expired JPS583815B2 (en) | 1975-07-23 | 1975-07-23 | Hatsupou Kouzou Tainoseikeihou |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS583815B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1992011122A1 (en) * | 1990-12-20 | 1992-07-09 | Asahi Kasei Kogyo Kabushiki Kaisha | Molded resin and method of production thereof |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57174224A (en) * | 1981-04-22 | 1982-10-26 | Noritaka Hayashi | Injection molding machine |
-
1975
- 1975-07-23 JP JP50089153A patent/JPS583815B2/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1992011122A1 (en) * | 1990-12-20 | 1992-07-09 | Asahi Kasei Kogyo Kabushiki Kaisha | Molded resin and method of production thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5213561A (en) | 1977-02-01 |
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