JP3550430B2

JP3550430B2 - Mold and method for molding laminated molded articles

Info

Publication number: JP3550430B2
Application number: JP266695A
Authority: JP
Inventors: 知和阿部; 義昭齋藤
Original assignee: Idemitsu Petrochemical Co Ltd
Current assignee: Idemitsu Petrochemical Co Ltd
Priority date: 1995-01-11
Filing date: 1995-01-11
Publication date: 2004-08-04
Anticipated expiration: 2019-08-04
Also published as: JPH08187730A

Description

【０００１】
【産業上の利用分野】
本発明は、積層成形品の成形用金型および成形方法に係り、自動車の内装品や事務用の椅子等、表面に表皮面材が被覆された積層成形品を製造する際に利用できる。
【０００２】
【背景技術】
従来より、自動車の内装品等として、良好な感触を付与する、あるいは、搭乗者の安全性を確保する等のために、表面の起毛性やクッション性等の有用な特質を備えた表皮面材を表面に被覆した積層成形品が用いられている。
このような積層成形品は、射出圧縮成形や射出プレス成形等の射出成形およびフロースタンピング成形等の成形法で製造でき、具体的には、予め金型内に表皮面材を配置しておき、この表皮面材が配置された金型の内部に溶融状態の樹脂を充填することで製造できる。
【０００３】
【発明が解決しようとする課題】
しかしながら、射出圧縮成形、射出プレス成形、および、フロースタンピング成形等の一般的な成形法では、表皮面材と樹脂とを一体成形すると、成形品の周囲から表皮面材の余剰部分がはみでるので、成形後に、この余剰部分を目立たないように成形品の裏側へ折り返して接着する作業等の処理加工が必要となり、この処理加工が積層成形品の製造効率を阻害しているという問題がある。
【０００４】
これに対し、成形時に表皮面材の端縁部分を成形品の裏側へ折り返す折り返し機構を有する金型が知られており、以下にその例を示す。
特開昭６１−１３７７１４号公報（以下「第１従来例」という）には、凹みを有する雌型と、この雌型の凹みの内部に挿入される雄型とに分割され、かつ、雌型の凹みの外周縁に表皮面材を挟んで固定する一対の固定枠を有し、この一対の固定枠のうち前記雌型と隣接するものを雌型の内側へ向かって突没可能とした金型が示されている。
このような金型によれば、固定枠に表皮面材を取付けた状態で金型を閉鎖するとともに、固定枠の一方を突出させることにより、表皮面材を雄型の外周面に押し付け、この状態で表皮面材および雄型の間に溶融樹脂を充填すると、表皮面材が成形品の端面部分となる部分を覆うように折り返されて接着されるので、成形後に表皮面材を折り返す作業等が一切不要となる。
また、特開平０５− ６４８２５号公報（以下「第２従来例」という）には、表皮面材の端縁部分を折り返すスライドコアと、折り返された表皮面材を加熱して樹脂に融着するヒータとを有する金型が示されている。
このような金型によれば、溶融樹脂が冷却・固化した後、スライドコアおよびヒータを作動させれば、表皮面材が折り返されて樹脂に接着されるので、成形後に表皮面材を折り返して接着する作業が不要となる。
しかし、第１および第２従来例では、金型の構造が複雑となり、金型の製造に手間や時間がかかり、金型の製造効率を低下させ、積層成形品のコストを高騰させる原因となるという問題がある。
また、第１従来例では、一面が開口となった箱形状の成形品を成形する場合、表皮面材の端縁部分は、折り返されても成形品の端面までしか接着されず、表皮面材の端縁を成形品の裏側までで折り返す必要がある場合には、別途折り返し作業および接着作業が必要となるという問題がある。
さらに、第２従来例では、溶融樹脂が冷却・固化する前に、スライドコアを作動させると、成形品の形を崩すおそれがあるので、溶融樹脂が完全に冷却・固化した後に、スライドコアおよびヒータを作動させなければならず、成形におけるサイクルタイムを長引かせ、成形品の製造効率が良くないという問題がある。
なお、特公昭６２− ５１７４８号公報には、成形時に表皮面材の端縁部分を圧縮して薄肉化し、成形後に成形品の端縁部分からはみでる表皮面材の端縁部分を成形品の裏側に折り返すことで、表皮面材が厚手のものであっても、成形品の端縁部分がシャープとなる成形品の製造方法が示されている。
しかし、この製造方法では、成形後に、表皮面材を折り返して接着する作業が必要となり、この作業により製造効率が阻害されるので、前述の問題を解決することはできない。
【０００５】
本発明の目的は、成形品の製造効率が向上される積層成形品の成形用金型および成形方法を提供することにある。
【０００６】
【課題を解決するための手段】
本発明の積層成形品の成形用金型は、予め表皮面材を配置しておいた金型の内部に溶融樹脂を充填することにより、前記表皮面材と前記樹脂とが積層された積層成形品の成形用金型であって、雄型と雌型とに分割されるとともに、前記雄型の外周面との間に前記表皮面材の端縁を挟み込む挟持手段が当該雄型に設けられ、この挟持手段は、前記雄型の外周面に沿って設けられたバンドであり、このバンドの両端は、当該バンドに所定の張力を付与する締付機構に係合されていることを特徴とする。
また、本発明の積層成形品の成形用金型は、予め表皮面材を配置しておいた金型の内部に溶融樹脂を充填することにより、前記表皮面材と前記樹脂とが積層された積層成形品の成形用金型であって、雄型と雌型とに分割されるとともに、前記雄型の外周面との間に前記表皮面材の端縁を挟み込む挟持手段が当該雄型に設けられ、この挟持手段は、前記雄型の外周面から進退自在とされた挟持片であり、この挟持片は、当該挟持片を前記雄型の外周面に対して進退駆動する締付機構に連結された構成としてもよい。
以上において、前記雄型と前記表皮面材との間に前記溶融樹脂を充填する充填孔が設けられ、前記溶融樹脂を成形するためのキャビティは、前記挟持手段が表皮面材を挟み込んだ位置よりも当該溶融樹脂の流れの下流側まで延出していることが望ましい。
また、前記締付機構は、流体の圧力で駆動する流体シリンダ装置を含んで構成されていることが望ましい。
【０００７】
本発明の積層成形品の成形方法は、表皮面材と樹脂とを積層させた積層成形品を一体成形する積層成形品の成形方法であって、前記金型は、雄型と雌型とに分割されるとともに、前記雄型の外周面との間に前記表皮面材の端縁を挟み込む挟持手段を備え、この挟持手段は、前記雄型の外周面に沿って設けられたバンドであり、このバンドの両端は、当該バンドに所定の張力を付与する締付機構に係合されており、前記表皮面材を前記挟持手段で前記金型に固定し、前記表皮面材と前記雄型との間に溶融樹脂を充填した後、充填された前記溶融樹脂を、前記挟持手段が表皮面材を挟み込んだ位置よりも当該溶融樹脂の流れの下流側まで展延させることを特徴とする。
また、本発明の積層成形品の成形方法は、表皮面材と樹脂とを積層させた積層成形品を一体成形する積層成形品の成形方法であって、前記金型は、雄型と雌型とに分割されるとともに、前記雄型の外周面との間に前記表皮面材の端縁を挟み込む挟持手段を備え、この挟持手段は、前記雄型の外周面から進退自在とされた挟持片であり、この挟持片は、当該挟持片を前記雄型の外周面に対して進退駆動する締付機構に連結されており、前記表皮面材を前記挟持手段で前記金型に固定し、前記表皮面材と前記雄型との間に溶融樹脂を充填した後、充填された前記溶融樹脂を、前記挟持手段が表皮面材を挟み込んだ位置よりも当該溶融樹脂の流れの下流側まで展延させる構成としてもよい。
以上において、前記挟持手段には、端縁近傍を弛ませて袋状にした状態の前記表皮面材が固定され、前記挟持手段と前記雌型との間には、前記溶融樹脂を成形するためのキャビティが延出し、前記表皮面材と前記雄型との間に前記溶融樹脂を充填することにより、前記溶融樹脂で前記表皮面材の袋状となった部分を膨らませることが望ましい。
【０００８】
また、以上のような成形方法では、次のような材料、および、成形装置を採用することができる。
（１）材料
表皮面材としては、熱可塑性樹脂シート、織布、不織布、編布、熱可塑性樹脂の発泡体、および、装飾模様等が印刷されたフィルムなどの単層表皮面材、ならびに、塩化ビニル（以下ＰＶＣと略す。）、熱可塑性エラストマ（以下ＴＰＯという。）織布、不織布、および、編布等からなる表皮層と、ポリプロピレンおよびポリウレタン等の発泡体からなるクッション層とを一体化した積層構造の多層表皮面材等が採用できる。
成形品の基部になる樹脂としては、ポリプロピレン、ポリスチレン、ポリエチレン、ＡＢＳ、ポリカーボネート等の熱可塑性樹脂、および、これらの熱可塑性樹脂にタルク、マイカ等のフィラーや、ガラス繊維、炭素繊維等の補強充填材を含有したもの等が採用できる。
（２）成形装置
成形装置としては、射出成形機、射出圧縮成形機、射出プレス成形機、および、移動側金型が取付けられる移動ダイプレートに当該移動金型部を固定金型部に向かって押圧する油圧装置等の押圧機構を設けた成形機等が採用できる。
【０００９】
【作用】
このような本発明では、挟持手段と雄型の外周面との間に前記表皮面材の端縁を挟んで固定した状態で、表皮面材と雄型との間に溶融樹脂を充填すれば、表皮面材の端縁近傍の部分は、金型の内部に拡がろうとする溶融樹脂の押圧力を受けて、挟持手段で固定された位置よりも下流側に移動しようする。
このため、溶融樹脂を成形するためのキャビティを、挟持手段が表皮面材を挟み込む位置よりも当該溶融樹脂の流れの下流側まで延出させれば、溶融樹脂は表皮面材を当該表皮面材の端縁を越えた位置まで押していき、成形される成形品の端縁となる部分は、表裏とも表皮面材に覆われるようになる。
この結果、成形品の表面を覆う表皮面材は、成形時に成形品の裏面にも折り返された状態で樹脂部分に接着され、これにより前記目的が達成される。
なお、挟持手段としてバンドを採用すれば、金型の構造が全体的に簡単なものとなる。また、バンドに張力を与えるための締付機構として、流体の圧力で駆動する流体シリンダ装置を備えたものを採用すれば、バンドを張る・緩めるが自在に行え、表皮面材の装着が容易・迅速に行え、製造効率の向上が図れる。
【００１０】
【実施例】
以下、本発明の一実施例を図面に基づいて説明する。
図１および図２には、本実施例の金型１が示されている。この金型１は、図中下方の雄型としての固定金型部１０と、上方の雌型としての可動金型部２０とに分割されたものとなっている。
固定金型部１０は、溶融樹脂を成形する成形面１１を突出させたものであるとともに、図示しない射出圧縮成形機に移動不可能に固定される金型である。
固定金型部１０には、射出圧縮成形機から射出される溶融樹脂を金型１のキャビティ２２内に導入する充填孔としてのスプルー１２が当該固定金型部１０の中央部分を貫通して設けられている。
固定金型部１０の成形面１１の端縁は、図中左側の半周が角の立ったエッジ１１Ａとされ、図中右側の半周が角の丸まったエッジ１１Ｂとされている。このうち、エッジ１１Ａは、表皮面材２（図２にのみ示す）を剪断するための刃となっている。
固定金型部１０の外周面１３には、成形面１１のエッジ１１Ｂ側の半周に巻付けられた挟持手段としてのバンド３０が設けられている。また、外周面１３には、バンド３０の下方に当該外周面１３から突き出た段付部１３Ａが設けられ、バンド３０の内側には、当該バンド３０を収納するための溝状の凹部１４が設けられている。
【００１１】
可動金型部２０は、底部が成形面２１となった凹みを有する雌型であり、前述の射出圧縮成形機に移動可能に設けられている。成形面２１は、金型１を閉鎖すると固定金型部１０の成形面１１とともにキャビティ２２（図１中では二点鎖線で示す）を形成するものである。
可動金型部２０の内周面２３には、成形面１１のエッジ１１Ａに対応して段差２４が設けられている。この段差２４のエッジ２５は、表皮面材２を剪断するための刃であり、固定金型部１０側のエッジ１１Ａとともに表皮面材２を剪断するものである。
段差２４の下方には、可動金型部２０の内周面２３と、固定金型部１０の外周面１３との間に隙間２６が形成される（図２にのみ示す）。この隙間２６は、表皮面材２の厚さ寸法に応じた所定間隔寸法ｔ１を有するものである。
可動金型部２０の図中上方には、図示しない型締装置が配置され、この型締装置により、可動金型部２０を移動して金型１が閉鎖されるようになっている。
この型締装置は、可動金型部２０を固定金型部１０に向かって圧縮するものであり、その圧縮力は、最大圧縮力の０〜１００％の範囲で連続的に調節できるようになっている。この型締装置を駆動することにより、キャビティ２２の内部に充填した溶融樹脂を展延させるとともに、展延完了後には溶融樹脂に内圧が与えられるようになっている。溶融樹脂に与えられる内圧は、樹脂を成形面１１，２１に押圧して所定の形状に維持するものであり、良好な成形性を得るためには欠かせない力となっている。
【００１２】
キャビティ２２は、バンド３０が表皮面材２を挟み込む位置イよりも溶融樹脂の流れの下流側（図では下方）まで延出している。ここで、スプルー１２は、固定金型部１０と表皮面材２との間に溶融樹脂を充填するようになっている。
バンド３０は、スチール製の薄板またはステンレスメッシュ等からなる柔軟性を備えた帯状のものである。バンド３０の両端は、このバンド３０に所定の張力を付与する締付機構４０に係合されている。
締付機構４０は、図３で示されるように、油圧で駆動する油圧式シリンダ装置４１と、固定金型部１０の内部に固定された係止ピン４２と、バンド３０の動きを円滑にさせるローラ４３とを備えたものであり、固定金型部１０の内部に設けられている。バンド３０の一端は、係止ピン４２に固定され、バンド３０の他端は、油圧式シリンダ装置４１の可動ロッド４４に固定されている。可動ロッド４４を後退させると、バンド３０に所定の張力が加わる一方、油圧式シリンダ装置４１の可動ロッド４４を前進させると、バンド３０は緩むようになっている。これにより、金型１に装着される表皮面材２の端縁は、バンド３０と固定金型部１０の外周面１３との間に挟まれて固定されるようになっている。
なお、表皮面材２としては、薄手の表皮層と、クッション性を具備した厚手のクッション層とからなる積層構造の面材、または、単層の表皮面材を用いる。
【００１３】
このような本実施例では、次のような手順により射出圧縮成形を行う。
まず、金型１を開け、バンド３０を緩めた状態で、図４（Ａ）に示されるように、バンド３０と固定金型部１０の外周面１３との間に表皮面材２の図中右側の端縁を差し込んだ後、可動ロッド４４を後退させてバンド３０を締め、固定金型部１０に表皮面材２を装着する。なお、表皮面材２の図中左側の端縁は固定しない。
ここで、表皮面材２の図中右側の端縁近傍は、図４（Ａ）の如く、弛ませて袋状にした状態としておく。
表皮面材２の装着後、可動金型部２０を固定金型部１０に向かって移動し、完全閉鎖位置よりも所定寸法（例えば、５〜１００ｍｍ程度）手前の位置に可動金型部２０を停止させ、この位置から可動金型部２０が後方に移動して開かないように、可動金型部２０をブロックし、この状態で溶融樹脂３をキャビティ２２に充填する。
この際、図４（Ｂ）に示されるように、可動金型部２０の前進により、固定金型部１０の外周面１３と可動金型部２０の内周面２３との間の隙間２６に、表皮面材２の図中左側の端縁が挟まれる。これにより、型締め時に表皮面材２には、適度な張力が型締めの始めから終わりまでの間加え続けられるようになる。
【００１４】
次いで、溶融樹脂３の充填工程の完了直前もしくは完了直後に、図示しない型締装置を駆動して金型１に圧縮力を加えて型締し、この型締めにより溶融樹脂３をキャビティ２２内に展延して充満させる。
ここで、金型１の型締めにより、充填された溶融樹脂３は、図４（Ｃ）に示されるように、バンド３０が表皮面材２を挟み込んだ位置イよりも当該溶融樹脂３の流れの下流側まで展延する。展延された溶融樹脂３は、表皮面材２の袋状となった部分に入り込んで、当該表皮面材２の袋状部分を膨らませる。
なお、表皮面材２の袋状部分が膨らむ際、表皮面材２の図中右側の端縁は、摩擦力に抗してバンド３０と固定金型部１０の外周面１３との間から僅かにキャビティ２２の内部へ引き込まれる。
また、金型１の型締完了直前には、固定金型部１０側のエッジ１１Ａと、可動金型部２０側のエッジ２５とが噛み合い、表皮面材２を成形品の端縁に沿って剪断する。これにより、成形品から表皮面材２の余剰部分が自動的にトリミングされる。
【００１５】
なお、溶融樹脂３が金型１のキャビティ２２の隅々まで充満したら、必要に応じて表皮面材２のクッション層が押し潰されないように、金型１に加わっている圧縮力を低下させる。これにより、圧縮力が低下している間に、クッション層が著しく溶融しない程度に溶融樹脂３の表面を冷却させることができ、その後、圧縮力を再度昇圧させ、溶融樹脂３を所定の形状に維持させるに充分な高圧縮力下で樹脂３の冷却・固化を行うことができる。
そして、溶融樹脂３の冷却固化が完了したら、金型１を開いて金型１の内部から成形品を取り出す。
【００１６】
前述のような本実施例によれば、次のような効果がある。
すなわち、固定金型部１０の外周面１３との間に表皮面材２の端縁を挟んで固定するバンド３０を設け、バンド３０が表皮面材２を挟み込んだ位置よりも溶融樹脂３の流れの下流側となる位置までキャビティ２２を延出させたので、成形面１１と表皮面材２との間に充填された溶融樹脂３は、バンド３０に固定された表皮面材２の端縁を越えた位置まで表皮面材２の端縁近傍の部分を押していく。この結果、成形品の表面を覆う表皮面材２は、成形時に端縁部分が成形品の裏側へも折り返された状態で成形品の樹脂層に接着されるので、別途表皮面材２の折り返えし作業等が不要となり、積層成形品の製造効率を向上できる。
【００１７】
また、固定金型部１０の成形面１１のエッジ１１Ａと、可動金型部２０の内周面２３に設けた段差２４のエッジ２５とで、表皮面材２のバンド３０で固定されない端縁部分を剪断する一対の刃を形成したので、成形品からはみでる表皮面材２の余剰部分を自動的にトリミングでき、この点からも積層成形品の製造効率を向上できる。
しかも、可動金型部２０の内周面２３に設けた段差２４により、固定金型部１０の外周面１３と可動金型部２０の内周面２３との間に隙間２６が形成され、この隙間２６に表皮面材２の固定されていない端縁を挟んだ状態で型締めするようにしたので、型締め時に表皮面材２に適度な張力が加わり、成形品の表面を覆う表皮面材２にシワが生じず、積層成形品の外観を良好なものとできる。
【００１８】
さらに、表皮面材２の固定された端縁部分を袋状に弛ませたので、溶融樹脂３の射出圧力や型締めの圧縮力が低くとも、キャビティ２２の隅々まで溶融樹脂３が確実に展延され、射出圧力や型締め力を低圧にすることにより、成形時において表皮面材２のクッション層を保護できる。しかも、金型が開いた状態で溶融樹脂を射出するため、高速で溶融樹脂を射出でき、射出時間が短くて済み、サイクルタイムを短縮できるうえ、成形装置の規模を縮小でき、ひいては積層成形品のコストを低減できる。
【００１９】
また、挟持手段として、柔軟性を有するバンド３０を採用したので、挟持手段の構造が簡単となり、金型１の構造を複雑にせず、金型１の製造コストを低減できるうえ、既存の金型の改造も容易なので、既存の金型に利用することも容易に行うことができる。
【００２０】
さらに、バンド３０に張力を与えるための締付機構として、油圧で駆動する油圧式シリンダ装置４１を設けたので、バンド３０を張る・緩めるが自在に行え、表皮面材２の装着が容易・迅速に行え、この点からも積層成形品の効率を向上することができる。
【００２１】
また、溶融樹脂３が充満した後、金型１に加わっている圧縮力を低下させたので、圧縮力が低下している間に、クッション層が著しく溶融しない程度に溶融樹脂３の表面を冷却し、その後、圧縮力を再度昇圧させ、溶融樹脂３を所定の形状に維持させるに充分な高圧縮力下で樹脂３の冷却・固化を行うようになるため、表皮面材２のクッション層のクッション性を維持でき、表皮面材２の特質であるクッション性が損なわれず、積層成形品の品質を優れたものとできる。
【００２２】
続いて、本発明の効果を具体的な実験例に基づいて説明する。
〔実験例１〕
本実験例１は、前記実施例の金型１で積層成形品を成形する実験である。
本実験例１の金型１は、幅寸法Ｗが４１０ｍｍ、奥行き寸法Ｄが４３０ｍｍ（図１参照）のキャビティ２２を備えるとともに、このキャビティ２２の中心付近にゲートを一点有するものである。また、金型１のバンド３０は、スチール性の帯状のものとされている。
〔比較例１〕
本比較例１は、本発明の効果を確認するために、従来からある単純なインロー構造の金型により、前記実験例１と同一の成形品を得ようとする実験である。本比較例１では、雌型の内周面および雄型の外周面との間隔寸法（前記実施例の寸法ｔ１に相当する寸法）が０．０２ｍｍに設定されている。
〔比較例２〕
本比較例２は、本発明の効果を確認するために、前記比較例１と同様に、従来からある単純なインロー構造の金型で、前記実験例１と同一の成形品を得ようとする実験である。
本比較例２では、雌型の内周面および雄型の外周面との間隔寸法（前記実施例の寸法ｔ１に相当する寸法）が０．４ｍｍに設定されている。
【００２３】
〔共通射出条件〕
実験例１、比較例１および比較例２では、互いに共通した材料、装置、および成形条件が採用される。これらの材料等は以下のようなものとなっている。
（１）材料
成形品の基部になる樹脂としては、ポリプロピレン（出光石油化学（株）製商品名：出光ポリプロＪ−５０５０ＨＭＩ：５５ｇ／１０分，２３０℃，２．１６ｋｇｆ）。
また、表皮面材としては、不織布からなる厚さ１．２ｍｍの単層シート材を採用する。
（２）成形装置
成形装置としては、汎用の横型射出成形機に射出圧縮成形機構を組み込んだ射出圧縮成形機（型締力８５０ｔ三菱重工製）を用いる。この射出圧縮成形機は、最大圧縮力の０〜１００％の間で連続的に圧縮力を調節できる。
（３）成形条件
▲１▼成形温度；１８０℃
▲２▼金型温度；４０℃
▲３▼樹脂の射出時間；２．６秒
▲４▼樹脂の射出圧力；１２０ｋｇ／ｃｍ^２（ゲージ圧）
▲５▼樹脂冷却時間；４０秒
▲６▼金型の圧縮量；４０ｍｍ
▲７▼型締め開始タイミング；射出開始から２．４秒経過後
▲８▼金型の圧縮速度；１０ｍｍ／秒
▲９▼型締め時の圧縮力；１５０ｔ
【００２４】
〔実験結果〕
実験例１では、成形品の表皮面材の表面には、シワの発生がないうえ、表皮面材の端縁部分は、成形品の裏側に折り返されて、外観の良好な積層成形品となった。
これに対し、比較例１では、金型を閉鎖する際に、雌型の開口の内側のエッジと、雄型の成形面の外周縁のエッジとが噛み合い、溶融樹脂の充填および型締めの前に、表皮面材が剪断された。この表皮面材の剪断により、金型内部の表皮面材には、張力を与えることはできない。
このため、溶融樹脂を充填・展延すると、溶融樹脂に押されて金型内部の表皮面材がずれ、得られた成形品の表面にはシワが発生する上、端縁に樹脂が露出し、外観が損なわれ、比較例１では、外観の良好な積層成形品が得られないことがわかる。
一方、比較例２では、金型を完全に閉鎖しても、表皮面材が剪断できないので、成形後にトリミング作業や、表皮面材の端縁を折り返す作業等の処理加工が必要となった。
しかも、雌型の内周面と、雄型の外周面との間に溶融樹脂が入り込むので、成形品の端縁にバリが生じ、このバリを取り除く作業が必要となる。従って、比較例２では、積層成形品の製造効率を向上できない。
【００２５】
以上、本発明について好適な実施例を挙げて説明したが、本発明は、この実施例に限られるものでなく、本発明の要旨を逸脱しない範囲において種々の改良並びに設計の変更が可能である。
例えば、表皮面材としては、不織布に限らず、各種厚みの織布、編布、あるいは、ＰＶＣやＴＰＯ等の単層表皮面材が採用できる。
さらに、表皮面材としては、単層表皮面材に限らず、前述の単層表皮面材を二種類以上ラミネートした多層表皮面材でもよい。
また、ポリプロピレン発泡体、ポリウレタン発泡体等の発泡シート、あるいは、これらの発泡シートと前記単層表皮面材との多層表皮面材も採用できる。
【００２６】
さらに、挟持手段としては、バンド等に限らず、図５および図６に示されるように、雄型である固定金型部１０の外周面１３から進退自在とされた挟持片３１を含んで構成されたものでもよい。そして、この挟持片３１を油圧式シリンダ装置３２等の締付機構で駆動すれば、固定金型部１０の外周面１３の全周に渡って表皮面材２の端縁を固定することができる。
以上において、締付機構としては、油圧式シリンダ装置に限らず、空気式シリンダ装置等の流体圧を利用するもの、および、電動機やソレノイド等の能動的に駆動力を発生させるもの、ならびに、ばね等の受動的に駆動力を発生させるものも採用できる。
【００２７】
また、成形品の基部になる樹脂としては、補強繊維等を含まないポリプロピレンに限らず、タルクやマイカ等のフィラー、または、ガラス繊維や炭素繊維等の補強充填材を含有したポリプロピレンでもよく、また、ポリエチレン、ポリスチレン、ＡＢＳ、ポリカーボネート等の他の合成樹脂、および、これらの繊維補強樹脂等も採用できる。
【００２８】
さらに、成形装置としては、射出圧縮成形機に限らず、射出プレス成形機等でもよく、要するに、型締めにより金型内に充填した溶融樹脂を展延できるものであればよい。
さらに、成形品としては、椅子の座部に限らず、ソファ等の家具の部分品、自動車の内装品、および、電気製品のケーシングなどでもよい。
さらに、圧縮力の設定値および各工程の開始時刻等の成形条件は、前記実験例１で示したものに限らず、成形品の大きさや樹脂の種類等に応じて様々な値が選択でき、具体的数値については実施にあたり適宜設定すればよい。
【００２９】
【発明の効果】
前述のように本発明によれば、表皮面材の端縁部分の折り返し・接着作業が不要となり、成形品の製造効率を向上できる。
【図面の簡単な説明】
【図１】本発明の一実施例の金型を示す分解斜視図である。
【図２】前記実施例の金型を示す断面図である。
【図３】同実施例の挟持手段を示す断面図である。
【図４】同実施例の成形手順を説明するための断面図である。
【図５】本発明の変形例を示す横断面図である。
【図６】同変形例の縦断面図である。
【符号の説明】
１金型
２表皮面材
３溶融樹脂
１０雄型としての固定金型部
１２充填孔としてのスプルー
１３雄型の外周面
２０雌型としての可動金型部
２２キャビティ
３０挟持手段としてのバンド
３１挟持手段としての挟持片
３２，４１締付機構としての油圧式シリンダ装置[0001]
[Industrial applications]
INDUSTRIAL APPLICABILITY The present invention relates to a molding die and a molding method for a laminated molded product, and can be used when producing a laminated molded product having a surface covered with a skin material, such as an interior part of an automobile or an office chair.
[0002]
[Background Art]
2. Description of the Related Art Conventionally, as a car interior component, a surface material having useful characteristics such as a raised surface and a cushioning property for imparting a good feel or ensuring passenger safety. Is used.
Such a laminated molded product can be manufactured by injection molding such as injection compression molding or injection press molding and a molding method such as flow stamping molding. Specifically, a skin surface material is previously arranged in a mold, It can be manufactured by filling a resin in a molten state into a mold in which the skin surface material is arranged.
[0003]
[Problems to be solved by the invention]
However, in a general molding method such as injection compression molding, injection press molding, and flow stamping molding, when the skin surface material and the resin are integrally molded, an excess portion of the skin surface material protrudes from around the molded product. After molding, it is necessary to perform a processing such as an operation of folding and bonding the surplus portion to the back side of the molded product so as to be inconspicuous, and this processing hinders the production efficiency of the laminated molded product.
[0004]
On the other hand, a mold having a folding mechanism for folding an edge portion of a skin material toward the back side of a molded product at the time of molding is known, and examples thereof are described below.
Japanese Unexamined Patent Publication No. 61-137714 (hereinafter referred to as "first conventional example") discloses a female mold having a recess and a male mold inserted into the recess of the female mold. A pair of fixing frames that are fixed to the outer peripheral edge of the recess with the skin facing material therebetween, and a pair of the fixing frames adjacent to the female mold can be protruded and retracted toward the inside of the female mold. The type is shown.
According to such a mold, the mold is closed while the skin is attached to the fixed frame, and one of the fixed frames is protruded to press the skin to the outer peripheral surface of the male mold. When the molten resin is filled between the skin surface material and the male mold in the state, the skin surface material is folded back and adhered so as to cover the part to be the end surface of the molded product. Becomes unnecessary at all.
Japanese Patent Application Laid-Open No. 05-64825 (hereinafter, referred to as "second conventional example") discloses a slide core that folds an edge portion of a skin surface material, and heats and fuses the folded skin surface material to a resin. A mold having a heater is shown.
According to such a mold, if the slide core and the heater are operated after the molten resin is cooled and solidified, the skin surface material is folded back and adhered to the resin. The work of bonding becomes unnecessary.
However, in the first and second conventional examples, the structure of the mold becomes complicated, and it takes time and effort to manufacture the mold, which reduces the production efficiency of the mold and increases the cost of the laminated molded product. There is a problem.
Further, in the first conventional example, when forming a box-shaped molded product having an opening on one side, the edge portion of the skin surface material is bonded only to the end surface of the molded product even if it is folded back, If it is necessary to fold the edge of the molded product up to the back side of the molded product, there is a problem that a separate folding operation and bonding operation are required.
Further, in the second conventional example, if the slide core is operated before the molten resin is cooled and solidified, there is a possibility that the shape of the molded product may be lost. There is a problem that the heater must be operated, the cycle time in molding is prolonged, and the production efficiency of molded products is not good.
Japanese Patent Publication No. Sho 62-51748 discloses that an edge portion of a skin surface material is compressed and thinned at the time of molding, and an edge portion of the skin surface material protruding from the edge portion of the molded product after molding is formed on the back side of the molded product. A method of manufacturing a molded product in which the edge portion of the molded product is sharpened even when the skin material is thick by folding back the material.
However, in this manufacturing method, it is necessary to fold and adhere the skin material after molding, and this operation hinders the manufacturing efficiency, so that the above-mentioned problem cannot be solved.
[0005]
An object of the present invention is to provide a molding die and a molding method for a laminated molded product in which the production efficiency of the molded product is improved.
[0006]
[Means for Solving the Problems]
The molding die of the laminated molded product of the present invention is formed by laminating the skin surface material and the resin by filling a molten resin into a mold in which a skin surface material is previously arranged. A mold for forming a product, wherein the male mold is provided with a clamping means which is divided into a male mold and a female mold, and which sandwiches an edge of the skin surface material between the male mold and an outer peripheral surface of the male mold.The holding means is a band provided along the outer peripheral surface of the male mold, and both ends of the band are engaged with a tightening mechanism for applying a predetermined tension to the band.It is characterized by having.
Further, the molding die of the laminated molded product of the present invention, by filling a molten resin into a mold in which a skin surface material is previously arranged, the skin surface material and the resin are laminated. A mold for molding a laminated molded product, wherein the male mold is divided into a male mold and a female mold, and a clamping means for sandwiching an edge of the skin surface material with an outer peripheral surface of the male mold is provided on the male mold. The holding means is a holding piece that is movable back and forth from the outer peripheral surface of the male mold, and the holding piece is a clamping mechanism that drives the holding piece to advance and retreat with respect to the outer peripheral surface of the male mold. It is good also as a structure connected.
In the above, a filling hole for filling the molten resin is provided between the male mold and the skin facing material, and a cavity for molding the molten resin is located at a position where the sandwiching means sandwiches the skin facing material. It is also desirable that the resin also extends to the downstream side of the flow of the molten resin.
Also,Preferably, the tightening mechanism includes a fluid cylinder device driven by the pressure of the fluid.
[0007]
The method of molding a laminated molded article of the present invention is a method of molding a laminated molded article in which a laminated molded article obtained by laminating a skin surface material and a resin is integrally molded, wherein the mold has a male mold and a female mold. And being provided with clamping means for sandwiching an edge of the skin facing material with the outer peripheral surface of the male mold while being divided.The holding means is a band provided along the outer peripheral surface of the male mold, and both ends of the band are engaged with a tightening mechanism for applying a predetermined tension to the band.The skin material is fixed to the mold by the holding means, and after filling the molten resin between the skin material and the male mold, the filled molten resin is filled by the holding means. It is characterized in that it extends to a downstream side of the flow of the molten resin from a position sandwiching the skin facing material.
Further, the method of molding a laminated molded article of the present invention is a method of molding a laminated molded article in which a laminated molded article in which a skin surface material and a resin are laminated is integrally molded, wherein the mold is a male mold and a female mold. And a holding means for holding an edge of the skin facing material between itself and the outer peripheral surface of the male mold, and the holding means comprises a holding piece which can be advanced and retracted from the outer peripheral surface of the male mold. The holding piece is connected to a fastening mechanism that drives the holding piece forward and backward with respect to the outer peripheral surface of the male mold, and fixes the skin surface material to the mold with the holding means, After filling the molten resin between the skin material and the male mold, the filled molten resin is spread to a downstream side of the flow of the molten resin from a position where the sandwiching means sandwiches the skin material. It is good also as composition which makes it do.
In the above, in the clamping means, the skin surface material in a state of being made into a bag by loosening the vicinity of an edge is fixed, and between the clamping means and the female mold, the molten resin is molded. It is preferable that the cavity is extended and the molten resin is filled between the skin facing material and the male mold, thereby inflating the bag-shaped portion of the skin facing material with the molten resin.
[0008]
In the above-described molding method, the following materials and molding apparatus can be employed.
(1) Materials
Examples of the skin surface material include a thermoplastic resin sheet, a woven fabric, a nonwoven fabric, a knitted fabric, a thermoplastic resin foam, and a single-layer skin surface material such as a film on which a decorative pattern or the like is printed, and vinyl chloride (hereinafter, referred to as “vinyl chloride”). PVC), thermoplastic elastomer (hereinafter referred to as TPO), a laminated structure in which a skin layer made of a woven fabric, a nonwoven fabric, a knitted fabric, or the like, and a cushion layer made of a foam such as polypropylene and polyurethane are integrated. A multi-layer skin material can be adopted.
The resin used as the base of the molded product is a thermoplastic resin such as polypropylene, polystyrene, polyethylene, ABS, or polycarbonate, and a filler such as talc or mica, or a reinforcing filler such as glass fiber or carbon fiber. A material containing a material can be employed.
(2) Molding device
Examples of the molding device include an injection molding machine, an injection compression molding machine, an injection press molding machine, and a hydraulic device that presses the movable mold portion toward a fixed mold portion on a movable die plate to which a movable side mold is attached. A molding machine or the like provided with the pressing mechanism can be adopted.
[0009]
[Action]
In the present invention as described above, the molten resin is filled between the skin surface material and the male mold in a state where the edge of the skin surface material is fixed between the holding means and the outer peripheral surface of the male mold. The portion near the edge of the skin facing material is moved downstream from the position fixed by the holding means by receiving the pressing force of the molten resin which is going to spread inside the mold.
For this reason, if the cavity for molding the molten resin is extended to the downstream side of the flow of the molten resin from the position where the sandwiching means sandwiches the skin surface material, the molten resin causes the skin surface material to be deformed. Of the molded product to be molded, and the front and back surfaces of the molded product are covered with the skin facing material.
As a result, the skin surface material covering the surface of the molded product is adhered to the resin portion in a state of being folded back also on the rear surface of the molded product at the time of molding, whereby the object is achieved.
If a band is adopted as the holding means, the structure of the mold becomes simple as a whole. If a tightening mechanism for applying tension to the band with a fluid cylinder device driven by the pressure of the fluid is adopted, the band can be freely stretched and loosened, making it easy to attach the skin material. It can be performed quickly and the production efficiency can be improved.
[0010]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1 and 2 show a mold 1 of the present embodiment. The mold 1 is divided into a fixed mold portion 10 as a lower male mold and a movable mold portion 20 as an upper female mold in the figure.
The fixed mold part 10 has a molding surface 11 for molding the molten resin protruding therefrom, and is a mold that is immovably fixed to an injection compression molding machine (not shown).
The fixed mold part 10 is provided with a sprue 12 as a filling hole for introducing a molten resin injected from an injection compression molding machine into the cavity 22 of the mold 1 so as to penetrate through the central part of the fixed mold part 10. Have been.
The end edge of the molding surface 11 of the fixed mold part 10 is a sharp edge 11A on the left half in the figure and a rounded edge 11B on the right half in the figure. Among them, the edge 11A is a blade for shearing the skin facing material 2 (shown only in FIG. 2).
On the outer peripheral surface 13 of the fixed mold portion 10, a band 30 is provided as a holding means wound around a half circumference of the molding surface 11 on the edge 11B side. Further, a stepped portion 13A protruding from the outer peripheral surface 13 is provided below the band 30 on the outer peripheral surface 13, and a groove-shaped concave portion 14 for accommodating the band 30 is provided inside the band 30. Have been.
[0011]
The movable mold part 20 is a female mold having a recess whose bottom is a molding surface 21 and is movably provided in the injection compression molding machine described above. The molding surface 21 forms a cavity 22 (shown by a two-dot chain line in FIG. 1) together with the molding surface 11 of the fixed mold part 10 when the mold 1 is closed.
On the inner peripheral surface 23 of the movable mold part 20, a step 24 is provided corresponding to the edge 11A of the molding surface 11. The edge 25 of the step 24 is a blade for shearing the skin facing material 2, and shears the skin facing material 2 together with the edge 11 </ b> A on the fixed mold part 10 side.
A gap 26 is formed below the step 24 between the inner peripheral surface 23 of the movable mold part 20 and the outer peripheral surface 13 of the fixed mold part 10 (only shown in FIG. 2). The gap 26 has a predetermined interval t1 corresponding to the thickness of the skin facing material 2.
A mold clamping device (not shown) is disposed above the movable mold portion 20 in the drawing, and the mold clamping device moves the movable mold portion 20 to close the mold 1.
This mold clamping device compresses the movable mold part 20 toward the fixed mold part 10, and the compression force can be continuously adjusted within a range of 0 to 100% of the maximum compression force. ing. By driving the mold clamping device, the molten resin filled in the cavity 22 is spread, and after the completion of the spreading, an internal pressure is applied to the molten resin. The internal pressure applied to the molten resin presses the resin against the molding surfaces 11 and 21 to maintain the resin in a predetermined shape, and is an essential force for obtaining good moldability.
[0012]
The cavity 22 extends to a downstream side (downward in the figure) of the flow of the molten resin from a position A where the band 30 sandwiches the skin facing material 2. Here, the sprue 12 fills the space between the fixed mold part 10 and the skin facing material 2 with molten resin.
The band 30 is made of a thin steel plate or a stainless steel mesh and has a flexible band shape. Both ends of the band 30 are engaged with a tightening mechanism 40 that applies a predetermined tension to the band 30.
As shown in FIG. 3, the tightening mechanism 40 smoothly moves the hydraulic cylinder device 41 driven by hydraulic pressure, the locking pin 42 fixed inside the fixed mold part 10, and the band 30. And a roller 43, which is provided inside the fixed mold part 10. One end of the band 30 is fixed to a locking pin 42, and the other end of the band 30 is fixed to a movable rod 44 of a hydraulic cylinder device 41. When the movable rod 44 is retracted, a predetermined tension is applied to the band 30, while when the movable rod 44 of the hydraulic cylinder device 41 is advanced, the band 30 is loosened. Thereby, the edge of the skin facing material 2 mounted on the mold 1 is sandwiched and fixed between the band 30 and the outer peripheral surface 13 of the fixed mold portion 10.
As the skin surface material 2, a surface material having a laminated structure including a thin skin layer and a thick cushion layer having cushioning properties, or a single-layer skin surface material is used.
[0013]
In this embodiment, injection compression molding is performed according to the following procedure.
First, with the mold 1 opened and the band 30 loosened, as shown in FIG. 4A, the skin facing material 2 is placed between the band 30 and the outer peripheral surface 13 of the fixed mold part 10 in the drawing. After inserting the right edge, the movable rod 44 is retracted, the band 30 is tightened, and the skin facing material 2 is mounted on the fixed mold portion 10. The left edge of the skin facing material 2 in the figure is not fixed.
Here, the vicinity of the right edge of the skin facing material 2 in the drawing is loosened and made into a bag shape as shown in FIG.
After the skin material 2 is mounted, the movable mold part 20 is moved toward the fixed mold part 10 and the movable mold part 20 is moved to a position before the completely closed position by a predetermined size (for example, about 5 to 100 mm). The movable mold part 20 is stopped so that the movable mold part 20 moves backward from this position and does not open, and the molten resin 3 is filled into the cavity 22 in this state.
At this time, as shown in FIG. 4 (B), as the movable mold part 20 advances, a gap 26 between the outer peripheral surface 13 of the fixed mold part 10 and the inner peripheral surface 23 of the movable mold part 20 is formed. , The left edge of the skin facing material 2 in the figure is sandwiched. Thereby, an appropriate tension is continuously applied to the skin facing material 2 from the beginning to the end of the mold clamping during the mold clamping.
[0014]
Next, immediately before or immediately after the completion of the filling step of the molten resin 3, a mold clamping device (not shown) is driven to apply a compressive force to the mold 1 to clamp the mold 1. Spread and fill.
Here, as shown in FIG. 4C, the molten resin 3 filled by the mold clamping of the mold 1 flows from the position a where the band 30 sandwiches the skin surface material 2 to the flow of the molten resin 3. To the downstream side of. The spread molten resin 3 enters the bag-shaped portion of the skin facing material 2 and expands the bag-shaped portion of the skin facing material 2.
When the bag-shaped portion of the skin facing material 2 is inflated, the right edge of the skin facing material 2 in the figure slightly extends from between the band 30 and the outer peripheral surface 13 of the fixed mold portion 10 against the frictional force. Is drawn into the cavity 22.
Immediately before the completion of the mold clamping of the mold 1, the edge 11A of the fixed mold portion 10 and the edge 25 of the movable mold portion 20 are engaged with each other, and the skin surface material 2 is moved along the edge of the molded product. Shear. Thus, the surplus portion of the skin facing material 2 is automatically trimmed from the molded product.
[0015]
When the molten resin 3 fills the corners of the cavity 22 of the mold 1, the compression force applied to the mold 1 is reduced as necessary so that the cushion layer of the skin material 2 is not crushed. Thereby, while the compression force is decreasing, the surface of the molten resin 3 can be cooled to such an extent that the cushion layer does not melt significantly. Thereafter, the compression force is increased again, and the molten resin 3 is formed into a predetermined shape. The resin 3 can be cooled and solidified under a sufficiently high compressive force to maintain it.
When the cooling and solidification of the molten resin 3 is completed, the mold 1 is opened and the molded product is taken out from the inside of the mold 1.
[0016]
According to the present embodiment as described above, the following effects are obtained.
That is, a band 30 is provided between the outer peripheral surface 13 of the fixed mold part 10 and the outer surface 13 so as to hold the edge of the skin material 2 therebetween, and the flow of the molten resin 3 is higher than the position where the band 30 sandwiches the skin material 2. The cavity 22 is extended to a position on the downstream side of the mold, so that the molten resin 3 filled between the molding surface 11 and the skin facing material 2 causes the edge of the skin facing material 2 fixed to the band 30 to move. The portion near the edge of the skin material 2 is pushed to the position beyond the edge. As a result, the skin facing material 2 covering the surface of the molded product is adhered to the resin layer of the molded product in a state where the edge portion is folded back to the back side of the molded product at the time of molding. The return operation and the like become unnecessary, and the production efficiency of the laminated molded product can be improved.
[0017]
Further, the edge 11A of the molding surface 11 of the fixed mold portion 10 and the edge 25 of the step 24 provided on the inner peripheral surface 23 of the movable mold portion 20 are not fixed by the band 30 of the skin surface material 2. Is formed, a surplus portion of the skin facing material 2 protruding from the molded product can be automatically trimmed, and the production efficiency of the laminated molded product can be improved from this point as well.
Moreover, a gap 26 is formed between the outer peripheral surface 13 of the fixed mold portion 10 and the inner peripheral surface 23 of the movable mold portion 20 due to the step 24 provided on the inner peripheral surface 23 of the movable mold portion 20. Since the mold is clamped with the unfixed edge of the skin facing material 2 sandwiched in the gap 26, an appropriate tension is applied to the skin facing material 2 at the time of mold clamping, and the skin facing material covers the surface of the molded product. No wrinkles are formed on the laminate 2, and the appearance of the laminated molded product can be improved.
[0018]
Further, since the fixed edge portion of the skin facing material 2 is loosened in a bag shape, even if the injection pressure of the molten resin 3 and the compressive force of the mold clamping are low, the molten resin 3 can be surely provided to every corner of the cavity 22. The cushion layer of the skin surface material 2 can be protected at the time of molding by spreading and reducing the injection pressure and the mold clamping force. Moreover, since the molten resin is injected with the mold open, the molten resin can be injected at a high speed, the injection time can be shortened, the cycle time can be shortened, the scale of the molding equipment can be reduced, and the laminated molded product can be reduced. Cost can be reduced.
[0019]
Further, since the band 30 having flexibility is employed as the holding means, the structure of the holding means is simplified, the structure of the mold 1 is not complicated, the manufacturing cost of the mold 1 can be reduced, and the existing mold can be reduced. Can be easily remodeled, so that it can be easily used for existing dies.
[0020]
Furthermore, since the hydraulic cylinder device 41 driven by hydraulic pressure is provided as a tightening mechanism for applying tension to the band 30, the band 30 can be freely stretched and loosened, and the mounting of the skin surface material 2 is easy and quick. This also improves the efficiency of the laminated molded product.
[0021]
Also, since the compressive force applied to the mold 1 was reduced after the molten resin 3 was filled, the surface of the molten resin 3 was cooled to such an extent that the cushion layer did not melt significantly while the compressive force was reduced. Thereafter, the compressive force is increased again, and the resin 3 is cooled and solidified under a sufficiently high compressive force to maintain the molten resin 3 in a predetermined shape. The cushioning property can be maintained, the cushioning property which is a characteristic of the skin facing material 2 is not impaired, and the quality of the laminated molded article can be improved.
[0022]
Subsequently, effects of the present invention will be described based on specific experimental examples.
[Experimental example 1]
The first experimental example is an experiment in which a laminated molded product is molded using the mold 1 of the above embodiment.
The mold 1 of this experimental example 1 has a cavity 22 having a width dimension W of 410 mm and a depth dimension D of 430 mm (see FIG. 1), and has one gate near the center of the cavity 22. The band 30 of the mold 1 is a steel band.
[Comparative Example 1]
Comparative Example 1 is an experiment in which the same molded product as that of Experimental Example 1 was obtained using a conventional simple mold having a spigot structure in order to confirm the effects of the present invention. In Comparative Example 1, the distance between the inner peripheral surface of the female mold and the outer peripheral surface of the male mold (a dimension corresponding to the dimension t1 in the above embodiment) is set to 0.02 mm.
[Comparative Example 2]
In Comparative Example 2, in order to confirm the effect of the present invention, similarly to Comparative Example 1, a mold having the same simple spigot structure as in Comparative Example 1 was used to obtain the same molded product as in Experimental Example 1. It is an experiment.
In Comparative Example 2, the distance between the inner peripheral surface of the female mold and the outer peripheral surface of the male mold (a dimension corresponding to the dimension t1 in the above embodiment) is set to 0.4 mm.
[0023]
[Common injection conditions]
In the experimental example 1, the comparative example 1 and the comparative example 2, the same material, apparatus, and molding conditions are adopted. These materials are as follows.
(1) Materials
Polypropylene (made by Idemitsu Petrochemical Co., Ltd., trade name: Idemitsu Polypro J-5050H MI: 55 g / 10 min, 230 ° C., 2.16 kgf) as a resin serving as a base of the molded product.
As the skin surface material, a single-layer sheet material made of nonwoven fabric and having a thickness of 1.2 mm is used.
(2) Molding device
As the molding device, an injection compression molding machine (a mold clamping force of 850 t, manufactured by Mitsubishi Heavy Industries) incorporating an injection compression molding mechanism in a general-purpose horizontal injection molding machine is used. This injection compression molding machine can continuously adjust the compression force between 0 and 100% of the maximum compression force.
(3) Molding conditions
(1) Molding temperature: 180 ° C
(2) Mold temperature: 40 ° C
(3) Injection time of resin; 2.6 seconds
(4) Injection pressure of resin: 120 kg / cm²(Gauge pressure)
(5) Resin cooling time: 40 seconds
(6) Amount of mold compression: 40 mm
(7) Mold clamping start timing; 2.4 seconds after the start of injection
(8) Compression speed of mold: 10 mm / sec
(9) Compression force at the time of mold clamping; 150t
[0024]
〔Experimental result〕
In Experimental Example 1, wrinkles did not occur on the surface of the skin surface material of the molded product, and the edge portion of the skin surface material was folded back to the back side of the molded product to form a laminated molded product having a good appearance. Was.
On the other hand, in Comparative Example 1, when closing the mold, the inner edge of the opening of the female mold and the edge of the outer peripheral edge of the molding surface of the male mold mesh with each other, and before filling the molten resin and clamping the mold. Then, the skin material was sheared. Due to the shearing of the skin facing material, tension cannot be applied to the skin facing material inside the mold.
For this reason, when the molten resin is filled and spread, the skin material inside the mold is displaced by being pushed by the molten resin, wrinkles are generated on the surface of the obtained molded product, and the resin is exposed at the edges. It can be seen that, in Comparative Example 1, a laminated molded product having good appearance was not obtained.
On the other hand, in Comparative Example 2, even when the mold was completely closed, the skin surface material could not be sheared, so that processing such as a trimming operation or an operation of turning the edge of the skin surface material after molding was required.
Moreover, since the molten resin enters between the inner peripheral surface of the female mold and the outer peripheral surface of the male mold, burrs are formed on the edge of the molded product, and it is necessary to remove the burrs. Therefore, in Comparative Example 2, the production efficiency of the laminated molded product cannot be improved.
[0025]
As described above, the present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to these embodiments, and various improvements and design changes can be made without departing from the gist of the present invention. .
For example, the skin facing material is not limited to a nonwoven fabric, but may be a woven or knitted fabric of various thicknesses, or a single-layer skin facing material such as PVC or TPO.
Furthermore, the skin surface material is not limited to a single-layer skin surface material, and may be a multilayer skin surface material obtained by laminating two or more types of the above-described single-layer skin surface materials.
Further, a foamed sheet such as a polypropylene foam or a polyurethane foam, or a multi-layered skin material comprising these foamed sheets and the single-layered skin surface material can be employed.
[0026]
Further, the holding means is not limited to a band or the like, and includes a holding piece 31 which can be advanced and retracted from the outer peripheral surface 13 of the fixed mold portion 10 which is a male type as shown in FIGS. It may be done. If the holding piece 31 is driven by a tightening mechanism such as a hydraulic cylinder device 32, the edge of the skin facing material 2 can be fixed over the entire outer circumference 13 of the fixed mold portion 10. .
In the above, the tightening mechanism is not limited to a hydraulic cylinder device, but a device that uses fluid pressure such as a pneumatic cylinder device, a device that actively generates a driving force such as an electric motor or a solenoid, and a spring device. And the like that passively generates a driving force can also be adopted.
[0027]
Further, the resin serving as the base of the molded product is not limited to polypropylene containing no reinforcing fibers, but may be a filler such as talc or mica, or a polypropylene containing a reinforcing filler such as glass fiber or carbon fiber, or Other synthetic resins such as polyethylene, polystyrene, ABS, polycarbonate, and fiber-reinforced resins thereof can also be used.
[0028]
Further, the molding device is not limited to the injection compression molding machine, but may be an injection press molding machine or the like. In short, any molding device may be used as long as it can spread the molten resin filled in the mold by clamping.
Further, the molded article is not limited to the seat portion of the chair, but may be a furniture part such as a sofa, an interior part of an automobile, a casing of an electric product, or the like.
Furthermore, the molding conditions such as the set value of the compressive force and the start time of each step are not limited to those shown in the experimental example 1, and various values can be selected according to the size of the molded product and the type of the resin. Specific numerical values may be set as appropriate upon implementation.
[0029]
【The invention's effect】
As described above, according to the present invention, it is not necessary to fold and bond the edge portion of the skin facing material, and it is possible to improve the manufacturing efficiency of the molded product.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a mold according to an embodiment of the present invention.
FIG. 2 is a sectional view showing a mold according to the embodiment.
FIG. 3 is a sectional view showing a holding means of the embodiment.
FIG. 4 is a cross-sectional view for explaining a molding procedure of the embodiment.
FIG. 5 is a cross-sectional view showing a modification of the present invention.
FIG. 6 is a longitudinal sectional view of the modification.
[Explanation of symbols]
1 Mold
2 Skin material
3 molten resin
10. Fixed mold part as male mold
12 Sprue as filling hole
13 Male outer surface
20 Movable mold part as female mold
22 cavities
30 Bands as clamping means
31 Clamping piece as clamping means
32, 41 Hydraulic cylinder device as tightening mechanism

Claims

By filling a molten resin into a mold in which a skin surface material is previously arranged, a molding die for a laminated molded product in which the skin surface material and the resin are stacked,
The male mold is divided into a male mold and a female mold, and a clamping means for clamping the edge of the skin facing material is provided between the male mold and the outer peripheral surface of the male mold. A band provided along an outer peripheral surface, wherein both ends of the band are engaged with a tightening mechanism for applying a predetermined tension to the band .

By filling a molten resin into a mold in which a skin surface material is previously arranged, a molding die for a laminated molded product in which the skin surface material and the resin are stacked,
The male mold is divided into a male mold and a female mold, and a clamping means for clamping the edge of the skin facing material is provided between the male mold and the outer peripheral surface of the male mold. A laminated piece formed to be able to advance and retreat from the outer peripheral surface, the clamping piece being connected to a tightening mechanism that drives the retractable piece forward and backward with respect to the outer peripheral surface of the male mold. Mold for molding.

The mold for molding a laminated molded product according to claim 1 or 2 , wherein a filling hole for filling the molten resin is provided between the male mold and the skin surface material, and the molten resin is molded. A cavity for extending the molten resin from the position where the sandwiching means sandwiches the skin facing material to a downstream side of the flow of the molten resin.

The mold for molding a laminated molded product according to any one of claims 1 to 3 , wherein the tightening mechanism includes a fluid cylinder device driven by a pressure of a fluid. Mold for forming laminated products.

A method of molding a laminated molded product by integrally molding a laminated molded product obtained by laminating a skin surface material and a resin,
The mold is divided into a male mold and a female mold, and further includes clamping means for clamping an edge of the skin surface material between the male mold and the outer peripheral surface of the male mold. A band provided along the outer peripheral surface, both ends of the band are engaged with a tightening mechanism that applies a predetermined tension to the band ,
After fixing the skin surface material to the mold by the holding means and filling the molten resin between the skin surface material and the male mold, the sandwiching means fills the filled molten resin with the skin surface material. A method of molding a laminated molded product, wherein the molding is extended to a downstream side of the flow of the molten resin from a position sandwiching the above.

A method of molding a laminated molded product by integrally molding a laminated molded product obtained by laminating a skin surface material and a resin,
The mold is divided into a male mold and a female mold, and further includes clamping means for clamping an edge of the skin surface material between the male mold and the outer peripheral surface of the male mold. It is a holding piece that is made to be able to advance and retreat from the outer peripheral surface, and this holding piece is connected to a tightening mechanism that drives the holding piece forward and backward with respect to the outer peripheral surface of the male mold,
After fixing the skin surface material to the mold by the holding means and filling the molten resin between the skin surface material and the male mold, the sandwiching means fills the filled molten resin with the skin surface material. A method of molding a laminated molded product, wherein the molding is extended to a downstream side of the flow of the molten resin from a position sandwiching the above.

In the method for forming a laminated molded product according to claim 5 or 6 ,
In the holding means, the skin surface material in a state of being formed into a bag by loosening the vicinity of an edge is fixed, and a cavity for molding the molten resin is provided between the holding means and the female mold. A laminated molded product characterized by extending and filling the molten resin between the skin facing material and the male mold to thereby inflate a bag-shaped portion of the skin facing material with the molten resin. Molding method.