JP3993140B2

JP3993140B2 - Foamed resin mold and foamed resin molded product with display

Info

Publication number: JP3993140B2
Application number: JP2003181208A
Authority: JP
Inventors: 進氏原; 達夫村井; 資郎天野; 正男中村
Original assignee: SANPOU KANAGATA SEISAKUSHO LTD.; Sekisui Kasei Co Ltd
Current assignee: SANPOU KANAGATA SEISAKUSHO LTD.; Sekisui Kasei Co Ltd
Priority date: 2003-06-25
Filing date: 2003-06-25
Publication date: 2007-10-17
Anticipated expiration: 2023-06-25
Also published as: JP2005014352A

Description

【０００１】
【発明の属する技術分野】
本発明は発泡樹脂成形品を製造するための発泡樹脂成形型と、その成形型を用いて製造された表示付き発泡樹脂成形品に関し、更に詳細には、発泡樹脂成形品の表面に明瞭な表示を形成可能な発泡樹脂成形型と、表面に深彫りによる明瞭な表示を有する表示付き発泡樹脂成形品に関する。
【０００２】
【従来の技術】
一般に容器形状の発泡樹脂成形品は、固定側のキャビティ金型と、このキャビティ金型に対して型閉め・型開き方向に移動可能なコア金型とからなり、型閉め時に目的の容器形状に一致するキャビティが形成される成形型を用い、前記キャビティ内に発泡性樹脂粒子を充填し、型内に蒸気を通して発泡性樹脂粒子を加熱し、型内発泡成形して製造される。
魚や野菜などを入れるための容器形状の発泡樹脂成形品（以下、容器と略記する場合がある。）は、意匠性を高めたり、出荷元等を表示するために、容器の立ち上がり部分（側壁部）の外側や容器の蓋の上面に、内容物の名前や会社の名前、ロゴマークなどを表示する場合が多い。
従来、発泡樹脂成形品の表面に文字やマーク等の表示を設ける方法としては、発泡樹脂成形品を製造するための金型に文字やマーク等を彫り込んでレリーフ文字で表示する方法や無地の成形品に後加工でカラー印刷などを施した粘着テープを貼り付ける方法などが行われている。これらの表示方法のうち、後加工で粘着テープを貼り付ける方法は、意匠的には美麗であるが、加工コストがかさみ、適正な対価が得られない問題がある。
【０００３】
発泡樹脂成形品の表面にレリーフ文字で表示するための成形型としては、例えばキャビティ金型（凹型）のへこみ部に文字板を取り付けておき、発泡成形品の外面に浮き出し文字を形成する構造が提案されている（例えば、特許文献１参照。）。この金型構造では、文字板の板圧とキャビティ金型のへこみ部の深さが同じであるため、文字板の表面とキャビティ金型の表面が面一になる。
また、発泡樹脂成形品の側面に穴加工をするために、キャビティ金型に回転式の中子を設け、コア金型が型閉め、型開きする際に中子がキャビティ内に入出する構造が提案されている（例えば、特許文献２参照。）。
また、成形型内で発泡成形した発泡樹脂成形品が離脱方向に移動するのを防ぐため、金型の開閉方向に対して交差する方向に成形品の側面にエアーシリンダーで押し付ける構造が提案されている（例えば、特許文献３参照。）。
また、アンダーカット部を持った製品を効率よく生産するために、コア金型にエアーシリンダーを設け、コア金型の背面側から成形関連部材をキャビティ内に突入させる構造が提案されている（例えば、特許文献４参照。）。
また、発泡樹脂成形品の表面に凹凸模様、文字等を現出するための成形用金型として、型の上面、及び下面に蒸気孔を穿設し、蒸気孔が穿設されていない面の金型に、該金型の成形体を取り出す方向の縁辺部にわたって連通し、開口部より内が幅広に形成された凹陥部を穿設し、該凹陥部に合致する小片体を嵌入せしめ、該小片体を成形体と共に取り出し可能とした成形用金型が提案されている（例えば、特許文献５参照。）。
【０００４】
【特許文献１】
実開昭６２−２８５２２号公報
【特許文献２】
実開平６−５５７３０号公報
【特許文献３】
実開昭５８−１５１０１５号公報
【特許文献４】
特開平６−１１４９５９号公報
【特許文献５】
実公昭４７−４２５４１号公報
【０００５】
【発明が解決しようとする課題】
しかしながら、特許文献１に記載された技術では、文字の高さが約２ｍｍ以上になると、型開きして発泡樹脂成形品を離型する際に、浮き出た文字が文字板にむしり取られるため、文字高さの低い、不明瞭な表示しか形成できない問題がある。
また、特許文献２に記載された技術は、運搬用に紐を通すための孔を穿設するためのものであり、型閉め時に中子を回転させてキャビティ内に挿入させる構造であるため、この構造を表示用に適用しようとしても製品面に対し直角に表示を彫り込むことができず、表示の肩の部分が丸くなってシャープな表示が得られない問題がある。
また、特許文献３に記載された技術では、エアーシリンダーによって表示用銘板等を型開き方向に対し直角に進退移動させることにより、成形品外面に表示を設けることができるが、エアーシリンダーの作動空間が必要となるため、多数の成形装置を作業場内にコンパクトに配置した多数個取りの成形設備に適用する場合、成形装置どうしの間のスペースが大きくなり、作業場内に設置できる成形装置の台数が減少して実質的に生産効率が低下してしまう問題がある。また、エアーシリンダーは熱の影響で作動不良を起こす可能性があり、蒸気が直接当たる所には設置できない。
また、特許文献４に記載された技術では、キャビティ金型に接する側の発泡樹脂成形品の外面に表示を設けることは不可能である。
また、特許文献５に記載された技術では、表示形成用の小片体を発泡樹脂成形品の離型後に分離し、次の成形工程までに再装着しなければならず、生産効率が低下する問題がある。
【０００６】
本発明は前記事情に鑑みてなされたもので、発泡樹脂成形品の表面に明瞭な表示を形成可能な発泡樹脂成形型と、表面に明瞭な表示を有する表示付き発泡樹脂成形品の提供を目的としている。
【０００７】
【課題を解決するための手段】
前記目的を達成するために本発明は、型閉め時に目的の成形形状に一致するキャビティが形成される、少なくとも一方が型閉め・型開き方向に移動可能な第１の成形型と第２の成形型とを備え、前記キャビティ内に発泡性樹脂粒子を充填し、型内発泡成形して発泡樹脂成形品を作製する発泡樹脂成形型において、前記第１の成形型と第２の成形型の少なくとも一方のキャビティ面に設けられた凹部内に出没可能で且つ凹部側に付勢されて設けられた銘板保持部と、該銘板保持部の発泡樹脂成形品と接する側に設けられた所望の表示を発泡樹脂成形品に転写する銘板と、型閉め時に前記銘板保持部に接近し、型開き時に前記銘板保持部から離れる押圧部材と、前記銘板保持部に設けられ、型閉め時に前記押圧部材と当接する傾斜面を有し、該押圧部材の押圧によって前記銘板保持部を前記凹部から押し出す方向に移動させる傾斜面部とを備えたことを特徴とする発泡樹脂成形型を提供する。
本発明の発泡樹脂成形型において、固定側の前記第１の成形型に、前記凹部と前記銘板保持部と前記銘板と前記押圧部材と前記傾斜面部とを含む表示形成機構が設けられ、前記押圧部材は、型開き時に、一部が第１の成形型から突出し、かつ該突出方向に向けて付勢された状態で設けられ、前記第２の成形型が移動して前記第１の成形型に嵌合した型閉め時、前記押圧部材の突出部分が前記第２の成形型により前記傾斜面に当接し押圧されるように構成することが好ましい。
また、押圧部材の先端部は、前記傾斜面をスライド可能な楔状であることが好ましい。
さらに、銘板に刻まれた表示は、表示の周囲に沿って深彫り用の突起が設けられ、該突起の高さが３〜１０ｍｍ、幅が３〜１０ｍｍであることが好ましい。
また本発明は、前記発泡樹脂成形型を用い、第１の成形型と第２の成形型とを型閉めし、前記キャビティ内に発泡性樹脂粒子を充填し、該発泡性樹脂粒子を蒸気加熱して型内発泡成形を行い、冷却後に型開きして発泡樹脂成形体を取り出すことにより製造されることを特徴とする表示付き発泡樹脂成形品を提供する。
本発明の表示付き発泡樹脂成形品において、発泡樹脂成形品の表面に設けられる表示が、該表示の周囲に沿って深彫りされてなり、該深彫り部の深さが３〜１０ｍｍ、幅が３〜１０ｍｍであることが好ましい。
また、発泡樹脂成形品が着色されていることが好ましい。
さらに本発明は、表面に表示が設けられた発泡樹脂成形品であって、表示が、該表示の周囲に沿って深彫りされてなり、該深彫り部の深さが３〜１０ｍｍ、幅が３〜１０ｍｍであることを特徴とする表示付き発泡樹脂成形品を提供する。
本発明の表示付き発泡樹脂成形品において、発泡樹脂成形品が着色されていることが好ましい。
【０００８】
【発明の実施の形態】
以下、図面を参照して本発明を説明する。
図１及び図２は、本発明に係る発泡樹脂成形型の一例を示すものであり、図１は型開き時、図２は型閉め時を示し、またこれらの図中符号Ａは発泡樹脂成形型である。
なお本例では、底板部とその周縁から立設された側壁部とからなる箱状の発泡樹脂成形品を製造するための発泡樹脂成形型を例示しているが、本発明はこれに限定されず、箱形以外の形状の発泡樹脂成形品を製造するための発泡樹脂成形型に適用可能である。
【０００９】
この発泡樹脂成形型Ａは、型閉め時に目的の成形形状に一致するキャビティ３が形成される、固定して設けられた第１の成形型（以下、キャビティ金型１と記す。）と、該キャビティ金型１に対し型閉め・型開き可能なように上下方向に昇降可能に設けられた第２の成形型（以下、コア金型２という。）とを備え、コア金型２を下降させてキャビティ金型１に嵌合させて型閉めし、両金型間のキャビティ３内に発泡性樹脂粒子を充填し、型内発泡成形して発泡樹脂成形品を作製するようになっている。
【００１０】
本例では、固定側のキャビティ金型１に、そのキャビティ３と接する面（以下、キャビティ面４と記す。）に設けた凹部５内に出没可能で且つ凹部５側に付勢されて設けられた銘板保持部６と、この銘板保持部６の発泡樹脂成形品と接する側に設けられた所望の表示を発泡樹脂成形品に転写する銘板７と、型閉め時に銘板保持部６に接近し、型開き時に銘板保持部７から離れるように上下方向に移動可能に設けられた押圧部材８と、銘板保持部６に設けられ、型閉め時に押圧部材８と当接する傾斜面９を有し、押圧部材８の押圧によって銘板保持部６を凹部５から押し出す方向に移動させる傾斜面部１０とを設けた構成になっている。
【００１１】
キャビティ金型１とコア金型２は、熱伝導率が良好な銅、アルミニウム、銅及びアルミニウムの合金、銅、アルミニウム、マグネシウム及びマンガンの合金（ジュラルミン）から形成されるのが好ましい。キャビティ金型１とコア金型２のいずれかの部位には、キャビティ３内に発泡性樹脂粒子を供給するための発泡性樹脂粒子供給管（図示せず）が一体的に設けられていると共にこの発泡性樹脂粒子供給管にはフィラー弁（図示せず）が介装され、更に、発泡樹脂成形品をキャビティ金型１から離型させるための押出ピン（図示せず）が一体的に設けられている。キャビティ金型１とコア金型２は中空構造とされ、この中空部（チャンバー）には蒸気や冷却水を流通させるための管路や真空排気用の管路が接続されている。またキャビティ金型１とコア金型２とのキャビティ面４には、これらの金型を型閉めして形成されるキャビティ３内と前記中空部とを連通させるための図示していない多数の蒸気穴が設けられている。
【００１２】
図３は、キャビティ金型１に設けられた表示形成機構の一例を示す図であり、この表示形成機構１１は、銘板保持部６と押圧部材８と傾斜面部１０とを含んで構成されている。この表示形成機構１１は、キャビティ金型１の凹部５に収容されている。この凹部５および表示形成機構１１は、箱状の発泡樹脂成形品の側壁部外面のうち、表示を形成する側壁部に応じてキャビティ金型１に１〜複数箇所設けることができる。例えば、発泡樹脂成形品の相対する２つの側壁部外面に表示を設ける場合には、それに対応するキャビティ金型１の位置に凹部５および表示形成機構１１を設けることができる。
【００１３】
前記銘板保持部６は、キャビティ面４側に銘板７が着脱可能に固定され、背面側に傾斜面部１０が固定された厚板状をなしている。この銘板保持部６は、図示しないバネにより、凹部５に向かう方向に付勢されている。この銘板保持部６の付勢構造は特に限定されず、凹部６と銘板保持部６とを直接引張りバネで接合して凹部５側に付勢してもよいし、バネを挿入したピンを凹部５側に設け、そのピンの他端を銘板保持部６に固定して凹部５側に付勢してもよい。
【００１４】
この銘板保持部６の成形面側には、１〜複数枚の銘板７が着脱可能に固定される。この銘板７の表示は、発泡樹脂成形体の外面に形成するべき文字やマーク等の表示を転写可能なものとされる。本発明の好ましい実施形態において、銘板７に刻まれた表示は、表示の周囲に沿って深彫り用の突起が設けられ、該突起の高さが３〜１０ｍｍ、幅が３〜１０ｍｍの範囲とされる。このような突起を有する銘板７を用いて形成される表示は、文字やマークの周囲に沿って深さが３〜１０ｍｍ、幅が３〜１０ｍｍの深い凹みを有し、この表示が形成された発泡樹脂成形品の外面を見る時、この深い凹みが陰となって、突出状態の表示中央部と明暗のコントラストが強調され、表示は遠くからでも鮮明に確認できるものとなる。銘板７によって発泡樹脂成形品に形成される表示は、文字、数字、模様、各種のマークなど種々の文字や記号を使用できる。
【００１５】
前記押圧部材８は、本例示では先端部に傾斜面９とスライド可能な傾斜面を有する楔状に形成されている。この先端部は２つに分割され、それら分割された部分の中央には、圧縮バネ１２によって上方に向けて付勢された支柱１３の上端が取り付けられている。この支柱１３の下端部は、キャビティ金型１に設けられた孔１４内に上下動可能に挿入されている。圧縮バネ１２は孔１４内に挿入不可能になっており、押圧部材８の下降にしたがって、この圧縮バネ１２が押圧部材８下端と孔１４上端周縁部との間で圧縮され、また型開き時にはその付勢力によって押圧部材８を上方に向けて移動させる。
【００１６】
前記押圧部材８の上端部は、図１に示す型開き時にはキャビティ金型１の上端よりも所定長さ突出するように設けられている。このキャビティ金型１の上端部は、図２に示す型閉め時に移行する際、コア金型２を取り付けて移動させるコア金型取付板１５の下面に当接し、コア金型取付板１５の下降にしたがって下方に押し下げられ、型閉め時にはキャビティ金型１の上端近傍の位置になる。
【００１７】
前記傾斜面部１０は、銘板保持部６の背面側に固着されている。この傾斜面部１０の傾斜面９は、銘板保持部６から斜め下方に向けて漸次肉厚を増加する方向に傾斜が付けられている。この傾斜面９は平面状であっても曲面状であってもよい。この傾斜面９の長さと傾斜角度は、押圧部材８の下端面が当接し、所定の間隔だけ下降する際に、銘板７が凹部５から出て発泡樹脂成形品の外面に表示が形成可能となるように、銘板保持部６をスムーズにスライドできるように適宜設定される。
【００１８】
次に、前記発泡樹脂成形型Ａを用い、側壁部の外面に表示を有する表示付き発泡樹脂成形品Ｂを作製する方法を説明する。
まず、図１に示すように、銘板保持部６に所望の表示を形成可能な銘板７を固定し、コア金型取付板１５を下降させてコア金型２をキャビティ金型１に嵌合して図２に示す型閉め状態とする。型閉め時には、キャビティ金型１とコア金型２とのそれぞれのキャビティ面４間に、製造するべき発泡樹脂成型品の形状に一致するキャビティ３が形成される。また型閉め時には、押圧部材８がコア金型取付板１５の下面に当接して押し下げられ、その先端の傾斜面が傾斜面部１０の傾斜面９を押圧し、凹部５内に収容されている銘板保持部６がコア金型２側にスライドし、銘板７のキャビティ面が凹部５から若干突出した位置となる。
【００１９】
コア金型２を下降させて図２に示す型閉め状態とした後、フィラー弁を開放して発泡性樹脂粒子供給管を通じてキャビティ３内に発泡性樹脂粒子を供給、充填する。
発泡性樹脂粒子は、発泡剤を含有させた合成樹脂粒子を予備発泡させて得られるものであり、この合成樹脂粒子を構成する合成樹脂としては、従来から発泡樹脂成形品製造のために用いられている樹脂材料の中から適宜選択して用いることができ、特に限定されず、例えば、ポリスチレン、ハイインパクトポリスチレン、スチレン−無水マレイン酸共重合体、スチレン−アクリロニトリル共重合体等のポリスチレン系樹脂、ポリエチレン、ポリプロピレン、エチレン−酢酸ビニル共重合体等のポリオレフィン系樹脂、ポリエチレンテレフタレート等のポリエステル系樹脂等を挙げることができ、強度と成形性の良さからポリスチレン系樹脂が好ましい。
【００２０】
また、前記発泡剤としては、沸点が合成樹脂の軟化点以下であって、常圧でガス状もしくは液状の有機化合物が適しており、例えば、プロパン、ブタン、ペンタン、シクロペンタン、シクロペンタジエン、ヘキサン、石油エーテル等の炭化水素、ジメチルエーテル、ジエチルエーテル、ジプロピルエーテル、メチルエチルエーテル等の低沸点のエーテル化合物、炭酸ガス、窒素等の無機ガス等が用いられる。これらの発泡剤は、一種のみを使用してもよく、また、二種以上を併用してもよい。発泡剤の含有率としては、合成樹脂粒子質量に対して１〜２０質量％、好ましくは２〜１０質量％である。発泡剤の含有量が前記範囲を下回ると、発泡成形品の発泡倍率が不十分で軽量発泡体が得られない。一方、発泡剤の含有量が前記範囲を超えても、発泡倍率の更なる上昇は実質的に見込めず、また発泡が不安定になり好ましくない。
【００２１】
キャビティ３内に発泡性樹脂粒子を充填した後、それぞれの金型のキャビティ面４に多数穿設してある蒸気孔を通してキャビティ３内の発泡性樹脂粒子を蒸気加熱し、粒子同士を融着させて型内発泡成形し、次いで冷却する。
この型内発泡成形時、キャビティ金型１の凹部５から若干突出した銘板７のキャビティ面は、発泡樹脂成形品の側壁部外面に当接し、この側壁部外面には、銘板７に刻まれた凹凸に沿った表示が転写される。
【００２２】
冷却後、コア金型取付板１５を上昇させ、コア金型２をキャビティ金型１から取り外して型開き状態とする。コア金型取付板１５を上昇させると、押圧部材８が圧縮バネ１２の付勢力により上昇し、押圧部材８による傾斜面９への押圧が解放される。押圧部材８の上昇に伴って、銘板保持部６が図示しないバネの付勢力によって凹部５側にスライドし、銘板７が発泡樹脂成形品の側壁部外面から離れ、凹部５内に入り込む。このように、型開き時に銘板７が発泡樹脂成形品から離れて凹部５内に引っ込むことで、発泡樹脂成形品に刻まれた表示が銘板７に食い込んだまま発泡樹脂成形品を離型して、表示の凸部が千切れるなどの不具合を生じることがない。型開き後、製造された表示付き発泡樹脂成形品をキャビティ金型１から取り出す。
【００２３】
この発泡樹脂成形型Ａは、キャビティ金型１のキャビティ面４に設けた凹部５内に出没可能で且つ凹部５側に付勢されて設けられた銘板保持部６と、該銘板保持部６のキャビティ面側に設けられた銘板７と、型閉め時に銘板保持部６に接近し、型開き時に銘板保持部から離れる押圧部材８と、銘板保持部６に設けられ、型閉め時に押圧部材８と当接する傾斜面９を有し、押圧部材８の押圧によって銘板保持部６を凹部５から押し出す方向に移動させる傾斜面部１０とを備えた構成としたので、型閉め・型開きの動作によって型内発泡成形時に銘板７が凹部７から突出して発泡樹脂成形品の外面に接触し、型開き時には銘板７が凹部５内に引っ込むように、自動的に銘板７をスライド移動させることができ、発泡樹脂成形品に刻まれた表示が銘板７に食い込んだまま発泡樹脂成形品を離型して、表示の凸部が千切れるなどの不具合を生じることがないので、発泡樹脂成形品の外面に明瞭な表示を形成することができる。
また、３ｍｍ以上の高さの凸部を有する表示であっても綺麗に形成することができるので、遠方からでも識別が容易な、意匠性に優れた表示を形成することができる。
また、キャビティ金型１の内部に設けた表示形成機構１１によって銘板７をスライド移動させるので、付設のために余分なスペースが必要なエアーシリンダー等の余分な機器を設ける必要がなく、表示形成機構を設けていない成形型と同等の設置スペースとすることができる。
また、この表示形成機構１１は、押圧部材８で銘板保持部６を押圧してスライドさせる単純な構造なので、耐熱性、耐久性に優れ、蒸気が当たる高温条件下でも故障することなく長期間使用でき、更にメンテナンスも容易である。
【００２４】
次に、表示付き発泡成形品について記す。
図４は、従来の表示付き発泡樹脂成形品を示す図である。図４（ａ）に示す表示付き発泡樹脂成形品（以下、成形品と記す。）Ｃは、長方形状をなす底板部２１と、その周縁から立設された側壁部２２とからなっており、側壁部２２の外面に表示２３が形成された構成になっている。この表示２３は、図４（ｂ）に示すように、側壁部２２に平坦な凹面２９が設けられ、その凹面２９上に文字やマーク等を表した凸面３０とからなっている。この表示２３は、平坦な凹面２９から文字やマーク等を表した凸面３０を突出させた表示構造であるので、この表示２３を外観視した際に、見る角度によって凸面３０と凹面２９との境界が鮮明でなくなる。
【００２５】
図５は、本発明に係る成形品の第１の例を示す図である。この成形品Ｂは、図５（ａ）に示す通り、底板部２１と、その周縁から立設された側壁部２２とからなっており、側壁部２２の外面に表示２４が形成されている。本例では、図５（ｂ）に示すように、表示２４の周囲に沿って凹溝３１による深彫りがなされ、この凹溝３１で文字やマーク等を表した凸面３２を区画している。このような表示構造を有する成形品Ｂは、本発明に係る発泡樹脂成形型Ａを用いて製造することができる。
【００２６】
この凹溝３１からなる深彫り部の深さは、２ｍｍ以上、好ましくは３〜１０ｍｍの範囲、幅は２ｍｍ以上、好ましくは３〜１０ｍｍの範囲とされる。このように凹溝３１で文字やマーク等の凸面３２の周囲を深彫りした表示２４は、通常の明るさの下で側壁部２２を目視すると、凹溝３１が陰となってこの部分が暗くなる一方、凸面３２は明るく見えることで、凹溝３１と凸面３２との境界が明瞭となり、凸面３２により表される文字やマーク等が明瞭で見やすくなり、遠くからでも識別でき、意匠性を向上できる。一方、凹溝３１の深さ及び幅が前記範囲未満であると、表示２４が不明瞭となる。
【００２７】
本発明の成形品Ｂは、表示の周囲に沿って凹溝３１を設けて深彫りされてなり、深彫り部の深さを３〜１０ｍｍ、幅を３〜１０ｍｍの範囲としたことによって、凹溝３１と凸面３２との境界が明瞭となり、凸面３２により表される文字やマーク等が明瞭で見やすくなり、遠くからでも識別でき、意匠性を向上できる。
また、前記第１の例において、成形品Ｂは、薄青色などの着色を施してあるものが好ましい。成形品Ｂに着色を施すことで、表示２４が一層明瞭なものとなる。着色する場合には、予め着色剤を配合した発泡性樹脂粒子を用いて型内発泡成形を行うことで容易に製造できる。
【００２８】
図６は、本発明に係る成形品の第２の例を示す図である。この成形品Ｂに形成した表示２５，２６は、前記第１の例における表示２４とほぼ同様であるが、凹溝３１の溝表面を粗面化した表示２５と、凸面２６に着色を施した表示２６とを備えている。
【００２９】
凹溝３１の溝表面を粗面化した表示２５を形成するには、凹溝３２を形成するために銘板７に設けた突起の表面をエッチングやサンドブラスト加工等によってナシ地のような粗面に形成しておき、この銘板７を用いて成形品Ｂを作製することで得られる。このように凹溝３１の溝表面を粗面化することで、凹溝３２がより暗く見え、凸面３２とのコントラストを際立たせることができる。
【００３０】
また、凸面２６に着色を施した表示２６は、成形品Ｂを作製後に適当な印刷方法を用いて着色し、形成される。この表示２６の色調は特に限定されない。
【００３１】
図７は、本発明に係る成形品の第３の例を示す図である。この成形品Ｂに形成した表示は、前記第１の例における表示２４とほぼ同様であるが、凹溝３１の凸面３２側の立ち上がり面をテーパー面とした表示２７（図７（ｂ））、または凹溝３１の凸面３２側の立ち上がり面を曲面とした表示２８（図７（ｃ））を備えている。これらの表示は、凹溝３２を形成するために銘板７に設けた突起にテーパー面や凹曲面形成しておき、この銘板７を用いて成形品Ｂを作製することで得られる。
【００３２】
図７（ｂ）に示す立ち上がり面をテーパー面とした表示２７、または（ｃ）に示す立ち上がり面を曲面とした表示２８は、凹溝３１の陰がテーパー面や曲面を横切る状態となるので、明暗がより明瞭となる。
【００３３】
【実施例】
図１，２に示すように構成された成形型を用い、図５に示す成形品を作製した。また比較のために、図４に示す従来の成形品を作製した。
発泡性樹脂粒子は、原料ビーズとして積水化成品工業社製の白色原料ＨＤＭと着色原料ＨＤＭダークブルー（以下、青色原料という。）を用いた。各原料ビーズを予備発泡機（積水工機社製、ＳＫＫ−１１０型）で発泡倍率６０倍に発泡し、通気性のあるサイロに約２４時間滞留させた後、成形機（積水工機社製、ＡＣＥ−３０ＱＳ）に、図５に示す表示構造を形成するための銘板と、図４に示す表示構造を形成するための銘板とを交互に取り付けて成形した。成形１サイクル中の主な工程と条件を表１に示す。成形１サイクル中には、前記工程の他にも、金型の開閉工程や離型工程などがあり、表中の各工程の秒数合計が実際の１サイクルの値にはならない。表１中、従来の成形品とは、図４に示す表示構造を形成するための銘板を取り付けて製造した成形品であり、また深彫り文字成形品とは、図５に示す表示構造を形成するための銘板を取り付けて製造した成形品である。
【００３４】
【表１】

【００３５】
次のような判読テストを行った。
・サンプル
（実施例１）：図５に示す表示構造を有する成形品を青色原料を用いて作製した。凹部深さは５ｍｍ、凹部幅は５ｍｍとした。
（実施例２）：図５に示す表示構造を有する成形品を白色原料を用いて作製した。凹部深さは５ｍｍ、凹部幅は５ｍｍとした。
（比較例１）：図４に示す表示構造を有する成形品を青色原料を用いて作製した。文字高さは５ｍｍとした。
（比較例２）：図４に示す表示構造を有する成形品を白色原料を用いて作製した。文字高さは５ｍｍとした。
【００３６】
・測定条件
光源が天井である部屋にサンプルを置き、視力（裸眼）１．０と０．５の２名の人間が所定の距離からサンプル外面の表示文字の判別を行った。文字付近の明るさは３３０ルックスであった。
【００３７】
・判読評価
◎：文字がはっきり判読できる。
○：文字が判読できる。
×：文字が判読できない。
【００３８】
・テスト結果
視力（裸眼）１．０のパネラーによって測定した結果を表２に示し、また視力（裸眼）０．５のパネラーによって測定した結果を表３にそれぞれ示す。
【００３９】
【表２】

【００４０】
【表３】

【００４１】
テストの結果、青色原料を用いた実施例１、白色原料を用いた実施例２ともに従来品である比較例１，２よりも文字が明瞭となった。
白色原料を用いた実施例２の成形品の場合は、陰の部分が灰色になり、文字が浮き出して見えるようになるので、遠くからでも文字が判読できた。
また、青色原料を用いた実施例１の成形品の場合は、陰の部分が濃い青になり、文字がさらに浮き出して見えるようになるので、さらに遠くからでも文字が判読できるようになった。
【００４２】
【発明の効果】
以上説明した通り、本発明の発泡樹脂成形型は、第１の成形型のキャビティ面に設けた凹部内に出没可能で且つ凹部側に付勢されて設けられた銘板保持部と、該銘板保持部のキャビティ面側に設けられた銘板と、型閉め時に銘板保持部に接近し、型開き時に銘板保持部から離れる押圧部材と、銘板保持部に設けられ、型閉め時に押圧部材と当接する傾斜面を有し、押圧部材の押圧によって銘板保持部を凹部から押し出す方向に移動させる傾斜面部とを備えた構成としたので、型閉め・型開きの動作によって型内発泡成形時に銘板が凹部から突出して発泡樹脂成形品の外面に接触し、型開き時には銘板が凹部内に引っ込むように、自動的に銘板をスライド移動させることができ、発泡樹脂成形品に刻まれた表示が銘板に食い込んだまま発泡樹脂成形品を離型して、表示の凸部が千切れるなどの不具合を生じることがないので、発泡樹脂成形品の外面に明瞭な表示を形成することができる。
また、３ｍｍ以上の高さの凸部を有する表示であっても綺麗に形成することができるので、遠方からでも識別が容易な、意匠性に優れた表示を形成することができる。
また、成形型の内部に設けた銘板をスライド移動させるので、付設のために余分なスペースが必要なエアーシリンダー等の余分な機器を設ける必要がなく、表示形成機構を設けていない成形型と同等の設置スペースとすることができる。
また、押圧部材で銘板保持部を押圧してスライドさせる単純な構造なので、耐熱性、耐久性に優れ、蒸気が当たる高温条件下でも故障することなく長期間使用でき、更にメンテナンスも容易である。
また本発明の成形品は、本発明の発泡樹脂成形型を用いて作製されたものなので、表示の凹凸を２ｍｍ以上、好ましくは３ｍｍ以上とすることができ、しかも凸部の立ち上がりがシャープなものとなるので、明瞭なものとなる。
また本発明の成形品は、表示の周囲に沿って凹溝を設けて深彫りされてなり、深彫り部の深さを３〜１０ｍｍ、幅を３〜１０ｍｍの範囲としたことによって、凹溝と凸面との境界が明瞭となり、凸面により表される文字やマーク等が明瞭で見やすくなり、遠くからでも識別でき、意匠性を向上できる。
また、本発明の成形品において、成形品を着色することによって、表示が一層明瞭なものとなる。
【図面の簡単な説明】
【図１】本発明の発泡樹脂成形型の一例を示し、型開き状態の断面図である。
【図２】同じ発泡樹脂成形型の形閉め状態の断面図である。
【図３】同じ発泡樹脂成形型に設けた表示形成機構を示す斜視図である。
【図４】従来の表示付き発泡樹脂成形品を示し、（ａ）は正面図、（ｂ）は（ａ）中のＡ−Ａ部断面図である。
【図５】本発明の表示付き発泡樹脂成形品の第１の例を示し、（ａ）は正面図、（ｂ）は（ａ）中のＡ−Ａ部断面図である。
【図６】本発明の表示付き発泡樹脂成形品の第２の例を示す正面図である。
【図７】本発明の表示付き発泡樹脂成形品の第３の例を示し、（ａ）は正面図、（ｂ）及び（ｃ）は（ａ）中のＡ−Ａ部断面図である。
【符号の説明】
Ａ…発泡樹脂成形型、Ｂ，Ｃ…表示付き発泡樹脂成形品、１…キャビティ金型（第１の成型形）、２…コア金型（第２の成形型）、３…キャビティ、４…キャビティ面、５…凹部、６…銘板保持部、７…銘板、８…押圧部材、９…傾斜面、１０…傾斜面部、１１…表示形成機構、１２…圧縮バネ、１３…支柱、１４…孔、１５…コア金型取付板、２１…底板部、２２…側壁部、２３〜２８…表示、２９…凹面、３０…凸面、３１…凹溝。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a foamed resin mold for producing a foamed resin molded article, and a foamed resin molded article with a display manufactured using the mold, and more specifically, a clear display on the surface of the foamed resin molded article. The present invention relates to a foamed resin molding die capable of forming a foamed resin mold and a foamed resin molded article with a display having a clear display by deep engraving on the surface.
[0002]
[Prior art]
Generally, a container-shaped foamed resin molded product consists of a cavity mold on the fixed side and a core mold that can move in the mold closing / opening direction with respect to this cavity mold. It is manufactured by using a molding die in which matching cavities are formed, filling the cavities with expandable resin particles, heating the foamable resin particles through steam into the mold, and performing in-mold foam molding.
A container-shaped foamed resin molded product (hereinafter sometimes abbreviated as “container”) for containing fish, vegetables, etc. is used to improve the design and to display the shipping origin, etc. ) Or on the top of the container lid, the name of the contents, the name of the company, or a logo is often displayed.
Conventionally, as a method of providing characters, marks, etc. on the surface of a foamed resin molded product, a method of engraving characters, marks, etc. in a mold for producing a foamed resin molded product and displaying them with relief characters, or plain molding A method of sticking an adhesive tape that has been subjected to color printing or the like in post-processing is performed. Among these display methods, the method of applying the adhesive tape in post-processing is beautiful in design, but there is a problem that processing cost is high and proper value cannot be obtained.
[0003]
As a mold for displaying relief characters on the surface of a foamed resin molded product, for example, there is a structure in which a dial is attached to the recessed portion of a cavity mold (concave mold) and a raised character is formed on the outer surface of the foamed molded product. It has been proposed (see, for example, Patent Document 1). In this mold structure, since the plate pressure of the dial is the same as the depth of the recessed portion of the cavity mold, the surface of the dial and the surface of the cavity mold are flush with each other.
In addition, in order to drill holes in the side of the foamed resin molded product, a rotary core is provided in the cavity mold, and the core mold closes and the core enters and exits into the cavity when the mold is opened. It has been proposed (see, for example, Patent Document 2).
Also, in order to prevent the foamed resin molded product foam-molded in the mold from moving in the release direction, a structure has been proposed in which the air cylinder is pressed against the side of the molded product in a direction crossing the mold opening / closing direction. (For example, refer to Patent Document 3).
In order to efficiently produce a product having an undercut portion, an air cylinder is provided in the core mold, and a structure in which a molding-related member enters the cavity from the back side of the core mold has been proposed (for example, , See Patent Document 4).
In addition, as a molding die for revealing uneven patterns, letters, etc. on the surface of the foamed resin molded product, steam holes are drilled on the upper surface and lower surface of the mold, and the surface on which the steam holes are not drilled The mold is communicated over the edge in the direction in which the molded body of the mold is taken out, a recess is formed with a width wider than the opening, and a small piece that matches the recess is inserted, There has been proposed a molding die that can take out a small piece together with a molded body (for example, see Patent Document 5).
[0004]
[Patent Document 1]
Japanese Utility Model Publication No. 62-28522
[Patent Document 2]
Japanese Utility Model Publication No. 6-55730
[Patent Document 3]
Japanese Utility Model Publication No. 58-15015
[Patent Document 4]
JP-A-6-114959
[Patent Document 5]
Japanese Utility Model Publication No. 47-42541
[0005]
[Problems to be solved by the invention]
However, in the technique described in Patent Document 1, when the height of the character is about 2 mm or more, when the mold is opened and the foamed resin molded product is released, the raised character is peeled off to the dial. There is a problem that only a low-profile and unclear display can be formed.
In addition, the technique described in Patent Document 2 is for making a hole for passing a string for transportation, and is a structure in which a core is rotated and inserted into a cavity when the mold is closed. Even if this structure is applied for display, there is a problem that the display cannot be engraved at right angles to the product surface, and the shoulder portion of the display is rounded and a sharp display cannot be obtained.
In the technique described in Patent Document 3, an indication can be provided on the outer surface of the molded product by moving a display nameplate or the like by an air cylinder at right angles to the mold opening direction. Therefore, when applying a large number of molding equipment to a multi-cavity molding facility that is compactly arranged in the workplace, the space between the molding equipment becomes large, and the number of molding equipment that can be installed in the workplace is large. There is a problem that the production efficiency decreases substantially due to the decrease. Also, air cylinders may malfunction due to the effects of heat, and cannot be installed where steam directly hits.
In the technique described in Patent Document 4, it is impossible to provide a display on the outer surface of the foamed resin molded product on the side in contact with the cavity mold.
Moreover, in the technique described in Patent Document 5, the small piece for display formation must be separated after releasing the foamed resin molded product and reattached by the next molding step, resulting in a decrease in production efficiency. There is.
[0006]
The present invention has been made in view of the above circumstances, and an object thereof is to provide a foamed resin mold that can form a clear display on the surface of the foamed resin molded product, and a foamed resin molded product with a display that has a clear display on the surface. It is said.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a first mold and a second mold in which at least one of the cavities is movable in the mold closing / opening direction is formed in which a cavity matching the target molding shape is formed when the mold is closed. A foamed resin molding die in which foamable resin particles are filled in the cavity, and foamed resin molding is produced by in-mold foam molding, wherein at least one of the first molding die and the second molding die A nameplate holder that can be projected and retracted in a recess provided on one cavity surface and urged toward the recess, and a desired display provided on the side of the nameplate holder that is in contact with the foamed resin molded product. A nameplate to be transferred to the foamed resin molded product, a pressing member that approaches the nameplate holding portion when the mold is closed, and is separated from the nameplate holding portion when the mold is opened, and is provided on the nameplate holding portion, and contacts the pressing member when the die is closed. And has an inclined surface By the pressing member to provide a resin foam form characterized in that it comprises an inclined surface portion is moved in a direction to push the nameplate holder from the recess.
In the foamed resin mold of the present invention, the first mold on the fixed side is provided with a display forming mechanism including the concave portion, the nameplate holding portion, the nameplate, the pressing member, and the inclined surface portion, and the pressing The member is provided in a state where a part of the member protrudes from the first mold and is biased toward the protruding direction when the mold is opened, and the second mold moves to move the first mold It is preferable that the projecting portion of the pressing member is in contact with and pressed against the inclined surface by the second molding die when the mold is fitted to.
Moreover, it is preferable that the front-end | tip part of a press member is a wedge shape which can slide the said inclined surface.
Further, the display engraved on the nameplate is preferably provided with a deep engraving protrusion along the periphery of the display, and the protrusion has a height of 3 to 10 mm and a width of 3 to 10 mm.
The present invention also uses the foamed resin mold, closes the first mold and the second mold, fills the cavity with foamable resin particles, and heats the foamable resin particles with steam. Thus, a foamed resin molded article with a display, which is manufactured by performing in-mold foam molding, opening the mold after cooling, and taking out the foamed resin molded body, is provided.
In the foamed resin molded product with display of the present invention, the display provided on the surface of the foamed resin molded product is deeply engraved along the periphery of the display, the depth of the deeply engraved portion is 3 to 10 mm, and the width is It is preferable that it is 3-10 mm.
Moreover, it is preferable that the foamed resin molded product is colored.
Furthermore, the present invention is a foamed resin molded article having a display on the surface, the display is deeply engraved along the periphery of the display, the depth of the deeply engraved portion is 3 to 10 mm, and the width is Provided is a foamed resin molded article with a display which is 3 to 10 mm.
In the foamed resin molded article with display of the present invention, the foamed resin molded article is preferably colored.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to the drawings.
1 and 2 show an example of a foamed resin molding die according to the present invention. FIG. 1 shows when the mold is opened, FIG. 2 shows when the mold is closed, and reference numeral A in these figures indicates foamed resin molding. It is a type.
In this example, a foamed resin molding die for producing a box-shaped foamed resin molded product composed of a bottom plate portion and a side wall portion standing from the periphery thereof is illustrated, but the present invention is not limited to this. It can be applied to a foamed resin molding die for producing a foamed resin molded product having a shape other than a box shape.
[0009]
The foamed resin molding die A includes a fixed first molding die (hereinafter referred to as a cavity mold 1) in which a cavity 3 that matches a target molding shape is formed when the mold is closed, and the cavity molding die 1. A second mold (hereinafter referred to as a core mold 2) provided so as to be movable up and down in a vertical direction so that the mold can be closed and opened with respect to the cavity mold 1; Then, the mold is fitted to the cavity mold 1 and the mold is closed, the foamable resin particles are filled in the cavity 3 between the two molds, and the foamed resin molded product is manufactured by in-mold foam molding.
[0010]
In this example, the cavity mold 1 on the fixed side can be projected and retracted in a recess 5 provided on a surface in contact with the cavity 3 (hereinafter referred to as a cavity surface 4) and is urged toward the recess 5 side. A nameplate holding portion 6, a nameplate 7 for transferring a desired indication provided on the side of the nameplate holding portion 6 in contact with the foamed resin molded product to the foamed resin molded product, and the nameplate holding portion 6 when the mold is closed, The pressing member 8 is provided so as to be movable in the vertical direction so as to be separated from the nameplate holding part 7 when the mold is opened, and the inclined surface 9 is provided on the nameplate holding part 6 and comes into contact with the pressing member 8 when the mold is closed. An inclined surface portion 10 is provided that moves the nameplate holding portion 6 in the direction of pushing out the recessed portion 5 by pressing the member 8.
[0011]
The cavity mold 1 and the core mold 2 are preferably formed from copper, aluminum, an alloy of copper and aluminum, and an alloy of copper, aluminum, magnesium and manganese (duralumin) having good thermal conductivity. A foamable resin particle supply pipe (not shown) for supplying foamable resin particles into the cavity 3 is integrally provided at any part of the cavity mold 1 and the core mold 2. A filler valve (not shown) is interposed in the foamable resin particle supply pipe, and an extrusion pin (not shown) for releasing the foamed resin molded product from the cavity mold 1 is integrally provided. It has been. The cavity mold 1 and the core mold 2 have a hollow structure, and a pipe for circulating steam and cooling water and a pipe for vacuum exhaust are connected to the hollow portion (chamber). The cavity surface 4 of the cavity mold 1 and the core mold 2 has a large number of steam (not shown) for communicating the inside of the cavity 3 formed by closing these molds with the hollow portion. A hole is provided.
[0012]
FIG. 3 is a view showing an example of a display forming mechanism provided in the cavity mold 1, and the display forming mechanism 11 includes a nameplate holding portion 6, a pressing member 8, and an inclined surface portion 10. . The display forming mechanism 11 is accommodated in the recess 5 of the cavity mold 1. The recessed part 5 and the display formation mechanism 11 can be provided in one or more places in the cavity mold 1 according to the side wall part which forms a display among the side wall part outer surfaces of a box-shaped foamed resin molded product. For example, when a display is provided on the outer surfaces of two opposite side walls of the foamed resin molded product, the recess 5 and the display forming mechanism 11 can be provided at the position of the cavity mold 1 corresponding thereto.
[0013]
The nameplate holding portion 6 has a thick plate shape in which a nameplate 7 is detachably fixed on the cavity surface 4 side and an inclined surface portion 10 is fixed on the back side. The nameplate holder 6 is urged in a direction toward the recess 5 by a spring (not shown). The urging structure of the nameplate holding portion 6 is not particularly limited, and the concave portion 6 and the nameplate holding portion 6 may be directly joined by a tension spring to be urged toward the concave portion 5, or the pin into which the spring is inserted is recessed. The other end of the pin may be fixed to the nameplate holding part 6 and urged toward the concave part 5 side.
[0014]
One to a plurality of nameplates 7 are detachably fixed to the molding surface side of the nameplate holding portion 6. The display on the nameplate 7 can transfer the display of characters and marks to be formed on the outer surface of the foamed resin molded body. In a preferred embodiment of the present invention, the display engraved on the nameplate 7 is provided with a deep engraving protrusion along the periphery of the display, the protrusion having a height of 3 to 10 mm and a width of 3 to 10 mm. Is done. The display formed using the nameplate 7 having such a protrusion has a deep recess having a depth of 3 to 10 mm and a width of 3 to 10 mm along the periphery of the character or mark, and this display is formed. When the outer surface of the foamed resin molded product is viewed, this deep dent is shaded to emphasize the contrast between the projected display center and the light and dark, and the display can be clearly confirmed even from a distance. The display formed on the foamed resin molded product by the nameplate 7 can use various characters and symbols such as letters, numbers, patterns, and various marks.
[0015]
In the illustrated example, the pressing member 8 is formed in a wedge shape having an inclined surface 9 and a slidable inclined surface at the tip. The tip portion is divided into two, and the upper end of a support column 13 urged upward by a compression spring 12 is attached to the center of the divided portion. The lower end portion of the column 13 is inserted into a hole 14 provided in the cavity mold 1 so as to be movable up and down. The compression spring 12 cannot be inserted into the hole 14, and as the pressing member 8 is lowered, the compression spring 12 is compressed between the lower end of the pressing member 8 and the peripheral edge of the upper end of the hole 14, and when the mold is opened. The pressing member 8 is moved upward by the urging force.
[0016]
The upper end of the pressing member 8 is provided so as to protrude a predetermined length from the upper end of the cavity mold 1 when the mold shown in FIG. 1 is opened. The upper end portion of the cavity mold 1 abuts on the lower surface of the core mold mounting plate 15 to which the core mold 2 is attached and moved when the mold is closed as shown in FIG. Therefore, when the mold is closed, the cavity mold 1 is positioned near the upper end.
[0017]
The inclined surface portion 10 is fixed to the back side of the nameplate holding portion 6. The inclined surface 9 of the inclined surface portion 10 is inclined in a direction in which the wall thickness gradually increases from the nameplate holding portion 6 toward an obliquely downward direction. The inclined surface 9 may be flat or curved. The length and the inclination angle of the inclined surface 9 are such that when the lower end surface of the pressing member 8 abuts and descends by a predetermined interval, the nameplate 7 comes out of the recess 5 and can form an indication on the outer surface of the foamed resin molded product. Thus, the nameplate holder 6 is appropriately set so that it can slide smoothly.
[0018]
Next, a method for producing a foamed resin molded product B with a display having a display on the outer surface of the side wall portion using the foamed resin mold A will be described.
First, as shown in FIG. 1, a nameplate 7 capable of forming a desired display is fixed to the nameplate holding portion 6, and the core mold mounting plate 15 is lowered to fit the core mold 2 to the cavity mold 1. The mold is closed as shown in FIG. When the mold is closed, a cavity 3 is formed between the cavity surfaces 4 of the cavity mold 1 and the core mold 2 to match the shape of the foamed resin molded product to be manufactured. When the mold is closed, the pressing member 8 comes into contact with the lower surface of the core mold mounting plate 15 and is pressed down. The inclined surface at the tip presses the inclined surface 9 of the inclined surface portion 10 and is stored in the recess 5. The holding part 6 slides to the core mold 2 side, and the cavity surface of the nameplate 7 is located at a position slightly protruding from the recess 5.
[0019]
After lowering the core mold 2 to the closed state shown in FIG. 2, the filler valve is opened, and the foamable resin particles are supplied and filled into the cavity 3 through the foamable resin particle supply pipe.
Expandable resin particles are obtained by pre-foaming synthetic resin particles containing a foaming agent. Synthetic resins constituting the synthetic resin particles are conventionally used for manufacturing foamed resin molded products. Can be appropriately selected from the resin materials that are used, and is not particularly limited, for example, polystyrene resins such as polystyrene, high impact polystyrene, styrene-maleic anhydride copolymer, styrene-acrylonitrile copolymer, Examples thereof include polyolefin resins such as polyethylene, polypropylene, and ethylene-vinyl acetate copolymer, and polyester resins such as polyethylene terephthalate. Polystyrene resins are preferred in terms of strength and moldability.
[0020]
Further, as the foaming agent, organic compounds that have a boiling point below the softening point of the synthetic resin and are gaseous or liquid at normal pressure are suitable. For example, propane, butane, pentane, cyclopentane, cyclopentadiene, hexane Further, hydrocarbons such as petroleum ether, low boiling point ether compounds such as dimethyl ether, diethyl ether, dipropyl ether, and methyl ethyl ether, inorganic gases such as carbon dioxide and nitrogen, and the like are used. These foaming agents may use only 1 type and may use 2 or more types together. As a content rate of a foaming agent, it is 1-20 mass% with respect to the synthetic resin particle mass, Preferably it is 2-10 mass%. When the content of the foaming agent is less than the above range, the foaming ratio of the foamed molded product is insufficient and a lightweight foam cannot be obtained. On the other hand, even if the content of the foaming agent exceeds the above range, a further increase in the expansion ratio cannot be substantially expected, and foaming becomes unstable, which is not preferable.
[0021]
After filling the cavity 3 with expandable resin particles, the foamable resin particles in the cavity 3 are vapor-heated through the vapor holes formed in the cavity surface 4 of each mold, thereby fusing the particles together. In-mold foam molding and then cooled.
During this in-mold foam molding, the cavity surface of the nameplate 7 slightly protruding from the recess 5 of the cavity mold 1 abuts on the outer surface of the side wall portion of the foamed resin molded product. The display along the unevenness is transferred.
[0022]
After cooling, the core mold mounting plate 15 is raised, and the core mold 2 is removed from the cavity mold 1 to be in the mold open state. When the core mold mounting plate 15 is raised, the pressing member 8 is lifted by the urging force of the compression spring 12, and the pressing to the inclined surface 9 by the pressing member 8 is released. As the pressing member 8 rises, the nameplate holding portion 6 slides toward the concave portion 5 by a biasing force of a spring (not shown), and the nameplate 7 moves away from the outer surface of the side wall portion of the foamed resin molded product and enters the concave portion 5. In this way, when the mold plate is opened, the nameplate 7 is separated from the foamed resin molded product and retracted into the recess 5, so that the foamed resin molded product is released while the display engraved on the foamed resin molded product is still in the nameplate 7. Inconveniences such as breaking of the convex portion of the display do not occur. After opening the mold, the manufactured foamed resin molded product with display is taken out from the cavity mold 1.
[0023]
The foamed resin mold A includes a nameplate holding portion 6 that can be projected and retracted in a recess 5 provided on the cavity surface 4 of the cavity mold 1 and is urged toward the recess 5, and the nameplate holding portion 6. A nameplate 7 provided on the cavity surface side, a pressing member 8 that approaches the nameplate holding portion 6 when the mold is closed and is separated from the nameplate holding portion when the mold is opened, and a pressing member 8 that is provided on the nameplate holding portion 6 and that is provided when the mold is closed. Since it has a configuration including an inclined surface 9 that has an abutting inclined surface 9 and moves the nameplate holding portion 6 in a direction of pushing out the recessed portion 5 by pressing of the pressing member 8, the mold is closed by mold closing and mold opening operations. The nameplate 7 protrudes from the recess 7 at the time of foam molding and contacts the outer surface of the foamed resin molded product, and the nameplate 7 can be automatically slid so that the nameplate 7 retracts into the recess 5 at the time of mold opening. The indication engraved on the molded product 7 to release the resin foam product remains bites, the convex portion of the display is prevented from causing troubles such as torn off, it is possible to form a clear display on the outer surface of the resin foam product.
In addition, even a display having a convex portion with a height of 3 mm or more can be formed neatly, so that a display with excellent design that can be easily identified from a distance can be formed.
Further, since the nameplate 7 is slid by the display forming mechanism 11 provided in the cavity mold 1, it is not necessary to provide an extra device such as an air cylinder which requires an extra space for attachment, and the display forming mechanism It can be set as the installation space equivalent to the shaping | molding die which is not provided.
Further, the display forming mechanism 11 has a simple structure in which the nameplate holding portion 6 is pressed and slid by the pressing member 8, so that the display forming mechanism 11 is excellent in heat resistance and durability, and is used for a long time without failure even under a high temperature condition where the steam hits. And maintenance is easy.
[0024]
Next, the foamed molded article with display will be described.
FIG. 4 is a view showing a conventional foamed resin molded product with a display. The foamed resin molded product with display (hereinafter referred to as a molded product) C shown in FIG. 4A is composed of a bottom plate portion 21 having a rectangular shape and a side wall portion 22 erected from the periphery thereof. The display 23 is formed on the outer surface of the side wall 22. As shown in FIG. 4B, the display 23 includes a flat concave surface 29 provided on the side wall portion 22, and a convex surface 30 representing characters, marks, and the like on the concave surface 29. Since the display 23 has a display structure in which a convex surface 30 representing characters, marks, and the like is projected from a flat concave surface 29, when the display 23 is viewed from the outside, the boundary between the convex surface 30 and the concave surface 29 depends on the viewing angle. Is not clear.
[0025]
FIG. 5 is a view showing a first example of a molded product according to the present invention. As shown in FIG. 5A, the molded product B includes a bottom plate portion 21 and a side wall portion 22 erected from the periphery thereof, and a display 24 is formed on the outer surface of the side wall portion 22. In this example, as shown in FIG. 5 (b), a deep engraving is made along the periphery of the display 24 by a concave groove 31, and a convex surface 32 representing characters, marks, etc. is defined by the concave groove 31. The molded product B having such a display structure can be manufactured using the foamed resin mold A according to the present invention.
[0026]
The depth of the deeply carved portion composed of the concave groove 31 is 2 mm or more, preferably 3 to 10 mm, and the width is 2 mm or more, preferably 3 to 10 mm. In this way, the display 24 in which the periphery of the convex surface 32 such as a character or a mark is deeply engraved with the concave groove 31, and when the side wall portion 22 is viewed under normal brightness, the concave groove 31 becomes a shade and this portion becomes dark. On the other hand, since the convex surface 32 looks bright, the boundary between the concave groove 31 and the convex surface 32 becomes clear, the characters and marks represented by the convex surface 32 are clear and easy to see, and can be identified from a distance, improving the design. it can. On the other hand, when the depth and width of the groove 31 are less than the above range, the display 24 becomes unclear.
[0027]
The molded product B of the present invention is deeply engraved by providing a concave groove 31 along the periphery of the display, and the depth of the deeply engraved portion is in the range of 3 to 10 mm and the width is in the range of 3 to 10 mm. The boundary between the groove 31 and the convex surface 32 becomes clear, the characters, marks, etc. represented by the convex surface 32 are clear and easy to see, can be identified from a distance, and the design can be improved.
In the first example, the molded product B is preferably colored light blue or the like. By coloring the molded product B, the display 24 becomes clearer. When coloring, it can manufacture easily by performing in-mold foam molding using expandable resin particles previously blended with a colorant.
[0028]
FIG. 6 is a view showing a second example of a molded product according to the present invention. The

indications

25 and 26 formed on the molded product B are substantially the same as the indication 24 in the first example, but the indication 25 obtained by roughening the groove surface of the concave groove 31 and the convex surface 26 are colored. Display 26.
[0029]
In order to form the display 25 in which the groove surface of the concave groove 31 is roughened, the surface of the protrusion provided on the nameplate 7 to form the concave groove 32 is roughened to a rough surface such as pear by etching or sandblasting. It is obtained by forming the molded product B using this nameplate 7 in advance. By roughening the groove surface of the concave groove 31 in this way, the concave groove 32 looks darker and the contrast with the convex surface 32 can be emphasized.
[0030]
In addition, the display 26 in which the convex surface 26 is colored is formed by coloring using a suitable printing method after the molded product B is manufactured. The color tone of the display 26 is not particularly limited.
[0031]
FIG. 7 is a view showing a third example of the molded product according to the present invention. The display formed on the molded product B is substantially the same as the display 24 in the first example, but a display 27 having a rising surface on the convex surface 32 side of the concave groove 31 as a tapered surface (FIG. 7B), Or the display 28 (FIG.7 (c)) which made the standing surface by the side of the convex surface 32 of the ditch | groove 31 curved is provided. These indications can be obtained by forming a taper surface or a concave curved surface on the projection provided on the name plate 7 in order to form the concave groove 32, and manufacturing the molded product B using the name plate 7.
[0032]
In the display 27 in which the rising surface shown in FIG. 7B is a tapered surface, or the display 28 in which the rising surface shown in FIG. 7C is a curved surface, the shade of the groove 31 crosses the tapered surface or the curved surface. Light and dark becomes clearer.
[0033]
【Example】
Using the mold configured as shown in FIGS. 1 and 2, the molded product shown in FIG. 5 was produced. For comparison, a conventional molded product shown in FIG. 4 was produced.
For the expandable resin particles, white raw material HDM and colored raw material HDM dark blue (hereinafter referred to as blue raw material) manufactured by Sekisui Plastics Co., Ltd. were used as raw material beads. Each raw material bead is foamed with a pre-foaming machine (Sekisui Koki Co., Ltd., SKK-110 type) at a foaming ratio of 60 times and retained in a breathable silo for about 24 hours, and then a molding machine (manufactured by Sekisui Koki Co., Ltd.). ACE-30QS), the nameplate for forming the display structure shown in FIG. 5 and the nameplate for forming the display structure shown in FIG. 4 were alternately attached and molded. Table 1 shows the main steps and conditions during one molding cycle. In addition to the above steps, there are mold opening / closing steps, mold releasing steps, and the like in one molding cycle, and the total number of seconds in each step in the table does not become the actual one cycle value. In Table 1, the conventional molded product is a molded product manufactured by attaching a name plate for forming the display structure shown in FIG. 4, and the deeply engraved character molded product forms the display structure shown in FIG. It is a molded product that is manufactured by attaching a nameplate for the purpose.
[0034]
[Table 1]

[0035]
The following interpretation test was conducted.
·sample
Example 1 A molded product having the display structure shown in FIG. 5 was produced using a blue raw material. The recess depth was 5 mm and the recess width was 5 mm.
Example 2 A molded product having the display structure shown in FIG. 5 was produced using a white raw material. The recess depth was 5 mm and the recess width was 5 mm.
Comparative Example 1 A molded product having the display structure shown in FIG. 4 was produced using a blue raw material. The character height was 5 mm.
(Comparative Example 2): A molded article having the display structure shown in FIG. 4 was produced using a white raw material. The character height was 5 mm.
[0036]
·Measurement condition
A sample was placed in a room where the light source was the ceiling, and two persons with visual acuity (naked eyes) of 1.0 and 0.5 discriminated display characters on the outer surface of the sample from a predetermined distance. The brightness near the characters was 330 lux.
[0037]
・ Interpretation evaluation
: Characters can be clearly read.
○: Characters can be read.
×: Characters cannot be read.
[0038]
·test results
The results measured with a panel with a visual acuity (naked eye) of 1.0 are shown in Table 2, and the results of measurement with a panel with a visual acuity (naked eye) of 0.5 are shown in Table 3, respectively.
[0039]
[Table 2]

[0040]
[Table 3]

[0041]
As a result of the test, both Example 1 using the blue material and Example 2 using the white material became clearer than the conventional Comparative Examples 1 and 2.
In the case of the molded product of Example 2 using a white raw material, the shaded portion was gray and the characters appeared to be raised, so that the characters could be read even from a distance.
Further, in the case of the molded product of Example 1 using a blue raw material, the shaded portion becomes dark blue and the characters appear to be further raised, so that the characters can be read even from a further distance.
[0042]
【The invention's effect】
As described above, the foamed resin mold of the present invention includes a nameplate holding part that can be projected and retracted in a recess provided in the cavity surface of the first mold and is biased toward the recess, and the nameplate holding The nameplate provided on the cavity surface side of the part, the pressing member that approaches the nameplate holding part when the mold is closed, and is separated from the nameplate holding part when the mold is opened, and the inclination that is provided on the nameplate holding part and contacts the pressing member when the mold is closed It has a surface and an inclined surface part that moves the nameplate holding part in the direction to push it out from the concave part by pressing the pressing member, so that the nameplate protrudes from the concave part during in-mold foam molding by mold closing and mold opening operations. The nameplate can be automatically slid so that the nameplate is retracted into the recess when the mold is opened, and the display engraved on the foamed resin molding remains in the nameplate. Foam resin And releasing the molded article, the convex portion of the display is prevented from causing troubles such as torn off, it is possible to form a clear display on the outer surface of the resin foam product.
In addition, even a display having a convex portion with a height of 3 mm or more can be formed neatly, so that a display with excellent design that can be easily identified from a distance can be formed.
In addition, because the nameplate provided inside the mold is slid, there is no need to install extra equipment such as an air cylinder that requires extra space for installation, and it is equivalent to a mold that does not have a display formation mechanism. Installation space.
In addition, since it has a simple structure in which the nameplate holding part is pressed and slid by the pressing member, it has excellent heat resistance and durability, can be used for a long time without failure even under high-temperature conditions where it is exposed to steam, and maintenance is also easy.
Further, since the molded product of the present invention is produced using the foamed resin mold of the present invention, the unevenness of the display can be 2 mm or more, preferably 3 mm or more, and the rising of the convex part is sharp. Therefore, it becomes clear.
Further, the molded product of the present invention is deeply engraved by providing a concave groove along the periphery of the display, and the depth of the deeply engraved portion is in the range of 3 to 10 mm and the width is in the range of 3 to 10 mm. The boundary between the convex surface and the convex surface becomes clear, the characters and marks represented by the convex surface become clear and easy to see, can be identified from a distance, and the design can be improved.
In the molded product of the present invention, the display becomes clearer by coloring the molded product.
[Brief description of the drawings]
FIG. 1 shows an example of a foamed resin molding die according to the present invention, and is a cross-sectional view in a mold open state.
FIG. 2 is a sectional view of the same foamed resin molding die in a closed state.
FIG. 3 is a perspective view showing a display forming mechanism provided in the same foamed resin mold.
4A and 4B show a conventional foamed resin molded article with a display, in which FIG. 4A is a front view, and FIG. 4B is a cross-sectional view taken along line AA in FIG.
5A and 5B show a first example of a foamed resin molded article with a display according to the present invention, in which FIG. 5A is a front view, and FIG. 5B is a cross-sectional view taken along line AA in FIG.
FIG. 6 is a front view showing a second example of the foamed resin molded article with display of the present invention.
FIGS. 7A and 7B show a third example of a foamed resin molded article with a display according to the present invention, in which FIG. 7A is a front view, and FIGS. 7B and 7C are cross-sectional views taken along line AA in FIG.
[Explanation of symbols]
A ... Foamed resin mold, B, C ... Foamed resin molded product with display, 1 ... Cavity mold (first mold), 2 ... Core mold (second mold), 3 ... Cavity, 4 ... Cavity surface, 5 ... concave portion, 6 ... nameplate holding portion, 7 ... nameplate, 8 ... pressing member, 9 ... inclined surface, 10 ... inclined surface portion, 11 ... display forming mechanism, 12 ... compression spring, 13 ... strut, 14 ... hole 15 ... Core mold mounting plate, 21 ... Bottom plate part, 22 ... Side wall part, 23-28 ... Display, 29 ... Concave surface, 30 ... Convex surface, 31 ... Concave groove.

Claims

A cavity that matches the target molding shape is formed when the mold is closed, at least one of which includes a first mold and a second mold that can move in the mold closing / opening direction, and the cavity has foamability In a foamed resin mold that is filled with resin particles and foamed in-mold to produce a foamed resin molded product,
A nameplate holding part that can be projected and retracted in a recess provided on at least one cavity surface of the first mold and the second mold and is biased toward the recess, and foaming of the nameplate holding part A nameplate for transferring a desired indication provided on the side in contact with the resin molded product to the foamed resin molded product, a pressing member that approaches the nameplate holding portion when the mold is closed, and is separated from the nameplate holding portion when the mold is opened, and the nameplate An inclined surface portion provided on the holding portion and having an inclined surface that comes into contact with the pressing member when the mold is closed, and moves the nameplate holding portion in a direction of pushing out the concave portion by pressing of the pressing member. Foaming resin mold.

The first molding die on the fixed side is provided with a display forming mechanism including the concave portion, the nameplate holding portion, the nameplate, the pressing member, and the inclined surface portion, and the pressing member is partially opened when the mold is opened. Projecting from the first mold and being biased toward the projecting direction, and when the mold is closed when the second mold is moved and fitted into the first mold, The foamed resin mold according to claim 1, wherein a protruding portion of the pressing member is configured to contact and be pressed against the inclined surface by the second mold.

The foamed resin mold according to claim 1 or 2, wherein a tip portion of the pressing member has a wedge shape that can slide on the inclined surface.

The display engraved on the nameplate is provided with a protrusion for deep engraving along the periphery of the display, and the protrusion has a height of 3 to 10 mm and a width of 3 to 10 mm. The foamed resin mold described.

Using the foamed resin mold according to any one of claims 1 to 4, the first mold and the second mold are closed, and the cavity is filled with expandable resin particles, A foamed resin molded article with a display, which is produced by subjecting foamable resin particles to steam heating to perform in-mold foam molding, and after cooling, to open the mold and take out the foamed resin molded article.

The display provided on the surface of the foamed resin molded article is deeply engraved along the periphery of the display, and the depth of the deeply engraved portion is 3 to 10 mm and the width is 3 to 10 mm. Foamed resin molded product with display.

The foamed resin molded article with a display according to claim 5 or 6, wherein the foamed resin molded article is colored.

A foamed resin molded product having a display on the surface, wherein the display is deeply engraved along the periphery of the display, and the depth of the deeply engraved portion is 3 to 10 mm and the width is 3 to 10 mm A foamed resin molded product with a display characterized by the above.

The foamed resin molded article with a display according to claim 8, wherein the foamed resin molded article is colored.