JP2004060794A

JP2004060794A - Vacuum heat insulating material, and manufacturing method of its core material

Info

Publication number: JP2004060794A
Application number: JP2002221016A
Authority: JP
Inventors: Tomonao Amayoshi; 天良　智尚; Yoshihide Hirai; 平井　善英; Yasuaki Tanimoto; 谷本　康明; Toshio Kobayashi; 小林　俊夫
Original assignee: Matsushita Refrigeration Co
Current assignee: Panasonic Holdings Corp
Priority date: 2002-07-30
Filing date: 2002-07-30
Publication date: 2004-02-26
Anticipated expiration: 2022-07-30
Also published as: JP3527730B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum heat insulating material capable of reducing generation amount of waste material of a core material. <P>SOLUTION: In the vacuum heat insulating material, the core material 1 formed by compression-molding an inorganic fiber assembly and solidifying it with a binder is coated with envelope material having gas barrier property, and its inside is decompressed. The core material 1 is constituted by a plurality of laminated sheet inorganic fiber assemblies 3. Ground products 4 of the waste material of the core material 1 remaining when the core material 1 having a required size is extracted by cutting in an intermediate part formed by removing ends of a molded body from the molded body as a base of the core material 1 are mixed between the laminated sheet inorganic fiber assemblies 3. Thus, wastage of the waste material of the core material 1 can be reduced, and resources can be used effectively. A harmful effect on strength and flatness of the outer surface of the core material 1 by mixing the ground products 4 of the waste material of the core material 1 can be minimized. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、無機繊維集合体からなる芯材を外被材で被覆した真空断熱材と、その芯材の製造方法に関する。
【０００２】
【従来の技術】
近年、地球温暖化防止の観点から省エネルギーが強く望まれており、家庭用電化製品についても省エネルギー化は緊急の課題となっている。特に、冷蔵庫、冷凍庫、自動販売機、電気ポット等の保温保冷機器では熱を効率的に利用するという観点から、芯材をガスバリア性のラミネートフィルムで覆って内部を減圧し封止した真空断熱材の使用が提案されている。
【０００３】
真空断熱材の芯材としては、様々な材料が提案されているが、特開平９−１４５２３９号公報では、比較的形状加工が容易な無機繊維集合体を芯材に使用している。
【０００４】
上記従来の無機繊維集合体から芯材を作る方法は、まず、無機繊維集合体にバインダーを加えて固め成型して得られた成型体から、成型体の端部を除いた中間部分において切断により必要な大きさの芯材を取り出すのである。
【０００５】
【発明が解決しようとする課題】
上記従来の真空断熱材の芯材は、成型体から、成型体の端部を除いた中間部分において切断により必要な大きさの芯材を取り出すので、成型体から芯材を取り出した後に芯材の廃材が残る。
【０００６】
特に真空断熱材の適用製品、適用箇所が増えてくると、様々な大きさ形状の複数種類の芯材が必要になり、少ない種類の成型体から様々な大きさ形状の複数種類の芯材を取り出そうとすると、廃材の発生量が増加するが、この廃材の処分が問題となる。
【０００７】
すなわち、この廃材は焼成時の熱履歴があり熱で硬化したバインダーが付着しているため、無機繊維集合体の原料に戻すことは経済性の観点から困難である。そのため、廃材は廃棄せざるを得ない。
【０００８】
しかしながら、近年、産業廃棄物の増加が大きな社会問題となっており、廃棄場所の確保は困難である。さらに資源を有効活用するという観点から見ても、この芯材の製造方法は無駄がある。
【０００９】
本発明は、上記課題に鑑み、芯材の廃材の発生量を減らすことができる真空断熱材とその芯材の製造方法を提供することを目的とする。
【００１０】
【課題を解決するための手段】
上記目的を達成するために、請求項１記載の発明の真空断熱材は、無機繊維集合体を圧縮成型してバインダーで固めた芯材をガスバリア性の外被材で被覆し内部を減圧した真空断熱材であって、前記芯材が、シート状無機繊維集合体を複数枚積層してなり、積層する前記シート状無機繊維集合体の間に、前記芯材の廃材の粉砕物が混入されている。
【００１１】
請求項１記載の発明では、芯材の廃材を粉砕して芯材に混入するので、芯材の廃材の無駄を減らすことができ、資源を有効利用することができる。また、シート状無機繊維集合体を複数枚積層したものを芯材に用いると共に、芯材の廃材の粉砕物は、積層するシート状無機繊維集合体の間に配置するので、芯材の廃材の粉砕物を混入することによる芯材の外表面の強度や平面性への悪影響を極力小さくすることができる。
【００１２】
また、請求項２記載の発明の真空断熱材は、請求項１記載の発明の真空断熱材の構成に加え、芯材は表面層が内側層より硬いという特徴を有するものであり、芯材の内側層を表面層に比べて柔らかく構成したので、芯材の内側層の部分が、シート状無機繊維集合体の間に配置した芯材の廃材の粉砕物による凹凸を吸収しやすくなり、請求項１記載の発明よりも、芯材の廃材の粉砕物を混入することによる芯材の外表面の強度や平面性への悪影響を極力小さくすることができる。
【００１３】
また、請求項３記載の発明の真空断熱材は、請求項１または２記載の真空断熱材の構成に加えて、廃材の粉砕物の大きさが、５ｍｍ以下であるという特徴を有するものであり、通常使用される芯材の厚み寸法などを考慮すると、廃材の粉砕物の大きさが、５ｍｍ以下であれば、芯材の廃材の粉砕物を混入することによる芯材の外表面の強度や平面性への悪影響を極力小さくすることができる。
【００１４】
また、請求項４記載の発明の真空断熱材は、請求項１から３のいずれか一項記載の真空断熱材の構成に加えて、廃材の粉砕物の大きさが、内部を減圧した後の外被材から芯材を取り出した状態での前記芯材の厚さ寸法に対して１／４以下の大きさであるという特徴を有するものであり、廃材の粉砕物の大きさを１／４以下の大きさにすれば、芯材の廃材の粉砕物を混入することによる芯材の外表面の強度や平面性への悪影響を極力小さくすることができる。
【００１５】
また、請求項５記載の発明の真空断熱材は、請求項１から４のいずれか一項記載の真空断熱材の構成に加えて、廃材の粉砕物の混入量が、芯材の０．５〜４０重量％であるという特徴を有するものであり、廃材の粉砕物の混入量を、芯材の０．５〜４０重量％とすることにより、芯材の廃材の粉砕物を混入することによる芯材の外表面の強度や平面性や真空断熱材の芯材としての断熱性能への悪影響を極力小さくしつつ、芯材の廃材の無駄を減らすことができ、これらのバランスが良い。
【００１６】
また、請求項６記載の発明の真空断熱材の芯材の製造方法は、無機繊維集合体を圧縮成型してバインダーで固めた成型体から、前記成型体の端部を除いた中間部分において切断により芯材を取り出す真空断熱材の芯材の製造方法であって、前記成型体から芯材を取り出した後に残った芯材の廃材を粉砕する粉砕工程と、略水平に配置したシート状無機繊維集合体の上面に前記粉砕工程で粉砕された芯材の廃材の粉砕物をまき、さらに別のシート状無機繊維集合体を上から重ねる積層工程と、前記積層工程で複数枚積層されたシート状無機繊維集合体の外面にバインダーを塗布し圧縮成型した状態で前記バインダーを硬化させる成型硬化工程と、前記成型硬化工程で作られた成型体から、前記成型体の端部を除いた中間部分において切断により必要な大きさの芯材を取り出す芯材取出工程とを有し、前記芯材取出工程で芯材を取り出した後に残った芯材の廃材を前記粉砕工程で粉砕するものである。
【００１７】
請求項６記載の発明では、芯材の廃材を粉砕して芯材に混入するので、芯材の廃材の無駄を減らすことができ、資源を有効利用することができる。また、シート状無機繊維集合体を複数枚積層したものを芯材に用いると共に、芯材の廃材の粉砕物は、積層するシート状無機繊維集合体の間に位置し、また、複数枚積層されたシート状無機繊維集合体の外面にバインダーを塗布するので、芯材の内側層が表面層に比べて柔らかくなるため、芯材の廃材の粉砕物を混入することによる芯材の外表面の強度や平面性への悪影響を極力小さくすることができる。
【００１８】
また、請求項７記載の発明の真空断熱材の芯材の製造方法は、請求項６記載の発明における粉砕工程で芯材の廃材を１５ｍｍ以下の大きさに粉砕し、成型硬化工程での圧縮により芯材の廃材の粉砕物が５ｍｍ以下の大きさに粉砕されるものであり、通常使用される芯材の厚み寸法などを考慮すると、廃材の粉砕物の大きさが、５ｍｍ以下であれば、芯材の廃材の粉砕物を混入することによる芯材の外表面の強度や平面性への悪影響を極力小さくすることができる。
【００１９】
また、粉砕工程で芯材の廃材を１５ｍｍ以下に粉砕しておけば、成型硬化工程での圧縮で廃材の粉砕物が５ｍｍ以下に粉砕されるので、粉砕工程で芯材の廃材を５ｍｍ以下まで小さく粉砕する必要がなく、生産性が向上する。
【００２０】
また、請求項８記載の発明の真空断熱材の芯材の製造方法は、請求項６または７記載の発明の積層工程において、積層するシート状無機繊維集合体の間に混入させる廃材の粉砕物の量が、芯材取出工程で取り出す芯材の０．５〜４０重量％であるという特徴を有するものであり、廃材の粉砕物の混入量を、芯材の０．５〜４０重量％とすることにより、芯材の廃材の粉砕物を混入することによる芯材の外表面の強度や平面性や真空断熱材の芯材としての断熱性能への悪影響を極力小さくしつつ、芯材の廃材の無駄を減らすことができ、これらのバランスが良い。
【００２１】
【発明の実施の形態】
以下、本発明の真空断熱材とその芯材の製造方法の実施の形態について図面を参照しながら説明する。
【００２２】
図１は本発明の一実施の形態の真空断熱材の断面図、図２は同実施の形態の真空断熱材の芯材１の断面図である。
【００２３】
本実施の形態の真空断熱材は、平均繊維径が５μｍ、繊維長が５〜５０ｍｍのグラスウールからなる無機繊維集合体を圧縮成型してホウ酸からなるバインダーで固めた厚さ１５ｍｍ、密度が２００ｋｇ／ｍ３の芯材１をガスバリア性の外被材２で被覆し内部を３Ｐａまで減圧した真空断熱材であって、芯材１が、シート状無機繊維集合体３を２枚積層してなり、積層するシート状無機繊維集合体３の間に、芯材１の廃材を２ｍｍ以下に粉砕した粉砕物４が芯材１に対して５重量％混入されている。
【００２４】
芯材１の表面層は内側層よりバインダー濃度が高く、芯材１の表面層部分には硬化層５が形成されている。
【００２５】
芯材１は、外被材２で被覆し内部を減圧した時に圧縮されて厚みが１４ｍｍに減少している。芯材１の減圧による厚みの減少は１０％以下であることが望ましい。
【００２６】
外被材２は、アルミ蒸着層またはアルミ箔を有するラミネート樹脂フィルムを使用している。
【００２７】
なお、本実施の形態のバインダーは、グラスウール１００重量部に対し、ホウ酸３重量部を水９７重量部に溶解し、ホウ酸水溶液１００重量部としたものを使用する。
【００２８】
なお、本実施の形態では、無機繊維としてグラスウールを使用しているが、これに限らず、グラスファイバー、アルミナ繊維、シリカアルミナ繊維、シリカ繊維、ロックウール、炭化ケイ素繊維等の無機繊維を使用できる。
【００２９】
また、本実施の形態では、平均繊維径を５μｍとしているが、０．１μｍ〜１０μｍであればよい。
【００３０】
また、本実施の形態では、バインダーにホウ酸を用いているが、これに限らず、ホウ酸、ホウ酸塩、或いはリン酸、リン酸塩、或いはそれらの加熱生成物のうち少なくともひとつを含むものが使用できる。
【００３１】
また、本実施の形態では、芯材１の厚さを１５ｍｍとしているが、これに限らず、５ｍｍ〜４０ｍｍの厚さでもよい。好ましくは１０〜２０ｍｍの厚さである。
【００３２】
なお、廃材の粉砕物４の大きさは、内部を減圧した後の外被材２から芯材１を取り出した状態での芯材１の厚さ寸法に対して１／４以下の大きさであることが好ましい。
【００３３】
本実施の形態では、厚さ約１５ｍｍの芯材に対して廃材の粉砕物４の大きさを２ｍｍ以下に粉砕しているが、約３．８ｍｍ以下の大きさへの粉砕でも構わない。厚さ１０ｍｍの芯材の場合は、２．５ｍｍ以下の大きさ、厚さ２０ｍｍの芯材の場合は、５ｍｍ以下の大きさ、厚さ３０ｍｍの芯材の場合は、約７．５ｍｍ以下の大きさ、厚さ４０ｍｍの芯材の場合は、１０ｍｍ以下の大きさに廃材を粉砕することが好ましい。
【００３４】
また、本実施の形態では、廃材の粉砕物４の混入量を、芯材の５重量％としているが、これに限らず、０．５〜４０重量％であればよい。好ましくは１〜２０重量％、さらに好ましくは２〜１０重量％である。
【００３５】
また、本実施の形態では、シート状無機繊維集合体３を２枚積層して芯材１を構成しているが、２枚に限らず、シート状無機繊維集合体３を３枚、４枚積層したものでも構わないが、４枚以上積層する場合の粉砕物４の混入は、芯材１の表面に粉砕物４混入の影響がでないように、芯材１の中央部に集中させる方が、望ましい。
【００３６】
また、本実施の形態では、芯材１の密度を２００ｋｇ／ｍ３としているが、これに限らず、１００〜４００ｋｇ／ｍ３であればよい。
【００３７】
次に、本実施の形態の真空断熱材の芯材の製造方法について説明する。
【００３８】
図３は成型体から芯材１を切断により取り出した後に残った芯材の廃材を示す平面図、図４は図３のＡ−Ａ線断面図である。図５は略水平に配置したシート状無機繊維集合体３の上面に芯材の廃材の粉砕物４をまいている様子を示す模式図である。図６は芯材の廃材の粉砕物４がまかれたシート状無機繊維集合体３の上にさらに別のシート状無機繊維集合体３を上から重ねる様子を示す模式図である。
【００３９】
図７は芯材の廃材の粉砕物４を間に挟んで積層したシート状無機繊維集合体３の一方の表面にバインダーを噴霧している様子を示す模式図である。図８は芯材の廃材の粉砕物４を間に挟んで積層したシート状無機繊維集合体３のもう一方の表面にバインダーを噴霧している様子を示す模式図である。
【００４０】
図９は芯材の廃材の粉砕物４を間に挟んで積層され両面にバインダーが塗布されたシート状無機繊維集合体３を常温で圧縮している様子を示す模式図である。図１０は常温で圧縮された後のシート状無機繊維集合体３の積層物を熱風循環炉中で圧縮している様子を示す模式図である。図１１は芯材１の基になる成形体の端部を切断している様子を示す模式図である。図１２は成形体の端部を切断した様子を示す模式図である。
【００４１】
本実施の形態の真空断熱材の芯材１は、無機繊維集合体を圧縮成型してバインダーで固めた成型体から、成型体の端部７を除いた中間部分において切断により取り出したものである。
【００４２】
成型体から芯材１を切断により取り出した後に、図３、図４に示すような芯材の廃材６が残る。例えば、成型体の縦横の寸法が芯材の寸法の１０３％の大きさである場合は、芯材の約６重量％の廃材が残る。
【００４３】
本実施の形態では、この芯材の廃材６を粉砕工程で粉砕装置（図示せず）により１５ｍｍ以下に粉砕する。
【００４４】
次に、積層工程で、図５に示すように、略水平に配置したシート状無機繊維集合体３の上面に粉砕工程で粉砕された芯材の廃材の粉砕物４を均一にまき、図６に示すように、さらに別のシート状無機繊維集合体３を上から重ねる。
【００４５】
次に、図７、図８に示すように、積層工程で複数枚積層されたシート状無機繊維集合体３の外面にバインダー８を噴霧装置９から噴霧することにより塗布する。この結果、シート状無機繊維集合体３の外面にバインダー８が染みこんだ部分１０ができる。
【００４６】
次に、図９に示すように、芯材の廃材の粉砕物４を間に挟んで積層され両面にバインダーが塗布されたシート状無機繊維集合体３を、プレス台１１の上に載せ、プレス板１２を降下させて、プレス台１１とプレス板１２とで圧縮する。この圧縮により、シート状無機繊維集合体３の比較的長い繊維が折れて短くなり、シート状無機繊維集合体３の繊維の配向方向が芯材１の厚み方向に対して垂直な方向に揃うと共に、シート状無機繊維集合体３の表面層部分に染みこんでいるバインダーがシート状無機繊維集合体３の内側層部分に浸透する。また、プレスの圧縮（押圧力）により、廃材６の粉砕物４が５ｍｍ以下であるところの２ｍｍ以下に粉砕される。
【００４７】
次に、成型硬化工程で、図１０に示すように、常温で圧縮された後のシート状無機繊維集合体３の積層物を、熱風循環炉１３の中のプレス台１１の上に載せ、プレス板１２を降下させて、バインダーの硬化温度以上の３５０〜４００℃の熱風循環炉１３の中でプレス台１１とプレス板１２とで約２０分間圧縮する。この加熱により、シート状無機繊維集合体３の積層物の中の水分が蒸発し、圧縮された状態でバインダーが硬化しシート状無機繊維集合体３の積層物が固まり、芯材１の基になる成形体１６が得られる。また、加熱圧縮時にも廃材６の粉砕物４の一部が小さく粉砕される。この成形体１６の表面層は内側層よりバインダー濃度が高く、成形体１６の表面層部分には硬化層５が形成されている。
【００４８】
次に、芯材取出工程で、図１１に示すように、成型硬化工程で作られた成型体１６の端部７を切断装置１７により切断して、図１２に示すように、必要な大きさの芯材１を取り出す。そして、芯材取出工程で、芯材１を取り出した後に残った芯材の廃材６は、粉砕工程で粉砕する。
【００４９】
次に、芯材取出工程で取り出された芯材１は、約１４０℃の乾燥炉で１時間乾燥された後、ガスバリア性の外被材２で被覆され、内部が３Ｐａまで減圧され、外被材２の開口部が熱溶着されて、真空断熱材が得られる。
【００５０】
以上のように本実施の形態は、無機繊維集合体を圧縮成型してバインダーで固めた芯材１をガスバリア性の外被材２で被覆し内部を減圧した真空断熱材において、芯材１を、シート状無機繊維集合体３の複数枚積層したもので構成し、積層するシート状無機繊維集合体３の間に、芯材１の廃材６の粉砕物４を混入するので、芯材１の廃材６の無駄を減らすことができ、資源を有効利用することができる。しかも、芯材の廃材の粉砕物を混入することによる芯材の外表面の強度や平面性への悪影響を極力小さくすることができる。
【００５１】
また、芯材１の表面層部に硬化層５を形成して芯材１の内側層より硬くし、芯材１の内側層を表面層に比べて柔らかく構成したので、芯材１の内側層の部分が、シート状無機繊維集合体３の間に配置した芯材１の廃材６の粉砕物４による凹凸を吸収しやすくなり、芯材１の廃材６の粉砕物４を混入することによる芯材１の外表面の強度や平面性への悪影響を極力小さくすることができる。
【００５２】
また、廃材６の粉砕物４の大きさを、５ｍｍ以下であるところの２ｍｍ以下としたので、芯材１の厚み寸法などを考慮すると、芯材１の廃材６の粉砕物４を混入することによる芯材１の外表面の強度や平面性への悪影響を極力小さくすることができる。
【００５３】
また、廃材６の粉砕物４の大きさが、内部を減圧した後の外被材２から芯材１を取り出した状態での芯材１の厚さ寸法１４ｍｍに対して１／４以下の大きさである２ｍｍにしたので、芯材１の廃材６の粉砕物４を混入することによる芯材１の外表面の強度や平面性への悪影響を極力小さくすることができる。
【００５４】
また、廃材６の粉砕物４の混入量を、芯材１の０．５〜４０重量％である５重量％としたことにより、芯材１の廃材６の粉砕物４を混入することによる芯材１の外表面の強度や平面性や真空断熱材の芯材１としての断熱性能への悪影響を極力小さくしつつ、芯材１の廃材６の無駄を減らすことができ、これらのバランスが良い。
【００５５】
また、本実施の形態の真空断熱材の芯材１の製造方法は、無機繊維集合体を圧縮成型してバインダーで固めた成型体１６から、成型体１６の端部７を除いた中間部分において切断により芯材１を取り出す真空断熱材の芯材１の製造方法であって、成型体１６から芯材１を取り出した後に残った芯材１の廃材６を粉砕する粉砕工程と、略水平に配置したシート状無機繊維集合体３の上面に粉砕工程で粉砕された芯材１の廃材６の粉砕物４をまき、さらに別のシート状無機繊維集合体３を上から重ねる積層工程と、積層工程で複数枚積層されたシート状無機繊維集合体３の外面にバインダー８を塗布し圧縮成型した状態でバインダーを硬化させる成型硬化工程と、成型硬化工程で作られた成型体１６から、成型体１６の端部７を除いた中間部分において切断により必要な大きさの芯材１を取り出す芯材取出工程とを有し、芯材取出工程で芯材１を取り出した後に残った芯材１の廃材６を粉砕工程で粉砕するので、芯材１の廃材６の無駄を減らすことができ、資源を有効利用することができる。また、芯材１の廃材６の粉砕物４を混入することによる芯材１の外表面の強度や平面性への悪影響を極力小さくすることができる。
【００５６】
また、粉砕工程で芯材の廃材を１５ｍｍ以下の大きさに粉砕し、成型硬化工程のプレスの圧縮（押圧力）により、廃材６の粉砕物４が５ｍｍ以下であるところの２ｍｍ以下に粉砕されるので、または、最終的には、内部を減圧した後の外被材２から芯材１を取り出した状態での芯材１の厚さ寸法に対して１／４以下の大きさに粉砕するので、芯材１の廃材６の粉砕物４を混入することによる芯材１の外表面の強度や平面性への悪影響を極力小さくすることができる。
【００５７】
また、積層工程において、積層するシート状無機繊維集合体３の間に混入させる廃材６の粉砕物４の量が、芯材取出工程で取り出す芯材１の０．５〜４０重量％、好ましくは１〜２０重量％、さらに好ましくは２〜１０重量％とすることにより、芯材１の廃材６の粉砕物４を混入することによる芯材１の外表面の強度や平面性や真空断熱材の芯材１としての断熱性能への悪影響を極力小さくしつつ、芯材１の廃材６の無駄を減らすことができ、これらのバランスが良い。
【００５８】
【発明の効果】
以上説明したように本発明は、シート状無機繊維集合体を複数枚積層したものを芯材に用いると共に、積層するシート状無機繊維集合体の間に、芯材の廃材の粉砕物が混入することにより、芯材の廃材の粉砕物を混入することによる芯材の外表面の強度や平面性への悪影響を極力小さくしながら、芯材の廃材の無駄を減らすことができ、資源を有効利用することができる。
【００５９】
ここで、芯材は、表面層が内側層より硬くし、芯材の内側層を表面層に比べて柔らかく構成すれば、芯材の内側層の部分が、シート状無機繊維集合体の間に配置した芯材の廃材の粉砕物による凹凸を吸収しやすくなり、さらに、芯材の廃材の粉砕物を混入することによる芯材の外表面の強度や平面性への悪影響を小さくすることができる。
【００６０】
また、廃材の粉砕物の大きさは、５ｍｍ以下、または、内部を減圧した後の外被材から芯材を取り出した状態での芯材の厚さ寸法に対して１／４以下の大きさにすれば、芯材の廃材の粉砕物を混入することによる芯材の外表面の強度や平面性への悪影響を小さくすることができる。
【００６１】
また、廃材の粉砕物の混入量は、芯材の０．５〜４０重量％とすれば、芯材の廃材の粉砕物を混入することによる芯材の外表面の強度や平面性や真空断熱材の芯材としての断熱性能への悪影響を極力小さくしつつ、芯材の廃材の無駄を減らすことができ、これらのバランスが良い。
【００６２】
また、本発明は、無機繊維集合体を圧縮成型してバインダーで固めた成型体から、前記成型体の端部を除いた中間部分において切断により芯材を取り出す真空断熱材の芯材の製造方法であって、前記成型体から芯材を取り出した後に残った芯材の廃材を粉砕する粉砕工程と、略水平に配置したシート状無機繊維集合体の上面に前記粉砕工程で粉砕された芯材の廃材の粉砕物をまき、さらに別のシート状無機繊維集合体を上から重ねる積層工程と、前記積層工程で複数枚積層されたシート状無機繊維集合体の外面にバインダーを塗布し圧縮成型した状態で前記バインダーを硬化させる成型硬化工程と、前記成型硬化工程で作られた成型体から、前記成型体の端部を除いた中間部分において切断により必要な大きさの芯材を取り出す芯材取出工程とを有し、前記芯材取出工程で芯材を取り出した後に残った芯材の廃材を前記粉砕工程で粉砕するものであるので、芯材の廃材の粉砕物を混入することによる芯材の外表面の強度や平面性への悪影響を極力小さくしながら、芯材の廃材の無駄を減らすことができ、資源を有効利用することができる。
【００６３】
ここで、粉砕工程で粉砕する廃材の粉砕物の大きさを、１５ｍｍ以下にして、成型硬化工程の圧縮により５ｍｍ以下の大きさにする場合は、芯材の廃材の粉砕物を混入することによる芯材の外表面の強度や平面性への悪影響を小さくすることができる。
【００６４】
また、積層工程において、積層するシート状無機繊維集合体の間に混入させる廃材の粉砕物の量は、芯材取出工程で取り出す芯材の０．５〜４０重量％とすれば、芯材の廃材の粉砕物を混入することによる芯材の外表面の強度や平面性や真空断熱材の芯材としての断熱性能への悪影響を極力小さくしつつ、芯材の廃材の無駄を減らすことができ、これらのバランスが良い。
【図面の簡単な説明】
【図１】本発明の一実施の形態の真空断熱材の断面図
【図２】同実施の形態の真空断熱材の芯材の断面図
【図３】同実施の形態の真空断熱材の芯材の廃材の平面図
【図４】図３のＡ−Ａ線断面図
【図５】同実施の形態の芯材の製造方法におけるシート状無機繊維集合体に芯材の廃材の粉砕物をまいている様子を示す模式図
【図６】同実施の形態の芯材の製造方法におけるシート状無機繊維集合体を積層している様子を示す模式図
【図７】同実施の形態の芯材の製造方法におけるシート状無機繊維集合体の積層物の一方の表面にバインダーを噴霧している様子を示す模式図
【図８】同実施の形態の芯材の製造方法におけるシート状無機繊維集合体の積層物のもう一方の表面にバインダーを噴霧している様子を示す模式図
【図９】同実施の形態の芯材の製造方法における両面にバインダーが塗布されたシート状無機繊維集合体の積層物を常温圧縮している様子を示す模式図
【図１０】同実施の形態の芯材の製造方法における常温圧縮された後のシート状無機繊維集合体の積層物を加熱圧縮している様子を示す模式図
【図１１】同実施の形態の芯材の製造方法における成形体の端部を切断している様子を示す模式図
【図１２】同実施の形態の芯材の製造方法における成形体の端部を切断した様子を示す模式図
【符号の説明】
１　　芯材
２　　外被材
３　　シート状無機繊維集合体
４　　粉砕物
５　　硬化層
６　　廃材
７　　端部
８　　バインダー
１６　成形体[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vacuum heat insulating material in which a core material made of an inorganic fiber aggregate is covered with a jacket material, and a method for manufacturing the core material.
[0002]
[Prior art]
In recent years, energy saving has been strongly demanded from the viewpoint of prevention of global warming, and energy saving has become an urgent issue for household electric appliances. In particular, vacuum insulation materials in which the core material is covered with a gas barrier laminate film and the inside is decompressed and sealed, from the viewpoint of efficiently using heat in refrigerators, freezers, vending machines, electric pots, and other heat and cold storage devices The use of has been proposed.
[0003]
Various materials have been proposed as the core material of the vacuum heat insulating material. In Japanese Patent Application Laid-Open No. 9-145239, an inorganic fiber aggregate that is relatively easy to shape is used as the core material.
[0004]
The method of making a core material from the above-mentioned conventional inorganic fiber aggregate is as follows. First, from a molded body obtained by adding a binder to the inorganic fiber aggregate and solidifying and molding, by cutting at an intermediate portion excluding the end of the molded body. The core material of the required size is taken out.
[0005]
[Problems to be solved by the invention]
The core material of the above-mentioned conventional vacuum heat insulating material is obtained by cutting the core material of a required size from the molded body by cutting at an intermediate portion excluding the end of the molded body. Waste remains.
[0006]
In particular, as the applications and locations of vacuum insulation materials increase, multiple types of cores of various sizes and shapes are required, and multiple types of cores of various sizes and shapes are reduced from small types of molded products. Attempting to remove it increases the amount of waste material generated, but disposal of this waste material becomes a problem.
[0007]
That is, since this waste material has a heat history at the time of firing and has a binder cured by heat attached thereto, it is difficult to return it to the raw material of the inorganic fiber aggregate from the viewpoint of economy. Therefore, waste materials must be discarded.
[0008]
However, in recent years, an increase in industrial waste has become a major social problem, and it is difficult to secure disposal sites. Further, from the viewpoint of effective use of resources, this method of manufacturing the core material is useless.
[0009]
In view of the above problems, an object of the present invention is to provide a vacuum heat insulating material that can reduce the amount of waste material of a core material and a method of manufacturing the core material.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a vacuum heat insulating material according to the first aspect of the present invention is a vacuum insulating material in which a core material obtained by compression-molding an inorganic fiber aggregate and solidifying with a binder is covered with a gas-barrier outer material, and the inside is depressurized. A heat insulating material, wherein the core material is obtained by laminating a plurality of sheet-like inorganic fiber aggregates, and a crushed material of the waste material of the core material is mixed between the laminated sheet-like inorganic fiber aggregates. I have.
[0011]
According to the first aspect of the present invention, since the waste material of the core material is crushed and mixed into the core material, waste of the waste material of the core material can be reduced, and resources can be effectively used. In addition, a core material obtained by laminating a plurality of sheet-like inorganic fiber aggregates is used, and a crushed waste material of the core material is disposed between the sheet-like inorganic fiber aggregates to be laminated. Adverse effects on the strength and flatness of the outer surface of the core material caused by mixing the pulverized material can be minimized.
[0012]
The vacuum heat insulating material according to the second aspect of the present invention is characterized in that, in addition to the structure of the vacuum heat insulating material according to the first aspect, the core material has a feature that the surface layer is harder than the inner layer. Since the inner layer is configured to be softer than the surface layer, the inner layer portion of the core material easily absorbs irregularities due to the crushed waste material of the core material disposed between the sheet-like inorganic fiber aggregates. As compared with the invention described in the first aspect, it is possible to minimize the adverse effect on the strength and flatness of the outer surface of the core material caused by mixing the pulverized waste material of the core material.
[0013]
The vacuum heat insulating material according to the third aspect of the present invention has a feature that, in addition to the structure of the vacuum heat insulating material according to the first or second aspect, the size of the crushed waste material is 5 mm or less. Considering the thickness of the core material that is usually used, if the size of the crushed waste material is 5 mm or less, the strength of the outer surface of the core material by mixing the crushed material of the waste core material and An adverse effect on flatness can be minimized.
[0014]
The vacuum heat insulating material of the invention according to claim 4 has, in addition to the configuration of the vacuum heat insulating material according to any one of claims 1 to 3, wherein the size of the crushed waste material is reduced after the internal pressure is reduced. The thickness of the core material in a state where the core material is taken out from the outer cover material is 1/4 or less of the thickness of the core material, and the size of the crushed waste material is reduced to 1/4. With the following size, it is possible to minimize the adverse effect on the strength and flatness of the outer surface of the core material caused by mixing the crushed waste material of the core material.
[0015]
According to a fifth aspect of the present invention, in addition to the configuration of the vacuum heat insulating material according to any one of the first to fourth aspects, the amount of crushed waste material mixed with the core material is 0.5%. -40% by weight, and the mixing amount of the crushed waste material is set to 0.5 to 40% by weight of the core material. The strength and flatness of the outer surface of the core material and the adverse effects on the heat insulating performance of the vacuum heat insulating material as the core material can be minimized, and the waste of the core material can be reduced.
[0016]
In the method of manufacturing a core material of a vacuum heat insulating material according to the invention of claim 6, the intermediate fiber is cut from a molded body obtained by compression-molding an inorganic fiber aggregate and solidified with a binder, excluding an end of the molded body. A method for manufacturing a core material of a vacuum heat insulating material, wherein a core material is removed from the molded body, and a pulverizing step of pulverizing waste material of the core material remaining after removing the core material from the molded body; and a sheet-like inorganic fiber disposed substantially horizontally. A laminating step of sowing the waste material of the core material pulverized in the pulverizing step on the upper surface of the aggregate, and further laminating another sheet-like inorganic fiber aggregate from above, and a sheet-like sheet laminated in the laminating step. A molding and curing step in which the binder is cured in a state where the binder is applied to the outer surface of the inorganic fiber aggregate and compressed and molded, and from the molded body produced in the molding and curing step, in an intermediate portion excluding the end of the molded body By cutting And a core material removal step of removing the core material of the main size, the waste of the remaining core material after removal of the core material in the core material removal process is to ground in the grinding step.
[0017]
According to the sixth aspect of the present invention, since the waste material of the core material is crushed and mixed into the core material, waste of the waste material of the core material can be reduced, and the resources can be effectively used. In addition, a core material obtained by laminating a plurality of sheet-like inorganic fiber aggregates is used, and a crushed waste material of the core material is located between the sheet-like inorganic fiber aggregates to be laminated, and a plurality of laminated materials are laminated. Since the binder is applied to the outer surface of the sheet-like inorganic fiber aggregate, the inner layer of the core material becomes softer than the surface layer, so the strength of the outer surface of the core material by mixing the crushed waste material of the core material And the adverse effect on flatness can be minimized.
[0018]
According to a seventh aspect of the present invention, in the method for manufacturing a core material of a vacuum heat insulating material, waste material of the core material is pulverized to a size of 15 mm or less in the pulverizing step according to the sixth aspect of the invention, and compressed in a molding and hardening step. The crushed material of the core material is crushed to a size of 5 mm or less, and if the size of the crushed material of the waste material is 5 mm or less in consideration of the thickness dimension of the core material normally used, etc. In addition, it is possible to minimize the adverse effect on the strength and flatness of the outer surface of the core material caused by mixing the crushed waste material of the core material.
[0019]
Also, if the waste material of the core material is pulverized to 15 mm or less in the pulverizing step, the pulverized material of the waste material is pulverized to 5 mm or less by compression in the molding and hardening step. There is no need to grind small, and productivity is improved.
[0020]
In the method for manufacturing a core material of a vacuum heat insulating material according to the invention of claim 8, the pulverized waste material mixed between the sheet-like inorganic fiber aggregates to be laminated in the laminating step of the invention according to claim 6 or 7. Is in the range of 0.5 to 40% by weight of the core material taken out in the core material removing step, and the mixed amount of the crushed waste material is 0.5 to 40% by weight of the core material. By reducing the adverse effect on the strength and flatness of the outer surface of the core material and the heat insulation performance of the vacuum insulation material as a core material by mixing the crushed material of the core material waste material, The waste can be reduced and these are well balanced.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a method for manufacturing a vacuum heat insulating material and a core material thereof according to the present invention will be described with reference to the drawings.
[0022]
FIG. 1 is a cross-sectional view of a vacuum heat insulating material according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view of a core material 1 of the vacuum heat insulating material according to the embodiment.
[0023]
The vacuum heat insulating material of the present embodiment has an average fiber diameter of 5 μm, a fiber length of 5 to 50 mm, and is formed by compression molding an inorganic fiber aggregate made of glass wool and solidified with a binder made of boric acid. / M3 is a vacuum heat insulating material in which a gas barrier material 2 is covered with a core material 1 and the inside is reduced to 3 Pa, and the core material 1 is formed by laminating two sheet-like inorganic fiber aggregates 3, Between the sheet-like inorganic fiber aggregates 3 to be laminated, a pulverized material 4 obtained by pulverizing the waste material of the core material 1 to 2 mm or less is mixed at 5% by weight with respect to the core material 1.
[0024]
The surface layer of the core material 1 has a higher binder concentration than the inner layer, and a hardened layer 5 is formed on the surface layer portion of the core material 1.
[0025]
The core material 1 is covered with the jacket material 2 and is compressed when the inside thereof is decompressed, and its thickness is reduced to 14 mm. It is desirable that the reduction in thickness of the core material 1 due to reduced pressure is 10% or less.
[0026]
The jacket material 2 uses a laminated resin film having an aluminum vapor-deposited layer or an aluminum foil.
[0027]
The binder used in the present embodiment is obtained by dissolving 3 parts by weight of boric acid in 97 parts by weight of water with respect to 100 parts by weight of glass wool to obtain 100 parts by weight of a boric acid aqueous solution.
[0028]
In the present embodiment, glass wool is used as the inorganic fiber, but not limited thereto, glass fiber, alumina fiber, silica alumina fiber, silica fiber, rock wool, inorganic fiber such as silicon carbide fiber can be used. .
[0029]
In the present embodiment, the average fiber diameter is 5 μm, but may be 0.1 μm to 10 μm.
[0030]
Further, in the present embodiment, boric acid is used as the binder. However, the present invention is not limited thereto, and boric acid, borate, or phosphoric acid, phosphate, or at least one of heat products thereof is included. Things can be used.
[0031]
Further, in the present embodiment, the thickness of the core material 1 is set to 15 mm, but is not limited thereto, and may be 5 mm to 40 mm. Preferably, the thickness is 10 to 20 mm.
[0032]
The size of the waste material pulverized material 4 is 1/4 or less of the thickness of the core material 1 in a state where the core material 1 is taken out from the jacket material 2 after decompression of the inside. Preferably, there is.
[0033]
In the present embodiment, the size of the waste material pulverized material 4 is pulverized to 2 mm or less for a core material having a thickness of about 15 mm, but pulverization to a size of about 3.8 mm or less may be performed. For a core material having a thickness of 10 mm, a size of 2.5 mm or less, for a core material of a thickness of 20 mm, a size of 5 mm or less, and for a core material of a thickness of 30 mm, a size of about 7.5 mm or less In the case of a core material having a size and a thickness of 40 mm, it is preferable to crush the waste material to a size of 10 mm or less.
[0034]
Further, in the present embodiment, the mixing amount of the crushed material 4 of the waste material is set to 5% by weight of the core material, but is not limited thereto, and may be 0.5 to 40% by weight. Preferably it is 1 to 20% by weight, more preferably 2 to 10% by weight.
[0035]
Further, in the present embodiment, the core material 1 is formed by laminating two sheet-like inorganic fiber aggregates 3, but the present invention is not limited to two sheets, and three or four sheet-like inorganic fiber aggregates 3 are formed. Although it may be a laminated one, the mixing of the crushed material 4 when four or more pieces are stacked is preferably concentrated on the center of the core material 1 so that the surface of the core material 1 is not affected by the mixing of the crushed material 4. ,desirable.
[0036]
Further, in the present embodiment, the density of the core material 1 is set to 200 kg / m3, but is not limited thereto, and may be 100 to 400 kg / m3.
[0037]
Next, a method of manufacturing the core material of the vacuum heat insulating material according to the present embodiment will be described.
[0038]
FIG. 3 is a plan view showing waste core material remaining after the core material 1 is removed from the molded body by cutting, and FIG. 4 is a sectional view taken along line AA of FIG. FIG. 5 is a schematic diagram showing a state in which a crushed material 4 of core waste material is sown on the upper surface of the sheet-like inorganic fiber aggregate 3 arranged substantially horizontally. FIG. 6 is a schematic diagram showing a state in which another sheet-like inorganic fiber aggregate 3 is overlaid on the sheet-like inorganic fiber aggregate 3 on which the crushed waste material 4 of the core material is spread.
[0039]
FIG. 7 is a schematic view showing a state in which a binder is sprayed on one surface of the sheet-like inorganic fiber aggregate 3 laminated with a crushed material 4 of core waste material interposed therebetween. FIG. 8 is a schematic diagram showing a state in which a binder is sprayed on the other surface of the sheet-like inorganic fiber aggregate 3 laminated with a ground waste material 4 interposed therebetween.
[0040]
FIG. 9 is a schematic diagram showing a state in which the sheet-like inorganic fiber aggregate 3 laminated with the ground material waste pulverized material 4 interposed therebetween and the binder applied to both sides is compressed at room temperature. FIG. 10 is a schematic diagram showing a state in which the laminate of the sheet-like inorganic fiber aggregates 3 after being compressed at normal temperature is compressed in a hot-air circulation furnace. FIG. 11 is a schematic view showing a state in which the end of the molded body on which the core material 1 is based is cut. FIG. 12 is a schematic view showing a state where the end of the molded body is cut.
[0041]
The core material 1 of the vacuum heat insulating material according to the present embodiment is obtained by cutting a molded body obtained by compression-molding an inorganic fiber aggregate and hardening it with a binder at an intermediate portion excluding the end 7 of the molded body. .
[0042]
After removing the core material 1 from the molded body by cutting, a waste material 6 of the core material as shown in FIGS. 3 and 4 remains. For example, when the vertical and horizontal dimensions of the molded body are 103% of the dimensions of the core, about 6% by weight of the waste of the core remains.
[0043]
In the present embodiment, the waste material 6 of the core material is pulverized to 15 mm or less by a pulverizer (not shown) in a pulverizing step.
[0044]
Next, in the laminating step, as shown in FIG. 5, the crushed material 4 of the core material crushed in the crushing step is uniformly spread on the upper surface of the sheet-like inorganic fiber aggregate 3 arranged substantially horizontally. As shown in the figure, another sheet-like inorganic fiber aggregate 3 is overlaid from above.
[0045]
Next, as shown in FIGS. 7 and 8, the binder 8 is applied to the outer surface of the sheet-like inorganic fiber aggregates 3 laminated in the laminating step by spraying from the spraying device 9. As a result, a portion 10 in which the binder 8 has permeated the outer surface of the sheet-like inorganic fiber aggregate 3 is formed.
[0046]
Next, as shown in FIG. 9, the sheet-like inorganic fiber assembly 3 laminated with the ground material waste 4 interposed therebetween and coated with a binder on both sides is placed on a press table 11 and pressed. The plate 12 is lowered and compressed by the press table 11 and the press plate 12. Due to this compression, the relatively long fibers of the sheet-like inorganic fiber aggregate 3 are broken and shortened, and the orientation direction of the fibers of the sheet-like inorganic fiber aggregate 3 is aligned in a direction perpendicular to the thickness direction of the core material 1. The binder permeating the surface layer portion of the sheet-like inorganic fiber aggregate 3 permeates into the inner layer portion of the sheet-like inorganic fiber aggregate 3. In addition, by the compression (pressing force) of the press, the crushed material 4 of the waste material 6 is crushed to 2 mm or less, which is 5 mm or less.
[0047]
Next, in the molding and curing step, as shown in FIG. 10, the laminate of the sheet-like inorganic fiber aggregates 3 after being compressed at room temperature is placed on the press table 11 in the hot-air circulating furnace 13 and pressed. The plate 12 is lowered and compressed by the press table 11 and the press plate 12 for about 20 minutes in a hot air circulating furnace 13 at 350 to 400 ° C. which is higher than the curing temperature of the binder. By this heating, the moisture in the laminate of the sheet-like inorganic fiber aggregates 3 evaporates, the binder is hardened in a compressed state, and the laminate of the sheet-like inorganic fiber aggregates 3 solidifies. A molded body 16 is obtained. Also, a part of the pulverized material 4 of the waste material 6 is pulverized to a small size during the heating and compression. The surface layer of the molded body 16 has a higher binder concentration than the inner layer, and the cured layer 5 is formed on the surface layer portion of the molded body 16.
[0048]
Next, in the core material removing step, as shown in FIG. 11, the end 7 of the molded body 16 produced in the molding and curing step is cut by a cutting device 17, and as shown in FIG. Take out the core material 1. Then, in the core material removal step, the core waste material 6 remaining after the core material 1 is taken out is crushed in the crushing step.
[0049]
Next, the core material 1 taken out in the core material taking out step is dried in a drying furnace at about 140 ° C. for 1 hour, and then coated with a gas-barrier outer material 2. The opening of the material 2 is thermally welded to obtain a vacuum heat insulating material.
[0050]
As described above, in the present embodiment, a core material 1 obtained by compressing an inorganic fiber aggregate and solidifying it with a binder is covered with a gas barrier coating material 2 and the inside thereof is decompressed. Since the crushed material 4 of the core material 1 is mixed between the sheet-like inorganic fiber aggregates 3 to be laminated, the crushed material 4 of the core material 1 is mixed. Waste of the waste material 6 can be reduced, and resources can be used effectively. Moreover, it is possible to minimize the adverse effect on the strength and flatness of the outer surface of the core material caused by mixing the crushed waste material of the core material.
[0051]
Further, the hardened layer 5 is formed on the surface layer portion of the core material 1 so as to be harder than the inner layer of the core material 1 and the inner layer of the core material 1 is softer than the surface layer. Is easy to absorb irregularities caused by the crushed material 4 of the waste material 6 of the core material 1 disposed between the sheet-like inorganic fiber aggregates 3, and the core formed by mixing the crushed material 4 of the waste material 6 of the core material 1 An adverse effect on the strength and flatness of the outer surface of the material 1 can be minimized.
[0052]
In addition, since the size of the crushed material 4 of the waste material 6 is set to 2 mm or less, which is 5 mm or less, the crushed material 4 of the waste material 6 of the core material 1 may be mixed in consideration of the thickness of the core material 1 and the like. As a result, the adverse effect on the strength and flatness of the outer surface of the core material 1 can be minimized.
[0053]
In addition, the size of the crushed material 4 of the waste material 6 is 1/4 or less of the thickness of the core material 14 in a state where the core material 1 is taken out from the jacket material 2 after decompressing the inside. Since the thickness is set to 2 mm, it is possible to minimize the adverse effect on the strength and flatness of the outer surface of the core material 1 caused by mixing the crushed material 4 of the waste material 6 of the core material 1.
[0054]
The amount of the crushed material 4 of the waste material 6 mixed with the crushed material 4 of the waste material 6 of the core material 1 is set to 5% by weight, which is 0.5 to 40% by weight of the core material 1. The strength and flatness of the outer surface of the material 1 and the adverse effect of the vacuum heat insulating material on the heat insulating performance of the core material 1 can be minimized, and the waste of the waste material 6 of the core material 1 can be reduced. .
[0055]
In addition, the method for manufacturing the core material 1 of the vacuum heat insulating material according to the present embodiment includes a method of manufacturing a molded body 16 obtained by compressing and molding an inorganic fiber aggregate by a binder and excluding an end portion 7 of the molded body 16 at an intermediate portion. A method for manufacturing a core material 1 of a vacuum heat insulating material for removing a core material 1 by cutting, comprising: a pulverizing step of pulverizing waste material 6 of the core material 1 remaining after removing the core material 1 from a molded body 16; A laminating step of sowing the crushed material 4 of the waste material 6 of the core material 1 crushed in the crushing step on the upper surface of the arranged sheet-like inorganic fiber aggregate 3 and further laminating another sheet-like inorganic fiber aggregate 3 from above; The molding and curing step of applying the binder 8 to the outer surface of the sheet-like inorganic fiber aggregate 3 laminated in a plurality of steps and curing the binder in a state of compression molding, and the molding 16 formed in the molding and curing step, In the middle part except the end 7 of 16 And a core material removing step of taking out the core material 1 having a required size by cutting. The waste material 6 of the core material 1 remaining after the core material 1 is taken out in the core material removing step is crushed in the grinding step. Waste of the waste material 6 of the core 1 can be reduced, and resources can be used effectively. Further, the adverse effect on the strength and flatness of the outer surface of the core material 1 caused by mixing the crushed material 4 of the waste material 6 of the core material 1 can be minimized.
[0056]
Further, in the pulverizing step, the waste material of the core material is pulverized to a size of 15 mm or less, and the compressed material (pressing force) of the press in the molding and curing step is pulverized to 2 mm or less where the pulverized material 4 of the waste material 6 is 5 mm or less. Therefore, or finally, the inner material 1 is pulverized to a size of 1/4 or less of the thickness of the core material 1 in a state where the core material 1 is taken out from the jacket material 2 after decompressing the inside. Therefore, the adverse effect on the strength and flatness of the outer surface of the core material 1 caused by mixing the crushed material 4 of the waste material 6 of the core material 1 can be minimized.
[0057]
Further, in the laminating step, the amount of the crushed material 4 of the waste material 6 to be mixed between the sheet-like inorganic fiber aggregates 3 to be laminated is 0.5 to 40% by weight of the core material 1 taken out in the core material removing step, preferably, By setting the content to 1 to 20% by weight, more preferably 2 to 10% by weight, the strength and flatness of the outer surface of the core material 1 by mixing the crushed material 4 of the waste material 6 of the core material 1 and the vacuum insulation material The waste of the waste material 6 of the core material 1 can be reduced while the adverse effect on the heat insulating performance of the core material 1 is minimized, and the balance between them is good.
[0058]
【The invention's effect】
As described above, the present invention uses, as a core, a laminate of a plurality of sheet-like inorganic fiber aggregates, and a crushed waste material of the core is mixed between the laminated sheet-like inorganic fiber aggregates. As a result, it is possible to reduce waste of core material while minimizing adverse effects on the strength and flatness of the outer surface of the core material caused by mixing crushed material of core material, and effectively use resources. can do.
[0059]
Here, if the core material is configured such that the surface layer is harder than the inner layer and the inner layer of the core material is softer than the surface layer, the inner layer portion of the core material is located between the sheet-like inorganic fiber aggregates. It becomes easy to absorb irregularities due to the crushed waste material of the disposed core material, and furthermore, it is possible to reduce the adverse effect on the strength and flatness of the outer surface of the core material by mixing the crushed waste material of the core material. .
[0060]
In addition, the size of the crushed waste material is 5 mm or less, or 1/4 or less of the thickness of the core material in a state where the core material is taken out from the jacket material after decompression of the inside. By doing so, it is possible to reduce the adverse effect on the strength and flatness of the outer surface of the core material caused by mixing the crushed waste material of the core material.
[0061]
If the amount of the crushed waste material is 0.5 to 40% by weight of the core material, the strength, flatness and vacuum insulation of the outer surface of the core material by mixing the crushed waste material of the core material are reduced. The waste of the core material can be reduced while the adverse effect on the heat insulating performance of the core material as much as possible is reduced as much as possible.
[0062]
Further, the present invention provides a method for manufacturing a core material of a vacuum heat insulating material, wherein a core material is removed from a molded body obtained by compressing and molding an inorganic fiber aggregate by a binder at an intermediate portion excluding an end portion of the molded body. A crushing step of crushing waste material of the core material remaining after removing the core material from the molded body, and a core material crushed in the crushing step on an upper surface of the sheet-like inorganic fiber aggregate arranged substantially horizontally. A pulverized material of the waste material was sowed, a laminating step of further laminating another sheet-like inorganic fiber aggregate from above, and a binder was applied to the outer surface of the sheet-like inorganic fiber aggregates laminated in the laminating step and compression-molded. A molding and curing step of curing the binder in a state, and removing a core material of a required size by cutting the molding from the molding produced in the molding and curing step at an intermediate portion excluding an end of the molding. Process Since the waste material of the core material remaining after removing the core material in the core material removing step is to be pulverized in the pulverizing step, the outside of the core material by mixing the pulverized waste material of the core material is removed. The waste of the core material can be reduced while the adverse effect on the surface strength and flatness is minimized, and the resources can be used effectively.
[0063]
Here, in the case where the size of the crushed waste material to be crushed in the crushing step is set to 15 mm or less, and the size is reduced to 5 mm or less by compression in the molding and hardening step, the crushed material of the core waste material is mixed. An adverse effect on the strength and flatness of the outer surface of the core material can be reduced.
[0064]
Further, in the laminating step, if the amount of the crushed waste material mixed between the sheet-like inorganic fiber aggregates to be laminated is 0.5 to 40% by weight of the core material extracted in the core material removing step, The waste of core material can be reduced while minimizing the adverse effect on the strength and flatness of the outer surface of the core material and the heat insulation performance of the vacuum insulation material as a core material by mixing the crushed waste material. , These are good balance.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a vacuum heat insulating material according to an embodiment of the present invention; FIG. 2 is a cross-sectional view of a core material of the vacuum heat insulating material according to the embodiment; FIG. FIG. 4 is a cross-sectional view taken along the line AA in FIG. 3. FIG. 5 is a sheet-like inorganic fiber aggregate in the method for manufacturing a core material according to the embodiment. FIG. 6 is a schematic view showing a state in which sheet-like inorganic fiber aggregates are laminated in the method for manufacturing a core material according to the embodiment; FIG. 7 is a schematic view showing a state of the core material according to the embodiment; FIG. 8 is a schematic view showing a state in which a binder is sprayed on one surface of the laminate of sheet-like inorganic fiber aggregates in the manufacturing method. FIG. 9 is a schematic view showing a state where a binder is sprayed on the other surface of the laminate. FIG. 10 is a schematic diagram showing a state in which a laminate of sheet-like inorganic fiber aggregates having a binder applied to both surfaces in a method of manufacturing a material is compressed at room temperature. FIG. 11 is a schematic view showing a state in which a laminate of sheet-like inorganic fiber aggregates after heating is compressed by heating. FIG. 11 shows a state in which an end of a molded body is cut in the method for manufacturing a core material according to the embodiment. FIG. 12 is a schematic diagram showing a state where an end of a molded body is cut in the method for manufacturing a core material according to the embodiment.
DESCRIPTION OF SYMBOLS 1 Core material 2 Jacket material 3 Sheet-like inorganic fiber aggregate 4 Pulverized material 5 Hardened layer 6 Waste material 7 End part 8 Binder 16 Molded object

Claims

A vacuum heat insulating material in which a core material obtained by compression molding an inorganic fiber aggregate and solidifying with a binder is covered with a gas barrier material and the inside is decompressed,
The core material is formed by laminating a plurality of sheet-like inorganic fiber aggregates, and a crushed waste material of the core material is mixed between the laminated sheet-like inorganic fiber aggregates. Vacuum insulation.

The vacuum heat insulating material according to claim 1, wherein the core material has a surface layer that is harder than an inner layer.

3. The vacuum heat insulating material according to claim 1, wherein the size of the crushed waste material is 5 mm or less.

The size of the ground material of the waste material is 1/4 or less of the thickness of the core material in a state where the core material is taken out from the jacket material after decompressing the inside. The vacuum insulation material according to any one of claims 1 to 3.

The vacuum heat insulating material according to any one of claims 1 to 4, wherein a mixed amount of the crushed waste material is 0.5 to 40% by weight of the core material.

A method for manufacturing a core material of a vacuum heat insulating material, wherein a core material is removed from a molded body obtained by compressing and molding an inorganic fiber aggregate with a binder, and removing a core material by cutting at an intermediate portion excluding an end portion of the molded body,
A crushing step of crushing waste material of the core material remaining after removing the core material from the molded body,
A laminating step of sowing the ground material waste of the core material pulverized in the pulverizing step on the upper surface of the sheet-like inorganic fiber aggregate arranged substantially horizontally, and further laminating another sheet-like inorganic fiber aggregate from above,
A molding and curing step of curing the binder in a state where a binder is applied to the outer surface of the sheet-like inorganic fiber aggregates laminated in the laminating step and compressed and molded,
A core material removal step of removing a core material of a required size by cutting at an intermediate portion excluding an end of the molded body from the molded body formed in the molding and curing step,
A method of manufacturing a core material for a vacuum heat insulating material, wherein waste material of a core material remaining after the core material is removed in the core material removing step is crushed in the grinding step.

The waste material of the core material is crushed to a size of 15 mm or less in the grinding process, and the crushed material of the waste material of the core material is crushed to a size of 5 mm or less by compression in the molding and curing process. Item 7. The method for producing a core material of a vacuum heat insulating material according to Item 6.

The amount of the crushed waste material mixed between the sheet-like inorganic fiber aggregates to be laminated in the laminating step is 0.5 to 40% by weight of the core material extracted in the core material removing step. Or a method for producing a core material of a vacuum heat insulating material according to claim 7.