JP3565597B2 - Wrap film storage box - Google Patents

Description

【００２０】
図４を用いて、不良現象の原因を考察した結果（即ち発明の背景）をまとめると下記のようになる。即ち、
（ａ）フイルムに当接していた鋸刃の歯山の跡（破線部）の形状と、実際に切断されたフイルム端の形状とがずれていることから考察すると、この場合のフイルムの切断は、必ずしも当接した歯山の山の稜線に沿って切断されているのではなく、歯山の先で穿たれた切断開始点から引裂伝播によって生じるフイルムの破断現象が伴なっている。
（ｂ）ジグザグ状切断端の山裾部や谷部の一部に生じた亀裂部Ｔは、上述した引裂伝播の破断が過剰に進行した部分であり、この過剰の進行は、相隣れる双方の歯山から進行する破断の時間的（或いは方向的）な違いよって、その双方の破断が合流する機会（位置）がずれたことにより生じたものである。
（ｃ）意図しない方向にフイルムが裂ける現象は、剥ぎとる時に摘んだフイルムの切断端部に存在していた亀裂部Ｔに基づくものである。
即ち、係止力による抵抗と剥ぎ採る張力との間に生じた力が亀裂部Ｔに集中し、その亀裂部Ｔから引裂伝播による破断が進行するのである。従ってその進行方向は、亀裂部Ｔの存在位置や亀裂部Ｔの先端形状により、或いは樹脂の結晶構造に添って、縦、横、斜めの方向（即ち意図しない方向）に破断することになる。
（ｄ）『意図しない方向へのフイルムの破断』は、係止力による抵抗と剥ぎとる張力との間で生じた力が大きい時に、そこに存在していた亀裂部Ｔで生じるものであるが、素材自体の引裂強度が大きいフイルムの場合は、仮に亀裂部Ｔが存在していてもフイルムが破断することは極めて少ない。
【００２１】
以下、この考察（ａ）〜（ｄ）に従って本発明の技術的意義を説明する。
先ず上記要件（イ）で規定する「フイルムの引裂強度が６ｇ以下」の技術的意義は、本発明が対象とするフイルムの『その強度の絶対値の小ささ』の規定である。
即ち、「意図しない方向にフイルムが裂ける現象」は、上述の考察（ｄ）で説明されているように、亀裂部Ｔで弱められたフイルムの引裂強度が、仮留め部が持つ係止力を下回る時に生じる現象である。よって元の引裂強度の絶対値が６ｇを超えて大きいフイルムでは前記の係止力を下回ることがないので、本発明の対象とはしないと言う意味である。
換言すれば、フイルムが持つ引裂強度の絶対値が小さいものほど、亀裂部の存在で生じる強度低下の悪影響は、仮留め部の持つ係止力の問題のみに留まらず、例えば、引出し操作上の僅かな過剰張力を受けた場合でも『直ちに伝播破断の発生』につながってしまう。
従って、包装用のフイルムでは一般に引裂強度は少なくとも約２ｇは備えていることになる。この様な裂け易い性質のフイルムが本発明の対象品であることを意味している。
具体的には、例えば、塩化ビニリデン系樹脂の肉厚が６〜１８μｍで２軸延伸フイルム等は、その引裂強度（縦・横の平均値）が、通常の市販品で約２〜６ｇ、肉厚を９〜１６μｍの範囲から厳選したものでも約４〜３ｇの範囲の低い値を示すので、本発明における最適な対象品となる。
つまり、本発明は、縦横の引裂強度の比で生じる伝播破断の切断を利用するものではなく、伝播破断の切断が生じ易い引裂強度の絶対値の小さいフイルムの伝播破断の切断をどう抑制するかを課題にしている。
【００２２】
次に上記要件（ロ）の［鋸刃の歯山の高さを０．８０ｍｍ以下に低める］ことの技術的意義は、フイルム切断の進行をできるだけ鋸刃を構成する歯山の形状縁に沿った切断に近づけるためのものである。
そのことにより、上記考察（ａ）で言う『切断開始点からの引裂伝播によりフイルムの破断』が伴う場合でも、考察（ｂ）で言う『破断の合流のずれ』が小さくなるので亀裂部Ｔの発生を少なくすることができ、結果的に剥ぎとる際の『意図しない方向へのフイルムの破断』の発生を抑制する効果が得られるのである。
【００２３】
補足すると、例えば図１（Ｂ）；参考品と図３とを比較して、上記表１に示すように、本発明に準ずる参考品と従来品との鋸刃形状が比較される。この比較において最も相違する点は、歯山の山の高さ（山の頂の仮想線と谷の底の仮想線間の距離）にあり、現実寸法の比較で、従来品（図３）の高さ（１．０ｍｍ）に対して参考品［図１（Ｂ）］の高さ（０．５０ｍｍ）は、約１／２と低くなっていることが分かる。
この図１（Ｂ）と図３の例では、歯山の傾斜角（山の稜線間の角度）を一定（６０度）に揃えてあるので、ピッチ（山の中心仮想線間の距離）を、夫々０．５８ｍｍと１．１６ｍｍにすることで山の高さの差を調整している。
この両者の切断端を比較すると、図４（Ａ）［従来の山の切り裂きフィルム］に比べて図２（Ａ）、（Ｂ）［山を低くした鋸歯による切り裂きフィルム］は、フイルムに当接していた鋸刃の歯山の跡（破線部）と実際に切断されたフイルムの切断端との間の、位置及び形状の双方の『ずれが小さくなる』という改善がなされており、亀裂部Ｔの発生率も約６０％程度少なく且つ若干発生している亀裂部Ｔも小さくなっていることが分かる。
【００２４】
本発明者等の研究結果によると、図２（Ｂ）；参考品で例示した上述の効果の発現には次の点に留意すべきことが確認される。
即ち、先ず歯山の高さは０．４０ｍｍ〜０．８０ｍｍの範囲から選択することが必要である。それは０．８０ｍｍを超えて高いものでは、亀裂部Ｔの発生を抑制する効果が期待できないし、逆に歯山の高さが０．４０ｍｍ未満の低いものでは、フイルムへの切断性能の低下する問題と、更には加工精度が保ち難くなる問題が生じるからである。さらに、亀裂部Ｔの発生の抑制と切断性能の維持との双方の調和をより高度に図る観点から、歯山の高さは０．４０ｍｍ〜０．６０ｍｍの範囲から選ぶことが望ましい。
【００２５】
一方、切断性能を確保しようと歯山の傾斜角を４５度未満に小さくする方向では、亀裂部Ｔの発生を抑制する効果が期待できないし、逆に歯山の傾斜角を７５度を超えて大きくする方向は、フイルムへの歯の食込みが悪くなり切断性能を低下させる傾向がある。
従って、亀裂部Ｔの発生の抑制と切断性能の維持との双方の調和を図る観点から、歯山の傾斜角は５０〜７０度の範囲から選ぶことがより望ましく、両者のより高度な調和を図る観点から、歯山の傾斜角は５５〜６５度の範囲から選ぶことが最も望ましい。
【００２６】
従って、本発明は、図１（Ｂ）；参考品と図１（Ａ）；発明品との比較でも明らかな様に、歯山の高さを０．４０以上０．８０ｍｍ以下の範囲に設計し、「相隣れる歯山間の谷部は０．３０ｍｍ以上０．８０ｍｍ以下の範囲の平坦状に形成された谷底部を配する」要件が付加されることが必要である。
そして、本発明が、優れた効果を示す理由は、主として一定幅の『平坦状に形成された谷底部（以下平坦状谷底部と言う）』の存在に基づくものである。
即ち；
（１）この『平坦状谷底部』の第１の役割は、個々の歯山について、歯先の切断開始点から歯山の形状に沿って引裂伝播によるフイルム破断の進行が『平坦状谷底部』で押え留められ、上記考察（ｂ）で言う『双方の破断が合流する機会（位置）のずれ』を防ぐことにある。
（２）この第２の役割は、平坦状谷底部の寸法を規定幅に置くことで歯山の先にかかる張力（フイルムの押圧）の集中性が高まり、採用できる歯山の傾斜角を広める利点がある。更に、上記張力の集中性は、歯山の切断開始点の『位置ずれ』を小さくし、結果的に歯山の形状に沿う切断を促がすことである。
【００２７】
この第１、２と言う二つの役割は共に、亀裂部Ｔの発生を抑制する効果に繋がるものである。さらに、付随的な効果として歯山のピッチの広がりが観測される。
ここで言う『平坦状谷底部』とは、通常の鋸刃での歯山間は、その山裾の谷底部はＶ字状に形成されているのが一般的であるのに対し、本発明の鋸刃では平らな谷部であることを意味している。
従って、必ずしも「真平らなもの」である必要はなく、例えば、見た目で平らな谷部であることが明らかであり、要するに『歯先から引裂伝播による破断の進行が抑止される平らかさ』があれば充分である。
しかし、鋸刃の加工は、雄型・雌型の一対の型で挟み切る所謂剪断力によるのが一般的であるので、対の型の噛み合わせを確実に且つ円滑にするために、例えば歯山の裾と谷底部との交点に小さな曲率半径のアールをとることができ、その立上がりの部分は必ずしも平坦でなくとも構わない。
【００２８】
そこで、本発明では、『平坦状谷底部』の存在をその実寸法である『平坦状谷底部の（幅）寸法』で表示することで明確にした。
従って、この平坦状谷底部分の寸法は０．３０〜０．８０ｍｍの範囲が必要である。
その理由は、０．８０ｍｍを超えて大きい場合は、上記考察（ｂ）で言う『破断が合流する機会のずれ』が大きすぎて、亀裂部Ｔが平坦状谷底部の延長線の方向に発生し、逆にその寸法が０．３０ｍｍ未満と小さいものでは、破断の進行を抑制する効果が期待できない傾向にある。
従って、破断の進行を抑制する為の厳密な平坦状谷底部分の寸法は、０．３０〜０．７０ｍｍの範囲から選ぶことがより望ましい。
【００２９】
更に、本発明では、下記の要件をも具備することが必要である。
即ち、歯山の傾斜角は４５度以上７５度以下の範囲および歯山のピッチは０．６３ｍｍ以上２．０３ｍｍ以下の範囲から選ぶことが必要である。
この範囲は切断性能の維持と亀裂部Ｔの発生率の抑制効果との調和を図る観点から定めたものである。
本発明は、歯山の高さを０．４０ｍｍ以上０．６０ｍｍ以下の最適範囲に選ぶ時には、歯山の傾斜角は５０〜７０度の範囲、歯山のピッチは０．６７〜１．５４ｍｍの範囲から選ぶことがより望ましく、歯山の傾斜角は５５〜６５度の範囲、歯山のピッチは０．７２〜１．４６ｍｍの範囲から選ぶことが最適である。
この範囲はいずれも、亀裂部Ｔの発生率の抑制効果を厳格にみる観点からのものである。
【００３０】
上述の歯山設計の考え方は、鋸刃の長手のほぼ全長に歯山の高さや歯山の傾斜角やそのピッチがほぼ均一な状態の歯山が分布し、且つその分布する歯山の相隣れる歯山間の全ての谷部に平坦状谷底部がある場合のものを、本発明の望ましい鋸刃として表現したものである。
この場合の歯山の高さを低くする鋸刃の設計には、平坦状谷底部の寸法と歯山の傾斜角とが決まれば、歯山のピッチ自体はおのずから定まる性格のものである。
しかし、上述の歯山の高さや平坦状谷底部の寸法や歯山の傾斜角および歯山のピッチの各々の規定値範囲は、いずれも亀裂部Ｔの発生抑制と切断性能の維持との双方を満たす観点から厳選されたものである。
従って、上記した規定値範囲のものであれば、鋸刃の長手に歯山の高さや歯山の傾斜角や歯山のピッチが幾分違えた組合せを部分的に混在させた状態に配置したものでも、亀裂部Ｔの発生抑制と切断性能の維持との双方が満たされものとなる。
また同様に、『平坦状谷底部』が全ての相隣れる歯山の谷部に存在したものが一番効果的で望ましいが、効果上で『平坦状谷底部』の存在は、鋸刃の長手全長の歯谷数の７０％以上存在していれば、亀裂部Ｔの発生を抑制する効果は充分に期待できる。
【００３１】
上記本発明の説明は、図５で代表されるような板紙でできた四角柱状で、しかも箱体の掩蓋片の先に全体の形状が直線状の金属製鋸刃を配した実用性に優れていて望ましい収納箱に重点を置いて行なっているが、その発明の効果は鋸刃の歯山の形状・デザインに基づくことは明白である。
従って、例えば箱の材質はプラスチック、木、金属等の薄板であってもよく、また箱断面の柱状形が、円形状、楕円形状、或いは３角形以上の多角形状等のもであっても使用できる。更に鋸刃の全体形状や鋸刃の取り付け位置も、図５の例示に留まらず従来公知の全てのものに応用できる。
【００３２】
本発明で言う「金属製鋸刃」とは、例えば鉄、銅、真鍮、アルミニウム、ステンレス等の厚み０．２５〜０．１５ｍｍ程度の薄板を切断加工して作られるものを指す。この場合に、防錆、加工精度の維持、切断具と堅牢性、経済性などの点から厳選したときの鋸刃の材質は、ＪＩＳ−Ｇ３３０３に定めるブリキを用いる場合が最も理想的である。
また、本発明で言う「仮留め部Ｑ」は、その材質、配置場所ともに従来公知のものであり、切断具のある手前の部位の適所に、例えば粘着性接着剤や表面が平滑な樹脂層を配したもの等がある。中でも紫外線架橋性硬化ニスを表面が平滑な樹脂層として用いたものは、全体としてのフイルム係止能が高いので本発明に有利となる。
【００３３】
本発明で言う「引裂強度」とは、ＪＩＳ−Ｐ８１１６に準拠して測定した値の、縦、横の平均値である。
尚、測定機には〔軽荷重引裂強度測定機：（株）東洋精機製作所製〕を用い、サンプルサイズは幅５０ｍｍ、長さ６３．５ｍｍに一枚づつ切り取り、縦、横各５枚ずつのサンプル数とした。測定には、サンプルの幅方向のほぼ中央に１２．７ｍｍの切れ目を入れて行なった。
即ち、本発明でいう「引裂強度」は低い値のものであり、通常用いるエレメンドルフ測定機では誤差が大きい。従って、軽荷重の測定方法を基準化したに近い紙の基準であるＪＩＳ−Ｐ８１１６に準拠させたのである。
【００３４】
本発明に用いた評価方法および評価尺度は次の通りである。
（１）鋸刃の寸法および角度の測定：
歯山の高さやピッチ、平坦状谷底部等の寸法、および歯山の傾斜角の測定は、鋸刃の長手方向にほぼ均等に１０分割し、その１分割部分当たり１０個の歯（合計１００個の歯）について、光学顕微鏡（倍率約１００）で拡大して測定したものである。
尚、測定値は、寸法関係は小数点以下３桁まで測定した値を平均し、小数点以下３桁目のところで五捨六入して小数点以下２桁に丸めた。また角度は、小数点以下１桁まで測定した値を平均し、小数点以下１桁目のところで五捨六入して小数点以上に丸めた。
（２）亀裂（Ｔ）の発生率：
この測定は、事前に行なった調査で１０回の切断について観測した値の平均値で示す結果と１回の切断について観測した値との間で、多くても約２％の値のずれしかなく、１回の切断について観測した値を用いてもその鋸刃が示す亀裂（Ｔ）の発生率の水準は示せるので、１回の切断について観測した値を用いた。
即ち、切断したフイルム端の全幅にある歯山の跡のについて光学顕微鏡（倍率約１７倍）で観測し、谷の数の全部と亀裂のある谷の数とを数え、次の式で計算して求めた。
【数１】
亀裂の発生率（％）＝（亀裂のある谷の数÷谷の数の全部）×１００
【００３５】
（３）切断性能：
（３）−１ 切断性（切れ味）：
熟練した（感性の高い）モニター１人を厳選し、常に従来（市販）品との対比で判断するモニターによる官能テストを実施した。
即ち、収納箱から約１５ｃｍ長のフイルムを引き出し、これを切断する操作を従来（市販）品と比較しながら繰り返し、切れ味の感触、切断端の揃い方で下記表２に従って評価する。
切断方法は『持ち上げ切り』と『水平開き切り』の２種類を採用し、夫々評価した。尚、ここで約１５ｃｍ長の引き出し−切断を採用している理由は、比較的困難な切断であるため、鋸刃の性能の良否が顕著に現われるからである。
【表２】

【００３６】
（３）−２ 切断性能の持続性：
上記の「約１５ｃｍ長のフイルムを引き出しこれを切断する操作」を、巻層フイルム（２０ｍ巻）の３本分（２本目からは補充）につき実施し、試験前後での収納箱（掩蓋片）の変形量の大きさで下記表３に従って評価した。
この切断は、収納箱に掛かる負担が相対的に大きく、従って切れ味が低下したものは、この変形量が大きくなることになる。変形量は、前板と掩蓋片との間の長手中央での隙間寸法の増加量（反り変形量）を求めた。
また、評価には、『水平開き切り』を採用した。理由はこの切断法が最も掩蓋片の反り変形を生じ易いことによる。
【表３】

【００３７】
【実施例】
本発明を下記の実施例により詳細に説明するが、これらは本発明の範囲を制限しない。
紙管に巻層された巻幅寸法約３００ｍｍの塩化ビニリデン系樹脂フイルム［商品名：サランラップ（旭化成（株）製）、引裂強度３〜４ｇ、巻き量２０ｍ］を収納した箱体を作成するに当たり、市販に供している収納箱を用意した。この箱体の基本構造は、図５に示す通りのものである。
即ち、前板１、底板２、後板３、及び脇板８とで形成された上部が開口した長方形の収納室１３と、その収納室１３の後板３の側縁から収納室開口部を覆う方向に連接した蓋板４と、その蓋板４の側縁から前板１を覆う方向に延した掩蓋片５と、掩蓋片５で覆われる前板１の表面に切断後のフイルムを係止する仮留め部Ｑを有した長方形の箱体であって、収納室１３に収納した巻回フイルムＲからラップフイルムＦの必要量を引き出し、掩蓋片５の先端に配備した全体としての形状が直線状である金属（ブリキ）製の鋸刃Ｋで切断して用いるラップフイルムの収納箱である。
【００３８】
この箱の前板１の部分仕様は、全体寸法は高さ４４ｍｍ、長さ３１０ｍｍであり、蓋をした時はその高さの上から約３０ｍｍの部分は掩蓋片５（先端に付いた切断具を含む）で覆われる。その覆われる前板の上端縁から４ｍｍを残した前板上方から下方側に幅１６ｍｍの仮留め部Ｑを長手全域に設けてある。
この仮留め部Ｑは、紫外線架橋性硬化ニス［商品名：フラッシュドライ、東洋インキ製造（株）製］を塗布、乾燥して作成したものである。
このラップフイルムの収納箱を基本にして、これに取り付ける上記長尺の鋸刃Ｋ｛材質＝［粗面仕上げ、調質度ＤＲ−８、厚み０．１７ｍｍのブリキ板製（ＪＩＳ−Ｇ３３０３）］｝の設計のみを変更し、下記の通り実施例と比較例に区分した。
【００３９】
（参考例１、参考比較例１、および参考応用例１）
この実験の内容は、本発明との比較のために、参考として示すものである。
即ち、変更した長尺鋸刃の歯山の高さ、歯山の傾斜角、歯山間ピッチは、表４の実験Ｎｏ．１〜１７（参考例１、参考比較例１）にまとめて示した内容の通りである。
（表４における×印は、本発明で規定する範囲外の値の場合を示す。）
【表４】

【００４０】
つまり、表４の値は長尺鋸刃の長手全長（約３０５ｍｍ）に同形の歯山が均等な分布で配列することを目標に作成して得た鋸刃を、本文に記載測定方法で評価した数値を示したものである。
実験Ｎｏ．１〜９は参考例で、実験Ｎｏ．１０〜１７は参考比較例である。
従来（現状）の技術水準との違い、即ち顧客の要望を満たすように設計された長尺鋸刃の付いた市販品の水準との違い（対比）を明らかにするために、２種類の現行市販品を用意し、夫々の鋸刃を本文に記載測定方法で評価し、得た数値の平均値を表１の［従来品］の欄に示した。
即ち、その１つの参考応用例は［商品名：サランラップ、旭化成（株）入りの収納箱］の市販品そのもの（実験Ｎｏ．１８−１）であり、もう１つの参考応用例は［商品名：ポリラップ＝ポリエチレン系樹脂製のもの（中国レジン社製）入りの収納箱］（実験Ｎｏ．１８−２）である。但し（実験Ｎｏ．１８−２）をこの実験に供したい理由は、採用されている長尺鋸刃の材質が板紙製（バルカナイズド硬質変性の処理をした板紙：長さ約３０５ｍｍ、厚み０．２８ｍｍ）であることである。
【００４１】
従って、他の実験品との諸条件を均しくするために、鋸刃を丁寧に取り外し、その鋸刃を他の実験品と同じ収納箱の掩蓋片の裏面に、金属針（マックス針、
Ｎｏ．１０−１Ｍ）により強固にカシメ固定をすることにし、巻層フイルムも巻幅寸法約３００ｍｍの塩化ビニリデン系樹脂フイルム［商品名：サランラップ（旭化成社製）、引裂強度３〜４ｇ、巻き量２０ｍ］に詰め換えた。
上記実験Ｎｏ．１〜９（参考例１）１０〜１７参考比較例１）および実験Ｎｏ．１８−１、１８−２（参考応用例１−１、２）の収納箱について、本文記載の方法で切断性能および亀裂部の発生率を評価し、その結果を表５にまとめて示した。
また、実験Ｎｏ．１の鋸刃自体とそれで切断したフイルム端との拡大模式図（光学顕微鏡で１７倍）写真を模写し、部分省略したもの）を、夫々、図１（Ｂ）；参考品と図２（Ｂ）；参考品に示した。
同様な方法で得た実験Ｎｏ．１８−１（参考応用例１−１）の鋸刃自体と、それで切断したフイルム端との拡大模式図を、夫々、図３；従来品と図４（Ａ）、（Ｂ）；従来品に示した。尚、図４（Ａ）は『水平開き切り』によるもの、図４（Ｂ）は『持ち上げ切り』によるものである。
【００４２】
【表５】

表５の結果は、次のことを示している。即ち：
(1) 板紙製（実験Ｎｏ．１８−２；参考応用例１−２）の鋸刃の切断性能は、本発明が目的とする切断性能の水準には遠く及ばない。これは材質に起因するもので、バルカナイズド硬質変性の処理をした板紙でも金属板の特性には至らない。また、亀裂部の発生率も多い。これは歯山の形状の相違によるものである。
(2) 金属製鋸刃付きの収納箱での『亀裂部の発生率』の対比で、参考例１の製品［例えば実験Ｎｏ．１］は、従来（現行市販）品（実験Ｎｏ．１８−１；参考応用例１−１）の約１／７に減少し発生率が改善する。
【００４３】
この相違を鋸刃の歯山でみると、歯山の高さが従来（現行市販）品が１．０
ｍｍであるのに対し、参考例の製品が０．５０ｍｍの（約１／２）に低めたことによる効果である。この減少効果には、歯山の高さを０．４０〜０．８０ｍｍの範囲とする必要がある（実験Ｎｏ．１〜９；参考例１と実験Ｎｏ．１０〜１７；参考比較例１との関係から分かる）。
この参考例による驚くべき効果の発現は、現行（市販）品および従来技術の知見からは予測ができないものである。
【００４４】
（３）従来（現行市販）品の切断性能を維持する前提で、亀裂部の発生率の減少効果が見られる参考例１の収納箱の鋸刃は、実験Ｎｏ．１〜９のものである。
即ち、歯山の高さを０．４０〜０．８０ｍｍの範囲に定める時である。その設計条件は、歯山の傾斜角は５０〜７０度の範囲、歯山のピッチは０．３７〜１．１２ｍｍの範囲にすることが望ましい。
（４）同様に切断性能を維持する前提で、更に亀裂部の発生率の減少効果を重視する観点からは、参考例１の中でも（実験Ｎｏ．１〜５）と（実験Ｎｏ．６〜９）との間で有意義の差がある。
この顕著な効果上の違いは、歯山の高さを０．４０〜０．６０ｍｍの望ましい範囲に定めたときに生ずるものであり、その時の設計条件は、歯山の傾斜角は５５〜６５度の範囲、歯山のピッチは０．４２〜０．６９ｍｍの範囲にすることが望ましい。
【００４５】
（実施例１、比較例１、および参考例１）
この実験の内容は、本発明に係るものである。
即ち、変更した長尺鋸刃の歯山の高さ、平坦状谷底部、歯山の傾斜角、および歯山間ピッチは、表６〜７の実験Ｎｏ．１９〜４３（実施例１）、実験Ｎｏ．４４〜５５（比較例１）にまとめて示した内容の通りである。
【表６】

【００４６】
以下、表７における×印は、本発明で規定する範囲外の値の場合を示す。
【表７】

【００４７】
つまり表６〜７の値は、長尺鋸刃の長手全長（約３０５ｍｍ）に同形の歯山が均等な分布で配列することを目標に作成して得た鋸刃を、本文に記載測定方法で評価した数値を示したものである。
従来品（現状）の技術水準との違いを示すために、ＧＬＡＤ ＷＲＡＰ［商品名：ＧＬＡＤ ＰＲＯＤＵＣＴＳ社（オーストラリア国）製、ポリエチレン系樹脂フイルム入り］収納箱を入手した。この収納箱に付いている長尺の金属製鋸刃（：長さ約３３８ｍｍ、厚み０．２５ｍｍ）は、その形態が本発明のものに外見上が似ているので、あえてここに採用することにした。
【００４８】
従って、他の実験品との諸条件を均しくするために、鋸刃のカシメ爪を丁寧に起こして鋸刃を取り外し、３０５ｍｍに切断し、その鋸刃を他の実験品と同じ収納箱の掩蓋片の裏面にカシメ爪により強固にカシメ固定することにし、巻層フイルムも巻幅寸法約３００ｍｍの塩化ビニリデン系樹脂フイルム［商品名：サランラップ（旭化成（株）製、引裂強度３〜４ｇ、巻き量２０ｍ］に詰め換えた。
この鋸刃の測定値は、表６〜７の参考応用例１の欄に実験Ｎｏ．５６として示した。
上記実験Ｎｏ．１９〜４３（実施例１）、Ｎｏ．４４〜５５（比較例１）および実験Ｎｏ．５６（参考応用例１）の収納箱について、本文記載の方法で切断性能および亀裂部の発生率を評価し、その結果を表８〜９にまとめて示した。
【００４９】
【表８】

【００５０】
【表９】

【００５１】
また、実験Ｎｏ．１９（実施例１）の鋸刃自体と、それで切断したフイルム端との拡大模式図（光学顕微鏡の１７倍の写真を模写し、部分省略したもの）を、夫々、発明品による鋸歯；図１（Ａ）と発明品による鋸歯で切断されたラップフィルム；図２（Ａ）に示した。
表８〜９の結果は、次のことを示している。即ち：
（ａ）参考応用例１（実験Ｎｏ．５６）の金属製鋸刃の切断性能は、本発明が目的とする切断性能の水準には遠く及ばない。また『亀裂部の発生率』も高い。 これはこの鋸刃の設計が、引裂強度が（縦／横＝３７／１４４ｇ）と大きく、且つ極めて伸び易いポリエチレン系樹脂フイルムの切断専用に考えられた鋸刃であることによる。
【００５２】
（ｂ）金属製鋸刃付きの収納箱での『亀裂部の発生率』の比較で、発明品［例えば（実験Ｎｏ．１９；実施例１）］は、従来（現行市販）品（実験Ｎｏ．１８−１；参考応用例１）の約１／１３に抑制改善する。
この相違を鋸刃の歯山でみると、歯山の高さが従来（現行市販）品が１．０ｍｍに対し、本発明品は０．５０ｍｍの（約１／２）に低めたことと、０．５０ｍｍの平坦状谷部を設けたこととの相乗効果による。
この歯山の高さを０．４０〜０．８０ｍｍの範囲の値にする必要がある点は、参考例１（実験Ｎｏ．１〜９）と共通している。
しかし、上述した平坦状谷部を設けたことの『亀裂部の発生率の抑制効果』を厳格に評価するときには、参考例［参考例１（実験Ｎｏ．１〜５）］と本発明［実施例１（実験Ｎｏ．１９〜２７）］を対比することになる。
この『亀裂部の発生率』の対比によれば、前者は１２〜１６％の水準であるのに対して後者は５〜１２％となり、明らかに平坦状谷部を設けた本発明の方が効果的であることが分かる。
【００５３】
（ｃ）従来（現行市販）品の切断性能を維持する前提で、亀裂部の発生率の抑制効果が見られる本発明の収納箱の鋸刃は、実験Ｎｏ．１９〜４３（実施例１）のものである。
即ち、歯山の高さを０．４０〜０．８０ｍｍの範囲に定める前提で、平坦状谷部を設けた鋸刃の歯山の設計である。その設計条件は、先ず平坦状谷部の寸法は０．３０〜０．８０ｍｍの範囲（実験Ｎｏ．１９〜４３；実施例１）にすることが必要になる。
その場合の歯山の傾斜角は４５〜７５度の範囲、歯山のピッチは０．６３〜２．０３ｍｍの範囲にする必要がある。
（ｄ）同様に切断性能を維持する前提で、更に亀裂部の発生率の減少効果を重視する観点からは、本発明品の中でも（実験Ｎｏ．１９〜２７；実施例１）と（実験Ｎｏ．２８〜３５；実施例１）は、（実験Ｎｏ．３６〜４３；実施例１の一部の実験）に比べ夫々に有意義の差異がある。
【００５４】
この顕著な効果の差異を得るには、先ず歯山の高さを０．４０〜０．６０ｍｍの望ましい範囲に、更に平坦状谷部の寸法を０．３０〜０．８０ｍｍの望ましい範囲に夫々設定して、歯山の傾斜角を厳選することになる。
その選択される歯山の傾斜角は、４５〜７５度が必要であり、５０〜７０度の範囲が更に望ましく、６５〜５５度の範囲が最も望ましい。この際の歯山のピッチは、歯山の高さ、平坦状谷部の寸法、および歯山の傾斜角が定まれば、おのずと定まる性格のものである。
そうした観点での歯山のピッチは、０．６３〜２．０３ｍｍが必要であり、０．６７〜１．５４ｍｍの範囲が更に望ましく、０．７２〜１．４６ｍｍの範囲が最も望ましいことになる。
【００５５】
【発明の効果】
以上の通り、本発明の特定の構成を持つ収納箱は、従来（現行市販）品の持つ切断性能（切断性、切断性能の持続性）を保持した状態で、切断したフイルム端に生じる亀裂部の発生率を大幅に抑制する効果がある。この亀裂部は、フイルム端を引き出す時にフイルムが『意図しない方向に裂ける』不良現象の元凶であるので、亀裂部の発生率を大幅に抑制する収納箱は、産業界に有益な優れた発明である。
【図面の簡単な説明】
【図１】本発明の実施例を説明する金属製鋸刃の拡大（１７倍）部分模式図である。
図１（Ａ）は最適な発明品；金属製鋸刃を示し、図１（Ｂ）は適した参考品；金属製鋸刃を示した部分模式図である。
【図２】本発明の実施例を説明する図１の鋸刃（発明品）で切断したフイルム端の拡大部分模式図である。
図２（Ａ）は最適な発明品の金属製鋸歯で切断したラップフイルム端を示し、図２（Ｂ）は適した参考品の金属製鋸歯で切断したラップフイルム端を示した部分模式図である。
【図３】従来（現行市販）品の収納箱に用いている鋸刃の歯山を拡大（１７倍）して示す部分摸式図である。
【図４】図３に示す鋸刃（従来品）で切断したフイルム端の拡大部分模式図である。
図４（Ａ）は『水平開き切り』をした場合のものを、図４（Ｂ）は『持ち上げ切り』をした場合のものである。
【図５】従来の収納箱の構造を示す模式図である。
図５（Ａ）は開封前の収納箱の状態を示す斜視図であり、図５（Ｂ）は開封した状態を示す斜視図である。
【符号の説明】
１ 前板
２ 底板
３ 後板
４ 蓋板
５ 掩蓋片
６ 開封片
８ 脇板
９ 局部接合部
１０ 切取り線
１１ 脇掩蓋片
１２ カシメ具
１３ 収納室
Ｑ 仮留め部（フイルム係止部）
Ｋ 切断具（長尺の金属製鋸刃）
Ｒ 巻回フイルム
Ｆ フイルム[0001]
[Industrial applications]
The present invention relates to a technique for improving a wrapping film storage box, which is generally used for direct packaging of food in general households and food retailers.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a wrap film storage box in which a rolled film is stored in a column-shaped box storage chamber as shown in FIG. 5 is known. As this columnar box, for example, various types of cylinders, triangular to octagonal polygonal columns are known.
FIG. 5 is a schematic view showing the structure of a conventional storage box. FIG. 5A is a perspective view showing the state of the storage box before opening, and FIG. 5B is a perspective view showing the state of opening the storage box.
The storage boxes shown in FIGS. 5A and 5B illustrate a case where the storage box is a quadrangular prism-shaped box which is widely marketed and widely used. In FIG. 5, a rectangular storage room 13 having an open top formed by a front plate 1, a bottom plate 2, a rear plate 3, and a side plate 8, and a storage room opening from the side edge of the rear plate 3 of the storage room 13. A winding box which is a rectangular box body having a cover plate 4 connected in a covering direction and a cover piece 5 extending from a side edge of the cover plate 4 in a direction to cover the front plate 1, and is stored in a storage room 13. The required amount of the wrap film F is pulled out from the film R, and is fixed to the tip of the cover piece 5 along the longitudinal direction of the box with the caulking device 12 and provided with the teeth of the long metal saw blade K. This is a storage box that is used by cutting along a box (for example, Japanese Utility Model Application Laid-Open No. 59-28022).issueGazette).
[0003]
Most of this type of box body is made of paperboard, and is formed by bending the plate surface of each part at substantially a right angle at each fold line portion, and a side cover extending from the cover plate 4 in a direction to cover the side plate 8. With the piece 11 or the side cover piece 11AbsentIfButis there.
Also, the overall shape of the saw blade (toothThe shape of a virtual line connecting the ends)lineA shape, a concave arc shape, a convex arc shape, a V-shaped protrusion, a trapezoidal protrusion and the like are known.
[0004]
FIG. 5 (A) is a perspective view showing a state in which the unsealing piece 6 is to be cut and removed along the perforated line 10 and the unsealing piece 6 is to be opened from the storage box while the peeling of the portion of the local joint 9 is proceeding. () Is a view showing a state in which the film F is drawn out and the film F is drawn out.
Cutting methods using this type of commercially available storage box are roughly classified into three types, commonly called “lifting cut”, “horizontal cutting”, and “center rotation cutting”. That is, in any of these cutting methods, the path of the film F drawn out with the lid first passes between the front surface of the front plate 1 and the back surface of the cover piece 5, and the film is cut at the tip of the cover piece 5. Refracted almost perpendicularly at the tooth of the toolReThe film edge is guided in a horizontal direction perpendicular to the cover piece, and further between the braking force with the thumb on the longitudinal center of the surface of the cover piece 5 and the hand holding the induced film end. A common feature is that tension is applied to the film, and the tooth tip is cut into the film by the tension.
[0005]
However, the method of applying the tension in this case is different. (A) The angle between the film between the front plate 1 and the cover piece 5 and the end of the film is set to an acute angle of 45 degrees or less. With the relative twisting motion between the hand holding the box and the hand holding the box and the hand holding the film end, the film abutting against the tooth tip is applied to the film in the direction in which the film abuts sequentially from one end of the saw blade to the other end. Applying tension, cutting from one end to the other end of the film width in order
(B) While maintaining the horizontal relationship between the box and the guided film, the wrist holding the box so that the longitudinal end of the box draws a horizontal arc around the longitudinal end of the box. `` Horizontal opening cut '' that applies tension by spreading the film horizontally and cutting the film sequentially from one end of the width to the other end,
(C) While maintaining the horizontal relationship between the above box and the guided film, rotate the holding box downward with the wrist, apply tension to the film with the tooth tips, and move both sides of the film from the center of the film width. It can be classified into three types, "center rotation cutting", which cuts sequentially toward the end.
[0006]
In each of these three cutting methods, the film is cut off at the tip of a long metal saw blade arranged substantially over the entire length of the box portion, and the film follows the shape of the saw blade. It takes advantage of the advantage of being cut accurately.
Therefore, the suitability according to the overall shape of the employed saw blade, that is, for example, a saw blade having a V-shaped overall shape is extremely excellent in "center rotation cutting", but the other two methods are somewhat inefficient. It is a hand, and a straight cutting tool with a flat overall shape is excellent for “lifting cut” and “horizontal open cutting”, but “center rotation cutting” is slightly inferior. Exists.
However, regarding the three types of cutting methods, a metal saw blade has a high level of cutting performance (performance due to the properties of the material) that cannot be achieved with a paper or plastic saw blade. There is an advantage that a cutting method that suits the user's preference can be provided.
[0007]
In other words, some saw blades in commercially available wrap film storage boxes still dare to stick to the use of long metal saw blades against the trend of changing to paper saw blades or plastic. The reason is that in the market for wrapping films, which require an unspecified number of people to always be able to cut with their preferred cutting method accurately and reliably while maintaining high cutting performance, there is a need for materials. Based on the results of market research, it was found that paper or plastic saw blades that could not meet the basic characteristics such as hardness and rigidity could not satisfy such high market demands.ZuIt is a spider.
The height of the tooth ridge (the distance between the imaginary line at the top of the mountain and the imaginary line at the bottom of the valley) is about 1.0 mm, and the inclination angle of the tooth hill (between the ridge lines of the mountain) Is about 60 degrees, and the pitch of the tooth ridges (distance between the imaginary lines of the ridges) is about 1.16 mm.
[0008]
The shape design of the tooth ridge of this metal saw blade is carefully selected from the viewpoint of ensuring the safety not to hurt the finger etc., the high cutting performance and the sustainability of the cutting performance, and the processing accuracy. Has been carefully evaluated in the process control, and in terms of film sharpness (high cutting performance and sustainability of performance), consumers have earned a reputation for being "extremely excellent" It is being done.
In this type of storage box, a temporary fixing portion Q of the film is arranged on the surface of the front plate 1 covered with the cover piece 5. The role of the temporary fixing portion Q of the film is to prevent the cut end of the drawn-out film from rewinding into the box due to the momentum at the time of cutting (the next drawing-out becomes difficult). It is.
[0009]
[Problems to be solved by the invention]
Recently, there have been many complaints that "this type of storage box is very troublesome because the film is torn in the vertical, horizontal and diagonal directions (that is, unintended directions)".
This failure phenomenon is common in, for example, a wrap film made of vinylidene chloride-based resin and having a thickness of 8 to 15 μm. In the case where a failure occurs, the end of the film locked by the above-mentioned temporary fixing portion Q is peeled off. When pulling out the film, the film tears in the vertical, horizontal, or diagonal directions (that is, unintended directions) from the tooth ridges (traces of the tooth ridges) on the edge of the film to be peeled. This makes it difficult to pull out the next film.
[0010]
The cause of making this phenomenon noticeable is that as a countermeasure to completely prevent the cut end of the drawn-out film from rolling back into the box, a recent measure to enhance the locking ability of the temporary fixing portion Q is to use the temporary fixing portion Q. This makes it difficult to peel off the film that has been locked.
However, if the locking ability of the temporary fixing portion Q is lowered to facilitate the peeling of the film, the phenomenon that the cut end of the film is rewound increases, which causes a failure phenomenon that the film tears in an unintended direction. The place is simply to move the place of occurrence from the temporary fixing portion Q to the surface of the rolled film R (that is, peeling off the cut end of the film that is in close contact with the surface of the rolled film), which is a drastic measure. I can't.
[0011]
On the other hand, as a proposal for preventing the film from being obliquely cut, a method described in, for example, JP-A-6-293335 is known. This proposal describes that a film having a tear strength of 2 to 100 gr and a vertical / horizontal strength ratio of 1.5 or more can be prevented from being skewed, which is erroneous as if the problem of the present invention had been solved.
However, the reality of this proposal is that a rolled film whose tear strength in the transverse (width) direction is relatively weakened in the longitudinal direction is housed in a storage box provided with a saw blade only at the longitudinal end of the box. A cut is made only on the side of the drawn-out film with a saw blade, and the film is torn (cut) in the lateral (width) direction from the cut by propagation of the tear. In this case, since no trace of the saw blade is left on the film end, the occurrence of diagonal cutting can be prevented, and the cutting (tearing) becomes easier as the lateral tear strength is weakened.
[0012]
Therefore, cutting along the teeth of a long saw blade is intended to avoid the uncertainty of the technique of tearing the film in the lateral (width) direction by tear propagation (the problem of uneven cutting edges). On the other hand, the technique described in the above-mentioned known publication is to cut a film by tear propagation, and the mode of cutting is essentially different. Further, no hint is given regarding the tooth profile design of the saw blade of the present invention.
[0013]
On the other hand, in the specification of the present application, references of paper saw blades and plastic saw blades, which have many proposals related to the design of tooth ridges, are not intentionally cited as prior art.
The reason for this is that the object of the present invention is to solve the problems that have occurred in conventional (current) long metal saw blades by changing the tooth crest design of the same long metal saw blade. On the other hand, the literature on paper saw blades and plastic saw blades does not compensate for some of the obstacles caused by the characteristics of materials compared to metal with toothed tooth designs, and the current metal Even close to the cutting performance of the saw bladeZuIt is merely a matter that is not related to the present invention because the content of the cutting is different, the problem to be solved is also different, and the level of cutting performance of the obtained tooth ridge design is completely different (low). It is.
[0014]
Therefore, the object of the present invention is based on the premise that the cutting performance of the film held by the currently commercially available metal saw blade is maintained, and the film after cutting is vertically, horizontally, or obliquely cut from the cut end. It is an object of the present invention to provide a storage box for a wrap film having a long metal saw blade, which can suppress the occurrence of a phenomenon in which the film is torn in a direction (i.e., an unintended direction).
[0015]
[Means for Solving the Problems]
That is, the present inventionPillarIt consists of a box-shaped box and a rolled film housed in a box storage room.The required amount of wrap film is pulled out from the rolled film, and the drawn-out film is deployed in a box with the teeth of a long metal saw blade. In the storage box of the wrap film used by cutting along the blade,
The metal saw blade has a tooth height of 0.40 mm or more and 0.80 mm or less,The inclination angle of the tooth ridge ranges from 45 to 75 degrees, and the pitch between the tooth ridges is from 0.63 mm to 2.03 mm. The valley between adjacent tooth ridges has a flat valley bottom in a range of 0.30 mm or more and 0.80 mm or less.The present invention provides a storage box for a wrap film.
[0016]
In describing the content of the present invention below, first,Of the present inventionThe background will be described.
the aboveThe present inventionThe difference from the prior art is that
(A) The target wrap film shall have a tear strength of 6 g or less measured in accordance with JIS-P8116.
(B) The metal saw blade to be used is (a) the tooth height is in the range of 0.40 mm to 0.80 mm, and (b)The inclination angle of the tooth ridge ranges from 45 degrees to 75 degrees,(C)The pitch between tooth ridges is in the range of 0.63mm or more and 2.03mm or lessWhenAnd,and(D)The valley between adjacent tooth ridges has a flat bottom formed in a range of 0.30 mm or more and 0.80 mm or less.It is in a combination of
[0017]
Hereinafter, the present invention will be specifically described with reference to the drawings.
FIG. 1 is an enlarged (17 ×) partial schematic view of a metal saw blade for explaining an embodiment of the present invention.(A) is an invention and (B) is a reference..
FIG. 2 illustrates the saw blade of FIG.(A)Invention, (B) Reference products]Corresponding to eachFIG. 4 is an enlarged partial schematic view of a film end.To.
FIG. 3 is a partial schematic diagram showing the tooth ridge of a saw blade used in a conventional (currently commercially available) storage box in an enlarged scale (17 times).
[0018]
FIG. 4 is an enlarged partial schematic view of a film end cut by the saw blade (conventional product) shown in FIG. FIG. 4 (A) shows the case where “horizontal opening cut” is performed, and FIG. 4 (B) shows the case where “lift up cut”.
In FIGS. 1 to 4, a solid line drawn in a zigzag shape (toward the drawings)leftThe (end) portion is the tooth ridge of the saw blade or the cut end of the film, and the arrows drawn in FIGS. 2 and 4 indicate the cutting direction when the film is cut.
In [Film Cutting End with Conventional Saw Blade] in FIG. 4, a portion shown by a broken line near the zigzag cutting end shows traces of tooth ridges of the saw blade that abuted the film at the time of cutting. In addition, a part (T) shown in a beard shape at a part of a crest or a valley of the zigzag cut end indicates a crack part T that has entered the film.
FIG. 4 is a schematic diagram of a photograph showing the details of the above-described failure phenomenon, which were finally elucidated by the present inventors after various investigations.
In order to facilitate comparison of metal saw blades, the designs of the tooth ridges of the saw blade and the results (incidence of cracks T) are listed as follows.
In Table 1, in order to compare the difference in tooth height (and the presence or absence of a flat valley), the design was adjusted with a constant inclination angle and pitch.
[0019]
[Table 1]

[0020]
The result of examining the cause of the failure phenomenon (that is, the background of the invention) with reference to FIG. 4 is as follows. That is,
(A) Considering that the shape of the trace of the tooth ridge of the saw blade abutting on the film (broken line portion) is displaced from the shape of the actually cut film end, the cutting of the film in this case is However, the film is not necessarily cut along the ridgeline of the tooth ridge which is in contact with the ridge, but the film is accompanied by a breakage phenomenon of the film caused by tear propagation from the cutting start point pierced at the tip of the tooth ridge.
(B) The crack portion T generated at a part of the crest or valley portion of the zigzag cut end is a portion where the above-described tear propagation breakage has excessively progressed. Due to the temporal (or directional) difference of the rupture proceeding from the tooth ridge, the opportunity (position) at which both ruptures merge is shifted.
(C) The phenomenon in which the film tears in an unintended direction is based on the crack T existing at the cut end of the film picked when the film is peeled off.ZuIt is a spider.
That is, the force generated between the resistance due to the locking force and the tension to be stripped concentrates on the crack T, and the fracture proceeds from the crack T by the propagation of the tear. Therefore, the traveling direction is broken in a vertical, horizontal, or oblique direction (that is, an unintended direction) depending on the existence position of the crack T, the tip shape of the crack T, or along with the crystal structure of the resin.
(D) "Film breaking in an unintended direction" is caused by a crack T existing there when a large force is generated between the resistance due to the locking force and the peeling tension. In the case of a film having a high tear strength of the material itself, the film is extremely unlikely to break even if the crack T is present.
[0021]
Hereinafter, according to the considerations (a) to (d),BookinventionofExplain the technical significance.
First, the technical significance of “the tear strength of the film is 6 g or less” specified in the requirement (A) is the definition of “the absolute value of the strength is small” of the film targeted by the present invention.
In other words, the "phenomenon of film tearing in unintended directions"(As described in d), this is a phenomenon that occurs when the tear strength of the film weakened at the crack portion T falls below the locking force of the temporary fastening portion. Accordingly, a film having an original absolute value of tear strength exceeding 6 g does not fall below the above-mentioned locking force, which means that it is not an object of the present invention.
In other words, as the absolute value of the tear strength of the film is smaller, the adverse effect of the decrease in strength caused by the presence of the crack is not limited to the problem of the locking force of the temporary fixing portion, for example, in the pulling operation. Even if it receives a slight excess tension, it leads to "immediate generation of propagation rupture".
Accordingly, a film for packaging generally has a tear strength of at least about 2 g. This means that the film having such a tearing property is the object of the present invention.
Specifically, for example, a biaxially stretched film or the like having a wall thickness of a vinylidene chloride-based resin of 6 to 18 μm has a tear strength (average length and width) of about 2 to 6 g for a normal commercial product, Even if the thickness is carefully selected from the range of 9 to 16 μm, it shows a low value in the range of about 4 to 3 g, so that it is an optimal target product in the present invention.
In other words, the present invention does not use the cutting of the propagation rupture that occurs at the ratio of the vertical and horizontal tear strengths, but how to suppress the cutting of the propagation rupture of a film having a small absolute value of the tear strength at which the cutting of the propagation rupture easily occurs. Is an issue.
[0022]
Next, the technical significance of [reducing the tooth height of the saw blade to 0.80 mm or less] of the above requirement (b) is that the progress of the film cutting should be performed along the edge of the tooth shape forming the saw blade as much as possible. This is to approximate the cutting.
Accordingly, even when "film breakage due to tear propagation from the cutting start point" described in the above discussion (a) accompanies, the "displacement of break merging" described in the discussion (b) becomes small, so that the crack T As a result, the occurrence of “breaking of the film in an unintended direction” at the time of peeling can be suppressed.
[0023]
Supplementally, for example, FIG.; Reference goodsFIG. 3 is compared with FIG.Reference according toThe saw blade shapes of the product and the conventional product are compared. The most different point in this comparison is the height of the peak of the tooth ridge (the distance between the virtual line at the top of the peak and the virtual line at the bottom of the valley). For height (1.0mm)referenceProduct [Fig.B)]] (0.50 mm) is as low as about 1/2.
This figure (BIn the example of FIG. 3 and FIG. 3, the inclination angle of the tooth ridge (the angle between the ridge lines of the ridge) is set to a constant value (60 degrees).0.58mm and 1.16 mm, the difference between the peak heights is adjusted.
Comparing the cut ends of the two, FIG.Tear film2 (A) and 2 (B) [mountain loweredSaw-tooth film] Shows that there is an improvement in that both the position and the shape between the trace of the tooth ridge of the saw blade abutting on the film (broken line portion) and the cut end of the actually cut film are reduced. It can be seen that the rate of occurrence of cracks T is about 60% less and the number of cracks T slightly generated is also smaller.
[0024]
According to the research results of the present inventors, FIG. 2 (B);Reference goodsIt is confirmed that the following points should be taken into account for the above-mentioned effects described in the above section.
That is, first, it is necessary to select the tooth height from the range of 0.40 mm to 0.80 mm. If it is higher than 0.80 mm, the effect of suppressing the generation of the crack portion T cannot be expected. Conversely, if the height of the tooth ridge is lower than 0.40 mm, the cutting performance to the film decreases. This is because there arises a problem and a problem that it is difficult to maintain the processing accuracy. Furthermore, from the viewpoint of achieving a higher level of harmony between the suppression of the generation of the crack portion T and the maintenance of the cutting performance, the height of the tooth ridge is 0.4.0It is desirable to select from the range of mm to 0.60 mm.
[0025]
On the other hand, to secure the cutting performance,45In the direction of reducing the angle to less than the degree, the effect of suppressing the generation of the crack portion T cannot be expected, and conversely, the inclination angle of the tooth ridge is reduced.75When the direction is increased beyond the degree, the bite of the teeth into the film becomes worse, and the cutting performance tends to decrease.
Therefore, the inclination angle of the tooth ridge may be selected from the range of 50 to 70 degrees from the viewpoint of harmonizing both the suppression of the generation of the crack portion T and the maintenance of the cutting performance.ThanDesirably, from the viewpoint of achieving a higher degree of harmony between the two, the inclination angle of the tooth ridge is most preferably selected from a range of 55 to 65 degrees.
[0026]
Therefore, the present inventionFIG. 1 (B);Reference goodsAnd FIG. 1 (A);InventionAs is clear from the comparison with the above, the height of the tooth ridge ranges from 0.40 to 0.80 mm.Designed toThe requirement that “the valleys between adjacent tooth ridges have a flat bottom formed in a range of 0.30 mm to 0.80 mm” is added.It is necessary.
AndThe present inventionThe main reasons for the improved effect areConstant widthThis is based on the existence of “a flat valley bottom (hereinafter referred to as a flat valley bottom)”.
That is;
(1) The first role of the “flat valley bottom” is that, for each tooth ridge, the progress of film breakage due to tear propagation along the shape of the tooth ridge from the cutting start point of the tooth tip is referred to as the “flat valley bottom”. To prevent the "displacement of the opportunity (position) at which both breaks join" referred to in the above discussion (b).
(2)thisThe second role is that by setting the dimension of the flat valley bottom to a specified width, the concentration of the tension (pressing the film) applied to the tip of the tooth ridge is increased, and there is an advantage that the inclination angle of the tooth ridge that can be used is widened. Further, the above-mentioned concentration of the tension is to reduce the "positional deviation" of the cutting start point of the tooth ridge, thereby promoting cutting along the shape of the tooth ridge.
[0027]
Say these first and secondBoth roles lead to the effect of suppressing the generation of the crack T. Further, as an additional effect, the spread of tooth pitch is observed.
The term “flat valley bottom” here means that between the tooth ridges with a normal saw blade, the valley bottom of the skirt is generally formed in a V-shape,BookIn the saw blade of the invention, it means a flat valley.
Therefore, it is not always necessary to be “a flat surface”, for example, it is apparent that the valley is a flat valley in appearance. It is enough.
However, the processing of the saw blade is generally performed by a so-called shearing force sandwiching between a pair of male and female dies. Therefore, in order to reliably and smoothly engage the pair of dies, for example, A radius of curvature with a small radius of curvature can be obtained at the intersection between the skirt of the mountain and the bottom of the valley, and the rising portion does not necessarily have to be flat.
[0028]
Therefore, in the present invention, the existence of the “flat valley bottom” is clarified by indicating the actual size of the “(width) dimension of the flat valley bottom”.
ThereforeThe dimension of the flat valley bottom needs to be in the range of 0.30 to 0.80 mm.
The reason is that, if it is larger than 0.80 mm, the “shift in the chance of the break joining” mentioned in the above discussion (b) is too large, and the crack T is generated in the direction of the extension of the flat valley bottom. Conversely, if the size is as small as less than 0.30 mm, the effect of suppressing the progress of fracture tends not to be expected.
Therefore, the size of the strict flat valley bottom portion for suppressing the progress of the fracture can be selected from the range of 0.30 to 0.70 mm.Thandesirable.
[0029]
Further, in the present invention, it is necessary to satisfy the following requirements..
That is, the inclination angle of the tooth ridge may be selected from a range of 45 degrees or more and 75 degrees or less, and the pitch of the tooth ridge may be selected from a range of 0.63 mm or more and 2.03 mm or less.is necessary.
This range is determined from the viewpoint of maintaining harmony between the maintenance of cutting performance and the effect of suppressing the rate of occurrence of cracks T.
BookThe invention selects the height of the tooth ridge in the optimum range of 0.40 mm or more and 0.60 mm or less.SometimesMore preferably, the inclination angle of the tooth ridge is selected from the range of 50 to 70 degrees and the pitch of the tooth ridge is selected from the range of 0.67 to 1.54 mm. The inclination angle of the tooth ridge is in the range of 55 to 65 degrees. Is optimally selected from the range of 0.72 to 1.46 mm.
Each of these ranges is from the viewpoint of strictly observing the effect of suppressing the rate of occurrence of cracks T.
[0030]
The concept of the tooth ridge design described above is that the tooth ridges in which the height of the tooth ridges, the inclination angle of the tooth ridges, and the pitch thereof are substantially uniform are distributed over substantially the entire length of the saw blade, and the phase of the tooth ridges distributed is almost uniform. The case where there is a flat valley bottom in all valleys between adjacent tooth ridges is expressed as a desirable saw blade of the present invention.
In designing the saw blade to lower the height of the tooth ridge in this case, the pitch of the tooth ridge itself is naturally determined if the size of the flat valley bottom and the inclination angle of the tooth ridge are determined.
However, the specified value ranges of the height of the tooth ridges, the dimension of the flat valley bottom, the inclination angle of the tooth ridges, and the pitch of the tooth ridges are both for suppressing the generation of the crack T and maintaining the cutting performance. It was carefully selected from the viewpoint of satisfying.
Therefore,RegulationValue range, saw blade lengthToEven when the combination of the tooth height, the tooth inclination angle and the tooth pitch slightly different from each other are arranged in a partially mixed state, both the suppression of the crack T and the maintenance of the cutting performance are improved. Will be satisfied.
Similarly, it is most effective and desirable that the “flat valley bottom” exist in all adjacent tooth valleys.soThe existence of the “flat valley bottom” can be expected to be sufficiently effective to suppress the generation of the crack T if the valleys are at least 70% of the number of tooth valleys along the entire length of the saw blade.
[0031]
The above inventionofThe explanation is a quadrangular prism made of paperboard as represented in FIG. 5, and the whole shape is directly attached to the tip of the box cover.lineWith emphasis on practical and desirable storage boxes with metal-shaped saw blades,ThatThe effect of the invention is based on the shape and design of the toothZuIt is clear that.
Therefore, for example, the material of the box may be a thin plate of plastic, wood, metal, or the like. Even if the columnar shape of the box cross section is a circular shape, an elliptical shape, or a polygonal shape of a triangle or more, it is used. it can. Further, the overall shape of the saw blade and the mounting position of the saw blade are not limited to those illustrated in FIG.
[0032]
The "metal saw blade" as used in the present invention refers to a metal saw blade formed by cutting a thin plate having a thickness of about 0.25 to 0.15 mm, such as iron, copper, brass, aluminum, and stainless steel. In this case, when the material of the saw blade is carefully selected from the viewpoints of rust prevention, maintenance of processing accuracy, cutting tools, robustness, economy and the like, it is most ideal to use a tinplate specified in JIS-G3303.
The “temporary fastening portion Q” referred to in the present invention is conventionally known in terms of both its material and location. For example, a tacky adhesive or a resin layer having a smooth surface may be provided at an appropriate position in front of the cutting tool. And the like. Above all, those using an ultraviolet-crosslinkable cured varnish as a resin layer having a smooth surface are advantageous to the present invention because of their high film locking ability as a whole.
[0033]
The “tear strength” referred to in the present invention is the average value in the vertical and horizontal directions of the value measured according to JIS-P8116.
The measuring device used was a [light-weight tear strength measuring device: manufactured by Toyo Seiki Seisaku-sho, Ltd.]. The sample size was 50 mm wide and 63.5 mm long. The number of samples was used. The measurement was performed with a cut of 12.7 mm at the approximate center in the width direction of the sample.
That is, the “tear strength” referred to in the present invention is a low value, and the error is large in a commonly used Elementdorf measuring instrument. Therefore, the method was based on JIS-P8116, which is a standard for paper that is close to the standardized light load measurement method.
[0034]
The evaluation method and evaluation scale used in the present invention are as follows.
(1) Measurement of size and angle of saw blade:
The measurement of the height and pitch of the tooth ridge, the dimension of the flat valley bottom, etc., and the inclination angle of the tooth ridge are performed by equally dividing the saw blade in the longitudinal direction into ten parts, and ten teeth per one divided part (total 100 teeth). Of the individual teeth) with an optical microscope (magnification: about 100).
As for the measured values, the dimensional relationship is the average of the values measured to three decimal places, and the three decimal placesEyeRounded off to 2 decimal places. Also, the angle is calculated by averaging the values measured to one decimal place, and one decimal placeEyeRounded off to the nearest whole number.
(2) Crack (T) incidence:
In this measurement, there was only a difference of at most about 2% between the result indicated by the average value of the values observed for 10 cuts in the survey conducted in advance and the value observed for one cut. Since the level of the crack (T) generation rate indicated by the saw blade can be indicated by using the value observed for one cut, the value observed for one cut was used.
That is, the trace of the tooth ridge in the entire width of the cut film end is observed with an optical microscope (magnification: about 17 times), the total number of valleys and the number of cracked valleys are counted, and calculated by the following equation. I asked.
(Equation 1)
Crack generation rate (%) = (number of valleys with cracks / total number of valleys) x 100
[0035]
(3) Cutting performance:
(3) -1 Cutting performance (sharpness):
One skilled (highly sensitive) monitor was carefully selected, and a sensory test was conducted with a monitor that was always compared with a conventional (commercially available) product.
That is, the operation of pulling out a film having a length of about 15 cm from the storage box and cutting the film is repeated while comparing with a conventional (commercially available) product, and evaluation is made according to the following Table 2 in terms of sharpness and uniformity of cut edges.
Two types of cutting methods, “lifting cut” and “horizontal cut”, were adopted and evaluated respectively. Here, the reason why the draw-cut of about 15 cm in length is adopted is that the quality of the saw blade is remarkably high because the cutting is relatively difficult.
[Table 2]

[0036]
(3) -2 Sustainability of cutting performance:
The above-mentioned operation of “drawing out a film of about 15 cm length and cutting it” is carried out for three (20 m rolls) of rolled film (refilled from the second), and storage boxes (cover pieces) before and after the test Was evaluated according to Table 3 below.
This cutting imposes a relatively large load on the storage box, and therefore, if the sharpness is reduced, the amount of deformation is increased. As the amount of deformation, the amount of increase in the gap size (warpage deformation) at the longitudinal center between the front plate and the cover piece was determined.
In the evaluation, “horizontal opening” was adopted. The reason is that this cutting method is most likely to cause warpage of the cover piece.
[Table 3]

[0037]
【Example】
The invention is illustrated in more detail by the following examples, which do not limit the scope of the invention.
In preparing a box containing a vinylidene chloride resin film having a winding width of about 300 mm (trade name: Saran Wrap (manufactured by Asahi Kasei Corporation), tear strength 3 to 4 g, winding amount 20 m) wound around a paper tube. And a storage box that is commercially available. The basic structure of this box is as shown in FIG.
That is, a rectangular storage room 13 formed by the front plate 1, the bottom plate 2, the rear plate 3, and the side plate 8 and having an opening at the top, and a storage chamber opening from the side edge of the rear plate 3 of the storage room 13. The cover plate 4 connected in the covering direction, the cover piece 5 extending from the side edge of the cover plate 4 in the direction to cover the front plate 1, and the cut film are attached to the surface of the front plate 1 covered with the cover piece 5. It is a rectangular box having a temporary fastening portion Q for stopping, and a required amount of the wrap film F is pulled out from the rolled film R stored in the storage room 13, and the whole shape provided at the tip of the cover piece 5 is as follows. straightlineThis is a storage box for a wrap film used by cutting with a metal (tin) saw blade K.
[0038]
The partial specification of the front plate 1 of this box is as follows: the overall dimensions are 44 mm in height and 310 mm in length, and when the lid is covered, the portion about 30 mm from the top of the height is the cover piece 5 (the cutting tool attached to the tip). Including). A temporary fixing portion Q having a width of 16 mm is provided in the entire longitudinal direction from the upper side to the lower side of the front plate leaving 4 mm from the upper edge of the front plate to be covered.
The temporary fixing portion Q is formed by applying and drying an ultraviolet-crosslinkable curing varnish (trade name: Flash Dry, manufactured by Toyo Ink Mfg. Co., Ltd.).
Based on this wrapped film storage box, the long saw blade K attached to the wrapped film is used. Material = [Rough surface finish, DR-8, 0.17 mm thick tin plate (JIS-G3303)] Only the design of｝ was changed and divided into Examples and Comparative Examples as described below.
[0039]
(referenceExample 1,referenceComparative Example 1 and ReferenceapplicationExample 1)
The content of this experiment wasIt is shown as a reference for comparison with.
That is, the height of the tooth ridge, the inclination angle of the tooth ridge, and the pitch between the tooth ridges of the changed long saw blade are the same as those of Experiment No. 1-17 (Reference Example 1, Reference Comparative Example 1) Is as shown in the following.
(The crosses in Table 4 indicate cases where the values are out of the range specified in the present invention.. )
[Table 4]

[0040]
In other words, the values in Table 4 were evaluated using the measuring method described in the text, with the saw blades being created with the aim of arranging the tooth teeth of the same shape in an even distribution over the entire length of the long saw blade (about 305 mm). It shows the numerical values obtained.
Experiment No. 1-9 arereferenceIn the example, experiment no. 10-17referenceIt is a comparative example.
In order to clarify the difference from the conventional (current) state of the art, that is, the difference (compared to) the level of a commercial product with a long saw blade designed to meet the needs of customers, two types of current technology are used. Prepare a commercial product, evaluate each saw blade by the measurement method described in the text,Average valueIn Table 1Conventional product] Column.
That is, one of theReference application exampleIs a commercial product itself (Experiment No. 18-1) [trade name: Saran Wrap, storage box containing Asahi Kasei Corporation].Reference application exampleIs [A storage box containing a product name: polywrap = polyethylene resin (manufactured by Resin China)] (Experiment No. 18-2). However, the reason why (Experiment No. 18-2) is to be subjected to this experiment is that the material of the long saw blade employed is made of paperboard (paperboard treated with vulcanized hard modification: about 305 mm long and 0.28 mm thick) ).
[0041]
Therefore, in order to equalize the conditions with the other experimental products, carefully remove the saw blade, and attach the saw blade to the metal box (max needle,
No. 10-1M), and the winding layer film is also a vinylidene chloride-based resin film having a winding width of about 300 mm [trade name: Saran Wrap (manufactured by Asahi Kasei Corporation), tear strength 3-4 g, winding amount 20 m]. Refilled.
In the above Experiment No. 1 to9(referenceExample 1)1017referenceComparative Example 1) and Experiment No. 18-1, 18-2 (referenceapplicationFor the storage boxes of Examples 1-1 and 2), the cutting performance and the rate of occurrence of cracks were evaluated by the method described in the text, and the results are shown in Table 5.
Experiment No. FIG. 1 (B); reference model and FIG. 2 (B), each of which is an enlarged schematic view of a saw blade 1 itself and a film edge cut therefrom (reproduced by photographing a photograph (17 times with an optical microscope) and partially omitted). ); Shown in Reference Products.
Experiment No. obtained by the same method. 18-1 (referenceapplicationFIG. 3 is an enlarged schematic view of the saw blade itself of Example 1-1) and a film edge cut by the saw blade.; Conventional productsAnd FIGS. 4A and 4B; Conventional productsIt was shown to. FIG. 4A is based on “horizontal opening”, and FIG. 4B is based on “lifting off”.
[0042]
[Table 5]

The results in Table 5 show the following. That is:
(1) Paperboard (Experiment No. 18-2; ReferenceapplicationExample 12The cutting performance of the saw blade of (1) is far below the level of cutting performance aimed at by the present invention. This is due to the material, and even a paperboard treated with vulcanized hard modification does not reach the properties of a metal plate. In addition, the incidence of cracks is high. This is due to the difference in the shape of the tooth ridge.
(2) Compared to the "incidence rate of cracks" in storage boxes with metal saw blades,Reference Example 1Product [for example, Experiment No. 1] is a conventional (currently available) product (Experiment No. 18-1; ReferenceapplicationIt is reduced to about 1/7 of Example 1-1), and the occurrence rate is improved.
[0043]
Looking at this difference in the tooth ridge of the saw blade, the height of the tooth ridge is 1.0% for the conventional (currently commercially available) product.
mmReference exampleThis is the effect of reducing the product to 0.50 mm (about 1/2). For this reduction effect, the height of the tooth ridge needs to be in the range of 0.40 to 0.80 mm (Experiment Nos. 1 to 9).Reference Example 1And Experiment No. 10-17;Reference Comparative Example 1From the relationship).
thisBy reference exampleThe manifestation of the surprising effect is unpredictable from current (commercially available) products and the knowledge of the prior art.
[0044]
(3) Assuming that the cutting performance of the conventional (currently available) product is maintained, an effect of reducing the incidence of cracks can be seen.Reference Example 1The saw blade of the storage box of Experiment No. 1-9.
That is, it is time to determine the height of the tooth ridge in the range of 0.40 to 0.80 mm. The design conditions are preferably such that the inclination angle of the tooth ridge is in the range of 50 to 70 degrees, and the pitch of the tooth ridge is in the range of 0.37 to 1.12 mm.
(4) Similarly, on the premise of maintaining the cutting performance, from the viewpoint of further emphasizing the effect of reducing the incidence of cracks,Reference Example 1Among them, there is a significant difference between (Experiment Nos. 1 to 5) and (Experiment Nos. 6 to 9).
This remarkable difference in effect occurs when the height of the tooth ridge is set to a desirable range of 0.40 to 0.60 mm, and the design condition at that time is that the inclination angle of the tooth ridge is 55 to 65 mm. It is desirable that the range of the degree and the pitch of the tooth ridge be in the range of 0.42 to 0.69 mm.
[0045]
(Example1, Comparative example1, And reference examples1)
The content of this experiment wasToIt is related.
That is, the tooth height, the flat valley bottom, the tooth inclination angle, and the tooth tooth pitch of the changed long saw blade are shown in Experiment Nos. 19 to 43 (Example1), Experiment No. 44 to 55 (Comparative Example1) Is as shown in the following.
[Table 6]

[0046]
Hereinafter, the crosses in Table 7 indicate cases where the values are outside the range specified in the present invention..
[Table 7]

[0047]
In other words, the values in Tables 6 and 7 are based on the measurement method described in the text of the saw blade obtained with the aim of arranging the tooth ridges of the same shape in an even distribution over the entire length (about 305 mm) of the long saw blade. Shows the numerical value evaluated inTo.
ConventionalGoodsIn order to show the difference from the state of the art, a GLAD WRAP [trade name: manufactured by GLAD PRODUCTS (Australia), containing polyethylene resin film] storage box was obtained. The long metal saw blade (: about 338 mm long, 0.25 mm thick) attached to this storage box is similar in appearance to that of the present invention. I made it.
[0048]
Therefore, in order to equalize the conditions with other experimental products, carefully raise the crimping nail of the saw blade, remove the saw blade, cut it to 305 mm, and place the saw blade in the same storage box as the other experimental products. The back film is firmly fixed by caulking with a caulking claw. The winding film is also a vinylidene chloride resin film having a winding width of about 300 mm [trade name: Saran Wrap (Asahi Kasei Corporation, tear strength 3 to 4 g, winding) 20m].
The measured values of this saw blade are shown in Tables 6 and 7.applicationAn example1In the column of Experiment No. 56.
In the above Experiment No. 19 ~43(Example 1),No. 44 ~55 (Comparative Example 1) And Experiment No. 56 (referenceapplicationAn example1For the storage box of (1), the cutting performance and the rate of occurrence of cracks were evaluated by the method described in the text, and the results are summarized in Tables 8 and 9.
[0049]
[Table 8]

[0050]
[Table 9]

[0051]
Experiment No. 19 (Example 1), The enlarged schematic diagram of the saw blade itself and the film edge cut with it (reproduced by a 17 times photograph of an optical microscope and partially omitted)Invented sawtoothFIG. 1 (A)Sawtooth cut wrap film according to the inventionAs shown in FIG.
The results in Tables 8-9 show the following. That is:
(A) ReferenceapplicationAn example1The cutting performance of the metal saw blade of (Experiment No. 56) is far from the level of the cutting performance aimed at by the present invention. Also, the “incidence rate of cracks” is high. This is because the saw blade is designed for cutting a polyethylene resin film having a large tear strength (length / width = 37/144 g) and being extremely stretchable.
[0052]
(B) By comparing the “rate of occurrence of cracks” in a storage box with a metal saw blade, the invention product [for example, (Experiment No. 19; Example 1)] is a conventional (currently commercially available) product (Experiment No. .18-1; ReferenceapplicationThe suppression is improved to about 1/13 of that of Example 1).
Looking at this difference in the tooth ridge of the saw blade, the height of the tooth ridge is 1.0 mm for the conventional (currently marketed) product,BookThe invention product is based on the synergistic effect of the reduction to 0.50 mm (about 1/2) and the provision of the flat valley of 0.50 mm.
The point that the height of the tooth ridge needs to be a value in the range of 0.40 to 0.80 mm is as follows.referenceCommon to Example 1 (Experiment Nos. 1 to 9)are doing.
However, when strictly evaluating the “effect of suppressing the incidence of cracks” of providing the flat valleys described above,Reference example[referenceExample 1 (Experiment Nos. 1 to 5)] andBookInvention [Example1(Experiment No.19To 27)].
According to the comparison of the "rate of occurrence of cracks", the former is at a level of 12 to 16%, while the latter is at a level of 12 to 16%.5~ 12%, clearly providing a flat valleyBookIt turns out that the invention is more effective.
[0053]
(C) Assuming that the cutting performance of conventional (currently commercially available) products is maintained, an effect of suppressing the rate of occurrence of cracks is seen.BookThe saw blade of the storage box of the present invention was manufactured in Experiment No. 19-43 (Example 1)belongs to.
That is, on the premise that the height of the tooth ridge is set in the range of 0.40 to 0.80 mm, the tooth ridge of the saw blade provided with the flat valley is designed. The design conditions are as follows: First, the dimension of the flat valley is in the range of 0.30 to 0.80 mm (Experiment No.19~ 43;Example 1).
In this case, the inclination angle of the tooth ridge is in the range of 45 to 75 degrees, and the pitch of the tooth ridge is in the range of 0.63 to 2.03 mm.There is a need.
(D) Similarly, on the premise of maintaining the cutting performance, from the viewpoint of further emphasizing the effect of reducing the incidence of cracks,BookAmong the invention products (Experiment No.19~ 27;Example 1) And (Experiment Nos. 28 to 35;Example 1) (Experiment Nos. 36 to 43;Some experiments of Example 1) Each have a significant difference.
[0054]
In order to obtain this remarkable difference in effect, first, the height of the tooth ridge is set to a desirable range of 0.40 to 0.60 mm, and the size of the flat valley is set to 0.30 to 0.80The inclination angle of the tooth ridge is carefully selected by setting each to a desirable range of mm.
The inclination angle of the selected tooth mountain is45 to 75 degrees is required, 50-70 degrees is more desirable, and 65-55 degrees is most desirable. The pitch of the tooth ridge at this time has a characteristic that is naturally determined if the height of the tooth ridge, the dimension of the flat valley, and the inclination angle of the tooth ridge are determined.
The pitch of the tooth mountain from such a viewpoint is0.63-2.03mm is required, 0.67 to 1.54 mm, more preferably 0.72 to 1.46 mm.
[0055]
【The invention's effect】
As described above, the storage box having the specific configuration of the present invention has a crack portion generated at the cut film end while maintaining the cutting performance (cutting property, sustainability of cutting performance) of the conventional (currently commercially available) product. Has the effect of significantly reducing the incidence of Since this crack is the cause of the failure phenomenon that the film tears in the unintended direction when the film end is pulled out, the storage box that greatly reduces the incidence of cracks is an excellent invention useful to the industry. is there.
[Brief description of the drawings]
FIG. 1 is an enlarged (17 ×) partial schematic view of a metal saw blade for explaining an embodiment of the present invention.
FIG. 1 (A) shows the optimalInventionFIG. 1B is a partial schematic view showing a metal saw blade, which is a suitable reference product;
FIG. 2 is an enlarged partial schematic view of a film end cut by the saw blade (invention product) of FIG. 1 for explaining an embodiment of the present invention.
FIG. 2 (A) is cut with the best inventive metal saw blade.WrapFIG. 2B shows a film edge, and FIG.With reference metal saw bladeCutWrapIt is the partial schematic diagram which showed the film end.
FIG. 3 is a partial schematic diagram showing a tooth ridge of a saw blade used in a storage box of a conventional (currently commercially available) product in an enlarged scale (17 times).
FIG. 4 is an enlarged partial schematic view of a film end cut by the saw blade (conventional product) shown in FIG.
FIG. 4 (A) shows the case where “horizontal opening cut” is performed, and FIG. 4 (B) shows the case where “lift up cut”.
FIG. 5 is a schematic view showing the structure of a conventional storage box.
FIG. 5A is a perspective view showing the state of the storage box before opening, and FIG. 5B is a perspective view showing the state of opening the storage box.
[Explanation of symbols]
1 Front plate
2 bottom plate
3 Rear plate
4 lid plate
5 Cover pieces
6 Opening pieces
8 Side plate
9 Local joints
10 Cut line
11 Armpit cover pieces
12 Caulking tool
13 storage room
Q Temporary fixing part (Film retaining part)
K cutting tool (long metal saw blade)
R rolled film
F film

Claims (1)

It consists of a columnar box and a rolled film housed in the box storage room.The required amount of wrap film is pulled out from the rolled film, and the drawn film is sawn with long metal saw blade teeth arranged in the box. In the storage box for a wrap film used by cutting along the blade, the metal saw blade has a tooth height in a range of 0.40 mm or more and 0.80 mm or less, and an inclination angle of the tooth peak is 45 degrees or more and 75 degrees. The following range, the pitch between the tooth ridges is in the range of 0.63 mm or more and 2.03 mm or less, and the valley between adjacent tooth ridges is formed in a flat shape in the range of 0.30 mm or more and 0.80 mm or less. A wrap film storage box, characterized by having a trough bottom .

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