【０００１】
【発明の属する技術分野】
本発明は、筒形底部を備えた細筒形袋の製造法に関し、特に細長い形状の物品を、その形状に合わせた袋体に装入し、包装外形を美しくするようにした筒形底部を備えた細筒形袋の製造法に関するものである。
【０００２】
【従来の技術】
従来、細長い形状の物品を包装する場合には、収納する物品よりも少し大きめの扁平な袋体を用い、この扁平状包装袋体内に所要の物品を装入し、必要に応じて口部を溶着その他の方法で閉じるようにしている。
そして、この扁平状包装袋体としては、一般にポリエチレンその他の合成樹脂シートよりなる袋体を使用している。
【０００３】
【発明が解決しようとする課題】
しかし、従来の扁平状包装袋体としては、一般に収納する物品よりも少し大きめの袋体を用いているため、物品を装入した後も収納する物品の外周部分に、扁平袋体の周縁部分が存在するようになり、これがため、包装した状態での収納物品の正確な形状を外部より識別することが困難となる。
また、収納物品を包装した状態で外観することにより、正確に物品の外観形状を識別することが求められる、例えば、購入時製品の形状を確認する必要がある高価で、精密な製品においては、包装した状態では外観より収納された製品形状を、容易に、かつ正確に識別することができず、このため包装袋を破り、製品を取り出して確認する必要があり、また確認後再び包装し直す手数を要し、さらには製品の価値を損なうという問題があった。
【０００４】
本発明は、従来の扁平状包装袋体の有する問題に鑑み、包装袋体の外部からも容易に、かつ正確に収納物品の形状などを識別できるように、また細長い製品でも容易に収納でき、その価値を損なわずに包装できるようにした筒形底部を備えた細筒形袋の製造法を提供することを目的とする。
【０００５】
【課題を解決するための手段】
上記目的を達成するため、本第１発明の筒形底部を備えた細筒形袋の製造法は、熱収縮性樹脂シートにて形成された筒形部材を一端側にのみ折り目を有するようにして切断し、次にこの素材を成形する細筒形袋の大きさに、かつ前記折目と交わる方向の両側端部を、ヒートシーラにて溶着切断して筒状に形成し、その一端側の開口部より成形用筒形型に挿入し、該成形用筒形型上方より折目部分を加熱し、成形用筒形型の先端部形状に沿って収縮させて袋底部を筒形に成形したことを特徴とする。
【０００６】
本発明の筒形底部を備えた細筒形袋の製造法によれば、従来熱収縮性樹脂シートを用いて、細長い袋体を製造することができなかったが、筒形部材を一端側にのみ折り目を有するようにして切断し、この素材を成形する細筒形袋の大きさに、かつ前記折目と交わる方向の両側端部を、ヒートシーラにて溶着切断して筒状に形成し、その一端側の開口部より成形用筒形型に挿入し、該成形用筒形型上方より折目部分を加熱し、成形用筒形型の先端部形状に沿って収縮させて袋底部を筒形に成形することにより、熱収縮性樹脂シートを用いての細長い袋体の製造も容易に、多量生産に適した方法で、しかも形成する底片部の形状を筒形とすることができるので、細長い棒状製品等の装入も容易に行え、かつ収納部品の形状も袋体の外部から容易に識別及び確認することができ、製品価値を向上することができる。
【０００７】
また、本第２発明の筒形底部を備えた細筒形袋の製造法は、熱収縮性樹脂シートにて形成された筒形部材を一端側にのみ折り目を有するようにして切断し、次にこの素材を成形する細筒形袋の大きさに切断した後、前記折目と交わる方向の両側端の切断縁に沿ってヒートシーラにて溶着して筒状に形成し、その一端側の開口部より、成形用筒形型に挿入し、該成形用筒形型上方より折目部分を加熱し、成形用筒形型の先端部形状に沿って収縮させて袋底部を筒形に成形したことを特徴とする。
【０００８】
本第２発明の筒形底部を備えた細筒形袋の製造法によれば、熱収縮性樹脂シートにて形成された筒形部材を一端側にのみ折り目を有するようにして切断し、この素材を成形する細筒形袋の大きさに切断した後、前記折目と交わる方向の両側端の切断縁に沿ってヒートシーラにて溶着して筒状に形成し、その一端側の開口部より、成形用筒形型に挿入し、該成形用筒形型上方より折目部分を加熱し、成形用筒形型の先端部形状に沿って収縮させて袋底部を筒形に成形するようにしているから、製造が簡単で、安価に、任意の大きさの細筒形袋を製造することができる。
【０００９】
本第３発明は、成形用筒形型を、少なくともその先端部分を円筒形或いは角筒形とすることができる。
【００１０】
この本第３発明においては、先端部分を円筒形或いは角筒形に形成した成形用筒形型を変更するだけで、簡単に成形する細筒形袋の底部形状を容易に変えることができるとともに、成形後の形状を美しくすることができる。
【００１１】
【発明の実施の形態】
以下、本発明の筒形底部を備えた細筒形袋の製造法の実施の形態を、図面に基づいて説明する。
図１〜図２は、本発明の筒形底部を備えた細筒形袋の製造法の第１実施例を示す。
【００１２】
本発明の筒形底部を備えた細筒形袋の製造法は、所定の熱収縮率を有する熱収縮性合成樹脂シート、例えばポリエチレン、塩化ビニールの単一シート或いはこれらの複合層シートなどの長尺チューブ形状（筒状）の筒形部材を用いる。この熱収縮性合成樹脂シートは、一般に連続して多量生産する場合、生産可能な長尺チューブ形状の筒サイズが限定され、極端に細い、例えば１０ｍｍ程度の筒形は成形することができなかった。
そこで、本発明では、製造可能な熱収縮性合成樹脂シート製長尺チューブ形状の筒形部材を用いる。例えば、もっとも効率よく使用できるものとして成形する筒形底部を備えた細筒形袋の長さＬのほぼ２倍長２Ｌの横幅を有する長尺チューブ形状（筒状）の素材を採用する。
【００１３】
そして、この長尺チューブ形状の素材Ｗをロール状に巻回した素材ロールＲを繰り出すとともに、その長手方向に沿って、幅方向のほぼ中央位置をもって切断し、この長尺チューブ形状の素材をその長手方向に沿って２分割とする。これにより、一側面に折目１を備えた２つ折り状の連続した素材Ｗ１を形成する。この幅方向のほぼ中央位置を切断する方法は、特に限定されるものではないが、効率的に行う切断方法として、図１に示すように、ロール状に巻回した素材ロールＲから長尺チューブ形状の素材Ｗを巻き戻して繰り出す際に、カッターＣの刃先を該素材Ｗの幅方向のほぼ中央位置に当てることにより、連続して簡単に正確に切断することができると同時に、１つの長尺チューブ形状の素材Ｗより２つの２つ折り状の素材Ｗ１，Ｗ１を得ることができる。
【００１４】
このように切断された扁平２つ折り状の素材Ｗ１は、一端側にのみ折目１（この折り目が底片部となる）を備えた２つ折り扁平状に形成される。次に、この扁平２つ折り状素材Ｗ１を、本第１発明においては、成形する細筒形袋の大きさ、特に袋の幅となる長さに合わせて、かつ底片部分となる折目１と交わる方向の両側端部２，３をヒートシーラＨ等にて溶着切断する。これは、図１（１）に示すように、前記扁平２つ折り状素材Ｗ１を、袋の幅となる長さとする所定間隔毎に、ヒートシーラＨを押圧することにより溶着と同時に切断をも行う。これにより、扁平２つ折り状素材Ｗ１より所要幅を有する扁平で両側端縁２，３がヒートシーラにて溶着された細い袋体Ｗ２（図１（２）参照）が形成される。
【００１５】
次に、この扁平な細い袋体Ｗ２を、図１（３）に示すように、その一端の開口部４より、所要形状の底部を成形するようにした成形用筒形型Ｋに挿入する。これは作業効率を鑑みて、成形用筒形型Ｋをほぼ垂直に樹立させた状態で固定し、この成形用筒形型Ｋに扁平な細い袋体Ｗ２を膨らませて、その開口部４から挿入して被せるようにする。この成形用筒形型Ｋは、成形する細筒形袋の内径より少し小径とし、容易に筒形型に細い袋体を挿入できるようにし、かつ少なくとも成形用筒形型Ｋの先端部分の形状を、細筒形袋Ｗ２の底部の底片形状、例えば円筒形、多角形等に合わせて予め成形しておくものとする。
【００１６】
そして、図１（４）に示すように、成形用筒形型Ｋの上方から折目部分、即ち底片となる折目１の周辺部分を、赤外線ヒータ等のヒータＨ１を用い、その赤外線の照射或いは輻射熱によりほぼ均一に加熱されるようにする。この時の加熱温度は、成形用筒形型Ｋに被せた扁平な細い袋体Ｗ２の底片部５がその半径方向に熱収縮する程度に、例えば扁平な細い袋体の材質、シート厚などにより適正に設定するものである。
また、底片部５の加熱は、赤外線ヒータ等による直接加熱方式するか、或いは温風を当てるようにして加熱する。この温風による加熱温度も、素材の熱収縮性合成樹脂シートが所定の熱収縮をきたす程度に設定する。
そして、この素材の熱収縮性合成樹脂シートが加熱により熱収縮する際、折目１部分周縁の素材が成形用筒形型の先端部形状に沿って収縮して細筒形袋の底片部５が筒形に形成される。このとき、成形用筒形型Ｋの底部形状が円筒形ならば、成形される底部形状は円筒形に、また六角形などの多角形のときは、多角形に形成される。
このように、底部５を形成後、図１（５）に示すように、成形用筒形型Ｋより細筒形袋Ｗ３を抜くことにより、製品とすることができる。
【００１７】
また、請求項２に記載された本発明の第２実施例を図３に示す。この第２実施例は、本第１発明において成形された扁平２つ折り状素材Ｗ１を、同様に用いるもので、本第２実施例においては、図３（１）に示すように、成形する細筒形袋の大きさ、特に袋の幅となる長さに合わせて、かつ底片側となる折目１と交わる方向に切断し、側端部２，３とする。これは前記扁平２つ折り状素材Ｗ１を、袋の幅となる長さとする所定間隔毎に、カッターＣ１を押圧することにより切断する。この後、図３（２）に示すように、折目１と交わる方向の両側端部２，３の縁に沿ってヒートシーラＨ等にて溶着する。
これにより、扁平２つ折り状素材Ｗ１より所要幅を有する扁平で両側縁がヒートシーラＨにて溶着された細い袋体Ｗ２が形成される。
【００１８】
次に、この扁平な細い袋体Ｗ２を、図３（３）に示すように、その一端の開口部４より、成形用筒形型Ｋに挿入するが、これ以後の作業は、本第１発明と同じで、成形する細筒形袋の内径より少し小径とし、少なくともその底部形状を、円筒形、多角形等に合わせて予め成形した成形用筒形型Ｋを、ほぼ垂直に樹立させた状態で固定し、この成形用筒形型Ｋに扁平な細い袋体Ｗ２を膨らませて開口部４を被せるようにして挿入し、その後、図示省略したが、図１（４），（５）にて示したようにして、成形用筒形型Ｋの上方から折目１部分、即ち底片５となる折目部分を、赤外線ヒータＨ１を用い、その赤外線の照射或いは輻射熱によりほぼ均一に加熱されるようにし、熱収縮させて底片部５を筒形に形成した後、成形用筒形型Ｋより引き抜き、製品Ｗ３とする。
【００１９】
【発明の効果】
本第１発明の筒形底部を備えた細筒形袋の製造法によれば、従来熱収縮性樹脂シートを用いて、細長い袋体を製造することができなかったが、筒形部材を一端側にのみ折り目を有するようにして切断し、次にこの素材を成形する細筒形袋の大きさに、かつ前記折目と交わる方向の両側端部を、ヒートシーラにて溶着切断して筒状に形成し、その一端側の開口部より成形用筒形型に挿入し、該成形用筒形型上方より折目部分を加熱し、成形用筒形型の先端部形状に沿って収縮させて袋底部を筒形に成形することにより、熱収縮性樹脂シートを用いての細長い袋体の製造も容易に、多量生産に適した方法で、しかも形成する底片部の形状を筒形とすることができるので、細長い棒状製品等の装入も容易に行え、かつ収納部品の形状も袋体の外部から容易に識別及び確認することができ、製品価値を向上することができる。
【００２０】
また、本第２発明によれば、熱収縮性樹脂シートにて形成された筒形部材を一端側にのみ折り目を有するようにして切断し、次にこの素材を成形する細筒形袋の大きさに切断した後、前記折目と交わる方向の両側端の切断縁に沿ってヒートシーラにて溶着して筒状に形成し、その一端側の開口部より、成形用筒形型に挿入し、該成形用筒形型上方より折目部分を加熱し、成形用筒形型の先端部形状に沿って収縮させて袋底部を筒形に成形するようにしているから、製造が簡単で、安価に、任意の大きさの細筒形袋を製造することができる。
【００２１】
また、本第３発明によれば、先端部分を円筒形或いは角筒形に形成した成形用筒形型を変更するだけで、簡単に成形する細筒形袋の底部形状を容易に変えることができるとともに、成形後の形状を美しくすることができる。
【図面の簡単な説明】
【図１】本発明の筒形底部を備えた細筒形袋の製造法の第１実施例を示す製造工程図である。
【図２】成形された細筒形袋の底辺部を示し、（Ａ）は底面図、（Ｂ）は正面図である。
【図３】本発明の筒形底部を備えた細筒形袋の製造法の第２実施例を示す製造工程図である。
【符号の説明】
Ｒ 素材ロール
Ｗ 長尺チューブ形状の素材
Ｗ１ ２つ折り状の素材
Ｗ２ 細い袋体
Ｗ３ 製品
Ｈ，Ｈ１ ヒータ
Ｋ 成形用筒形型
Ｃ，Ｃ１ カッター
１ 折目
２ 側端部
３ 側端部
４ 開口部
５ 底辺部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a thin cylindrical bag having a cylindrical bottom, and particularly, to insert a long and narrow shaped article into a bag conforming to the shape, and to form a cylindrical bottom with a beautiful package outer shape. The present invention relates to a method for producing a thin cylindrical bag provided with the same.
[0002]
[Prior art]
Conventionally, when packaging an elongated article, a flat bag slightly larger than the article to be stored is used, the required article is loaded into the flat packaging bag, and the mouth is opened as necessary. It is closed by welding or other methods.
As the flat packaging bag, a bag made of polyethylene or other synthetic resin sheet is generally used.
[0003]
[Problems to be solved by the invention]
However, since the conventional flat packaging bag is a bag slightly larger than the generally stored article, the outer peripheral portion of the article to be stored after the article is loaded still has a peripheral portion of the flat bag. This makes it difficult to externally identify the exact shape of the stored article in the packaged state.
In addition, it is required to accurately identify the appearance of the article by external appearance in a state where the stored article is packaged, for example, in an expensive and precise product that needs to confirm the shape of the product at the time of purchase, In the packaged state, the shape of the stored product cannot be easily and accurately identified from the external appearance, so it is necessary to break the packaging bag, take out the product, and confirm it. There has been a problem that it takes time and further impairs the value of the product.
[0004]
The present invention has been made in view of the problem of the conventional flat packaging bag, and can be easily and accurately identified from the outside of the packaging bag, such as the shape of the stored article, and can be easily stored even in an elongated product, It is an object of the present invention to provide a method of manufacturing a thin cylindrical bag having a cylindrical bottom portion that can be packed without deteriorating its value.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a method of manufacturing a thin cylindrical bag having a cylindrical bottom according to the first aspect of the present invention is such that a cylindrical member formed of a heat-shrinkable resin sheet has a fold only at one end. And then cut to the size of the thin cylindrical bag for molding this material, and cut both ends in the direction intersecting with the fold by welding with a heat sealer to form a cylindrical shape. The bag was inserted into the cylindrical mold through the opening, the fold was heated from above the cylindrical mold, and shrunk along the shape of the tip of the cylindrical mold to form the bottom of the bag into a cylindrical shape. It is characterized by the following.
[0006]
According to the method for manufacturing a thin cylindrical bag having a cylindrical bottom portion of the present invention, an elongated bag body could not be manufactured using a conventional heat-shrinkable resin sheet. Cut only to have a fold, the size of the narrow cylindrical bag for molding this material, and both ends in the direction intersecting with the fold, welded and cut with a heat sealer to form a tubular, It is inserted into the cylindrical mold for molding from the opening on one end side, the fold portion is heated from above the cylindrical mold for molding, and the bag is shrunk along the shape of the tip of the cylindrical mold for molding to form the cylinder bottom. By molding into a shape, it is easy to manufacture an elongated bag using a heat-shrinkable resin sheet, and in a method suitable for mass production, and since the shape of the bottom piece to be formed can be cylindrical, Easily insert long and thin rod-shaped products, etc., and easily change the shape of storage parts from outside the bag. It is possible to separate and confirmation, it is possible to improve the product value.
[0007]
Further, in the method for producing a thin cylindrical bag having a cylindrical bottom according to the second invention, the cylindrical member formed of the heat-shrinkable resin sheet is cut so that only one end has a fold, After cutting to the size of a narrow cylindrical bag for molding this material, it is welded with a heat sealer along the cutting edges on both sides in the direction intersecting with the fold to form a cylindrical shape, and an opening at one end thereof From the part, it was inserted into the cylindrical mold for molding, the fold part was heated from above the cylindrical mold for molding, and shrunk along the tip shape of the cylindrical mold for molding, and the bag bottom was molded into a cylindrical shape. It is characterized by the following.
[0008]
According to the method for manufacturing a thin cylindrical bag having a cylindrical bottom portion of the second invention, the cylindrical member formed of the heat-shrinkable resin sheet is cut so that only one end has a fold, After cutting to the size of the narrow cylindrical bag for molding the material, it is welded with a heat sealer along the cutting edges on both sides in the direction intersecting with the fold to form a tube, and from the opening at one end side Then, insert into the molding cylinder, heat the fold from the top of the molding cylinder, shrink along the shape of the tip of the molding cylinder to mold the bag bottom into a cylinder. Therefore, it is possible to manufacture a small-sized cylindrical bag of any size easily and inexpensively.
[0009]
According to the third aspect of the present invention, at least a tip portion of the cylindrical mold for molding can be formed into a cylindrical shape or a rectangular cylindrical shape.
[0010]
In the third aspect of the present invention, the shape of the bottom of the thin cylindrical bag to be easily formed can be easily changed only by changing the cylindrical shape for forming the tip portion of which is formed into a cylindrical shape or a rectangular cylindrical shape. The shape after molding can be made beautiful.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a method for manufacturing a thin cylindrical bag having a cylindrical bottom according to the present invention will be described with reference to the drawings.
1 and 2 show a first embodiment of a method for manufacturing a thin cylindrical bag having a cylindrical bottom according to the present invention.
[0012]
The method for producing a thin cylindrical bag having a cylindrical bottom according to the present invention is characterized in that a heat-shrinkable synthetic resin sheet having a predetermined heat shrinkage rate, such as a single sheet of polyethylene or vinyl chloride or a composite sheet thereof, is used. A tubular member in the shape of a long tube (tubular) is used. In general, when mass-producing this heat-shrinkable synthetic resin sheet continuously, the tube size of a long tube shape that can be produced is limited, and a very thin tube, for example, a tube of about 10 mm, cannot be formed. .
Therefore, in the present invention, a long tubular member made of a heat-shrinkable synthetic resin sheet that can be manufactured is used. For example, a long tube-shaped (tubular) material having a width 2L, which is almost twice as long as the length L of the narrow cylindrical bag provided with the cylindrical bottom to be molded as the one that can be used most efficiently, is adopted.
[0013]
Then, a material roll R obtained by winding the material W in the form of a long tube into a roll is drawn out, and cut along the longitudinal direction thereof at a substantially central position in the width direction. It is divided into two along the longitudinal direction. As a result, a two-fold continuous material W1 having a fold 1 on one side surface is formed. The method of cutting the substantially central position in the width direction is not particularly limited. As an efficient cutting method, as shown in FIG. 1, a long tube is cut from a material roll R wound in a roll shape. When the material W having the shape is unwound and unwound, the cutting edge of the cutter C is applied to a substantially center position in the width direction of the material W, so that the material W can be continuously and easily cut accurately, and at the same time, one length is obtained. It is possible to obtain two folded materials W1 and W1 from the long tube-shaped material W.
[0014]
The flat folded two-piece material W1 cut in this manner is formed into a folded two-fold shape having a fold 1 only at one end side (the fold becomes a bottom piece). Next, in the first aspect of the present invention, the flat two-fold material W1 is combined with a fold 1 serving as a bottom piece according to the size of the narrow cylindrical bag to be molded, particularly the length of the width of the bag. Both ends 2 and 3 in the intersecting direction are welded and cut with a heat sealer H or the like. In this method, as shown in FIG. 1 (1), the flat two-fold material W1 is simultaneously welded and cut by pressing the heat sealer H at predetermined intervals of a length corresponding to the width of the bag. Thereby, a flat bag W2 (see FIG. 1 (2)) having a required width from the flat folded material W1 and having both side edges 2, 3 welded by a heat sealer is formed.
[0015]
Next, as shown in FIG. 1 (3), the flat and thin bag W2 is inserted into an opening 4 at one end thereof into a molding cylinder K for forming a bottom of a required shape. In view of the work efficiency, the molding cylindrical mold K is fixed in a state of being substantially vertically established, and a flat thin bag body W2 is inflated into the molding cylindrical mold K and inserted through the opening 4 thereof. And cover it. This molding cylinder K has a diameter slightly smaller than the inner diameter of the narrow cylinder bag to be molded so that the thin bag can be easily inserted into the cylinder, and at least the shape of the tip of the molding cylinder K Is formed in advance according to the shape of the bottom piece of the bottom of the small cylindrical bag W2, for example, a cylindrical shape, a polygonal shape, or the like.
[0016]
Then, as shown in FIG. 1 (4), the fold portion from above the forming cylindrical mold K, that is, the peripheral portion of the fold 1 serving as the bottom piece is irradiated with infrared rays by using a heater H1 such as an infrared heater. Alternatively, it is made to be heated substantially uniformly by radiant heat. The heating temperature at this time depends on, for example, the material and sheet thickness of the flat thin bag W2, to the extent that the bottom piece 5 of the flat thin bag W2 covered on the forming cylindrical mold K is thermally contracted in the radial direction. It is set appropriately.
The bottom piece 5 is heated by a direct heating method using an infrared heater or the like, or by heating with hot air. The heating temperature by the hot air is also set to such an extent that the heat-shrinkable synthetic resin sheet of the material causes a predetermined heat shrinkage.
Then, when the heat-shrinkable synthetic resin sheet of this material is thermally contracted by heating, the material around the fold 1 part shrinks along the shape of the tip of the cylindrical mold for molding, and the bottom piece 5 of the small cylindrical bag is formed. Are formed in a cylindrical shape. At this time, if the bottom shape of the molding die K is cylindrical, the bottom shape to be formed is cylindrical, and if it is a polygon such as a hexagon, the shape is polygonal.
In this way, after forming the bottom portion 5, as shown in FIG. 1 (5), the product can be obtained by removing the small cylindrical bag W3 from the cylindrical tube K for molding.
[0017]
FIG. 3 shows a second embodiment of the present invention described in claim 2. In the second embodiment, the flat two-fold material W1 formed in the first invention is similarly used. In the second embodiment, as shown in FIG. The cylindrical bag is cut in accordance with the size of the cylindrical bag, particularly the length of the bag, and in a direction intersecting the fold 1 on one side of the bottom, to obtain side ends 2 and 3. In this method, the flat two-fold material W1 is cut by pressing the cutter C1 at predetermined intervals of a length corresponding to the width of the bag. Thereafter, as shown in FIG. 3 (2), welding is performed with a heat sealer H or the like along the edges of both ends 2 and 3 in the direction intersecting the fold 1.
As a result, a flat bag W2 having a required width from the flat folded material W1 and having both side edges welded by the heat sealer H is formed.
[0018]
Next, as shown in FIG. 3 (3), the flat and thin bag W2 is inserted into the forming cylindrical mold K through the opening 4 at one end thereof. Same as the invention, a cylindrical cylindrical mold K preformed with a diameter slightly smaller than the inner diameter of the narrow cylindrical bag to be molded and at least the bottom shape thereof adjusted to a cylindrical shape, a polygonal shape, etc. was established almost vertically. In this state, the flat thin bag body W2 is inflated and inserted into the cylindrical cylindrical mold K so as to cover the opening 4. Thereafter, although not shown, FIGS. 1 (4) and (5) As shown in the above, the fold 1 part, that is, the fold part which becomes the bottom piece 5 from above the molding cylinder K is almost uniformly heated by the infrared irradiation or radiant heat thereof using the infrared heater H1. And then heat-shrink to form the bottom piece 5 into a cylindrical shape, and then pull it out from the cylindrical mold K for molding. , And the product W3.
[0019]
【The invention's effect】
According to the method for manufacturing a narrow cylindrical bag having a cylindrical bottom portion of the first invention, an elongated bag body could not be manufactured using a heat-shrinkable resin sheet conventionally. Cut only to have a fold on the side, and then cut into the size of the narrow cylindrical bag for molding this material, and cut and weld both ends in the direction intersecting the fold with a heat sealer. And inserted into the cylindrical mold for molding from the opening on one end side, heat the fold from above the cylindrical mold for molding, and shrink along the shape of the tip of the cylindrical mold for molding. By molding the bottom of the bag into a cylindrical shape, it is easy to manufacture an elongated bag using a heat-shrinkable resin sheet, and in a method suitable for mass production, and the shape of the bottom piece to be formed is cylindrical. Can be easily inserted into a long and thin rod-shaped product. Can be easily identified and confirmed, it is possible to improve the product value.
[0020]
According to the second aspect of the present invention, the cylindrical member formed of the heat-shrinkable resin sheet is cut so as to have a fold only at one end side, and then the size of the narrow cylindrical bag for molding this material is obtained. After being cut into pieces, it is welded with a heat sealer along the cutting edges on both sides in the direction intersecting the fold to form a cylinder, and from the opening on one end side, inserted into the cylindrical mold for molding, The folded part is heated from the upper part of the molding cylinder and shrunk along the shape of the tip of the molding cylinder to form the bottom of the bag into a cylinder, which is simple and inexpensive to manufacture. In addition, a thin cylindrical bag of any size can be manufactured.
[0021]
According to the third aspect of the present invention, it is possible to easily change the shape of the bottom portion of the thin cylindrical bag to be easily formed only by changing the cylindrical shape for forming the cylindrical portion or the rectangular cylindrical shape at the tip portion. It is possible to make the shape after molding beautiful.
[Brief description of the drawings]
FIG. 1 is a manufacturing process diagram showing a first embodiment of a method for manufacturing a thin cylindrical bag having a cylindrical bottom according to the present invention.
FIGS. 2A and 2B show a bottom portion of a molded small cylindrical bag, wherein FIG. 2A is a bottom view and FIG. 2B is a front view.
FIG. 3 is a manufacturing process diagram showing a second embodiment of the method for manufacturing a thin cylindrical bag having a cylindrical bottom according to the present invention.
[Explanation of symbols]
R Material roll W Long tube-shaped material W1 Folded material W2 Thin bag W3 Product H, H1 Heater K Forming cylinder C, C1 Cutter 1 Fold 2 Side end 3 Side end 4 Opening 5 Bottom