JPH0820068A - Molding of inflation film - Google Patents
Molding of inflation filmInfo
- Publication number
- JPH0820068A JPH0820068A JP15745294A JP15745294A JPH0820068A JP H0820068 A JPH0820068 A JP H0820068A JP 15745294 A JP15745294 A JP 15745294A JP 15745294 A JP15745294 A JP 15745294A JP H0820068 A JPH0820068 A JP H0820068A
- Authority
- JP
- Japan
- Prior art keywords
- film
- air
- molding
- gas
- inflation film
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000465 moulding Methods 0.000 title abstract description 23
- 238000000034 method Methods 0.000 claims abstract description 11
- 229920005992 thermoplastic resin Polymers 0.000 claims abstract description 6
- 238000001816 cooling Methods 0.000 abstract description 16
- 238000007664 blowing Methods 0.000 abstract description 4
- 239000007789 gas Substances 0.000 description 14
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 6
- 239000000155 melt Substances 0.000 description 5
- 229910052786 argon Inorganic materials 0.000 description 3
- 239000001569 carbon dioxide Substances 0.000 description 3
- 229910002092 carbon dioxide Inorganic materials 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 229920001903 high density polyethylene Polymers 0.000 description 2
- 239000004700 high-density polyethylene Substances 0.000 description 2
- -1 polyethylene Polymers 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 239000002356 single layer Substances 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- 229920001328 Polyvinylidene chloride Polymers 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- KYKAJFCTULSVSH-UHFFFAOYSA-N chloro(fluoro)methane Chemical compound F[C]Cl KYKAJFCTULSVSH-UHFFFAOYSA-N 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 239000005038 ethylene vinyl acetate Substances 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 1
- 229910000041 hydrogen chloride Inorganic materials 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920005672 polyolefin resin Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 239000005033 polyvinylidene chloride Substances 0.000 description 1
- 229910052704 radon Inorganic materials 0.000 description 1
- SYUHGPGVQRZVTB-UHFFFAOYSA-N radon atom Chemical compound [Rn] SYUHGPGVQRZVTB-UHFFFAOYSA-N 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 230000037303 wrinkles Effects 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、上向き空冷インフレー
ションフィルム成形時の偏肉精度が良好であり、かつ高
速成形可能な上向き空冷インフレーションフィルムの成
形方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an upward air-cooled inflation film which has a good accuracy of uneven thickness when forming an upward air-cooled inflation film and which can be formed at a high speed.
【０００２】[0002]
【従来の技術】熱可塑性樹脂を押出機により溶融状態で
管状ダイから管状に押出し、内圧で膨張させながら冷却
固化し、連続的に巻き取るインフレ−ションフィルム成
形においては、高生産性を確保するため高速成形が要求
されている。上向き空冷インフレーションフィルム成形
においては、高速成形のために溶融バブルを冷却固化さ
せ、フロストラインの高さを低くするために冷却風量を
増量する必要がある。しかし、冷却風量を増量すると、
溶融バブルが不安定となり、また、局所的に溶融バブル
が偏平状となるためフィルムの偏肉調整が困難となる。2. Description of the Related Art A thermoplastic resin is extruded in a molten state into a tubular shape by an extruder, cooled and solidified while being expanded by an internal pressure, and is continuously wound to ensure high productivity in an inflation film molding. Therefore, high-speed molding is required. In upward air-cooled inflation film molding, it is necessary to increase the amount of cooling air in order to cool and solidify the molten bubbles for high-speed molding and reduce the height of the frost line. However, when the cooling air volume is increased,
The melt bubble becomes unstable, and the melt bubble locally becomes flat, which makes it difficult to adjust the uneven thickness of the film.
【０００３】かかる溶融バブルの揺れを防止し、高速成
形を行うために、各種のエアーリング（例えばマルチリ
ップ方式）が開発されている。但し、この方法ではフィ
ルムの偏肉精度を良好にすることはできず、フィルムの
原反に皺やタルミが発生し、フィルムの二次加工工程に
おける印刷性やスリット性またはフィルム製袋時の製袋
速度の低下やヒートシール不良をおこす等種々の問題を
抱えていた。Various air rings (for example, a multi-lip system) have been developed in order to prevent the swaying of the molten bubble and perform high-speed molding. However, with this method, it is not possible to improve the uneven thickness accuracy of the film, wrinkles and talumi are generated in the original film of the film, printability in the secondary processing step of the film and slitability There were various problems such as a decrease in bag speed and poor heat sealing.
【０００４】最近空冷インフレーションフィルム成形の
高速化のために開発された内部冷却方式は、バブルの内
部循環空気によりバブルの冷却効率を高め安定した高速
成形を実現しようとするものであるが、成形されたフィ
ルムの厚み偏差は必ずしも小さくはならなかった。The internal cooling system recently developed for increasing the speed of air-cooled blown film is intended to improve the cooling efficiency of the bubbles by the air circulating inside the bubbles to realize stable high-speed molding. The thickness deviation of the film was not always small.
【０００５】[0005]
【発明が解決しようとする課題】本発明は、フィルムの
偏肉精度が良好で、且つ、高速成形が可能な上向き空冷
インフレーションフィルムの成形方法を提供することを
課題とする。SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for forming an upward air-cooled blown film, which has good uneven thickness accuracy of the film and is capable of high speed molding.
【０００６】[0006]
【課題を解決するための手段】上記課題は、押出機によ
り熱可塑性樹脂を溶融状態で管状ダイから押出し、密度
が空気より大きな気体を吹き込み、その内圧で膨張させ
ながら冷却固化し、連続的に巻き取る、上向き空冷イン
フレ−ションフィルムの成形方法により解決される。[Means for Solving the Problem] The above-mentioned problems are solved by extruding a thermoplastic resin in a molten state from a tubular die by an extruder, blowing a gas having a density higher than air, and cooling and solidifying while expanding the internal pressure to expand the gas. It is solved by a method of forming an upward air-cooled inflation film which is wound up.
【０００７】本発明で使用される熱可塑性樹脂はインフ
レーション成形可能なものであれば特に限定されず、例
えばポリエチレン、ポリプロピレン、エチレンプロピレ
ン共重合体、エチレン酢酸ビニル共重合体等のポリオレ
フィン系樹脂、ポリスチレン、ポリ塩化ビニル、ポリ塩
化ビニリデン、ポリアミド、ポリビニルアルコール、ポ
リエステル等が挙げられる。The thermoplastic resin used in the present invention is not particularly limited as long as it can be inflation-molded, and examples thereof include polyolefin resins such as polyethylene, polypropylene, ethylene propylene copolymer, ethylene vinyl acetate copolymer, polystyrene. , Polyvinyl chloride, polyvinylidene chloride, polyamide, polyvinyl alcohol, polyester and the like.
【０００８】本発明で使用される押出機は通常のフィル
ム成形機に使用されるものでよく、１機でも複数機を用
いてもよい。また、溶融バブルを冷却する目的で使用す
る空冷リングの形状は特に特殊なものは必要なく、１段
でも、複数段でもよい。The extruder used in the present invention may be one used in a usual film forming machine, and one machine or a plurality of machines may be used. Further, the shape of the air-cooling ring used for the purpose of cooling the molten bubble does not need to be particularly special, and may be one step or plural steps.
【０００９】本発明で使用されるインフレーションダイ
スは単層ダイスであっても多層ダイスであってもよい。
ダイスのリップギャップは樹脂によって適当な広さのも
のを使用すればよい。例えば高密度ポリエチレンの空冷
インフレーション成形においてはリップギャップを０．
８ｍｍ〜２．０ｍｍ程度にするのが好ましい。リップギ
ャップが０．８ｍｍ未満では高押出時にメルトフラクチ
ャーが発生し、２．０ｍｍを超えると成形したフィルム
の偏肉が悪い。The inflation die used in the present invention may be a single layer die or a multilayer die.
The lip gap of the die may be of a suitable size depending on the resin. For example, in air-cooled inflation molding of high density polyethylene, the lip gap is set to 0.
It is preferably about 8 mm to 2.0 mm. If the lip gap is less than 0.8 mm, melt fracture occurs during high extrusion, and if it exceeds 2.0 mm, the uneven thickness of the formed film is poor.
【００１０】本発明では密度が空気より大きな気体を吹
き込むことが必要である。この気体の吹き込みは、イン
フレーション溶融バブルに内圧をかけるために必要とさ
れる。気体の密度は、空気より大きいことが必要であ
り、標準状態（０℃、１気圧）における密度が０．００
１５ｇ／ｃｍ3 以上が好ましく、０．００２０ｇ／ｃｍ
3 以上が特に好ましい。気体の密度が空気の密度以下で
は、冷却風量を強くしてもフロストラインがあまり低下
しないためフィルムの高速成形性が悪く、また溶融バブ
ルの内外圧力差が小さいため、溶融バブルの延伸過程で
フィルムが均一に薄くならず、フィルムの偏肉精度が悪
くなる。In the present invention, it is necessary to blow a gas having a density higher than that of air. This gas blowing is required to apply the internal pressure to the inflation melt bubble. The density of gas needs to be larger than that of air, and the density in the standard state (0 ° C, 1 atm) is 0.00
15 g / cm 3 or more is preferable, 0.0020 g / cm
Particularly preferred is 3 or more. When the density of the gas is less than that of the air, the frost line does not decrease much even if the cooling air volume is increased, so the high-speed moldability of the film is poor, and because the pressure difference between the inside and the outside of the melt bubble is small, the film is drawn in the process of stretching the melt bubble. Does not become evenly thin, and the uneven thickness accuracy of the film deteriorates.
【００１１】密度が空気より大きい気体としては、二酸
化炭素、塩素、塩化水素、アルゴン、キセノン、ラド
ン、フロンガス等が挙げられる。しかし、爆発等の恐れ
がなく、作業上危険がなく、かつ無毒な気体が好まし
く、二酸化炭素、アルゴン、フロンガスが特に好まし
い。Examples of the gas having a density higher than that of air include carbon dioxide, chlorine, hydrogen chloride, argon, xenon, radon and freon gas. However, a gas that is free from the danger of explosion and the like, has no danger in work, and is non-toxic, and carbon dioxide, argon, or chlorofluorocarbon is particularly preferable.
【００１２】バブルの内部に吹き込む気体はインフレー
ションフィルム成形の立ち上げのときに特に必要であ
り、その後は少量を補充するのみでよい。従って、連続
生産を行う場合でも使用される気体の量は少なくてよ
く、高価な気体を使用したとしてもランニングコストは
あまりかからない。The gas blown into the inside of the bubble is particularly necessary at the time of starting up the blown film, and after that, only a small amount needs to be replenished. Therefore, even when performing continuous production, the amount of gas used may be small, and even if an expensive gas is used, the running cost is not so high.
【００１３】空冷インフレーションフィルムの成形に
は、上向き空冷インフレーションフィルムの成形と、下
向き空冷インフレーションフィルムの成形とがあるが、
本発明では上向き空冷インフレーションフィルムの成形
であることが必要である。上向き空冷インフレーション
フィルムの成形は、熱可塑性樹脂を押出機により溶融状
態で管状ダイから上向きに管状に押出して成形する方法
である。ダイから押し出された溶融バブルは、バブル内
に吹き込まれた気体の内圧により膨脹され、空冷リング
により冷却固化され、その後、連続的に巻き取られる。Molding of an air-cooled inflation film includes molding of an upward air-cooled inflation film and molding of a downward air-cooled inflation film.
In the present invention, it is necessary to form an upward air-cooled blown film. The upward air-cooled blown film is formed by extruding a thermoplastic resin in a molten state by an extruder from a tubular die to form an upward tubular shape. The molten bubble extruded from the die is expanded by the internal pressure of the gas blown into the bubble, cooled and solidified by the air cooling ring, and then continuously wound.
【００１４】ダイス径に対するバブル最大径の比である
ブローアップ比は一般に１．１〜１０であり、１．５〜
８．０が好ましく、２．０〜６．０が特に好ましい。ブ
ローアップ比が１．１未満でも、１０を超えても縦横の
強度のバランスの良い高品質のフィルムは得られない。The blow-up ratio, which is the ratio of the maximum bubble diameter to the die diameter, is generally 1.1 to 10, and 1.5 to
8.0 is preferable and 2.0-6.0 is especially preferable. If the blow-up ratio is less than 1.1 or more than 10, it is impossible to obtain a high-quality film with well-balanced longitudinal and lateral strength.
【００１５】以下、実施例及び比較例により、本発明を
更に説明する。The present invention will be further described below with reference to examples and comparative examples.
【００１６】[0016]
【実施例】以下の実施例、比較例において、フィルムの
成形安定性はバブルの上下動や横揺れによるフィルム巾
の変動により評価した。◎、〇、×は下記の状態を表示
する。 ◎：バブルが安定し、フィルム巾の変動が２ｍｍ未満で
ある。 〇：バブルがやや上下動しフィルム巾の変動が２ｍｍ以
上５ｍｍ未満である。 ×：バブルの上下動が著しく、フィルム巾の変動が５ｍ
ｍ以上である。 またフィルムの厚み偏差はフィルム連続厚み計により測
定し、フィルム厚みの最大値と最小値の差をフィルムの
厚み偏差とした。EXAMPLES In the following Examples and Comparative Examples, the molding stability of the film was evaluated by the fluctuation of the film width due to the vertical movement and the lateral movement of the bubble. ◎, ○, × indicate the following states. ⊚: Bubbles are stable, and the fluctuation of the film width is less than 2 mm. ◯: Bubbles moved slightly up and down, and fluctuation in film width was 2 mm or more and less than 5 mm. ×: Bubbles move up and down remarkably and the film width fluctuates by 5 m
m or more. The thickness deviation of the film was measured by a film thickness gauge, and the difference between the maximum value and the minimum value of the film thickness was defined as the film thickness deviation.
【００１７】（実施例１〜２）スクリュー口径が７５ｍ
ｍφである押出機の先端に出口口径１００ｍｍφ、リッ
プギャップ１．２ｍｍのインフレーションダイスを取り
付け、成形温度２００℃にて上向き空冷インフレーショ
ンフィルムの成形を行った。エアーリングは単層の上部
吹き出しタイプの物を使用し、内部安定体を用いて成形
した。樹脂として、密度０．９４８ｇ／ｃｍ3 ，メルト
フローレート０．０５ｇ／１０分の高密度ポリエチレン
（昭和電工（株）製シヨウレックス２０１０ＨＦ）を用
いた。フロストラインの高さが９００ｍｍとなるように
外部冷却エアーの風量をコントロールし（インバータモ
ーターの周波数により風量を調節）、ブローアップ比は
３．５で、溶融バブルの内部に二酸化炭素を吹き込み、
成形速度を変えて成形し、厚みが２０μｍで巾が５５０
ｍｍのフィルムを得た。引取速度は５０ｍ／分及び７０
ｍ／分で上向き空冷インフレーション成形を行った。結
果を表１に示す。引取速度７０ｍ／分においても、やや
バブルの微動があったものの安定成形が可能であった。
外部冷却風量は５５Ｈｚ（インバータモーターの周波
数）であり、成形したフィルムの厚み偏差は３．５μｍ
であった。(Examples 1 and 2) Screw diameter is 75 m
An inflation die having an outlet diameter of 100 mmφ and a lip gap of 1.2 mm was attached to the tip of the extruder having mφ, and an upward air-cooled inflation film was formed at a forming temperature of 200 ° C. As the air ring, a single-layer top-blowing type was used, and it was molded using an internal stabilizer. As the resin, a high-density polyethylene (Sholex 2010HF manufactured by Showa Denko KK) having a density of 0.948 g / cm 3 and a melt flow rate of 0.05 g / 10 min was used. The amount of external cooling air is controlled so that the height of the frost line is 900 mm (the amount of air is adjusted by the frequency of the inverter motor), the blow-up ratio is 3.5, and carbon dioxide is blown into the molten bubble.
Molded at different molding speeds, with a thickness of 20 μm and a width of 550
A film of mm was obtained. Collection speed is 50m / min and 70
Upward air-cooled inflation molding was performed at m / min. The results are shown in Table 1. Even at a take-up speed of 70 m / min, stable molding was possible, although there was slight movement of bubbles.
The amount of external cooling air is 55 Hz (frequency of the inverter motor), and the thickness deviation of the formed film is 3.5 μm.
Met.
【００１８】（実施例３〜４）溶融バブルの内部にアル
ゴンガスを吹き込んだ以外は、実施例１〜２と同様にフ
ィルムを成形した。結果を表１に示す。引取速度７０ｍ
／分においてもバブルの微動もなく安定成形が可能であ
った。外部冷却風量は５１Ｈｚであり、成形したフィル
ムの厚み偏差は３μｍであった。(Examples 3 to 4) Films were formed in the same manner as in Examples 1 to 2 except that argon gas was blown into the molten bubble. The results are shown in Table 1. Collection speed 70m
It was possible to perform stable molding at a minute / minute without slight movement of bubbles. The external cooling air flow rate was 51 Hz, and the thickness deviation of the formed film was 3 μm.
【００１９】（比較例１〜２）溶融バブルの内部に空気
を吹き込んだ以外は、実施例１〜２と同様にフィルムを
成形した。結果を表１に示す。引取速度７０ｍ／分にお
いてはバブルの微動があり安定成形が行えず、外部冷却
風量を最大の６０Ｈｚにしてもフロストラインは１０５
０ｍｍ程度までにしか下がらなかった。フィルムの厚み
偏差も６μｍと大きかった。(Comparative Examples 1 and 2) Films were formed in the same manner as in Examples 1 and 2 except that air was blown into the molten bubbles. The results are shown in Table 1. At a take-up speed of 70 m / min, there is a slight movement of bubbles and stable molding cannot be performed. Even if the external cooling air volume is 60 Hz, the frost line is 105
It fell only to about 0 mm. The thickness deviation of the film was as large as 6 μm.
【００２０】[0020]
【表１】 [Table 1]
【００２１】[0021]
【発明の効果】本発明の上向き空冷インフレ−ションフ
ィルムの成形方法を用いることにより、少ない冷却風量
においてもフロストライン高さを低くすることができる
ため、高速安定成形が可能となった。本発明の上向き空
冷インフレーションフィルムの成形方法によれば、溶融
バブルの内部に空気を吹き込む通常の成形方法と比較
し、（１）少ない冷却風量で溶融バブルのフロストライ
ンを低くすることができ、（２）高速成形においても溶
融バブルの微動が少なく成形が安定化し、（３）成形さ
れたフィルムの偏肉精度が優れる等の特徴を有する。By using the upward air-cooled inflation film forming method of the present invention, the height of the frost line can be reduced even with a small amount of cooling air, and high-speed stable forming is possible. According to the method for forming an upward air-cooled blown film of the present invention, (1) it is possible to lower the frost line of the molten bubble with a smaller amount of cooling air, as compared with the normal forming method in which air is blown into the inside of the molten bubble. 2) It has features such that the fine movement of the molten bubble is small even in high-speed molding and the molding is stabilized, and (3) the uneven thickness accuracy of the molded film is excellent.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 川原田 博 神奈川県川崎市川崎区千鳥町３番２号 昭 和電工株式会社川崎樹脂研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Kawarada 3-2 Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Akira Kawasaki Plastics Research Laboratory
Claims (2)
管状ダイから押出し、密度が空気より大きな気体を吹き
込み、その内圧で膨張させながら冷却固化し、連続的に
巻き取る、上向き空冷インフレ−ションフィルムの成形
方法。1. An upward air-cooled inflation in which a thermoplastic resin is extruded in a molten state by an extruder from a tubular die, a gas having a density higher than that of air is blown, the internal pressure expands to cool and solidify, and the coil is continuously wound. Film forming method.
０１５ｇ／ｃｍ3 以上であることを特徴とする請求項１
記載の上向き空冷インフレ−ションフィルムの成形方
法。2. The density of the gas is 0.0 in the standard state.
The amount is 015 g / cm 3 or more.
A method for forming the upward air-cooled inflation film described above.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15745294A JPH0820068A (en) | 1994-07-08 | 1994-07-08 | Molding of inflation film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15745294A JPH0820068A (en) | 1994-07-08 | 1994-07-08 | Molding of inflation film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0820068A true JPH0820068A (en) | 1996-01-23 |
Family
ID=15649972
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15745294A Pending JPH0820068A (en) | 1994-07-08 | 1994-07-08 | Molding of inflation film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0820068A (en) |
-
1994
- 1994-07-08 JP JP15745294A patent/JPH0820068A/en active Pending
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