JPH0339817B2 - - Google Patents
Info
- Publication number
- JPH0339817B2 JPH0339817B2 JP57137362A JP13736282A JPH0339817B2 JP H0339817 B2 JPH0339817 B2 JP H0339817B2 JP 57137362 A JP57137362 A JP 57137362A JP 13736282 A JP13736282 A JP 13736282A JP H0339817 B2 JPH0339817 B2 JP H0339817B2
- Authority
- JP
- Japan
- Prior art keywords
- film
- die
- cooling
- molding
- air
- 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.)
- Expired - Lifetime
Links
- 239000010408 film Substances 0.000 claims description 50
- 238000001816 cooling Methods 0.000 claims description 29
- 238000000034 method Methods 0.000 claims description 29
- 238000000465 moulding Methods 0.000 claims description 24
- 239000010409 thin film Substances 0.000 claims description 16
- 229920005989 resin Polymers 0.000 claims description 8
- 239000011347 resin Substances 0.000 claims description 8
- 229920013716 polyethylene resin Polymers 0.000 claims description 7
- 239000007788 liquid Substances 0.000 claims description 2
- 239000007787 solid Substances 0.000 claims description 2
- 229920000092 linear low density polyethylene Polymers 0.000 description 8
- 239000004707 linear low-density polyethylene Substances 0.000 description 8
- 238000002347 injection Methods 0.000 description 7
- 239000007924 injection Substances 0.000 description 7
- 238000005096 rolling process Methods 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 5
- 238000004806 packaging method and process Methods 0.000 description 5
- 230000000704 physical effect Effects 0.000 description 4
- -1 polypropylene Polymers 0.000 description 4
- 239000000498 cooling water Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- VXNZUUAINFGPBY-UHFFFAOYSA-N 1-Butene Chemical compound CCC=C VXNZUUAINFGPBY-UHFFFAOYSA-N 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- YWAKXRMUMFPDSH-UHFFFAOYSA-N pentene Chemical compound CCCC=C YWAKXRMUMFPDSH-UHFFFAOYSA-N 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- AFFLGGQVNFXPEV-UHFFFAOYSA-N 1-decene Chemical compound CCCCCCCCC=C AFFLGGQVNFXPEV-UHFFFAOYSA-N 0.000 description 1
- LIKMAJRDDDTEIG-UHFFFAOYSA-N 1-hexene Chemical compound CCCCC=C LIKMAJRDDDTEIG-UHFFFAOYSA-N 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 239000000112 cooling gas Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 229920001903 high density polyethylene Polymers 0.000 description 1
- 239000004700 high-density polyethylene Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 239000005022 packaging material Substances 0.000 description 1
- 229920005672 polyolefin resin Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 238000007613 slurry method Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000003892 spreading Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 239000004711 α-olefin Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/25—Component parts, details or accessories; Auxiliary operations
- B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
- B29C48/911—Cooling
- B29C48/9135—Cooling of flat articles, e.g. using specially adapted supporting means
- B29C48/914—Cooling of flat articles, e.g. using specially adapted supporting means cooling drums
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
- B29C48/07—Flat, e.g. panels
- B29C48/08—Flat, e.g. panels flexible, e.g. films
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/25—Component parts, details or accessories; Auxiliary operations
- B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
- B29C48/911—Cooling
- B29C48/9135—Cooling of flat articles, e.g. using specially adapted supporting means
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
- B29K2995/0018—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds having particular optical properties, e.g. fluorescent or phosphorescent
- B29K2995/0026—Transparent
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Extrusion Moulding Of Plastics Or The Like (AREA)
Description
(産業上の利用分野)
本発明は直線状ダイ(いわゆるTダイ)を用い
た直鎖状ポリエチレン樹脂製フイルムの成形方法
に関する。
さらに詳しくは、前記樹脂製フイルムの高速成
形方法に関する。
(従来の技術)
従来、Tダイを用いるポリオレフイン樹脂製フ
イルムの成形は、通常は第5図に示すように、押
出機1とTダイ2を用いて直線状ダイ出口3から
溶融ポリオレフイン樹脂を押し出し、直ちに冷却
用のチルロール4に巻き掛けて急冷、固化したの
ち、巻き取りロールに巻き取る方法が採られてい
るが、この方法によればTダイを出た溶融状態の
薄膜Fは自然放冷される前に可及的に早く直線状
エアーナイフ(直線状噴射口から射出される空気
噴流)5によりチルロール4に押しつけられ、薄
膜とチルロール間への空気の巻き込みが防止さ
れ、チルロール表面に均一にはりつけられた状態
で冷却されつつ進む間に固化されて巻き取りロー
ルに巻き取られるのである。
しかし、ポリプロピレンとか通常の高密度ポリ
エチレンの場合と異なり、密度0.935g/cm3以下
の短鎖分岐を有する直鎖状ポリエチレン樹脂
(LLDPE)に、この成形方法を適用し、成形速度
を速く(約100m/min以上)すると溶融した薄
膜Fがチルロール4に接触する時点で空気巻き込
み防止ができず、巻き込まれた空気の泡により、
不均一で表面に凹凸のあるフイルムしか得られな
い。また走行する薄い膜Fにサージング(波打
ち)が生じて、フイルムが切断してしまうなど、
この種のポリエチレンはこのチルロール法によつ
ては高速では良質なフイルムが得られなかつた。
また、チルロールを用いるこの方法はLLDPE
に限らず大径のチルロール4を2ないし数本使用
するため生産原価も高くなり好ましくない。
このチルロールによる場合の問題点を解決する
方法として第4図に示すごとく直接、巻き取りロ
ールまたは引き取り用案内ロール6に巻きかけそ
の途中において1対(一段)のエアーナイフ5,
5の形で薄膜両面に冷却空気噴流を噴射口5より
出してあてる方法もあるが、約80m/min以下で
は安定成形ができ透明性のよいものができるもの
の、約100m/min以上になるとヤング率が低く、
摩擦係数の大きいものしか得られない。換言すれ
ば、ヤング率の高い、滑り性のよい、すなわち包
装、袋などに用いる場合の扱い易さを持つ透明性
のよい、しかも成形時に安定性のよい前記直鎖状
ポリエチレン樹脂製フイルムは、約100mm/min
以上という高速では得ることができない。
一方、チルロール法に代わる更に他の成形方法
として、我々は上記のごとき1対(一段)の冷却
空気噴流を用いる手段の改良として、該冷却空気
噴流を当てた後、続いて特殊な手段で水中に導入
し冷却水に接触させる方法を提案した(特開昭55
−105532号)。この方法で製造した場合は初期の
目的の透明性は充分上げうるが、フイルムの表面
が高度に平滑になるためか、またはヤング率が低
いためかフイルム間の滑り性が悪く、製袋時と包
装時におけるフイルムの取り扱い(作業)性が悪
い他、フイルム成形時に使用の付着した冷却水の
除去操作が必要であり、製造工程上問題があつ
た。
(発明が解決しようとする課題)
従つて、本発明は、チルロール法、1対のエア
ーナイフによる一段法、或は前記一段式エアーナ
イフ法と水冷法との組み合わせ法とかの方法を用
いることなく約100m/min以上の高速でTダイ
を用いて透明性、取り扱い性のよいLLDPEフイ
ルムを成形する方法を提供することを目的とす
る。
(課題を解決するための手段)
本発明者等はこの課題を解決すべく鋭意検討し
た結果、Tダイから出たLLDPE溶融フイルムを
特定条件下で空冷することにより高速成形に成功
し、本発明を完成した。
即ち本発明の要旨は、密度0.935g/cm3以下の、
短鎖分岐を有する直鎖状ポリエチレン樹脂を直線
状ダイから薄膜状に溶融押し出し、冷却固化して
引き取るフイルム成形方法において、約100m/
min以上の速度で引き取るにあたり、押し出され
た該樹脂薄膜を上記ダイ出口から案内ロールに達
するまで他固体または液体に触れさせることな
く、ダイ出口から30〜600mmの範囲内において、
ダイに平行かつ互いに隔離され、該薄膜より両面
にそれぞれ80mm以上離れることのない、複数対の
気体噴出口から該薄膜両面に冷却エアーナイフを
均等にあて多段冷却する前記直鎖状ポリエチレン
樹脂フイルムの成形方法にある。
以下、本発明の内容を図面を用いて説明する。
第1図は本発明の一実施例を示し、チルロール
を用いることなくダイ出口3から出た薄膜Fが、
直接、巻き取りロールまたは引き取り案内ロール
6に約100m/min以上の高速で巻き掛けられて
おり、ダイ出口3と該ロール6との間の、下記に
説明する特定の位置に設けられた3対の空気噴出
口から出る冷却空気噴流がエアーナイフ5,5の
形で薄膜Fの両面にあてられている。
第2図は上記エアーナイフ3対の場合のTダイ
2から引き取り案内ロール6に到る間の平面図で
あり、上記3対のエアーナイフ用噴出口はそれぞ
れTダイ出口3よりl1,l2,l3の位置に設けられ
ている。
第3図は第1図における3対のエアーナイフの
噴出口5a,5aのうち、代表的に1対を選び、
それをTダイから出た溶融フイルムFとの相対的
位置関係(フイルムと噴射口との間隔はXで示し
た)を示したものである。
エアーナイフ5,5は第1〜3図に示すごとく
直線状噴射口5a,5bの全長から冷却気体とし
て均等に吹き出されて形成されている。この場
合、噴射口5aの空気出口間隙(第3図yに相当
する)は0.5mm未満ではフイルム冷却が不十分に
なり易く、フイルムの透明性が低下するが、逆に
8mmを越えると冷却噴流の流速不足のため走行す
る溶融フイルムFの安定性に問題を生ずる。この
実施例においては空気出口間隙は2mm程度、空気
圧4.8mmAqで噴流速度8.3m/secが標準的である
が、空気圧32.5mmAq、流速16.5m/secでも両面
の風圧均衡をはかれば、成形安定性に悪影響はな
かつた。噴射角は膜面に直角とは限らず、わずか
に傾斜していても両面対称的であれば特には支障
はない。
これらのエアーナイフ5が1対しかない場合で
も80m/min以下の比較的低速度では、フイルム
成形性の安定性を有するほかヤング率等の包装適
性に係る物性も満たされるが、より高速の場合、
成形安定性は約100m/minが限度であり、上記
ヤング率等の包装適性に係る物性は満たされなく
なる。
本発明はこのエアーナイフ用噴出口を特定の位
置に2対以上用いることにより、LLDPEの高速
成形時のこれらの問題を解決したものである。
エアーナイフによる冷却は、最初の冷却噴出口
5aから30mm未満ではダイ出口の安定性を害する
気流が起こるためか押し出し状態に安定性がなく
なり好ましくない。一方、600mm以上になると急
速冷却の状態にはいる時期が遅くなるためか急速
冷却の効果がなくなり透明性に欠けるようにな
る。
最初の噴出口5a,5aがこの間にあつても1
対では高速成形をしようとしても前記のごとく満
足なフイルムを得がたい。本発明は更に1対以上
加えて用いるものでダイ出口から30mm〜600mmの
間で実質的に固化を完了させるようにするもので
ある。本発明に基づき、従来、エアーナイフ5が
1対だけでは成形(製膜)速度が最高約80m/
min程度であつたものが、さらに1対加えると冷
却効率の向上により100m/min、2対加えた場
合は更に向上して200m/min以上と増大する結
果を得、フイルム物性も高品質のものが得られ
た。
この場合において、ダイ出口3からの位置は3
対の場合、第2図に示すl1,l2,l3は30mm〜600mm
以内になければならないが、その間にあれば各対
のエアーナイフの噴出口の相対的位置関係には特
に制限はない。しかし、1個所に集中するよりは
適宜、間隔を設ける方が好ましいことは当然であ
る。
一方、l1,l2,l3を適当に選ぶことにより、成
形フイルム幅は相当の範囲にわたり自由に変えら
れ、この点からも、複数対の噴射口を設けること
は、有利である。
以下、実施例でもつて説明をする。
エアーナイフの噴出口を2対、及び3対用いる
場合(実施例)と1対しか用いない場合(比較
例)の成形条件とその結果を示す。
〈成形条件〉
(1) 成形条件(A)
押 出 機 90mm
Tダイ出口 600mm幅×1.2mm間隙
溶融樹脂温度 200℃
使用樹脂 LLDPE
(MI:0.8g/10min、d:0.918g/cm3)
フイルム厚み 20μ
(2) 成形条件(B)
第1表に示す。
〈成形結果〉
第1表に示す。同表において、
(1) 安定性の表示マーク
◎:製膜状態が非常に安定しており、フイルム
幅変動が1mm以内
〇:製膜状態が安定しており、フイルム幅変動
が3mm以内で工場生産が可能
△:製膜はできるがフイルムの幅変動が3mmを
超え連続生産困難、フイルム表面に凹凸あ
り。
×:サージング現象等によりフイルムの幅変動
が50mm以上で、耳切れ等により安定性産不能
(2) Haze:(%)、ASTM D1003
(3) ヤング率:ASTM D882
(4) 静摩擦係数:ASTM D1984
(Industrial Application Field) The present invention relates to a method for molding a linear polyethylene resin film using a linear die (so-called T-die). More specifically, the present invention relates to a method for high-speed molding of the resin film. (Prior art) Conventionally, in the molding of a polyolefin resin film using a T-die, as shown in FIG. , is immediately wound on a chill roll 4 for cooling, rapidly cooled and solidified, and then wound on a take-up roll. According to this method, the molten thin film F that exits the T-die is allowed to cool naturally. It is pressed against the chill roll 4 by a linear air knife (air jet ejected from a linear jet) 5 as soon as possible before the thin film is released, preventing air from being caught between the thin film and the chill roll, and uniformly spreading the air onto the chill roll surface. While being cooled while being attached to the paper, it solidifies and is then wound onto a winding roll. However, unlike polypropylene or ordinary high-density polyethylene, this molding method is applied to linear polyethylene resin (LLDPE) with short chain branches with a density of 0.935 g/cm 3 or less, increasing the molding speed (approx. 100m/min or more), air entrainment cannot be prevented when the molten thin film F contacts the chill roll 4, and the entrained air bubbles cause
Only a non-uniform film with an uneven surface can be obtained. In addition, surging (waving) may occur in the thin film F as it travels, causing the film to break.
With this type of polyethylene, a film of good quality could not be obtained at high speed by this chill roll method. This method using a chill roll also
However, since two or several large-diameter chill rolls 4 are used, the production cost increases, which is undesirable. As shown in FIG. 4, a method for solving the problem of using a chill roll is to wind it directly onto a take-up roll or take-up guide roll 6, and in the middle of the winding, a pair of (single stage) air knives 5,
There is also a method in which a jet of cooling air is applied to both sides of the thin film from the injection port 5 as shown in Fig. 5, but stable molding is possible at a speed of about 80 m/min or less and a product with good transparency can be obtained, but at a speed of about 100 m/min or more The rate is low;
Only those with a large friction coefficient can be obtained. In other words, the linear polyethylene resin film has a high Young's modulus, good slipperiness, that is, easy to handle when used for packaging, bags, etc., good transparency, and good stability during molding. Approximately 100mm/min
It cannot be obtained at higher speeds. On the other hand, as yet another forming method to replace the chill roll method, as an improvement on the method using a pair (single stage) of cooling air jets as described above, after applying the cooling air jets, we subsequently used special means to submerge the proposed a method of introducing it into cooling water and bringing it into contact with cooling water (Japanese Unexamined Patent Publication No. 1983
−105532). When manufactured using this method, the initial target transparency can be sufficiently increased, but the slipperiness between the films is poor, perhaps because the surface of the film is highly smooth or because the Young's modulus is low. In addition to poor handling (work) of the film during packaging, it was necessary to remove the cooling water used during film molding, which caused problems in the manufacturing process. (Problems to be Solved by the Invention) Therefore, the present invention can solve the problem without using a chill roll method, a one-stage method using a pair of air knives, or a combination method of the one-stage air knife method and a water cooling method. The object of the present invention is to provide a method for forming an LLDPE film with good transparency and ease of handling using a T-die at a high speed of about 100 m/min or more. (Means for solving the problem) As a result of intensive studies to solve this problem, the present inventors succeeded in high-speed molding by air cooling the LLDPE molten film released from the T-die under specific conditions, and the present invention completed. That is, the gist of the present invention is that the density is 0.935 g/cm 3 or less,
A film forming method in which linear polyethylene resin with short chain branches is melted and extruded into a thin film through a linear die, cooled and solidified, and then taken off.
When withdrawing at a speed of min or more, the extruded thin resin film is kept within a range of 30 to 600 mm from the die exit without contacting other solids or liquids until it reaches the guide roll from the die exit.
The linear polyethylene resin film is cooled in multiple stages by applying a cooling air knife evenly to both surfaces of the thin film from a plurality of pairs of gas jet ports which are parallel to the die and separated from each other and are not separated by more than 80 mm from the thin film on both sides. It's in the molding method. Hereinafter, the contents of the present invention will be explained using the drawings. FIG. 1 shows an embodiment of the present invention, in which a thin film F exits from the die outlet 3 without using a chill roll.
It is directly wound on a take-up roll or take-up guide roll 6 at a high speed of about 100 m/min or more, and three pairs are provided at specific positions described below between the die exit 3 and the roll 6. Cooling air jets emanating from air outlets are applied to both sides of the thin film F in the form of air knives 5,5. FIG. 2 is a plan view from the T-die 2 to the take-up guide roll 6 in the case of the three pairs of air knives, and the three pairs of air knife outlets are l 1 and l from the T-die outlet 3, respectively. It is located at position 2 , l3 . FIG. 3 shows one representative pair selected from the three pairs of air knife nozzles 5a, 5a in FIG.
It shows the relative positional relationship between it and the molten film F coming out of the T-die (the distance between the film and the injection port is indicated by X). As shown in FIGS. 1 to 3, the air knives 5, 5 are formed by uniformly blowing out cooling gas from the entire length of linear injection ports 5a, 5b. In this case, if the air outlet gap of the injection port 5a (corresponding to y in Figure 3) is less than 0.5 mm, film cooling tends to be insufficient and the transparency of the film decreases, but if it exceeds 8 mm, the cooling jet Due to the insufficient flow rate, a problem arises in the stability of the traveling molten film F. In this example, the air outlet gap is about 2 mm, the air pressure is 4.8 mmAq, and the jet velocity is 8.3 m/sec as standard, but even if the air pressure is 32.5 mmAq and the flow rate is 16.5 m/sec, the forming can be stabilized by balancing the wind pressure on both sides. There were no negative effects on sexuality. The spray angle is not necessarily perpendicular to the film surface, and even if it is slightly inclined, there is no particular problem as long as it is symmetrical on both sides. Even if there is only one pair of these air knives 5, at a relatively low speed of 80 m/min or less, the film has stable film formability and also satisfies physical properties related to packaging suitability such as Young's modulus, but at higher speeds,
The molding stability is limited to about 100 m/min, and the physical properties related to packaging suitability such as the Young's modulus mentioned above are no longer satisfied. The present invention solves these problems during high-speed molding of LLDPE by using two or more pairs of air knife jets at specific positions. Cooling with an air knife is not preferable because the extrusion state becomes unstable, probably because an air flow that impairs the stability of the die exit occurs at a distance less than 30 mm from the first cooling jet port 5a. On the other hand, if the thickness exceeds 600 mm, the rapid cooling effect will be lost and transparency will be lost, perhaps because the time to reach the rapid cooling state will be delayed. Even if the first spout ports 5a and 5a are located between this time, 1
As mentioned above, it is difficult to obtain a satisfactory film even if high-speed molding is attempted. In the present invention, one or more pairs are further added so that solidification is substantially completed between 30 mm and 600 mm from the die exit. Based on the present invention, conventionally, with only one pair of air knives 5, the maximum molding (film forming) speed was approximately 80 m/m/m.
When one pair was added, the cooling efficiency was improved to 100 m/min, and when two pairs were added, the result was increased to over 200 m/min, and the film properties were also of high quality. was gotten. In this case, the position from the die exit 3 is 3
In the case of a pair, l 1 , l 2 , l 3 shown in Figure 2 are 30 mm to 600 mm
However, as long as it is within that range, there is no particular restriction on the relative positional relationship of the jet ports of each pair of air knives. However, it is natural that it is preferable to provide appropriate intervals rather than concentrating on one place. On the other hand, by appropriately selecting l 1 , l 2 , and l 3 , the width of the formed film can be freely changed over a considerable range, and from this point of view as well, it is advantageous to provide a plurality of pairs of injection ports. Examples will also be explained below. The molding conditions and results are shown for cases in which two pairs and three pairs of air knife nozzles are used (examples) and cases in which only one pair is used (comparative example). <Molding conditions> (1) Molding conditions (A) Extruder 90mm T-die outlet 600mm width x 1.2mm gap Melt resin temperature 200℃ Resin used LLDPE (MI: 0.8g/10min, d: 0.918g/ cm3 ) Film Thickness: 20μ (2) Molding conditions (B) Shown in Table 1. <Molding results> Shown in Table 1. In the same table, (1) Stability markings ◎: The film forming condition is very stable, and the film width fluctuation is within 1 mm. ○: The film forming condition is stable, and the film width fluctuation is within 3 mm. Production is possible △: Film can be formed, but the film width variation exceeds 3 mm, making continuous production difficult, and the film surface is uneven. ×: Film width fluctuation of 50 mm or more due to surging phenomenon, etc., and stability failure due to edge breakage, etc. (2) Haze: (%), ASTM D1003 (3) Young's modulus: ASTM D882 (4) Static friction coefficient: ASTM D1984
【表】【table】
【表】
一段冷却の場合100m/min以上の成形速度は
成形性の点でとることができなかつた。しかし、
80m/minを越えて100m/minくらいまでは成形
性は安定し、Haze値もよいがヤング率が低くな
り、摩擦係数が高くなりフイルムとしての実用上
問題が生ずる。即ち、一段冷却法では約100m/
min以上の高速成形はできない。
二ないし三段の多段冷却の場合は高速
(100m/minを越えても、例えば200〜300m/
minでも)成形可能で、安定性、フイルム物性と
もに優れている。
比較実験結果からは、薄膜と冷却空気噴出口5
aとの距離xが100mmという大きい値であつたり、
ダイ出口3からエアーナイフ5までの距離が30〜
600mm範囲外になると100m/min以上という高速
成形においては成形安定性に欠け、更に、いくつ
かのフイルム物性に欠陥が生じることが分かる。
従来のチルロール法では15m/minの低い成形
速度でも成形性は良くない。
以上、一段〜多段冷却法の実験結果を説明した
が、この発明は約100/min以上という高速成形
を前提とした場合、前述の通り溶融フイルムの冷
却に従来のチルロール法または一段冷却法ではな
し得ないことを示し、フイルムの両面に複数対の
冷却噴流をその風圧が均衡するように、特殊条件
の下に当てることを主な特徴とするもので、その
要旨を変えることがなければ広く変化、応用が行
われうることは言うまでもない。なお、エアーナ
イフの直線状噴射口は上記実施例に挙げたものの
ほか直線状に並んだ小噴射口でもよい。
本発明に係る方法によれば樹脂の溶融張力だけ
で膜状に保たれている弱い樹脂膜でも、ダイを出
た後、所定の距離内においてその両面の風圧を均
衡させて、かつ繰り返して強力に冷却するので他
物に接触させて冷却するときの問題もない。
また、成形した製品フイルムの物性も、この発
明に係るものは、ヤング率が高くて適度の剛性を
持ち、摩擦係数が低く滑り性もよく、透明性に優
れていて包装材としての適性を備えている。
上記実験はチルロール法または一段法によつて
は生産速度を向上しえない種類の樹脂、つまり、
LLDPEに対して、この発明方法の優秀性を実証
したものである。
なお、上記直鎖状ポリエチレンLLDPEはエチ
レンと炭素数3〜12のα−オレフイン例えばプロ
ピレン、ブテン−1、ヘキセン−1、4メチル−
1−ペンテン、オクテン−1、デセン−1等の少
なくともひとつを、従来公知の中低圧法、または
高圧法によつて共重合させて製造されるものであ
る。さらに中低圧法としては、気相法、スラリー
法、溶液法いずれの方法によるものでもよい。
前記のごとくこの発明は特定条件下での非接触
冷却法で複数の対向噴流が均衡してLLDPE膜の
100m/min以上という高速かつ安定走行を可能
にしたこと、多段噴流により強力な冷却を加え、
生産速度を向上させられたこと、そしてそれらに
より、透明性、ヤング率、滑り性、など包装適性
に優れる、画期的効果を有する方法であることに
特徴がある。[Table] In the case of one-stage cooling, a molding speed of 100 m/min or higher was not possible due to moldability considerations. but,
Above 80 m/min to about 100 m/min, the formability is stable and the haze value is good, but the Young's modulus is low and the coefficient of friction is high, causing practical problems as a film. In other words, in the one-stage cooling method, the distance is approximately 100m/
It is not possible to form at high speeds higher than min. In the case of two or three stage multi-stage cooling, high speed (over 100m/min, e.g. 200-300m/min)
It can be formed (even at a minimum of 100 min) and has excellent stability and film properties. From the comparative experiment results, thin film and cooling air outlet 5
If the distance x from a is a large value of 100 mm,
The distance from die exit 3 to air knife 5 is 30~
It can be seen that outside the 600 mm range, molding stability is lacking in high-speed molding of 100 m/min or higher, and furthermore, some defects occur in the physical properties of the film. With the conventional chill roll method, the formability is not good even at a low forming speed of 15 m/min. The experimental results of the one-stage to multi-stage cooling methods have been explained above, but this invention does not require the conventional chill roll method or single-stage cooling method to cool the molten film, as mentioned above, when high-speed molding of approximately 100/min or higher is assumed. The main feature is that multiple pairs of cooling jets are applied to both sides of the film under special conditions so that the wind pressure is balanced, and it can be widely varied without changing the gist. , it goes without saying that applications can be made. In addition to the linear injection ports of the air knife mentioned in the above embodiments, small injection ports arranged in a straight line may be used. According to the method of the present invention, even a weak resin film that is maintained in a film form only by the melt tension of the resin can be strengthened repeatedly by balancing the wind pressure on both sides within a predetermined distance after leaving the die. Since it is cooled to a certain temperature, there is no problem when cooling it by contacting it with other objects. In addition, regarding the physical properties of the formed product film, the film according to the present invention has a high Young's modulus, moderate rigidity, low coefficient of friction, good slipperiness, and excellent transparency, making it suitable as a packaging material. ing. The above experiments were conducted on resins for which the production rate cannot be increased by the chill-roll or one-step process, i.e.
This demonstrates the superiority of this invented method for LLDPE. The above-mentioned linear polyethylene LLDPE is composed of ethylene and α-olefin having 3 to 12 carbon atoms, such as propylene, butene-1, hexene-1, and 4-methyl-
It is produced by copolymerizing at least one of 1-pentene, octene-1, decene-1, etc. by a conventionally known medium-low pressure method or high-pressure method. Further, the medium-low pressure method may be a gas phase method, a slurry method, or a solution method. As mentioned above, this invention uses a non-contact cooling method under specific conditions to balance the opposing jets and cool the LLDPE film.
High-speed and stable running of over 100m/min is possible, and multi-stage jets provide powerful cooling.
The method is characterized by being able to improve production speed and, as a result, having excellent packaging suitability such as transparency, Young's modulus, slipperiness, etc., and has an epoch-making effect.
第1図は本願発明に係る多段冷却法の一実施例
の3段冷却法の縦断面図を、第2図は第1図の正
面図である。第3図は第1図の縦断面図におけ
る、ひとつの噴出口近辺を詳細に示すものであ
り、第4図は従来法の一段式エアーナイフの縦断
面図である。第5図は従来のチルロール法の縦断
面図を示す。図面に用いた主な符号を説明する。
3……Tダイ出口、5……エアーナイフ、5a
……直線状噴出口、F……樹脂薄膜。
FIG. 1 is a longitudinal sectional view of a three-stage cooling method, which is an embodiment of the multi-stage cooling method according to the present invention, and FIG. 2 is a front view of FIG. 1. FIG. 3 shows in detail the vicinity of one ejection port in the longitudinal sectional view of FIG. 1, and FIG. 4 is a longitudinal sectional view of a conventional single-stage air knife. FIG. 5 shows a longitudinal cross-sectional view of the conventional chill roll method. The main symbols used in the drawings will be explained. 3...T-die exit, 5...Air knife, 5a
...Linear jet nozzle, F...Resin thin film.
Claims (1)
直鎖状ポリエチレン樹脂を直線状ダイから薄膜状
に溶融押し出し、冷却固化して引き取るフイルム
成形方法において、約100m/min以上の速度で
引き取るにあたり、押し出された該樹脂薄膜を上
記ダイ出口から案内ロールに達するまで他固体ま
たは液体に触れさせることなく、ダイ出口から30
〜600mmの範囲内においてダイに平行かつ互いに
隔離され、該薄膜より両側にそれぞれ80mm以上離
れることのない、複数対の気体噴出口から該薄膜
両面に冷却エアーナイフを均等にあてて多段冷却
することを特徴とする前記直鎖状ポリエチレン樹
脂製フイルムの成形方法。1 A film forming method in which linear polyethylene resin with short chain branches and a density of 0.935 g/cm 3 or less is melted and extruded from a linear die into a thin film, cooled and solidified, and then taken off at a speed of about 100 m/min or more. In this process, the extruded thin resin film is heated for 30 minutes from the die exit without coming into contact with other solids or liquids until it reaches the guide roll from the die exit.
Multi-stage cooling is performed by applying cooling air knives evenly to both surfaces of the thin film from multiple pairs of gas jet ports that are parallel to the die and isolated from each other within a range of ~600 mm, and are not separated by more than 80 mm on either side of the thin film. The method for molding the linear polyethylene resin film, characterized in that:
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP57137362A JPS5929125A (en) | 1982-08-09 | 1982-08-09 | Method for molding thermoplastic resin film |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP57137362A JPS5929125A (en) | 1982-08-09 | 1982-08-09 | Method for molding thermoplastic resin film |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5929125A JPS5929125A (en) | 1984-02-16 |
JPH0339817B2 true JPH0339817B2 (en) | 1991-06-17 |
Family
ID=15196890
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP57137362A Granted JPS5929125A (en) | 1982-08-09 | 1982-08-09 | Method for molding thermoplastic resin film |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5929125A (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS61175858U (en) * | 1985-04-19 | 1986-11-01 | ||
JPS61255830A (en) * | 1985-05-08 | 1986-11-13 | Idemitsu Petrochem Co Ltd | Preparation of amorphous thermoplastic resin film |
DK1386718T3 (en) * | 2002-08-03 | 2006-04-24 | Reifenhaeuser Gmbh & Co Kg | Device for smoothing and cooling a plastic web running from a slot nozzle |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS501896A (en) * | 1973-04-24 | 1975-01-09 | ||
JPS55105532A (en) * | 1979-02-01 | 1980-08-13 | Showa Denko Kk | Molding method for thermoplastic resin film |
JPS57137361A (en) * | 1981-02-18 | 1982-08-24 | Sumitomo Chem Co Ltd | Dye composition |
-
1982
- 1982-08-09 JP JP57137362A patent/JPS5929125A/en active Granted
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS501896A (en) * | 1973-04-24 | 1975-01-09 | ||
JPS55105532A (en) * | 1979-02-01 | 1980-08-13 | Showa Denko Kk | Molding method for thermoplastic resin film |
JPS57137361A (en) * | 1981-02-18 | 1982-08-24 | Sumitomo Chem Co Ltd | Dye composition |
Also Published As
Publication number | Publication date |
---|---|
JPS5929125A (en) | 1984-02-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3223764A (en) | Process for production of biaxially oriented polypropylene film | |
US9162403B2 (en) | Apparatus for manufacturing and processing pre-stretch films having strips of increased thickness | |
NO821045L (en) | PROCEDURE FOR REDUCING MELT Fracturing During Extrusion of an Ethylene Copolymer | |
JPH0339817B2 (en) | ||
JPS6210816B2 (en) | ||
US3862285A (en) | Production of thermoplastic sheet | |
US20140265059A1 (en) | Apparatus for manufacturing and processing films having strips of increased thickness | |
WO2014144205A2 (en) | Apparatus for manufacturing and processing pre-stretch films having strips of increased thickness | |
JPS6213317A (en) | Preparation of thermoplastic resin film | |
US4693677A (en) | Flat die neck-in control device | |
JPH0478117B2 (en) | ||
JPH0361575B2 (en) | ||
EP0077661A2 (en) | Process and apparatus for forming a plastics film | |
JP3490721B2 (en) | Manufacturing method of blown film | |
JP4759394B2 (en) | Thermoplastic resin sheet and manufacturing method thereof | |
JP3467279B2 (en) | Manufacturing method of blown film | |
JPS6245811B2 (en) | ||
JPS5929124A (en) | Apparatus for molding thermoplastic resin film | |
NZ200980A (en) | Manufacture of a thermoplastic resin film or sheet | |
JP6642500B2 (en) | Method of forming resin film | |
JPS5971828A (en) | Cooler | |
JP3506443B2 (en) | Manufacturing method of blown film | |
JP3490723B2 (en) | Manufacturing method of blown film | |
CA3010436A1 (en) | Thermoformed microcapillary sheeting | |
JPH11268097A (en) | High speed molding method for t-die film and t-die film |