JPH0376626A - Thermoforming of polyester sheet - Google Patents
Thermoforming of polyester sheetInfo
- Publication number
- JPH0376626A JPH0376626A JP21268789A JP21268789A JPH0376626A JP H0376626 A JPH0376626 A JP H0376626A JP 21268789 A JP21268789 A JP 21268789A JP 21268789 A JP21268789 A JP 21268789A JP H0376626 A JPH0376626 A JP H0376626A
- Authority
- JP
- Japan
- Prior art keywords
- sheet
- mold
- temperature
- polyester
- thermoforming
- 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.)
- Granted
Links
- 229920000728 polyester Polymers 0.000 title claims description 33
- 238000003856 thermoforming Methods 0.000 title claims description 15
- 238000000465 moulding Methods 0.000 claims abstract description 13
- 238000002425 crystallisation Methods 0.000 claims abstract description 10
- 230000008025 crystallization Effects 0.000 claims abstract description 10
- 238000000034 method Methods 0.000 claims description 19
- 238000010438 heat treatment Methods 0.000 abstract description 10
- 229920000139 polyethylene terephthalate Polymers 0.000 description 14
- 239000005020 polyethylene terephthalate Substances 0.000 description 14
- -1 polyethylene terephthalate Polymers 0.000 description 13
- 238000007666 vacuum forming Methods 0.000 description 11
- 238000001816 cooling Methods 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 7
- 230000002093 peripheral effect Effects 0.000 description 4
- 238000004891 communication Methods 0.000 description 3
- 238000007665 sagging Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 229920001225 polyester resin Polymers 0.000 description 2
- 239000004645 polyester resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 230000037303 wrinkles Effects 0.000 description 1
Landscapes
- Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は、ポリエステルシートの熱成形方法に関し、例
えばプラスチック包装容器の製造に利用することができ
る。DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for thermoforming polyester sheets, and can be used, for example, in manufacturing plastic packaging containers.
［背景技術］
ポリエステル樹脂を用いた製膜において、急速冷却を行
うことにより得られる透明ポリエステルシートは、熱成
形性がよいため、容易に容器に成形することができる。[Background Art] In film formation using a polyester resin, a transparent polyester sheet obtained by rapid cooling has good thermoformability and can be easily formed into a container.
しかし、この成形されたポリエステル製容器は、６５°
Ｃ以上の温度で熱収縮してしまうため、９０℃前後の高
温充填用の容器としては使用できなかった。However, this molded polyester container
Because it thermally shrinks at temperatures above 90°C, it could not be used as a container for high-temperature filling at around 90°C.
そこで、従来、透明ポリエステルシートを熱成形して得
られる成形品の熱収縮温度を上げる方法として、種々の
方法が提案されている。Therefore, various methods have been proposed to raise the heat shrinkage temperature of a molded product obtained by thermoforming a transparent polyester sheet.
例えば、シートを１軸に延伸し、次に所定温度に加熱し
て収縮させた後、熱成形する方法（特開昭５０−２１０
５１号公報）、シートを２軸延伸し、不活性ガス中での
加熱と金型での深絞りを行った後、２次転移温度以下に
急冷する方法（特開昭５７−５３３１６号公報）、シー
トを２軸延伸し、Ｔｃ （結晶化温度）以下及び（Ｔ
ｃ−７０℃）以上の金型で熱処理後、冷却型で冷却する
方法（特公平１−２７８５０号公報、米国特許第４３８
８３５６号公報）、シートを２軸延伸して１５０ ”Ｃ
における収縮率を３％以下とし、１８０〜２４０ ’Ｃ
で圧空成形する方法（特開昭５８−６７４１１号公報）
等である。For example, a method of stretching a sheet uniaxially, then heating it to a predetermined temperature to shrink it, and then thermoforming it (Japanese Patent Laid-Open No. 50-210
51), a method in which the sheet is biaxially stretched, heated in an inert gas, deep drawn in a mold, and then rapidly cooled to below the secondary transition temperature (Japanese Patent Application Laid-open No. 57-53316). , the sheet is biaxially stretched to a temperature below Tc (crystallization temperature) and (T
A method in which heat treatment is performed in a mold at a temperature of -70°C or higher, followed by cooling in a cooling mold (Japanese Patent Publication No. 1-27850, U.S. Patent No. 438)
8356), the sheet was biaxially stretched to 150"C
The shrinkage rate at 180-240'C is 3% or less.
A method of air pressure forming (Japanese Patent Application Laid-Open No. 58-67411)
etc.
［発明が解決しようとするｉ！！！題］上述したように
、ポリエステルシート成形品の熱収縮温度を上げるため
の種々の方法が提案されているが、いずれの熱成形方法
であっても、効果及び生産性の点で満足すべき結果は得
られていない。[The invention attempts to solve i! ! ! As mentioned above, various methods have been proposed to increase the heat shrinkage temperature of polyester sheet molded products, but none of the thermoforming methods yields satisfactory results in terms of effectiveness and productivity. has not been obtained.
なお、既存の熱成形方法でポリエステルシートを熱成形
すると、加熱温度の上昇と共に、急速な垂下（ドローダ
ウン）が発生する。従って、成形が可能な垂下限界とな
る加熱温度の上限は１００゛Ｃ＠後であるため、実際に
は６５℃以上の耐熱性を有する透明ポリエステル容器の
熱成形は不可能である。Note that when a polyester sheet is thermoformed using existing thermoforming methods, rapid drooping (drawdown) occurs as the heating temperature increases. Therefore, since the upper limit of the heating temperature at which molding is possible, which is the drooping limit, is after 100°C, it is actually impossible to thermoform a transparent polyester container that has a heat resistance of 65°C or higher.
本発明は、熱収ｗｉ温度が高く、かつ絞り性及び透明性
の良好な成形品が得られるポリエステルシートの熱成形
方法を提供することを目的とする。An object of the present invention is to provide a method for thermoforming a polyester sheet, which yields a molded product with a high heat absorption temperature and good drawability and transparency.
［！！ｌｆｌを解決するための手段及び作用］本発明に
係るポリエステルシートの熱成形方法は、透明ポリエス
テルシートを成形金型の周縁部に固定し、このシートを
低温結晶化温度以上に加熱してキャビティの開口上端か
らシートの最大垂下点までの垂直距離で金型開口部の直
径の５〜５０％、好ましくは１０〜５０％垂下させた後
、７０°Ｃ以下、好ましくは４０″Ｃ以下に冷却した成
型金型により前記シートを成形することを特徴とする。[! ! [Means and effects for solving lfl] In the thermoforming method for polyester sheets according to the present invention, a transparent polyester sheet is fixed to the periphery of a molding die, and the sheet is heated to a temperature higher than the low-temperature crystallization temperature to form a cavity. After sagging by 5 to 50%, preferably 10 to 50%, of the diameter of the mold opening in the vertical distance from the upper edge of the opening to the maximum sagging point of the sheet, it is cooled to below 70°C, preferably below 40''C. The method is characterized in that the sheet is molded using a mold.
透明ポリエステルシートとしては、非品性ポリエステル
シート（無配向）、延伸ポリエステルシート（配向）、
共重合非品性ポリエステルシート（無配向）等がある。Transparent polyester sheets include non-quality polyester sheets (non-oriented), stretched polyester sheets (oriented),
There are copolymerized polyester sheets (non-oriented), etc.
この共重合非品性ポリエステルシート（無配向）とは、
例えば１，４−シクロヘキサンジメタツール等のモノマ
ーとポリエステルとの共重合体である。なお、結晶性ポ
リエステルシート（無配向）は不透明であり、本成形方
法によっても透明な成形品が得られない。What is this copolymerized polyester sheet (non-oriented)?
For example, it is a copolymer of a monomer such as 1,4-cyclohexane dimetatool and polyester. Note that the crystalline polyester sheet (non-oriented) is opaque, and a transparent molded product cannot be obtained even by this molding method.
ポリエステルシートを成形金型の周縁部に固定しないと
、成形品のフランジに皺が発生する。また、真空成形の
場合には、真空度が上がらなくなる。シートを成形金型
の周縁部に固定するための具体的手段としては、例えば
金型の周縁全周を押圧するリング状のクランプを用いる
ことができる。If the polyester sheet is not fixed to the periphery of the mold, wrinkles will occur on the flange of the molded product. Furthermore, in the case of vacuum forming, the degree of vacuum cannot be increased. As a specific means for fixing the sheet to the periphery of the mold, for example, a ring-shaped clamp that presses the entire periphery of the mold can be used.
シートを低温結晶化温度（冷結晶化温度）以上に加熱す
るのは、低温結晶化温度未満では垂下（ドローダウン）
が生じないからである。この低温結晶化温度は、例えば
ポリエチレンテレフタレ−） （ＰＥＴ）の場合、１３
５〜１４０″Ｃである。Heating the sheet above the low-temperature crystallization temperature (cold crystallization temperature) will cause drooping (drawdown) if the sheet is below the low-temperature crystallization temperature.
This is because it does not occur. For example, in the case of polyethylene terephthalate (PET), this low temperature crystallization temperature is 13
5 to 140″C.
シートの垂下量を金型開口部の直径の５〜５０％とする
のは、５％未満では成形品の熱収縮温度が低くなり、ま
た４０％を越えるとシートが垂れ過ぎてシートに孔があ
き、成形が不可能になるからである。なお、金型開口部
の形状が円形ではなく、角形の場合には、直径の代わり
に対角線の長さとする。The reason why the amount of sheet sagging should be 5 to 50% of the diameter of the mold opening is that if it is less than 5%, the heat shrinkage temperature of the molded product will be low, and if it exceeds 40%, the sheet will sag too much and holes will be formed in the sheet. This is because molding becomes impossible. Note that if the shape of the mold opening is square rather than circular, the length of the diagonal line is used instead of the diameter.
成型金型を７０″Ｃ以下に冷却するのは、７０℃より高
い場合には、得られる成形品の透明性が不良になり、ま
た成型金型に成形品が付着して離型性が不良になるから
である。Cooling the mold to below 70"C is because if it is higher than 70"C, the resulting molded product will have poor transparency, and the molded product will adhere to the mold, resulting in poor mold releasability. This is because it becomes
成型金型内への成形方法は、真空成形、圧空成形、プラ
グ成形等の従来の成形方法を任意に使用することができ
るが、圧空成形又はプラグ成形を行う場合、金型上のヒ
ータを１手動にする必要があるため、装置の簡略化の要
請からは真空成形が好ましい、なお、真空成形の場合、
その真空度は、５００＋＊ｍＨｇ以上とするのが好まし
い。Any conventional forming method such as vacuum forming, pressure forming, plug forming, etc. can be used for forming the mold into the mold. However, when performing pressure forming or plug forming, the heater on the mold is Since it needs to be done manually, vacuum forming is preferable in order to simplify the equipment.
The degree of vacuum is preferably 500+*mHg or more.
本発明において、シートには厚さの薄いフィルム状のも
のも含む。In the present invention, the sheet also includes a thin film-like sheet.
［実施例］
図面を参照して本発明に係るポリエステルシートの熱成
形方法の実施例を説明する。[Example] An example of the method for thermoforming a polyester sheet according to the present invention will be described with reference to the drawings.
先ず、本実施例において使用する熱成形装置の構成を説
明する。First, the configuration of the thermoforming apparatus used in this example will be explained.
第１図に示すように、この熱成形装置は、真空成形用金
型１１と、この真空成形用金型１１の上方に設けられた
ヒータ１２と、真空戒形用金型１１のシート供給側に設
けられた上下一対の予熱ヒータ１３Ａ、１３Ｂとを備え
て構成される。As shown in FIG. 1, this thermoforming apparatus includes a vacuum forming mold 11, a heater 12 provided above the vacuum forming mold 11, and a sheet supply side of the vacuum forming mold 11. It is configured to include a pair of upper and lower preheating heaters 13A and 13B provided in the.
前記真空成形用金型１１は、ポリエステルｌが賦形され
る円形のキャビティ１４を有し、このキャビティ１４の
底部１１Ａ及び成形される容器２のフランジ成形部１１
Ｂとｒａ’＋縁部１１Ｃとの間にそれぞれ真空連通孔１
５が形成されている。金型１１には、図示しない冷却手
段である冷却用水路等が設けられ、成形時に７０℃以下
の温度が保たれる。この真空成形用金型１１は、上下方
向に可動となっている。また、周縁部１１Ｃの上方には
、周縁部１１Ｃの全周に沿ってポリエステルシートｌを
固定するためのリング状のクランプ１６が設けられる。The vacuum forming mold 11 has a circular cavity 14 in which the polyester 1 is formed, and the bottom 11A of the cavity 14 and the flange molding part 11 of the container 2 to be molded.
A vacuum communication hole 1 is provided between B and ra'+edge 11C, respectively.
5 is formed. The mold 11 is provided with a cooling channel (not shown), which is a cooling means, and maintains a temperature of 70° C. or lower during molding. This vacuum forming mold 11 is movable in the vertical direction. Moreover, a ring-shaped clamp 16 for fixing the polyester sheet l is provided above the peripheral edge 11C along the entire circumference of the peripheral edge 11C.
前記ヒータ１２，１３Ａ、１３Ｂは、赤外線ヒータ等の
任意の加熱手段を選ぶことができる。As the heaters 12, 13A, and 13B, any heating means such as an infrared heater can be selected.
上記熱成形装置を使用して、次のようにして、ポリエス
テルシートｌを容器２に熱成形する。Using the thermoforming apparatus described above, the polyester sheet 1 is thermoformed into a container 2 in the following manner.
先ず、第１図（Ａ）に示すように、ポリエステル樹脂を
一般的な押出機より２９５℃で押し出し、Ｔダイを通し
て製膜した厚さ０．１５〜１．５１１ｆｉの透明ポリエ
ステルシーに１を熱成形装置に供給する。First, as shown in Figure 1 (A), polyester resin was extruded at 295°C using a general extruder, and 1 was heated onto a transparent polyester sheet having a thickness of 0.15 to 1.511 fi formed through a T-die. Supply to molding equipment.
ポリエステルシートｌは、予熱ヒータ１３Ａ、１３Ｂで
予熱された後、金型１１の位置するステージに送られ、
ここで金ｆｆ１ｌｌの上昇によりクランプ１６と金型１
１の周縁部１１Ｃとの間に挟まれて固定される。なお、
この予熱温度は、シー）１が垂下しない温度、具体的に
は９０°Ｃ以下が好ましい。After being preheated by preheaters 13A and 13B, the polyester sheet l is sent to the stage where the mold 11 is located.
Here, due to the rise of gold ff1ll, clamp 16 and mold 1
It is sandwiched and fixed between the peripheral edge part 11C of 1 and the peripheral edge 11C of 1. In addition,
This preheating temperature is preferably a temperature at which the sheet 1 does not droop, specifically, 90°C or less.
次に、第１図（Ｂ）に示すように、このポリエステルシ
ートＩを金型１１上方のヒータＩ２により低温結晶化温
度以上に加熱して所定量垂下させる。この所定の垂下量
りは、キャビティＩ４の開口上端からシートｌの最大垂
下点までの垂直距離を測った値であり、このＬが金型開
口部の直径の５〜５０％となるように加熱する。Next, as shown in FIG. 1(B), this polyester sheet I is heated to a temperature equal to or higher than the low temperature crystallization temperature by a heater I2 above the mold 11, and is caused to hang down by a predetermined amount. This predetermined drooping amount is the value measured from the upper end of the opening of the cavity I4 to the maximum drooping point of the sheet L, and heating is performed so that this L becomes 5 to 50% of the diameter of the mold opening. .
次に、第１図（Ｃ）、（Ｄ）に示すように、シート１が
加熱されて所定量垂下し、かつ１４０〜１７０℃になっ
た時点で金型１１の真空連通孔１５より真空吸引し、７
０℃以下に冷却されている手中ビティ１４内でシート１
を賦形する。Next, as shown in FIGS. 1(C) and 1(D), the sheet 1 is heated and droops by a predetermined amount, and when the temperature reaches 140 to 170°C, vacuum is sucked from the vacuum communication hole 15 of the mold 11. 7
Sheet 1 is placed inside the hand bit 14 which is cooled to below 0°C.
Shape.
次に、第１図（Ｄ）に示すように、金型１１を下降させ
て、成形された容器２をキャビティ１４から離型する。Next, as shown in FIG. 1(D), the mold 11 is lowered to release the molded container 2 from the cavity 14.
以下、上記と同様の工程を繰り返して容器２を連続的に
成形する。Thereafter, the same steps as above are repeated to continuously form the container 2.
なお、上記実施例では、予熱ヒータ１３Ａ、１３Ｂを設
けて成形前のポリエステルシート１を予熱したが、予熱
ヒータ１３Ａ、１３Ｂを設けないで、金型ｔｉ上方のヒ
ータ１２だけでシートｌを加熱してもよい、しかし、予
熱し−タ１３Ａ、１３Ｂを設けることにより、加熱処理
を速めることができる。In the above embodiment, the preheating heaters 13A and 13B were provided to preheat the polyester sheet 1 before molding, but the sheet l was heated only by the heater 12 above the mold ti without providing the preheating heaters 13A and 13B. However, by providing preheaters 13A and 13B, the heating process can be accelerated.
また、本実施例における真空成形は、プラグを使用した
プラグアシスト真空成形であってもよい。Further, the vacuum forming in this embodiment may be plug-assisted vacuum forming using a plug.
且笠且
上記実施例において、透明ポリエステルシートｌとして
下記のポリエチレンテレフタレートシートを使用し、ま
た熱成形条件を下記のように設定して各実験例に係る容
器２を成形した。これらの各容器２について、絞り性及
び透明性を評価し、熱収縮温度を測定した結果を下記の
表−１に示す。In the above examples, the following polyethylene terephthalate sheet was used as the transparent polyester sheet 1, and the thermoforming conditions were set as below to mold the container 2 according to each experimental example. The drawability and transparency of each of these containers 2 were evaluated, and the heat shrinkage temperature was measured. The results are shown in Table 1 below.
また、比較例として、実験例とは異なる熟成形条件の下
で各比較例に係る容器を成形した。これらの各容器につ
いても、実験例と同様の評価及び測定を行った結果を下
記の表−１に併せて示す。In addition, as comparative examples, containers according to each comparative example were molded under aging molding conditions different from those of the experimental examples. Each of these containers was also evaluated and measured in the same manner as in the experimental examples, and the results are also shown in Table 1 below.
１、透明ポリエステルシートの種類
（ａ）非品性無配向ポリエチレンテレフタレートシート
・・・ポリエチレンテレフタレート樹脂を押出機から押
し出し、Ｔダイを通して製膜した後、静電印加法で６０
℃に急冷することにより製造した。1. Types of transparent polyester sheets (a) Non-oriented non-oriented polyethylene terephthalate sheet... Polyethylene terephthalate resin is extruded from an extruder, formed into a film through a T-die, and then heated to 60% by electrostatic application method.
Produced by rapid cooling to ℃.
（ｂ）結晶性配向ポリエチレンテレフタレートシート・
・・上記非品性無配向ポリエチレンテレフタレートシー
トを１００℃で１軸に２倍延伸することにより製造した
。(b) Crystalline oriented polyethylene terephthalate sheet
...Produced by uniaxially stretching the above-mentioned non-oriented non-oriented polyethylene terephthalate sheet 2 times at 100°C.
（Ｃ）結晶性無配向ポリエチレンテレフタレートシート
・・・結晶化剤を添加したポリエチレンテレフタレート
樹脂を使用して、上記（ａ）と同様に製造した。(C) Crystalline non-oriented polyethylene terephthalate sheet: produced in the same manner as in (a) above using polyethylene terephthalate resin to which a crystallizing agent was added.
■、熱威形条件
（ａ）金型・・・キャビティ１４の絞り比（深さ／開口
部径）が０．５ と１．０の２種類の金型１１を使用し
た。金型開口部の直径は、いずれも８ｏｒＩｎである。(2) Heat-forming conditions (a) Molds Two types of molds 11 were used in which the drawing ratio (depth/opening diameter) of the cavity 14 was 0.5 and 1.0. The diameter of the mold opening is 8 or In in each case.
（ｂ）金型の温度・・・金型１１に設けられた冷却手段
により２０″Ｃ又は８０°Ｃに保った。(b) Mold temperature: maintained at 20''C or 80°C by cooling means provided in the mold 11.
（ｃ）金型上方のヒータの温度・・・４５０ ’Ｃに加
熱した。(c) Temperature of heater above the mold: Heated to 450'C.
（ｄ）金型上方のヒータとシートとの距離・・・金型１
１の上方のヒータ１２と垂下前のシート１との距離を１
５０ｍ５とした。(d) Distance between the heater above the mold and the sheet...Mold 1
The distance between the heater 12 above 1 and the sheet 1 before drooping is 1
It was set to 50m5.
（ｅ）シートの加熱温度・・・金型上方のヒータ１２に
より加熱された成形直前のシートｌの表面温度である。(e) Sheet heating temperature: This is the surface temperature of the sheet l immediately before molding, which is heated by the heater 12 above the mold.
（ｆ）真空成形の真空度・・・７５０−■Ｈｇとした。(f) Vacuum degree of vacuum forming: 750-■Hg.
■、評価方法
（ａ）絞り性・・・成形された容器２の絞り比（深さ／
開口部径）がキャビティ１４の絞り比通りであるかどう
かを評価した。■ Evaluation method (a) Squeezability...Drawing ratio (depth/
It was evaluated whether the opening diameter) corresponded to the aperture ratio of the cavity 14.
（ｂ）透明性・・・目視により透明度を評価した。(b) Transparency: Transparency was evaluated visually.
（ｃ）熱収縮温度・・・容器２をエアーオーブン中に３
０分間放置して、目視で約３％の収縮が発生する温度を
測定した。(c) Heat shrinkage temperature...Place container 2 in air oven 3
The sample was left to stand for 0 minutes, and the temperature at which about 3% shrinkage occurred was visually measured.
表−１に示す通り、実験例１〜５によれば、透明ポリエ
ステルシート１として非品性無配向又は結晶性配向のポ
リエチレンテレフタレートシートを使用し、垂下量を金
型開口部の直径の５〜５０％、即ち４〜４０ｍａ＋の範
囲内とし、また金型１１の温度を７０℃以下に保ったの
で、絞り性及び透明性が良好であり、加えて熱収量温度
の高い容器２が得られることがわかる。従って、この容
器２を使用して従来不可能であった９０℃前後の高温充
填が可能になる。また、熱成形工程が簡単であるから、
高い生産性が得られる。As shown in Table 1, according to Experimental Examples 1 to 5, a non-quality unoriented or crystalline oriented polyethylene terephthalate sheet was used as the transparent polyester sheet 1, and the amount of droop was set to 5 to 5 times the diameter of the mold opening. 50%, that is, within the range of 4 to 40 ma+, and the temperature of the mold 11 was kept below 70°C, so that a container 2 with good drawability and transparency and a high heat yield temperature could be obtained. I understand. Therefore, using this container 2, it becomes possible to perform high-temperature filling at around 90° C., which was previously impossible. In addition, since the thermoforming process is simple,
High productivity can be obtained.
これに対して、比較例１．２，６．７によれば、シート
として透明の非品性無配向又は結晶性配向のポリエチレ
ンテレフタレートシートを使用し、また金型温度が本発
明の所定温度以下であっても、垂下量が本発明の所定範
囲外の場合には、絞り性、透明性及び熱収縮温度のいず
れか１つ以上について良好な特性が得られないことがわ
かる。なお、比較例６では、垂下中にシートに孔があき
、容器に成形できなかった。On the other hand, according to Comparative Examples 1.2 and 6.7, a transparent non-oriented or crystalline oriented polyethylene terephthalate sheet was used as the sheet, and the mold temperature was below the predetermined temperature of the present invention. However, it can be seen that if the amount of droop is outside the predetermined range of the present invention, good characteristics in any one or more of drawability, transparency, and heat shrinkage temperature cannot be obtained. In Comparative Example 6, holes were formed in the sheet during hanging, and the sheet could not be formed into a container.
比較例３によれば、金型温度は、本発明の所定温度以下
であるが、シートが不透明の結晶性無配向ポリエチレン
テレフタレートシートであることに加えて、垂下させな
かったので、絞り性及び透明性に関して良好な特性が得
られなかった。According to Comparative Example 3, the mold temperature was below the predetermined temperature of the present invention, but in addition to the fact that the sheet was an opaque crystalline non-oriented polyethylene terephthalate sheet, it was not allowed to droop, so the drawability and transparency were improved. Good properties regarding properties were not obtained.
比較例４によれば、垂下量及び金型温度は、本発明の所
定範囲内であるが、シートが不透明の結晶性無配向ポリ
エチレンテレフタレートシートであるため、透明性が不
良であった。According to Comparative Example 4, the amount of droop and the mold temperature were within the predetermined ranges of the present invention, but the sheet was an opaque crystalline non-oriented polyethylene terephthalate sheet, so the transparency was poor.
比較例５によれば、シートが透明の非品性無配向のポリ
エチレンテレフタレートシートであり、また垂下量も本
発明の所定範囲内であるが、金型温度が本発明の所定温
度範囲を越えているため、透明性が不良であった。According to Comparative Example 5, the sheet is a transparent non-oriented polyethylene terephthalate sheet, and the amount of droop is within the predetermined range of the present invention, but the mold temperature exceeds the predetermined temperature range of the present invention. Transparency was poor due to
［発明の効果］
本発明によれば、熱収縮温度が高いことに加えて、絞り
性及び透明性の良好な成型品が得られる。[Effects of the Invention] According to the present invention, a molded product not only has a high heat shrinkage temperature but also has good drawability and transparency.
第１図（Ａ）〜（Ｅ）は本発明の一実施例に係る成型方
法を示す工程図である。
１・・・ポリエステルシート、２・・・容器、１１・・
・金型、１２・・・ヒータ、１４・・・キャビティ、１
５・・・真空連通孔、１６・・・クランプ。
第１図FIGS. 1A to 1E are process diagrams showing a molding method according to an embodiment of the present invention. 1... Polyester sheet, 2... Container, 11...
・Mold, 12... Heater, 14... Cavity, 1
5...Vacuum communication hole, 16...Clamp. Figure 1
Claims (1)
定し、このシートを低温結晶化温度以上に加熱してキャ
ビティの開口上端からシートの最大垂下点までの垂直距
離で金型開口部の直径の５〜５０％垂下させた後、７０
℃以下に冷却した成型金型により前記シートを成形する
ことを特徴とするポリエステルシートの熱成形方法。(1) A transparent polyester sheet is fixed to the periphery of the mold, and the sheet is heated above the low-temperature crystallization temperature to determine the vertical distance from the upper end of the cavity opening to the maximum drooping point of the sheet to determine the diameter of the mold opening. After dropping 5 to 50% of
1. A method for thermoforming a polyester sheet, comprising molding the sheet using a mold cooled to below .degree.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21268789A JPH0649334B2 (en) | 1989-08-18 | 1989-08-18 | Thermoforming method for polyester sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21268789A JPH0649334B2 (en) | 1989-08-18 | 1989-08-18 | Thermoforming method for polyester sheet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0376626A true JPH0376626A (en) | 1991-04-02 |
| JPH0649334B2 JPH0649334B2 (en) | 1994-06-29 |
Family
ID=16626761
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21268789A Expired - Lifetime JPH0649334B2 (en) | 1989-08-18 | 1989-08-18 | Thermoforming method for polyester sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0649334B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5618486A (en) * | 1995-05-16 | 1997-04-08 | Sekisui Plastics Co., Ltd. | Process for manufacturing a heat-resistant molded foam product |
| JP2006056108A (en) * | 2004-08-19 | 2006-03-02 | Sekisui Plastics Co Ltd | Method for molding foamed polyethylene terephthalate sheet |
-
1989
- 1989-08-18 JP JP21268789A patent/JPH0649334B2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5618486A (en) * | 1995-05-16 | 1997-04-08 | Sekisui Plastics Co., Ltd. | Process for manufacturing a heat-resistant molded foam product |
| JP2006056108A (en) * | 2004-08-19 | 2006-03-02 | Sekisui Plastics Co Ltd | Method for molding foamed polyethylene terephthalate sheet |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0649334B2 (en) | 1994-06-29 |
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