JPH0671759B2 - Injection stretch blow molding method for flat containers - Google Patents

Injection stretch blow molding method for flat containers

Info

Publication number
JPH0671759B2
JPH0671759B2 JP24494191A JP24494191A JPH0671759B2 JP H0671759 B2 JPH0671759 B2 JP H0671759B2 JP 24494191 A JP24494191 A JP 24494191A JP 24494191 A JP24494191 A JP 24494191A JP H0671759 B2 JPH0671759 B2 JP H0671759B2
Authority
JP
Japan
Prior art keywords
preform
mold
temperature
flat container
injection
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
Application number
JP24494191A
Other languages
Japanese (ja)
Other versions
JPH0557782A (en
Inventor
竹内節行
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Aoki Technical Laboratory Inc
Original Assignee
Aoki Technical Laboratory Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Aoki Technical Laboratory Inc filed Critical Aoki Technical Laboratory Inc
Priority to JP24494191A priority Critical patent/JPH0671759B2/en
Publication of JPH0557782A publication Critical patent/JPH0557782A/en
Publication of JPH0671759B2 publication Critical patent/JPH0671759B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

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
    • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
    • B29C49/42—Component parts, details or accessories; Auxiliary operations
    • B29C49/64—Heating or cooling preforms, parisons or blown articles
    • B29C49/6409—Thermal conditioning of preforms
    • B29C49/6436—Thermal conditioning of preforms characterised by temperature differential
    • 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
    • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
    • B29C49/071—Preforms or parisons characterised by their configuration, e.g. geometry, dimensions or physical properties
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/07—Preforms or parisons characterised by their configuration
    • B29C2949/0715—Preforms or parisons characterised by their configuration the preform having one end closed
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/07—Preforms or parisons characterised by their configuration
    • B29C2949/072—Preforms or parisons characterised by their configuration having variable wall thickness
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/07—Preforms or parisons characterised by their configuration
    • B29C2949/072—Preforms or parisons characterised by their configuration having variable wall thickness
    • B29C2949/0721—Tangentially varying thickness
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/07—Preforms or parisons characterised by their configuration
    • B29C2949/072—Preforms or parisons characterised by their configuration having variable wall thickness
    • B29C2949/0722—Preforms or parisons characterised by their configuration having variable wall thickness at neck portion
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/07—Preforms or parisons characterised by their configuration
    • B29C2949/072—Preforms or parisons characterised by their configuration having variable wall thickness
    • B29C2949/0724—Preforms or parisons characterised by their configuration having variable wall thickness at body portion
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/07—Preforms or parisons characterised by their configuration
    • B29C2949/073—Preforms or parisons characterised by their configuration having variable diameter
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/07—Preforms or parisons characterised by their configuration
    • B29C2949/073—Preforms or parisons characterised by their configuration having variable diameter
    • B29C2949/0731—Preforms or parisons characterised by their configuration having variable diameter at neck portion
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/07—Preforms or parisons characterised by their configuration
    • B29C2949/073—Preforms or parisons characterised by their configuration having variable diameter
    • B29C2949/0733—Preforms or parisons characterised by their configuration having variable diameter at body portion
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/07—Preforms or parisons characterised by their configuration
    • B29C2949/074—Preforms or parisons characterised by their configuration having ribs or protrusions
    • B29C2949/0744—Preforms or parisons characterised by their configuration having ribs or protrusions at neck portion
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/07—Preforms or parisons characterised by their configuration
    • B29C2949/076—Preforms or parisons characterised by their configuration characterised by the shape
    • B29C2949/0761—Preforms or parisons characterised by their configuration characterised by the shape characterised by overall the shape
    • B29C2949/0764—Elliptic or oval cross-section shape
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/07—Preforms or parisons characterised by their configuration
    • B29C2949/076—Preforms or parisons characterised by their configuration characterised by the shape
    • B29C2949/0768—Preforms or parisons characterised by their configuration characterised by the shape characterised by the shape of specific parts of preform
    • B29C2949/077—Preforms or parisons characterised by their configuration characterised by the shape characterised by the shape of specific parts of preform characterised by the neck
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/07—Preforms or parisons characterised by their configuration
    • B29C2949/076—Preforms or parisons characterised by their configuration characterised by the shape
    • B29C2949/0768—Preforms or parisons characterised by their configuration characterised by the shape characterised by the shape of specific parts of preform
    • B29C2949/078—Preforms or parisons characterised by their configuration characterised by the shape characterised by the shape of specific parts of preform characterised by the bottom
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/07—Preforms or parisons characterised by their configuration
    • B29C2949/081—Specified dimensions, e.g. values or ranges
    • B29C2949/0811—Wall thickness
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/07—Preforms or parisons characterised by their configuration
    • B29C2949/081—Specified dimensions, e.g. values or ranges
    • B29C2949/082—Diameter
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/07—Preforms or parisons characterised by their configuration
    • B29C2949/081—Specified dimensions, e.g. values or ranges
    • B29C2949/0829—Height, length
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/20—Preforms or parisons whereby a specific part is made of only one component, e.g. only one layer
    • B29C2949/22—Preforms or parisons whereby a specific part is made of only one component, e.g. only one layer at neck portion
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/20—Preforms or parisons whereby a specific part is made of only one component, e.g. only one layer
    • B29C2949/24—Preforms or parisons whereby a specific part is made of only one component, e.g. only one layer at flange portion
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/20—Preforms or parisons whereby a specific part is made of only one component, e.g. only one layer
    • B29C2949/26—Preforms or parisons whereby a specific part is made of only one component, e.g. only one layer at body portion
    • 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
    • B29C2949/00—Indexing scheme relating to blow-moulding
    • B29C2949/20—Preforms or parisons whereby a specific part is made of only one component, e.g. only one layer
    • B29C2949/28—Preforms or parisons whereby a specific part is made of only one component, e.g. only one layer at bottom portion
    • 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
    • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
    • B29C49/02—Combined blow-moulding and manufacture of the preform or the parison
    • B29C49/06—Injection blow-moulding
    • 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
    • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
    • B29C49/42—Component parts, details or accessories; Auxiliary operations
    • B29C49/64—Heating or cooling preforms, parisons or blown articles
    • B29C49/6409—Thermal conditioning of preforms
    • B29C49/6436—Thermal conditioning of preforms characterised by temperature differential
    • B29C49/6458—Thermal conditioning of preforms characterised by temperature differential tangentially, i.e. along circumference

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Geometry (AREA)
  • Thermal Sciences (AREA)
  • Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】この発明は、合成樹脂によるプリ
フォームの射出成形から薄肉扁平容器への延伸吹込成形
を連続して行う成形方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding method for continuously performing injection molding of a preform of synthetic resin and stretch blow molding into a thin flat container.

【０００２】[0002]

【従来の技術】射出延伸吹込成形による扁平容器の成形
方法としては、特公昭５９−４２９２号に記載された方
法が知られている。2. Description of the Related Art As a method for molding a flat container by injection stretch blow molding, a method described in Japanese Patent Publication No. 59-4292 is known.

【０００３】この成形方法は、プリフォームにおける扁
平容器の膨張比率が小なる前後部を形成する部分の肉厚
を、扁平容器の膨張比率が大なる両側部を形成する部分
よりも厚肉に形成して熱容量を大きくし、その厚肉部分
を吹込金型の扁平容器の前後面を形成する型面に臨ませ
て吹込成形する、というものである。In this molding method, the wall thickness of the front and rear portions of the preform where the expansion ratio of the flat container is small is made thicker than the wall portions of both sides where the expansion ratio of the flat container is large. Then, the heat capacity is increased, and the thick portion is blow-molded so as to face the mold surfaces forming the front and rear surfaces of the flat container of the blow mold.

【０００４】またこの成形方法は、射出金型からコアと
共に離型したのち、直ちに吹込金型に移送して吹込成形
を行う場合と、一旦加熱炉に送って温度調節をしてから
吹込金型に移送して、吹込成形を行う場合のいずれにも
採用できるとされているが、実際には温度調節したのち
に吹込成形を行っている。In this molding method, after the mold is released from the injection mold together with the core, the mold is immediately transferred to a blow mold for blow molding, and the mold is once sent to a heating furnace to adjust the temperature and then the blow mold. It is said that it can be used for any of the cases of carrying out blow molding by transferring to, but the blow molding is actually carried out after temperature adjustment.

【０００５】[0005]

【発明が解決しようとする課題】肉厚の差により温度差
を持たせたプリフォームを、そのままの状態で吹込金型
に移行して扁平容器に吹込成形することの困難さは、離
型から吹込成形を行う時間の設定にあり、特にコアと共
に移送した場合には、コア自体の温度の影響を受けて、
満足な扁平容器の吹込成形は一層困難であった。It is difficult to transfer a preform having a temperature difference due to a difference in wall thickness to a blow mold as it is to blow-mold a flat container from the mold release. There is a time setting for blow molding, especially when it is transferred with the core, it is affected by the temperature of the core itself,
Blow molding of satisfactory flat containers has been more difficult.

【０００６】また温度調節を行う場合も、その調整に経
験を要し、一度に多数個の扁平容器を成形する場合に
は、プリフォームを一本ごとに温調しなければならぬな
ど、極めて手数のかかるものであった。[0006] Also, when adjusting the temperature, experience is required for the adjustment. When molding a large number of flat containers at one time, it is extremely necessary to adjust the temperature of each preform. It was troublesome.

【０００７】この発明は、上記従来の扁平容器の延伸吹
込成形における課題を解決するために考えられたもので
あって、その目的は、射出成形したプリフォームを直ち
に吹込成形するものでありながら、設計通りの肉厚分布
の薄肉扁平容器を成形することができる新たな扁平容器
の射出延伸吹込成形方法を提供することにある。The present invention was conceived in order to solve the problems in the above-mentioned conventional stretch blow molding of a flat container, and its purpose is to immediately blow mold an injection-molded preform, It is an object of the present invention to provide a new injection stretch blow molding method for a flat container, which is capable of molding a thin flat container having a wall thickness distribution as designed.

【０００８】[0008]

【課題を解決するための手段】[Means for Solving the Problems]

【０００９】上記目的によるこの発明の特徴は、溶融樹
脂を射出金型に射出充填して所要のプリフォームに形成
し、そのプリフォームをリップ型により口部を保持して
射出金型から吹込金型に移送し、吹込金型内にて薄肉で
扁平な容器に延伸吹込成形するにあたり、射出金型内に
てプリフォームにおける扁平容器の膨張比率が小なる前
後面を形成する部分の肉厚を、扁平容器の膨張比率が大
なる両側部を形成する部分よりも厚肉に形成して熱容量
を大きくし、そのプリフォームの射出金型からの離型
を、急冷により表面に生じたスキン層により形状の維持
が可能な状態にあり、かつ内部冷却が未完で高温状態に
あるうちに行い、扁平容器への延伸吹込成形を、自己の
内部温度により上昇するプリフォームの表面温度がピー
ク温度に達するまでの時間内にて行うことにある。The feature of the present invention according to the above object is that a molten resin is injected and filled into an injection mold to form a required preform, and the preform is held by a lip mold to hold the mouth portion and blown from the injection mold. When it is transferred to the mold and stretch blow-molded into a thin and flat container in the blow mold, the wall thickness of the part that forms the front and rear surfaces in the injection mold where the expansion ratio of the flat container in the preform is small , The flat container is made thicker than the part that forms the both sides where the expansion ratio is large to increase the heat capacity, and the preform is released from the injection mold by the skin layer generated on the surface by quenching. Performing while the shape can be maintained and internal cooling is incomplete and at high temperature, stretch blow molding into a flat container rises due to its own internal temperature The surface temperature of the preform reaches the peak temperature. Until There to be carried out in time within.

【００１０】[0010]

【作 用】射出充填された射出金型内の溶融樹脂は、急
冷により型面に接する樹脂が極めて短時間に硬化してス
キン層を形成する。また硬化に伴う収縮により表面が型
面から離れるため、内部に対する冷却は悪くなり、冷却
未完の状態で高温を保っている。[Operation] The molten resin in the injection mold filled by injection is rapidly cooled so that the resin in contact with the mold surface is cured in an extremely short time to form a skin layer. Further, since the surface is separated from the mold surface due to shrinkage accompanying curing, cooling to the inside becomes worse, and the high temperature is maintained in a state where cooling is not completed.

【００１１】しかしプリフォームは硬いスキン層によ
り、離型可能な状態となり、また離型後にも形状が維持
される。このため抜き勾配に左右されず早期の離型が可
能となる。However, the hard skin layer allows the preform to be released from the mold and maintains its shape after the mold is released. For this reason, early mold release is possible without being affected by the draft.

【００１２】このような高温のプリフォームでは、離型
後においても表面温度がピークに達するまでは、半溶融
状態の内部樹脂がスキン層に包まれた状態にあるから、
スキン層が軟化した時点にて延伸すると、まずスキン層
が内部樹脂を連れて薄く伸びて行く。In such a high temperature preform, since the internal resin in a semi-molten state is wrapped in the skin layer until the surface temperature reaches the peak even after the mold release,
When the skin layer is stretched when it is softened, the skin layer first grows thin with the internal resin.

【００１３】この延伸の過程において、表面積の増加等
によりプリフォーム全体の温度が低下し、内部樹脂の温
度までが延伸に適した温度となる。それまでスキン層に
つれられて延びていた内部樹脂が、途中からスキン層と
同様に薄く伸びるようになり、その結果、プリフォーム
は肉厚分布が均一な成形品となる。In the process of stretching, the temperature of the entire preform decreases due to an increase in surface area and the like, and the temperature of the internal resin reaches a temperature suitable for stretching. The internal resin, which has been stretched along with the skin layer, is stretched from the middle to be thin like the skin layer. As a result, the preform becomes a molded product having a uniform wall thickness distribution.

【００１４】このような延伸の過程は、扁平容器の膨張
比率が小なる前後面を形成する部分の肉厚を、扁平容器
の膨張比率が大なる両側部を形成する部分よりも厚肉に
形成して熱容量を大きくしたプリフォームにおいても同
様であるが、そこに付与された温度差から、プリフォー
ム全体の延伸状態に差が生じ、延伸は熱容量の高いほう
が先行する。In such a stretching process, the thickness of the front and rear surfaces of the flat container having a small expansion ratio is made thicker than the portions of the flat container having both expansion parts having a large expansion ratio. The same applies to a preform having a large heat capacity, but the temperature difference applied to the preform causes a difference in the stretched state of the entire preform, and the higher the heat capacity is, the more precedent the stretching.

【００１５】また溶融樹脂を金型に射出充填して、プリ
フォームを射出成形し、このプリフォームを射出金型か
らできるだけ高温のうちに離型して、室温中にそのまま
放置しておくと、プリフォームの表面温度は、図５に示
すように、表面温度の高低差に関係無く、同様な温度変
化を示す。Further, when a molten resin is injection-filled in a mold, a preform is injection-molded, the preform is released from the injection mold at the highest temperature possible, and left as it is at room temperature. As shown in FIG. 5, the surface temperature of the preform shows the same temperature change regardless of the difference in surface temperature.

【００１６】この表面温度の経時変化はピーク温度に達
する迄の時間にある程度の差はあっても、容器の成形に
用いられる熱可塑性樹脂の殆どが同様な経過を示す。こ
の初期の表面温度の上昇原因は、高温離型されたプリフ
ォームでは、金型のキャビティ面やコアと接しているプ
リフォーム表面が、金型の冷却により固化してスキン層
を形成するが、内部冷却は未完で高温で半溶融状態にあ
り、これが離型により冷却を断たれたのちのスキン層を
内部から加熱することにある。The surface temperature changes with time, although there is some difference in the time until the peak temperature is reached, most of the thermoplastic resins used for molding the container show the same process. The cause of this initial increase in surface temperature is that in a high-temperature mold release preform, the preform surface in contact with the cavity surface or core of the mold solidifies by cooling the mold to form a skin layer, The internal cooling is incomplete and is in a semi-molten state at high temperature, and this is to heat the skin layer from the inside after cooling is cut off by releasing.

【００１７】これまでの実験では、ポリエチレンテレフ
タレートによるプリフォームの離型後の表面温度が８０
℃以下であると白濁が発生し易くなる。また離型直後の
プリフォームの表面温度が６０℃以上で、極めて短時間
の経過の後に延伸吹込成形を行った場合には、クレージ
ングの発生が殆どないということである。In the experiments conducted so far, the surface temperature after releasing the preform made of polyethylene terephthalate was 80.
If the temperature is below ℃, white turbidity is likely to occur. Further, when the surface temperature of the preform immediately after release from the mold is 60 ° C. or higher and stretch blow molding is carried out after an extremely short period of time, crazing hardly occurs.

【００１８】しかし、このような場合でも、冷却時間が
長く離型直後の温度が６０℃以下になると、延伸吹込成
形温度がピーク前の８０℃以上であっても、そこに延伸
吹込成形された成形品に白濁が生じ易いことも明らかと
なった。However, even in such a case, when the cooling time was long and the temperature immediately after the mold release was 60 ° C. or lower, the stretch blow molding was performed there even if the stretch blow molding temperature was 80 ° C. or higher before the peak. It was also clarified that white turbidity was likely to occur in the molded product.

【００１９】したがって、冷却温度が一定な射出金型に
より成形された肉厚分布が異なるプリフォームでは、最
も薄肉な部分の表面温度が８０℃以下にならない範囲
で、しかも図５に示すピーク温度に達する前に、吹込成
形を開始すれば、極めて短時間の間に扁平容器の膨張比
率が小なる前後部を形成する部分の延伸が先行し、次い
で膨張比率が大なる両側部が延伸して、そこに設計肉厚
の扁平容器が得られることになる。Therefore, in a preform molded by an injection mold having a constant cooling temperature and having a different wall thickness distribution, the surface temperature of the thinnest portion does not fall below 80 ° C. and reaches the peak temperature shown in FIG. Before reaching, if blow molding is started, stretching of the part forming the front and rear parts where the expansion ratio of the flat container is small precedes in an extremely short time, and then both side parts where the expansion ratio is large are stretched, A flat container with a designed wall thickness can be obtained there.

【００２０】[0020]

【実施例】ポリエチレンテレフタレートの溶融樹脂を射
出金型に射出充填し、急冷により図１に示すような細口
のプリフォーム１を成形した。EXAMPLE A molten resin of polyethylene terephthalate was injected and filled in an injection mold, and rapidly cooled to form a preform 1 having a narrow mouth as shown in FIG.

【００２１】このプリフォーム１は図２に示すように、
前部１１と後部１２は１５０°角の範囲にて両側部１
３，１３より内側を順次厚肉に形成してある。This preform 1 is, as shown in FIG.
The front part 11 and the rear part 12 are both side parts 1 within a range of 150 ° angle.
The inner side of 3, 13 is formed thicker in order.

【００２２】プリフォームの設計寸法 全体の長さ １４５mm 口部の直径 ２６mm、 前部肉厚１１（最高） ３．０５mm 後部肉厚１２（最高） ３．１５mm 両側部肉厚 （平均） ２．８mmPreform design dimensions Overall length 145 mm Mouth diameter 26 mm, Front wall thickness 11 (maximum) 3.05 mm Rear wall thickness 12 (maximum) 3.15 mm Side wall thickness (average) 2.8 mm

【００２３】なお、全部と後部の肉厚に差を持たせたの
は、扁平容器の用途上からで、通常の扁平容器では、そ
の両方の肉厚は同一に設計される。The reason why the thicknesses of the whole and the rear part are different is from the application of the flat container. In a normal flat container, the thicknesses of both are designed to be the same.

【００２４】図５の表面温度は底部から７５mmの所を室
温中（２２℃）測定したもので、平均値である。温度測
定器は、デジタル放射温度計ＩＲ−ＡＨＯＴ（株式会社
チノン製）を使用した。The surface temperature in FIG. 5 is an average value measured at room temperature (22 ° C.) at a position 75 mm from the bottom. A digital radiation thermometer IR-AHOT (manufactured by Chinon Co., Ltd.) was used as the temperature measuring device.

【００２５】射出成形条件 射出温度 ２７０℃ 金型温度（冷却水） １３℃ 抜き勾配 １．５° 射出充填時間 ６．０秒 冷却時間 ３．０秒Injection molding conditions Injection temperature 270 ° C. Mold temperature (cooling water) 13 ° C. Draft gradient 1.5 ° Injection filling time 6.0 seconds Cooling time 3.0 seconds

【００２６】上記プリフォーム１を、離型後に口部を保
持して直ちに吹込金型に移送し、前部１１と後部１２を
扁平容器の前部と後部とを成形する型面にそれぞれ臨ま
せ、各部の表面温度がピークに達する前の時間内にて延
伸吹込成形を行った結果、図３及び図４に示す形状の扁
平容器２を得た。その際の成形条件は下記のとおりであ
った。The above-mentioned preform 1 is transferred to a blow mold immediately after holding the mouth part while releasing the mold, and the front part 11 and the rear part 12 are exposed to the mold surfaces for molding the front part and the rear part of the flat container, respectively. As a result of stretch blow molding within the time before the surface temperature of each part reached its peak, the flat container 2 having the shape shown in FIGS. 3 and 4 was obtained. The molding conditions at that time were as follows.

【００２７】吹込成形条件 延伸吹込成形 離型後７秒 表面温度（図５参照） 前部肉厚 ９９．２℃ 後部肉厚 １０６．６℃ 両側部肉厚 ８８．２℃ 吹込空気圧 １４kg／cmBlow molding conditions Stretch blow molding 7 seconds after demolding Surface temperature (see Fig. 5) Front wall thickness 99.2 ° C Rear wall thickness 106.6 ° C Both side wall thickness 88.2 ° C Blow air pressure 14kg / cm

【００２８】吹込成形品（扁平容器） 容 量 ４００cc 全体の高さ ２２５mm 横 幅 １８０mm 縦 巾 ３５mm 胴部肉厚 ０．４〜０．５mmBlow-molded product (flat container) Capacity 400cc Overall height 225mm Horizontal width 180mm Vertical width 35mm Body thickness 0.4-0.5mm

【００２９】[0029]

【発明の効果】この発明は上述のように、射出成形した
プリフォームを直ちに延伸吹込成形するものでありなが
ら、設計通りの薄肉扁平容器を成形することができる。
またピーク温度に達する前の高温状態にあるうちに延伸
吹込成形を行うため、白化現象も起こらず、延伸吹込成
形に要する時間がこれまでより著しく短くなるので、成
形サイクルも早くなり、時間当たり生産量が増すなどの
利点をも有する。As described above, according to the present invention, a thin flat container as designed can be formed while the injection-molded preform is immediately stretch blow-molded.
Also, since stretch blow molding is performed while the temperature is high before reaching the peak temperature, the whitening phenomenon does not occur, and the time required for stretch blow molding is significantly shorter than before, so the molding cycle is faster and the production per hour is longer. It also has the advantage of increasing the amount.

【図面の簡単な説明】[Brief description of drawings]

【図１】プリフォームの側面図である。FIG. 1 is a side view of a preform.

【図２】肉厚分布を示すプリフォームの平断面図であ
る。FIG. 2 is a plan sectional view of a preform showing a wall thickness distribution.

【図３】同上のプリフォームから延伸吹込成形した扁平
容器の正面図である。FIG. 3 is a front view of a flat container stretch-blow molded from the above preform.

【図４】同上の平面図である。FIG. 4 is a plan view of the above.

【図５】ポリエチレンテレフタレートにより射出成形し
たプリフォームの表面温度の経時変化図である。FIG. 5 is a diagram showing changes with time in surface temperature of a preform injection-molded from polyethylene terephthalate.

【符合の説明】[Explanation of sign]

１ プリフォーム １１ プリフォームの前部 １２ プリフォームの後部 １３ プリフォームの両側部 ２ 扁平容器 1 Preform 11 Front part of preform 12 Rear part of preform 13 Both sides of preform 2 Flat container

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 溶融樹脂を射出金型に射出充填して所要
のプリフォームに形成し、そのプリフォームをリップ型
により口部を保持して射出金型から吹込金型に移送し、
吹込金型内にて薄肉で扁平な容器に延伸吹込成形するに
あたり、射出金型内にてプリフォームにおける扁平容器
の膨張比率が小なる前後部を形成する部分の肉厚を、扁
平容器の膨張比率が大なる両側部を形成する部分よりも
厚肉に形成して熱容量を大きくし、そのプリフォームの
射出金型からの離型を、急冷により表面に生じたスキン
層により形状の維持が可能な状態にあり、かつ内部冷却
が未完で高温状態にあるうちに行い、扁平容器への延伸
吹込成形を、自己の内部温度により上昇するプリフォー
ムの表面温度がピーク温度に達するまでの時間内にて行
うことを特徴とする扁平容器の射出延伸吹込成形方法。1. A molten resin is injection-filled into an injection mold to form a required preform, and the preform is transferred from an injection mold to a blow mold while holding a mouth portion by a lip mold,
When stretch-blow molding into a thin, flat container in the blow mold, the expansion of the flat container is performed by adjusting the wall thickness of the part forming the front and rear parts in the injection mold where the expansion ratio of the flat container in the preform is small. It is made thicker than the part that forms both sides with a large ratio to increase the heat capacity, and the preform can be released from the injection mold, and the shape can be maintained by the skin layer generated on the surface by rapid cooling. In this state, and while the internal cooling is incomplete and at a high temperature, stretch blow molding into a flat container is performed within the time until the surface temperature of the preform, which rises due to its own internal temperature, reaches the peak temperature. An injection stretch blow molding method for a flat container, the method comprising:
JP24494191A 1991-08-30 1991-08-30 Injection stretch blow molding method for flat containers Expired - Lifetime JPH0671759B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP24494191A JPH0671759B2 (en) 1991-08-30 1991-08-30 Injection stretch blow molding method for flat containers

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP24494191A JPH0671759B2 (en) 1991-08-30 1991-08-30 Injection stretch blow molding method for flat containers

Publications (2)

Publication Number Publication Date
JPH0557782A JPH0557782A (en) 1993-03-09
JPH0671759B2 true JPH0671759B2 (en) 1994-09-14

Family

ID=17126243

Family Applications (1)

Application Number Title Priority Date Filing Date
JP24494191A Expired - Lifetime JPH0671759B2 (en) 1991-08-30 1991-08-30 Injection stretch blow molding method for flat containers

Country Status (1)

Country Link
JP (1) JPH0671759B2 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4687855B2 (en) * 2001-06-29 2011-05-25 株式会社青木固研究所 Preform for small flat container and small flat container
JP2019130251A (en) * 2018-02-02 2019-08-08 テルモ株式会社 Cylindrical preform for manufacturing medical liquid storage container body and method of manufacturing medical liquid storage container body

Also Published As

Publication number Publication date
JPH0557782A (en) 1993-03-09

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