JPS6139178B2 - - Google Patents

Description

【発明の詳細な説明】 本発明は、中空部をもつ二重壁部分などを有す
る複雑な複数コアーを用いた凹凸形状品流し台等
の熱可塑性樹脂の中空成形品を、しわがなく、ま
た偏肉が少なく、しかも短時間に成形せんとする
成型方法に係る。DETAILED DESCRIPTION OF THE INVENTION The present invention provides hollow molded thermoplastic resin products such as sinks that use complex multiple cores having double walled portions with hollow portions, etc., without wrinkles or unevenness. It relates to a molding method that uses less meat and can be molded in a short time.

従来二重壁部分などを有する複雑な流し台等全
壁面に凹凸部分をもつ複雑形状の熱可塑性樹脂の
中空成形品を成形する場合には、内外壁面形状が
複雑な割金型にパリソンを供給して中空成形する
もので、熔融パリソンを膨張させる際、割金型内
面の突出した部分の金型が他の部分よりも先に熔
融状態のパリソンと接触するので、該部にパリソ
ンが冷却されて局部的に延び率が悪くなつて厚肉
となるか、又は突出部の先行接触で大きく吹き延
ばされる部分が出来、これが薄肉になりやすく、
得られる中空成形品に偏肉や、しわが生ずる。又
型締中途に型外にはみ出て破損するという欠点が
あつた。 Conventionally, when molding a complex-shaped thermoplastic resin hollow molded product with uneven parts on the entire wall surface, such as a complicated sink with a double-walled part, the parison is supplied to a split mold with complicated inner and outer wall shapes. When the molten parison is expanded, the protruding part of the inner surface of the split mold comes into contact with the molten parison before other parts, so the parison is cooled in that part. Either the elongation rate deteriorates locally, resulting in a thick wall, or there is a portion that is greatly blown out due to the prior contact of the protrusion, which tends to result in a thin wall.
Uneven thickness and wrinkles occur in the resulting hollow molded product. Another drawback was that it protruded out of the mold during mold clamping and was damaged.

ここにおいて本発明者は、このような従来の中
空成形法における欠点を改善すべく種々検討した
結果、キヤビテイの一部を構成する型面をもつた
進退自在のコアーを有する割金型の開放下、熱可
塑性樹脂からなる熔融パリソンまたは二枚の熱軟
化シート（以下パリソンと呼称）のいずれかによ
る加熱軟化した袋体を該割金型間に供給し、該袋
体内部に低圧空気を吹込んで膨張させ、ひき続き
予熱適温とした該割金型の周壁をなす枠部材を閉
鎖しつつ、該枠部材内のコアーを所定位置に進退
待機させパリソンとの接触をさけると共に、その
際膨れたパリソンと該割金型のキヤビテイ間にあ
る残つた空気を該金型のキヤビテイに先に設けた
小径穴を通じて外部から吸引除去なさしめつつ型
締を低圧力保持下にプリプローし、次いで上記割
金型の閉鎖下のコアーを順次前進させて成形素材
の内部を一定圧力に保持しつつ型締を終ると同時
にダイの中心に垂下した空気供給ピン又は別設し
た空気供給ピンより高圧の空気を吹込み、型締め
成形を終らせ、該割金型内の成形品を冷却し、所
望形状の中空成形品を成形する方法を見出すに至
つた。 As a result of various studies to improve the shortcomings of the conventional blow molding method, the present inventor has developed an open bottom mold for a split mold having a core that can move forward and backward and has a mold surface that forms a part of the cavity. A heat-softened bag made of either a molten parison made of thermoplastic resin or two heat-softened sheets (hereinafter referred to as parison) is supplied between the split molds, and low-pressure air is blown into the inside of the bag. While closing the frame member forming the peripheral wall of the split mold which was inflated and then preheated to an appropriate temperature, the core within the frame member is moved back and forth to a predetermined position to avoid contact with the parison, and at the same time, the expanded parison is removed. The remaining air between the mold and the cavity of the split mold is suctioned and removed from the outside through a small diameter hole previously provided in the cavity of the mold, and the mold clamp is pre-filled while maintaining a low pressure. The closed core is advanced one after another to maintain a constant pressure inside the molding material, and at the same time as mold clamping is completed, high-pressure air is blown from an air supply pin hanging down at the center of the die or from an air supply pin installed separately. The inventors have now discovered a method of completing mold clamping, cooling the molded product in the split mold, and molding a hollow molded product of a desired shape.

つぎに、本発明を図面によりさらに具体的に説
明する。本発明の実施にあたつては、第１図に示
すように、左右一対の半割型４ａ，４ｂと、この
半割型４ａ，４ｂの内部に水平方向に進退自在の
キヤビテイの一部を構成する型面をもつた三個の
限定ストロークをもつた左、右、下方の三方に待
機状のコアー５，６，７（図示では３個）と基台
１０上に定着された垂直方向に進退自在のキヤビ
テイの一部を構成する型面をもつた案内筒９に嵌
入されたコアー８が所定の位置又は開放状態にあ
る際に、その上方に設けてある押出機のダイ１か
ら押出された熱可塑性樹脂の有底パリソン２を両
半割型４ａ，４ｂの型締中心線Ｘ−Ｘ線上に向つ
て垂下させる。 Next, the present invention will be explained in more detail with reference to the drawings. In carrying out the present invention, as shown in FIG. 1, a pair of left and right half molds 4a, 4b and a part of a cavity that can move horizontally into and out of the half molds 4a, 4b are installed. Three cores 5, 6, 7 (three in the figure) stand by on the left, right, and lower sides with three limited strokes and have forming mold surfaces, and the cores 5, 6, and 7 (three in the figure) are fixed on the base 10 in the vertical direction. When the core 8 fitted into the guide tube 9 with a mold surface forming a part of the cavity that can move forward and backward is in a predetermined position or in an open state, the core 8 is extruded from the die 1 of the extruder provided above. The bottomed parison 2 made of thermoplastic resin is hung down toward the clamping center line X--X of both half molds 4a and 4b.

ついでダイ１に設けてある空気供給ピン３より
低圧空気を吹込んでパリソン２をプリプローさせ
る。ひき続き、型締装置のシリンダー１４に嵌入
されたロツト１５によつて半割型４ａ，４ｂをＸ
−Ｘ線に向つて閉鎖移動しながらコアー５，８を
限定ストローク間に一旦後退させる。ここで半割
型４ａ，４ｂと各コアー５，６，７，８は、パリ
ソン２とほぼ同温度位に予熱した各コアーの型面
の空気吸引孔１３により加熱空気等を吹き出し、
各コアー先端を予熱しつつパリソン２の接触を一
定時防ぐ如く低圧力の加熱空気を矢符１６の如く
吹き出し、パリソン２との接触部分が局部的に冷
却固化するのを防止する。また半割型４ａ，４ｂ
の閉鎖移動と連動して、パリソン２と割金型間に
ある残溜空気を空気吸引孔１１，１３を通じて外
部大気に向つて吸引除去する。 Next, low pressure air is blown into the die 1 through an air supply pin 3 to pre-pop the parison 2. Subsequently, the half molds 4a and 4b are held in an
- The cores 5, 8 are once retracted during a limited stroke while moving closed toward the X-ray. Here, the half molds 4a, 4b and each core 5, 6, 7, 8 blow out heated air etc. through the air suction hole 13 on the mold surface of each core, which has been preheated to approximately the same temperature as the parison 2.
While preheating the tip of each core, low-pressure heated air is blown out as shown by arrow 16 so as to prevent contact with the parison 2 for a certain period of time, thereby preventing the contact portion with the parison 2 from being locally cooled and solidified. Also half-split type 4a, 4b
In conjunction with the closing movement of the parison 2 and the split mold, residual air between the parison 2 and the split mold is sucked and removed toward the outside atmosphere through the air suction holes 11 and 13 .

この空気吸引除去操作により、第２図に示すよ
うに、パリソン２が均一な厚みて閉鎖割金型のキ
ヤビテイ内壁面と密着し、各コアーの進動により
型締される。このため成型品は偏肉が少なくブロ
ー成形される。即ちこの成形行程の最終段階とし
て第３図図に示すようにコアー５，６，７，８を
順次内圧の急上昇を防ぐよう（減圧弁（図示省
略）等を介在）前進させ、パリソン２内に空気供
給ピン３を介するか、別設空気供給ピン（図示省
略）より成形品の中空部２′に比較的高圧の空気
を吹込み、割金型を冷却して所望形状の中空成形
品に成形する。以上により、第４図に示すような
複雑な形状の偏肉の少ない、しわのない中空成形
品（台所用流し台）１２が得られる。 As a result of this air suction and removal operation, the parison 2 has a uniform thickness and comes into close contact with the inner wall surface of the cavity of the closed split mold, as shown in FIG. 2, and the mold is clamped by the movement of each core. For this reason, the molded product is blow molded with less uneven thickness. That is, as the final stage of this molding process, as shown in FIG. Relatively high pressure air is blown into the hollow part 2' of the molded product through the air supply pin 3 or from a separate air supply pin (not shown) to cool the split mold and form the hollow molded product into the desired shape. do. Through the above process, a wrinkle-free hollow molded product (kitchen sink) 12 having a complicated shape with little unevenness in thickness as shown in FIG. 4 can be obtained.

ここでは、成形素材として熱可塑性樹脂の有底
パリソン２を用いたが、二枚の熱軟化状態にある
熱可塑性樹脂シートによる袋体を用いる場合に前
者と同様に中空成形すればよい。 Here, a bottomed parison 2 made of thermoplastic resin was used as the molding material, but when a bag made of two thermoplastic resin sheets in a heat-softened state is used, it may be blow-molded in the same manner as the former.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図ないし第３図は、本発明の一実施例にお
ける成形装置主要部と中空成形品との相互位置関
係を示す断面図であり、第１図は開放割金型内で
パリソンを膨張させた状態、第２図は閉鎖割金型
内のコアーを後退させた状態、第３図はコアーを
前進させた最終成形段階の状態を示す、第４図は
得られた中空成形品（台所用流し台）の斜視図で
ある。 １は押出機のダイ、２はパリソン、３は空気供
給ピン、４ａ，４ｂは半割型、５，６，７はコア
ー、９はコアー案内筒、１０は半割型の基台、１
２は中空成形品流し台、１１，１３は空気吸引
孔、Ｘ−Ｘは型締中心線。 1 to 3 are cross-sectional views showing the mutual positional relationship between the main parts of a molding device and a hollow molded product in an embodiment of the present invention, and FIG. 1 shows a parison expanded in an open split mold. Figure 2 shows the state in which the core in the closed split mold is retracted, Figure 3 shows the state in the final molding stage with the core advanced, and Figure 4 shows the obtained hollow molded product (for kitchen use). FIG. 2 is a perspective view of a sink. 1 is an extruder die, 2 is a parison, 3 is an air supply pin, 4a, 4b are half molds, 5, 6, 7 are cores, 9 is a core guide tube, 10 is a base for half molds, 1
2 is a hollow molded product sink, 11 and 13 are air suction holes, and X-X is the mold clamping center line.

Claims (1)

【特許請求の範囲】[Claims] １ キヤビテイの一部を構成する型面をもつ進退
自在の複数のコアーをもつた割金型の開放下、熱
可塑性樹脂からなるパリソン又は二枚の加熱軟化
シートのいずれかによる袋体を割金型間に供給
し、該袋体内部には低圧空気を吹込んで膨張さ
せ、ひき続き予め所定温度にしてある該割金型を
型締をなしつつ該金型内のコアーを所定位置迄進
退させると共に、その際膨れたバリソンと該割金
型のキヤビテイ間に残つた空気を外部から吸引、
型外大気に除去させつつ続いて上記割金型の閉鎖
下にある待機中の１〜複数のコアーを順次所定位
置に進動させて一定圧力保持下、型締を終らせる
と同時に、成形素材内部に向つて空気供給ピンよ
り高圧の空気を吹込み型締成形を終らせ、冷却、
複数のコアーをもつ割金型による凹凸部をもつ二
重構造品の成型方法。1. A bag body made of either a parison made of thermoplastic resin or two heat-softened sheets is molded into a split mold with a plurality of cores that can move forward and backward and whose mold surface forms part of the cavity is opened. Supplied between molds, low pressure air is blown into the inside of the bag to expand it, and the core inside the mold is moved back and forth to a predetermined position while clamping the split mold, which has been previously heated to a predetermined temperature. At the same time, the air remaining between the swollen balisong and the cavity of the split mold is sucked from the outside.
While removing the core from the atmosphere outside the mold, one or more waiting cores in the closed split mold are sequentially advanced to a predetermined position, and the mold clamping is completed while maintaining a constant pressure. High-pressure air is blown inward from the air supply pin to complete molding, cooling,
A method for molding double-structured products with uneven parts using a split mold with multiple cores.