JP2004322544A - Extrusion method for synthetic resin pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extrusion method for a synthetic resin pipe capable of obtaining the synthetic resin pipe reduced in deformation by a simple method even if the synthetic resin pipe is formed by extrusion using a hard synthetic resin, for example, a blend resin comprising a styrenic thermoplastic elastomer and polypropylene as a raw material. <P>SOLUTION: The synthetic resin pipe extruded from an extruder E is taken over while regulated to a predetermined outer diameter by one set of guide rolls 1, which have semicircular recessed grooves 11 carved in the peripheral surfaces thereof, under cooling within a cooling water tank C. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００１４】
表１から明らかな如く、硬い合成樹脂を原料としているにも拘らず、実施例の合成樹脂管は、比較例の合成樹脂管に比して変形が少なく、断面が円形に近いものであることが判る。
【００１５】
【発明の効果】
本発明の合成樹脂管の押出成形方法は、叙上の通り構成されているので、硬い合成樹脂を原料として合成樹脂管を押出成形した場合にも、簡易な方法で変形の少ない合成樹脂管を容易に得ることが出来る。
【図面の簡単な説明】
【図１】本発明の合成樹脂管の押出成形方法を示す説明図。
【図２】本発明の合成樹脂管の押出成形方法に用いられる１組のガイドロールの１例を示す斜視図。
【図３】従来の合成樹脂管の押出成形方法に用いられるガイドロールの１例を示す斜視図。
【図４】押出成形された合成樹脂管を示す断面図。
【符号の説明】
１ ガイドロール
２ ガイドロール
１１ 凹溝
２１ 凹溝
Ｅ 押出機
Ｔ 合成樹脂管
Ｃ 冷却水槽
Ｐ 引取装置[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for extruding a synthetic resin tube.
[0002]
[Prior art]
When extruding a synthetic resin tube, the synthetic resin tube extruded from an extruder is usually provided with a guide roll with a semicircular groove cut in the peripheral surface so that the synthetic resin tube does not float above the water surface. In the cooling water tank, the outer diameter is regulated by a guide roll from above the synthetic resin pipe while cooling, and it is taken out and cut to a fixed size by a cutting machine.
[0003]
[Problems to be solved by the invention]
However, in such an extrusion molding method, for example, when a synthetic resin pipe is extruded from a synthetic resin such as a blend resin of a styrene-based elastomer and polypropylene, a soft synthetic resin such as soft polyvinyl chloride is used. As compared with the case where a resin is used as a raw material, there is a problem that the resin is easily deformed into a flat elliptical shape in a vertical direction.
[0004]
The present invention solves the conventional problems described above, and even when a synthetic resin tube is extruded from a hard synthetic resin as a raw material, the extrusion of the synthetic resin tube can be obtained with a simple method and with less deformation. An object is to provide a molding method.
[0005]
[Means for Solving the Problems]
In the method of extrusion molding a synthetic resin pipe according to the present invention, the synthetic resin pipe extruded from the extruder is regulated to a predetermined outer diameter by a set of guide rolls having a semicircular concave groove formed on the peripheral surface. It is characterized by taking off while cooling.
[0006]
In the method for extruding a synthetic resin tube of the present invention, the material of one set of guide rolls that regulates the outer diameter of the synthetic resin tube extruded from the extruder is not particularly limited, but one set of guide rolls is not limited to a horizontal type. It is preferable that the synthetic resin pipes are sandwiched from both sides.
[0007]
In the extrusion method of the synthetic resin tube of the present invention, the material of the hard synthetic resin is not particularly limited, and examples thereof include thermoplastic elastomer (TPE), polyolefin (homopolymer and copolymer) and styrene-based TPE. A polymer blend such as a blend resin with polypropylene (PP) may be used.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a method for extruding a synthetic resin pipe according to the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view showing an extrusion molding method of a synthetic resin tube of the present invention, FIG. 2 is a perspective view showing an example of a set of guide rolls used in the extrusion molding method of a synthetic resin tube of the present invention, and FIG. FIG. 4 is a perspective view showing an example of a guide roll used in a conventional synthetic resin tube extrusion molding method, and FIG. 4 is a cross-sectional view showing an extruded synthetic resin tube.
[0009]
〔Example〕
As shown in FIG. 1, a synthetic resin tube T having an outer diameter of 6.5 mm and an inner diameter of 5.0 mm was fed from an extruder E using a styrene-based TPE / PP blend resin (Shore hardness 83) as a raw material. Was extruded.
[0010]
As shown in FIG. 2, a pair of guide rolls 1 of the same shape and the same size having a semicircular concave groove 11 with a radius of 3.3 mm formed on the peripheral surface of the synthetic resin pipe T as shown in FIG. Into the cooling water tank C, which is continuously connected to the cooling water tank C. The cooling pipe is pressed by the guide roll 1 from both sides to regulate the outer diameter, and is taken out by the take-off device P while cooling, and cut into a fixed length by a cutting machine to cut the synthetic resin pipe. Obtained.
[0011]
(Comparative example)
As shown in FIG. 3, in a cooling water tank provided with a guide roll 2 provided with a semicircular concave groove 21 having a radius of 6.0 mm on the peripheral surface, a pressure is applied from above the synthetic resin pipe. A synthetic resin tube was obtained in the same manner as in Example except that cooling was performed while regulating the outer diameter.
[0012]
In a natural state, the extruded synthetic resin tube is deformed into a flat elliptical shape in a vertical direction as shown in FIG. 4 by gravity. Therefore, the outer major axis and the outer minor axis of each of the ten synthetic resin tubes obtained by the above-mentioned Examples and Comparative Examples were measured using a universal projector, and the average value, difference, and ratio of each were calculated. The results are summarized in Table 1.
[0013]
[Table 1]

[0014]
As is clear from Table 1, despite the fact that the hard synthetic resin is used as a raw material, the synthetic resin pipe of the example has less deformation and a cross section close to a circle as compared with the synthetic resin pipe of the comparative example. I understand.
[0015]
【The invention's effect】
Since the synthetic resin tube extrusion molding method of the present invention is configured as described above, even when a synthetic resin tube is extruded from a hard synthetic resin as a raw material, a synthetic resin tube with little deformation can be obtained by a simple method. Can be easily obtained.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a method for extruding a synthetic resin tube according to the present invention.
FIG. 2 is a perspective view showing an example of one set of guide rolls used in the method for extruding a synthetic resin pipe of the present invention.
FIG. 3 is a perspective view showing an example of a guide roll used in a conventional synthetic resin tube extrusion molding method.
FIG. 4 is a sectional view showing an extruded synthetic resin tube.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 guide roll 2 guide roll 11 concave groove 21 concave groove E extruder T synthetic resin pipe C cooling water tank P take-off device

Claims (1)

Synthesizing a synthetic resin tube extruded from an extruder while cooling it while controlling it to a predetermined outer diameter with a set of guide rolls having a semicircular concave groove formed in the peripheral surface. Extrusion molding method for resin pipe.

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