JP3557066B2 - Manufacturing method of composite material - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a composite material comprising a core material and a thermoplastic resin covering the periphery of the core material.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a composite material including a core material such as a metal plate and a sheet and a thermoplastic resin covering the periphery of the core material has been widely used for eaves gutters and the like.
For example, JP-A-57-33660, JP-B-61-43873, and JP-A-61-27397 disclose a composite material made of a metal plate and a thermoplastic resin coated around the metal plate. Eaves gutters are shown.
The method for producing such a composite material generally uses a crosshead mold to extrude a molten thermoplastic resin around a core material passing through the mold, and to apply a thermoplastic resin around the core material. It is to be coated.
[0003]
For example, Japanese Patent Publication No. Hei 6-98691 discloses that a core material is a prepreg sheet in which many parallel long fibers are fixed with a thermoplastic resin (thermoplastic fixing material), and the same type of thermoplastic resin as the thermoplastic fixing material is used. A method for producing a composite material in which a core material is coated with a composite material is described.
Japanese Patent Publication No. Hei 7-110514 discloses an eaves gutter in which this prepreg sheet is used as a core material and a composite material in which the core material is coated with a thermoplastic resin of the same type as the thermoplastic fixing material is formed into an eaves gutter shape. A manufacturing method is described.
[0004]
On the other hand, as described in Japanese Utility Model Publication No. 60-8004, a general eaves gutter is often used in which a thermoplastic resin such as a vinyl chloride resin or a metal is formed into an eaves gutter shape.
[0005]
However, the eaves gutter molded from the above thermoplastic resin into an eaves gutter shape, if it is used by attaching it to the eaves tip, the eaves gutter will be exposed to direct sunlight and become hot, softening or expanding, Problems arise in that the gutter is deformed such as being bent or bent, and cracks occur.
[0006]
An eaves gutter formed of metal in the shape of an eaves gutter does not deform but has a problem that it is easily rusted.
Also, eaves gutters made of a composite material consisting of a core material made of a metal plate and a thermoplastic resin coated around the core material have good heat resistance, small expansion and contraction, and are hardly rusted. Since the metal is exposed on the surface, there is a problem that the exposed portion rusts.
[0007]
Also, the eaves gutter manufactured from a composite material in which a prepreg sheet in which long fibers are fixed with a thermoplastic resin for fixing is used as a core material, and the core material is coated with the same type of thermoplastic resin as the fixing thermoplastic resin, It is very preferable because it has good heat resistance, has small expansion and contraction, and is hardly rusted, but has a problem that it is expensive.
Therefore, a belt-like body in which inexpensive short fibers are fixed with a fixing thermoplastic resin (first thermoplastic resin) is used as a core material, and a second thermoplastic resin having a melting point lower than that of the first thermoplastic resin is used. When the core material was covered, a composite material which was inexpensive and had good heat resistance was obtained.
[0008]
[Problems to be solved by the invention]
However, when shaping the composite material, for example, when shaping into an irregular shape such as an eaves gutter, the core material is shaped into a shape to be substantially molded in advance, and the core material is formed with a second thermoplastic resin. However, when shaping the core material into a shape to be substantially molded in advance, the core material itself is generally formed by roll forming or a shaping block, so that the core material itself does not crush or break. It is necessary to heat the core material in advance. Then, the first thermoplastic resin is softened, and the force for holding the fibers is weakened. As a result, the fibers are oriented in the thickness direction at the time of shaping, and the thickness of the core material becomes wider than a predetermined thickness, or becomes longer. There were problems such as the mechanical properties in the axial direction being lower than in the thickness direction.
[0009]
The present invention solves the above problems, and provides a method for producing a composite material that can be stably molded, does not cause burrowing or destruction of the core material, and does not vary in mechanical properties, and can be suitably used as an eaves gutter. To provide.
[0010]
[Means for Solving the Problems]
In the method for producing a composite material according to the present invention, a core material composed of a band in which short fibers oriented substantially randomly are fixed with a first thermoplastic resin is used. Above the temperature and below the temperature at which the short fibers can be held, shaped into a shape to be substantially molded, and the second thermoplastic resin is heated at a temperature lower than the melting point of the first thermoplastic resin. Characterized in that it is coated around.
[0011]
As the short fiber used in the present invention, any fiber can be used as long as it can withstand the molding temperature of the thermoplastic resin, but carbon fiber, metal fiber, inorganic fiber such as glass fiber, Kepler, and organic fiber such as cotton fiber can be used. Fibers and the like can be suitably used.
The diameter and length of the short fiber are appropriately selected according to the required performance of the core material, and a length of 100 μm to 100 mm and a diameter of 5 to 50 μm are often used.
[0012]
The first thermoplastic resin and the second thermoplastic resin used in the present invention can be fused to each other, and the second thermoplastic resin has a lower moldable temperature than that of the first thermoplastic resin. Although it is not particularly limited, as the first thermoplastic resin, for example, an acrylic resin, polyethylene terephthalate, nylon or the like is suitably used, and as the second thermoplastic resin, for example, a vinyl chloride resin, an acrylic resin, In addition, a copolymer of vinyl chloride and another monomer, a copolymer of an acrylic monomer and another monomer, and the like are preferably used.
[0013]
The method for producing the core material is not particularly limited, and it is possible to obtain a belt-like body in which the short fibers oriented substantially randomly are fixed with the first thermoplastic resin by a powder impregnation method, a liquid impregnation method, or the like. However, it is preferable that the first thermoplastic resin is formed into short fibers, mixed with the short fibers by air, stirring, or the like, and then heated and pressurized because of easy production.
[0014]
(Action)
In the method for producing a composite material according to the present invention, a core material composed of a band in which short fibers oriented substantially randomly are fixed with a first thermoplastic resin is used. Above the temperature and below the temperature at which the short fibers can be held, shaped into a shape to be substantially molded, and the second thermoplastic resin is heated at a temperature lower than the melting point of the first thermoplastic resin. For example, a core material is passed through a crosshead die, and a second thermoplastic resin heated to a molding temperature and melted is extruded around the core material to produce a composite material. However, the short fibers fixed with the first thermoplastic resin do not fall apart, and the second thermoplastic resin becomes not only a composite material fused to the first thermoplastic fixing material but also a stable material. The core material does not burrow or break and the mechanical properties vary. Kukoto is not.
[0015]
Further, the composite material obtained by the present invention is composed of a core material and a second thermoplastic resin covering the periphery of the core material, and furthermore, since the short fibers are not separated as described above, When this composite material is used as an eaves gutter, similar to an eaves gutter manufactured from a composite material in which a conventional prepreg sheet is used as a core material and this core material is coated with a thermoplastic resin of the same type as the first thermoplastic resin, It is very preferable because it has good heat resistance, small expansion and contraction, and hardly rusts. Therefore, forming this composite material into an eaves gutter shape results in an ideal eaves gutter.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.
FIG. 1 shows an example of a composite material obtained by the present invention, wherein (a) is a partially cutaway perspective view of the composite material, and (b) is a perspective view showing a part of a core material.
[0017]
In FIG. 1, reference numeral 1 denotes a composite material. The composite material 1 includes a core material 2 and a second thermoplastic resin 3 covering the periphery of the core material 2.
The core material 2 is formed by depositing a short fiber (a fiber length of 1 to 40 mm, a fiber diameter of 10 μm) 21 made of carbon fiber and a first thermoplastic resin 22 in which polyethylene terephthalate fiber is shortened by air to form a layer. The carbon fiber 21 is heated and pressed at a temperature not lower than the softening temperature (140 ° C.) of the polyethylene terephthalate fiber to fix the carbon fiber 21 with the polyethylene terephthalate 22 and molded into a belt-like body. As shown in (b), the carbon fibers 21 are randomly oriented, and the carbon fibers 21 are a belt-like body fixed by polyethylene terephthalate 22.
[0018]
The second thermoplastic resin 3 is a vinyl chloride resin.
The molding temperature (die temperature) of the vinyl chloride resin as the second thermoplastic resin 3 is usually about 180 ° C., lower than the melting point (256 ° C.) of the polyethylene terephthalate as the polyethylene terephthalate 22, and also good. It fuses.
[0019]
FIG. 2 is an explanatory view showing a method for manufacturing a composite material (eave gutter) of the present invention.
Reference numeral 5 denotes an extruder. The extruder 5 includes a hopper 51, a barrel (not shown), and a screw (not shown) provided in the barrel.
[0020]
Reference numeral 6 denotes a preforming device for forming the core material 2, and reference numeral 61 denotes a hot air heating device for heating only a part of the core material 2.
Reference numeral 7 denotes a mold composed of a crosshead die. The mold 7 is attached to the tip of the extruder 5.
[0021]
Reference numeral 65 denotes a sizing device for forming the composite material 1 extruded from the mold 7 into the shape of the eaves gutter 4 into a substantially accurate shape.
Numeral 8 denotes a take-up device provided with caterpillars 81, 81 on the upper and lower sides. In the take-up device 5, the composite material 1 which comes out of the mold 7 and is formed into a nearly accurate eaves gutter shape by the sizing device 65 is used. The upper and lower capillaries 81, 81 sandwich the same and take it.
[0022]
FIG. 3 is a sectional view of a mold 7 for producing a composite material (eave gutter).
The mold 7 has a gap 71 having substantially the same shape as the composite material (eave gutter) to be formed.
The method of using the mold 7 is such that the core material 2 formed in the same shape as the eaves gutter to be formed is passed through the gap 71 by the preforming device 6, and the upper and lower resin passages 72, 72 are used. By extruding the molten vinyl chloride resin 3, the periphery of the core material 2 is covered with the vinyl chloride resin 3, and the composite material 1 in which the vinyl chloride resin 3 and the polyethylene terephthalate 22 are fused is almost in the shape of an eaves gutter. Is pushed out.
[0023]
FIG. 4 is an explanatory view showing a cross section of the eaves gutter 4 manufactured by the method for manufacturing a composite material of the present invention.
In the method for manufacturing a composite material according to the present invention, first, the core corresponding to the corners 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4i, 4j of the eaves gutter 4 in the hot air heating device 61 (FIG. 2). Only the position of the material 2 is heated to a temperature higher than the softening point of polyethylene terephthalate (140 ° C.) and lower than the temperature at which the carbon fiber can be retained (200 to 220 ° C.). Next, the core material 2 is formed into a substantially eaves gutter 4 shape by the preforming device 6 and passed through the gap 71 of the mold 7.
On the other hand, the vinyl chloride resin 3 is put into the hopper 51 of the extruder 5, and the extruder 5 is operated. Then, by the rotation of the screw (not shown), the vinyl chloride resin 3 in the hopper 51 advances toward the mold 7 in the barrel (not shown).
[0024]
The vinyl chloride resin 3 is melted by a heater mounted around the barrel (not shown) while traveling through the barrel (not shown), and passes through a resin passage 72 in the mold 7 to form a core. The material 3 is extruded from above and below at a temperature of 190 ° C. to cover the periphery of the core material 3. As a result, the periphery of the core material 2 is covered with the thermoplastic resin 3, and is extruded as a composite material 1 formed into a substantially eaves gutter 4 shape.
[0025]
The composite material 1 extruded in this manner has a substantially accurate shape of the eaves gutter 4 by the sizing device 65, is taken out by being sandwiched between upper and lower capillaries 81, 81, and cut into a fixed length to form the eaves gutter 4.
[0026]
【The invention's effect】
Since the method for producing a composite material according to the present invention is as described above, the short fibers fixed with the first thermoplastic resin do not fall apart, and the second thermoplastic resin has the first thermoplastic resin. Not only is the composite material having good heat resistance fused to the resin, but the core material is not crushed or cracked, and the obtained composite material is free from deformation and strength reduction.
[0027]
Therefore, when this composite material is formed into an eaves gutter and used as an eaves gutter, it is a very preferable eaves gutter because it has good heat resistance, little expansion and contraction, and is hard to rust.
Moreover, the core material of the composite material used in the present invention is a belt-like body in which randomly oriented short fibers are fixed with the first thermoplastic resin, and thus is less expensive than a conventional prepreg sheet. Accordingly, eaves gutters formed from this composite material into eaves gutters are less expensive.
[Brief description of the drawings]
FIG. 1 shows an example of a composite material obtained by the present invention, (a) is a partially cutaway perspective view of the composite material, and (b) is a perspective view showing a part of a core material.
FIG. 2 is an explanatory view showing a method for manufacturing a composite material (eave gutter) of the present invention.
FIG. 3 is a sectional view of a mold for producing a composite material (eave gutter).
FIG. 4 is an explanatory view showing an eaves gutter manufactured by the manufacturing method of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Composite material 2 Core material 21 Short fiber 22 1st thermoplastic resin 3 2nd thermoplastic resin 4 Eaves 5 Extruder 6 Preforming device 61 Hot air heating device 65 Sizing device 7 Cross head die 8 Pickup device

Claims (1)

A core material composed of a belt-like body in which short fibers oriented substantially randomly are fixed with a first thermoplastic resin, and only a part of the core material can hold the short fibers at or above the softening point of the first thermoplastic resin. Heating to below the temperature, shaping into a shape to be substantially molded, and coating the second thermoplastic resin around the core at a temperature lower than the melting point of the first thermoplastic resin. Manufacturing method of composite material.

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