JPH06155691A - Method for producing fiber composite - Google Patents

Abstract

(57) [Summary] [Purpose] A high-strength fiber composite can be easily produced in a single step. [Structure] A thermoplastic resin strand 2 extruded from a strand die is a composite sheet 1 of a thermoplastic resin and an inorganic fiber.
After being laminated on the thermoplastic resin strand 2, a composite sheet of the thermoplastic resin and the inorganic fiber is further laminated on the thermoplastic resin strand 2 and then heated to a temperature equal to or higher than the melting temperature of the thermoplastic resin of each of the strand and the composite sheet. , The composite sheet and the thermoplastic resin strand are bonded and integrated by compressing to a certain thickness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber composite suitable as an interior material having excellent heat moldability, particularly as an automobile ceiling material.

[0002]

2. Description of the Related Art Generally, for automobile ceiling materials and the like, materials that are lightweight and have excellent properties such as rigidity, heat resistance, moldability, dimensional stability, and recyclability are required. BACKGROUND ART As a ceiling material for automobiles, a resin reinforced sheet including a thermoplastic resin foam as a core material and a composite of a thermoplastic resin and an inorganic fiber is conventionally used, for example, as described in Japanese Patent Publication No. 3-52342. A laminate or the like used as a surface material is preferably used. This laminate is a resin reinforced sheet obtained by impregnating an organic fiber nonwoven fabric with a styrene emulsion in which inorganic fibers are dispersed, and is laminated on both sides of a polystyrene resin foam sheet, and has a lightweight and high rigidity property. Had. Then, this laminated body is prepared by using a pre-expanded bead of polystyrene resin to form a foamed sheet using an extrusion foaming method or an in-mold foaming method,
It was manufactured by a manufacturing method in which a resin-reinforced sheet is adhered to both surfaces of the sheet to strengthen the surface layer.

[0003]

However, since the above-mentioned laminated body has a sandwich structure in which the core material is formed of the thermoplastic resin foam in which the core material is uniformly highly foamed, the strength of the core material, and hence the strength of the laminated body. There was a problem that it was slightly inferior.
Further, there is a problem that the manufacturing cost is high because the manufacturing is performed through a plurality of steps.

The fiber composite of the present invention has been made in view of the above problems, and it is a fiber composite which can solve the above problems and can easily produce a high strength fiber composite in a single step. It is intended to provide a manufacturing method.

[0005]

The method for producing a fiber composite according to the present invention comprises laminating a thermoplastic resin strand extruded from a strand die on a composite sheet of a thermoplastic resin and an inorganic fiber, and further forming the thermoplastic resin strand. Laminate a composite sheet of thermoplastic resin and inorganic fiber on top, and then heat to a temperature above the melting temperature of each of the thermoplastic resin of the strand and the composite sheet, then compress to a certain thickness and heat the composite sheet and It is characterized in that it is integrally bonded with a plastic resin strand.

As the composite sheet used in the method for producing a fiber composite of the present invention, it is preferable to use a fiber reinforced sheet in which glass fibers opened into monofilaments are dispersed in a thermoplastic resin. When such a fiber reinforced sheet is used, it has general versatility and can improve heat moldability, heat resistant dimensional stability, bending strength and the like. Examples of the thermoplastic resin include polystyrene, polyethylene, polypropylene, polybutene, nylon, polyester, polyvinyl acetate, and the like, and it is preferable to use a polyolefin resin because of its moldability, temperature, price, and the like. As a method for creating a composite sheet, for example, 25 mm
Commercially available glass paper (10 g / m ^{2 to} 7) which is a thin non-woven fabric obtained by a so-called papermaking method mainly containing the following short fibers.
It is preferable that a thermoplastic resin film is laminated to 5 g / m ^{2 (} preferably 5 g / m ² ), heated to a temperature equal to or higher than the melting point of the thermoplastic resin, and then compressed by a press or a roll to form a composite. From the viewpoint of lightness, the thickness of this thermoplastic resin film is preferably about 50 to 150 μm. Further, as the composite sheet, various glass fiber non-woven fabrics can be used instead of the glass paper in the above-mentioned production method. For example, opened glass fibers are entangled by a mechanical method such as needle punching method, glass fiber nonwoven fabric, chopped strand mat in which cut roving is bound with a special binder, or continuous strand mat made by continuous roving. Or a surface mat can be used.

Further, the content of the inorganic fibers contained in the composite sheet is preferably 1 to 40 parts by weight, preferably 15 to 30 parts by weight, based on 100 parts by weight of the resin component, from the viewpoint of strength and moldability. From desirable.

The thermoplastic resin of the thermoplastic resin strand is preferably a thermoplastic resin such as polyethylene, polypropylene or polystyrene. Further, additives such as a foaming agent can be added to these thermoplastic resins as needed. It is preferable to use a thermal decomposition type foaming agent as the foaming agent, and specific examples thereof include azodicarbonamide, azobisisobutyronitrile, N, N′-dinitrosopentamethylenetetramine and pp′-oxybis. Examples thereof include benzenesulfonyl human radimide, barium azodicarboxylate, and trihydrazinotriazine. In addition, additives such as an antioxidant, a heat stabilizer and a plasticizer may be added if necessary. Further, as long as the gel fraction is low (no insoluble matter is generated even when immersed in a solvent for a long time), it is possible to add a crosslinking agent such as peroxide to stabilize foaming. The peroxide used has a relatively high decomposition temperature,
Chemically stable dialkyl peroxides are preferred.
For example, ditertiary butyl peroxide, 2,5 dimethyl 2,5 ditertiary butyl peroxyhexyne-3 can be mentioned. It is also useful to add an unsaturated acid such as maleic anhydride to make the foaming reaction mild, or to give the resin a glass fiber adhesive property. Further, short glass fibers may be added in the range of 1 to 40% by weight in order to improve the heat-resistant dimensional stability.

If a separating comb for separating the thermoplastic resin strand extruded from the strand die and the strand is provided between the strand die and the composite sheet and the separating comb is reciprocally moved cyclically, the composite sheet can be obtained. It is desirable that the thermoplastic resin strand can be laminated thereon in a corrugated or mesh-shaped pattern, and the longitudinal and transverse strengths of the fiber composite can be made substantially the same.

Further, the composite sheet is continuously transferred by a transfer conveyor or the like, and while the stack is continuously transferred, it is heated to a temperature above the melting temperature of the thermoplastic resin and compressed to a certain thickness to bond the whole. If they are integrated, it is desirable because the fiber composite can be continuously manufactured in a single process.

Further, in order to shape the fiber composite produced by the method for producing a fiber composite of the present invention, it may be reheated to a temperature not lower than the melting temperature of the resin and cold-pressed, for example, an automobile ceiling. When it is used as a material, it may be shaped by laminating a cosmetic skin material such as vinyl chloride leather or a non-woven fabric during cold pressing.

The method for producing the fiber composite of the present invention will be described with reference to the drawings. 1 is a plan view showing a state in which thermoplastic resin strands showing an embodiment of the method for producing a fiber composite of the present invention are laminated on a composite sheet in a corrugated pattern, FIG.
FIG. 4 is a plan view showing a state where thermoplastic resin strands are laminated on a composite sheet in a mesh pattern. 1 and 2, 1 is a composite sheet, 2 is a thermoplastic resin strand laminated on the composite sheet 1, and 3 is a separating comb for separating the thermoplastic resin strand 2. The composite sheet 1 is transported in the arrow X direction, and the separating comb 3 is reciprocated in the arrow Y direction.

A molten resin is extruded from a strand die to form a thermoplastic resin strand 2. In this case, the extruded thermoplastic resin strand 2 preferably has a diameter of about 1 to 3 mm. When a thermoplastic resin containing a foaming agent is extruded to form a strand, the extrusion temperature is set to the decomposition temperature of the foaming agent or lower.

Next, while moving the composite sheet 1 of the thermoplastic resin and the inorganic fiber in the direction of the arrow X at a constant speed, the thermoplastic resin strand extruded from the strand die over the composite sheet 1 over substantially the entire area thereof. 2 is placed and laminated in a highly fluid state. A separating comb 3 which is provided between the strand die and the moving composite sheet 1 at the time of stacking and prevents fusion of the thermoplastic resin strands 2 with each other is regularly arranged by a cam or the like to separate arrows by a cam or the like. Reciprocate in the Y direction. In this case, if the separating combs 3 are all reciprocally moved in synchronization with each other, the thermoplastic resin strands 2 are formed on the composite sheet 1 in a wavy pattern as shown in FIG.
If every one of them is reciprocated with a delay of a half cycle, they are laminated in a mesh pattern as shown in FIG.

Next, a composite sheet is further laminated on the thermoplastic resin strands laminated on the composite sheet 1, and for example, the whole is set between hot plates having a gap of about 1 to 4 mm, and the resin component is set. At the same time as melting, the composite sheet of the surface material and the thermoplastic resin strand of the core material are bonded and integrated. In this case, the upper and lower composite sheets preferably have the same thermoplastic resin and the same inorganic fiber, but different composite sheets may be used depending on the case. The set temperature of the hot platen should be higher than the melting temperature of the resin used. If the temperature is not higher than the melting temperature, the adhesion and integration will be insufficient. or,
When the resin contains a foaming agent, the temperature of the heating platen should be between the decomposition temperature of the foaming agent and 20 ° C. above the decomposition temperature in order to prevent the structure after foaming from being disturbed due to sudden foaming. It is desirable to be set.

Next, if necessary, after confirming the adhesion and integration of the surface material and the core material, the gap of the heating plate is gradually expanded to the product thickness. It is preferable to gradually widen the gap of the hot platen to the product thickness because the thermoplastic resin strands can be extended in the thickness direction of the product and the compressive strength of the product, and consequently the bending properties, can be greatly improved. Further, when the resin contains a foaming agent, the expansion thickness can be regulated to be thin so that the thermoplastic resin strands can be foamed and increased in the lateral direction. Finally, when the completion of the expansion is confirmed, the whole fiber composite obtained is quickly taken out from the hot plate and cooled.

[0017]

In the method for producing the fiber composite of the present invention, the thermoplastic resin strand extruded from the strand die is laminated on the composite sheet of the thermoplastic resin and the inorganic fiber, and the thermoplastic resin strand is further covered with the thermoplastic resin strand. After laminating a composite sheet of resin and inorganic fiber, and then heating to a temperature equal to or higher than the melting temperature of each thermoplastic resin of the strand and the composite sheet, the composite sheet and the thermoplastic resin strand are compressed to a certain thickness. Since they are bonded and integrated, the thermoplastic resin strands are arranged on the composite sheet, and the composite sheet is further laminated thereon and heat-fused. This makes it possible to easily obtain a high-strength fiber composite having a sandwich structure in which the thermoplastic resin strand and the composite sheet are integrally bonded.

If a separating comb for separating the thermoplastic resin strands extruded from the strand die is provided between the strand die and the composite sheet and the separating comb is reciprocated, the heat on the composite sheet is reduced. The plastic resin strands are laminated in a corrugated shape, a mesh shape, or the like to form a honeycomb-shaped core material, and the fiber composites obtained have substantially the same longitudinal and transverse strengths.

[0019]

EXAMPLES Next, an example of the method for producing a fiber composite of the present invention, the physical properties of the fiber foam obtained in this example, and the physical properties of the fiber composite obtained by the conventional method for producing a fiber composite. And a comparative example.

Example 1 Glass paper (45 g / m ² , glass fiber diameter 13 μm, length about 15 mm, EVP-manufactured by Olivebest Co., Ltd.)
045), a high-density polyethylene resin film having a thickness of 90 μm was laminated and compressed with a hot platen heated to a temperature of 200 ° C. under a pressure of 30 kg / cm ² . Then, the whole laminated body was cooled and the composite sheet was created. A high-density polyethylene resin having a melt index of 1 was supplied to a 50 mm single screw extruder and extruded from a strand die at a temperature of 200 ° C.
The strand die was a crosshead, and the thermoplastic resin strand was extruded downward, and the extrusion amount was adjusted so that the diameter of the thermoplastic resin strand was about 2 mm. Also, the interval between the thermoplastic resin strand outlets of the strand die is about 8
mm.

Next, separating combs for separating the thermoplastic resin strands one by one were placed between the strand die and the composite sheet, and the separating combs were reciprocally moved in synchronization with each other. The amplitude of the periodic motion was about 11 mm, and the period was 3 seconds. Next, the above-mentioned composite sheet is about 32 cm /
It was moved under the strand die at a speed of minutes.

The thermoplastic resin strand laminated on the composite sheet through this operation has a corrugated pattern as shown in FIG. 1, and its amplitude is about 8 mm and its wavelength is about 16 m.
It was a sine wavelength of m.

Then, a composite sheet is further laminated on this, and the whole is a thin-walled box of 1 mm in thickness made of stainless steel (internal dimensions of length and width 250 × 250 mm, thickness 2-5 m).
m, the side surface is not airtight and the pressure is normal during foaming, and the thickness of the box can be arbitrarily changed), and the box was sandwiched between heating plates heated to 170 ° C. Then, after about 2 minutes, the thickness of the box was set to 2 mm, the thermoplastic resin strand and the composite sheet were melt-bonded, and then the thickness of the box was slowly raised to 5 mm. After about 2 minutes and 30 seconds, the product was taken out, sandwiched between cooling presses that were cooled with water, and after cooling, the product of the present invention was taken out.

The obtained fiber composite has a thickness of about 4.5 mm, and the composite sheet of the surface material and the thermoplastic resin strand of the core material are completely adhered to each other, which may be called a sandwich structure. It was 50 from the resulting fiber composite
The sample was cut into a size of mm × 150 mm, the bending strength and the bending elastic modulus were measured, and the average value of 5 measurements was obtained.
The direction of the sample is defined as the longitudinal direction of the wave. The results are shown in Table 1.

[0024]

Example 2 The same method as in Example 1 was carried out except that the reciprocating motion of the adjacent separating combs in Example 1 was delayed by exactly a half cycle. The pattern of the thermoplastic resin strands formed at this time was a mesh pattern as shown in FIG. The results are shown in Table 1.

[0025]

Example 3 5 parts by weight of azodicarbonamide was added as a blowing agent to 100 parts by weight of high-density polyethylene (having a melt index of 20) as a component of the thermoplastic resin strand in Example 1 to prepare a thermoplastic resin strand. The extrusion temperature of was controlled at 150 ° C. In addition, after the box and the composite sheet were fused by sandwiching the box-shaped body in the heating plate which was set to 170 ° C. in Example 1, the temperature of the heating plate was set to 220 ° C. and the thermoplastic resin strand was expanded while expanding. Let Otherwise, the same method as in Example 1 was carried out. The results are shown in Table 1.

[0026]

[Comparative Example 1] A sandwich obtained by a conventional manufacturing method in which a resin extruded from an extruder is formed into a sheet shape instead of a strand shape, and a core material is formed of a uniformly highly expanded thermoplastic resin foam. Example 1 is a sample of a fiber composite having a structure.
The flexural strength and flexural modulus were measured in the same manner as in. The results are shown in Table 1.

[0027]

[Table 1]

As a result, in each of the examples, the bending strength and bending elastic modulus were improved as compared with the comparative example. Further, in each of the examples, since the core material was formed in a honeycomb shape, a high-strength fiber composite having substantially the same strength in the transverse direction and the longitudinal direction was obtained.

[0029]

EFFECTS OF THE INVENTION In the method for producing a fiber composite of the present invention, since it is constructed as described above, the thermoplastic resin strands are arranged on the composite sheet, and the composite sheet is further laminated thereon and heated. Fused. This makes it possible to manufacture a high-strength fiber composite having a sandwich structure in which the thermoplastic resin strand and the composite sheet are integrally bonded.

If a separating comb for separating the thermoplastic resin strands extruded from the strand die is provided between the strand die and the composite sheet and the separating comb is reciprocated, the heat will be applied to the composite sheet. The core material can be formed into a honeycomb shape by laminating the plastic resin strands in a corrugated shape, a mesh shape, or the like, and a fiber composite having substantially the same longitudinal and transverse strengths can be manufactured.

[Brief description of drawings]

FIG. 1 is a plan view showing a state where a thermoplastic resin strand is laminated on a composite sheet in a wavy pattern in one embodiment of the method for producing a fiber composite of the present invention.

FIG. 2 is a plan view showing a state in which thermoplastic resin strands are laminated on a composite sheet in a mesh pattern in another embodiment of the method for producing a fiber composite of the present invention.

[Explanation of symbols]

 1 composite sheet 2 thermoplastic resin strand 3 separating comb

Claims (1)

[Claims] 1. A thermoplastic resin strand extruded from a strand die is laminated on a thermoplastic resin / inorganic fiber composite sheet, and the thermoplastic resin / inorganic fiber composite sheet is further laminated on the thermoplastic resin strand. , And then heating to a temperature equal to or higher than the melting temperature of the thermoplastic resin of each of the strand and the composite sheet, and then compressed to a certain thickness to integrally bond the composite sheet and the thermoplastic resin strand to each other. Method for producing composite.