JPH04228665A - Production of fiber composite material - Google Patents

Abstract

PURPOSE:To provide a method for producing a fiber composite material capable of homogenizing product strength. CONSTITUTION:The subject method is a method for producing a fiber composite material in which a thermoplastic resin is impregnated into matlike materials 1 consisting essentially of inorganic fiber. The following steps are successively performed. A laminating step for sandwiching a thermoplastic resin 2 between the above-mentioned matlike materials 1, carrying out needle punching treatment, simultaneously laminating thermoplastic resin films 4 to the surface on at least one side of the resultant sandwiched substance 3 and forming a laminate 5; a heating step for heating the aforementioned laminate 5 to a temperature above the melting temperature of the above-mentioned resin component and melting the resin component; a compressing step for compressing the laminate 5 in the molten state; an extending step for extending the aforementioned laminate 5 in the state of the melted resin component and increasing the thickness of the laminate 5 and a cooling step for cooling the extended laminate 5.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a fiber composite material suitable for use as a ceiling material for automobiles.

0002

[Prior Art] Generally, automobile ceiling materials are lightweight and
Materials with excellent properties such as rigidity, heat resistance, sound absorption, and moldability are required.

Conventionally, as a method for manufacturing this type of material, a method as disclosed in, for example, Japanese Patent Application Laid-open No. 77664/1983 has been known. That is, in this method, first, thermoplastic resin films are laminated on both sides of a mat-like material mainly composed of inorganic fibers. Then, this laminate is heated and then compressed to impregnate the inside of the mat-like material with the molten thermoplastic resin. Thereafter, the thermoplastic resin is expanded in a molten state to increase the thickness of the laminated sheet, and then cooled to obtain a composite material.

0004

[Problems to be Solved by the Invention] However, with the composite material obtained by the above-mentioned conventional method, uniform impregnation of the thermoplastic resin film into the mat-like material cannot be achieved due to factors such as variations in the thickness of the mat-like material. A disadvantage arises in that a portion with extremely low compressive strength occurs, resulting in non-uniformity in product strength. On the other hand, automotive ceiling materials need to be strong enough to withstand the installation process, but such composite materials have uneven strength, and if there are particularly weak areas, stress will concentrate there and cause problems such as bending. This will cause inconvenience.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a fiber composite that can achieve uniformity in product strength.

[0006]

[Means for Solving the Problems] A method for producing a fiber composite according to claim 1 is a method for producing a fiber composite in which a thermoplastic resin is impregnated into a mat-like material mainly composed of inorganic fibers. Then, a thermoplastic resin is sandwiched between the mat-like materials and subjected to needle punching treatment, and a thermoplastic resin film is laminated on at least one surface of the sandwiched body thus obtained to form a laminate. a lamination step, a heating step of heating the laminate to a temperature higher than the melting temperature of the resin component to melt the resin component, a compression step of compressing the laminate in this molten state, and a state in which the resin component is molten. In this method, the laminate is expanded to increase the thickness of the laminate, and a cooling step is performed to cool the expanded laminate.

[0007] The mat-like material used in the present invention is mainly composed of inorganic fibers, and examples of the inorganic fibers include glass fibers and rock wool, and the length of the mat-like material depends on the formability of the mat-like material. Preferably 5 to 200 mm from the point 5
It is more preferable that 70% by weight or more of particles having a diameter of 0 mm or more is contained. In addition, the thickness is preferably 5 to 30 μm, more preferably 7 to 20 μm, because the thinner the thickness, the lower the mechanical strength, and the thicker the thickness, the heavier the bulk density.
It is μm.

[0008] Any method may be used to produce the above-mentioned mat-like material, such as a method in which inorganic fibers are fed to a card machine, defibrated and mixed to produce a mat-like material. Furthermore, thermoplastic organic fibers such as polyethylene, polypropylene, saturated polyester, polyamide, polyacrylonitrile, etc. may be added to bond inorganic fibers or to reduce the bulk density of the mat-like material. Furthermore, in order to increase the strength of the mat-like material, needle punching may be applied, and the punch density is 10 to 7 per cm2.
It is preferable that the process be performed at 0 locations.

[0009] As the thermoplastic resin impregnated into the mat-like material, polyethylene, polypropylene, saturated polyester, etc. can be suitably used. Further, in consideration of impregnating properties into a mat-like material when melted, the melt viscosity of the thermoplastic resin is preferably 5 or more in terms of melt flow index.
More preferably, the number is 10 or more.

Next, a method for producing a fiber composite according to the first aspect will be explained. First, in the lamination step, as shown in FIGS. 1 and 2, the thermoplastic resin 2 is sandwiched between the mat-like materials 1 and 1, and a needle punching process is performed, and the sandwiched body 3 obtained in this way is A laminate 5 is obtained by laminating thermoplastic resin films 4, 4 on both sides of the laminate.

Next, in the heating step, this laminate 5 is heated to a temperature higher than the melting temperature of the thermoplastic resin 2 and the thermoplastic resin film 4.

In the compression step, the laminate 5 is compressed while the thermoplastic resin 2 and thermoplastic resin film 4 in the laminate 5 are melted.

At this time, polyethylene, polypropylene, polyamide, polyester, etc. are considered suitable for the thermoplastic resin films 4 to be laminated on both sides of the sandwiching body 3.

[0014] Any heating method may be employed, such as a hot air heating method, a radiant heating method using an infrared heater, etc.

[0015] Further, any method may be used for the compression method, such as a pressing method, a method of compressing with a roll, etc. Press pressure is 0.1~20Kg/c
m2 and the compression time should be 1 to 10 seconds. Also, when compressing with rolls, the space between the rolls should be 80% of the material thickness.
It is preferable to set it to ~5%. When compressing with a press or a roll, it is preferable that the thermoplastic resin be heated to a temperature higher than the melting temperature of the thermoplastic resin.

Thereafter, in the expansion step, the thickness of the laminate 5 is increased by decompressing the laminate 5 and expanding it in the opposite direction to the compression direction. At this time, when heated and compressed, the molten thermoplastic resin is impregnated into the mat-like material 1. Next, when the pressure is released, the mat-like material 1 tries to recover to its original thickness, but because the inorganic fibers, which are the main components of the mat-like material 1, have been crushed once, the mat-like material 1 does not fully recover. Therefore, by performing an expansion process such as performing vacuum suction from above and below, the thickness of the laminate 5 is increased.

Finally, in the cooling step, the molten thermoplastic resin is sufficiently cooled to obtain a fiber composite.

In order to shape the fiber composite thus obtained, it is reheated to a temperature higher than the melting temperature of the resin component, and
Compression molding using a press or the like may be performed. For example, in order to use it as a ceiling material for an automobile, it may be formed by laminating a decorative skin material such as vinyl chloride leather or nonwoven fabric during compression molding.

The method for producing a fiber composite according to claim 2 is a method for producing a fiber composite in which a thermoplastic resin is impregnated into a mat-like material mainly composed of inorganic fibers,
A thermoplastic resin containing a foaming agent is sandwiched between the mat-like materials and subjected to a needle punching treatment, and a thermoplastic resin film is laminated on at least one surface of the sandwiched body thus obtained to form a laminate. a heating step of heating the laminate to a temperature above the melting temperature of the resin component and below the decomposition temperature of the blowing agent to melt the resin component; a compression step of compressing the laminate at a temperature; an expanding step of expanding the laminate in a state where the resin component is molten to increase the thickness of the laminate; and cooling the expanded laminate. The cooling process is performed sequentially.

As the mat-like material, a material similar to that of the invention described in claim 1 can be used.

[0021] As the thermoplastic resin material containing a blowing agent,
Polyethylene, polypropylene, saturated polyester, etc. are suitable, and the material may be in the form of film, powder, or fiber. Further, the blowing agent contained in this thermoplastic resin material is not particularly limited as long as it has a decomposition temperature of 180 degrees Celsius or higher. Examples include azodicarbonamide, dinitrosopentamethylenetetramine, barium azodicarboxylate, hydrazodicarbonamide, and P-toluenesulfonyl semicarbazide.

Next, the method for producing a fiber composite according to claim 2 will be explained in comparison with the invention according to claim 1.

First, in the lamination step, a laminate is obtained by changing the thermoplastic resin sandwiched between the mat-like materials to a thermoplastic resin material containing a foaming agent.

Next, in the heating step, this laminate is heated to a temperature above the melting temperature of the thermoplastic resin material and the thermoplastic resin film and below the decomposition temperature of the blowing agent.

In the compression step, the molded body is compressed at a temperature higher than the decomposition temperature of the blowing agent. At this time, as a compression method, it is preferable to use a press heated to a temperature equal to or higher than the decomposition temperature of the blowing agent. Press pressure is 0.1-20K
g/cm2, and the compression time is preferably 1 to 20 seconds.

[0026] Thereafter, in the expansion step, this laminate is decompressed and expanded in a direction opposite to the compression direction, thereby increasing the thickness of this laminate. At this time, if the temperature at the time of pressurization is higher than the decomposition temperature of the blowing agent, foaming will begin after pressurization, which will help the molten resin impregnate between the inorganic fibers and expand the material. It happens.

In order to shape the fiber composite thus obtained, first, after laminating a thermoplastic resin film on at least one side of the laminate above the melting temperature of the resin component, the thermoplastic resin is melted. The thermoplastic resin is melted by heating above the temperature and below the decomposition temperature of the blowing agent, and then compressed under pressure at a temperature above the decomposition temperature of the blowing agent.

[0028]

[Function] According to the method for producing a fiber composite according to claim 1, since the thermoplastic resin is sandwiched between the mat-like materials,
In a state where the thermoplastic resin film is molten, the thermoplastic resin is impregnated into the inside of the mat-like material. In this state, by compressing and expanding, the thermoplastic resin impregnated inside the mat material will be sufficiently diffused, and the impregnation of the thermoplastic resin into the thin part of the mat material will be improved. The decrease in strength of that part is alleviated.

Further, according to the method for manufacturing a fiber composite according to claim 2, since the thermoplastic resin material containing the foaming agent is sandwiched between the mat-like materials, the thermoplastic resin material is in a molten state. , the thermoplastic resin is impregnated inside the mat-like material. In this state, by compressing and expanding at a temperature higher than the decomposition temperature of the foaming agent, the thermoplastic resin impregnated inside the mat-like material is sufficiently diffused by the decomposition action of the foaming agent, and the mat-like material is The impregnation of thermoplastic resin into thin parts of objects is improved, and the decrease in strength of those parts is alleviated.

[0030]

[Example] Next, an example of the present invention will be described.

[0031]

[Example 1] Length 40-200mm, diameter 9-13μm
The glass fibers were fed into a card machine, mixed and woven into a mat-like material, and needle punched at 30 locations per 1 cm2 to obtain two mat-like products having a thickness of 4 mm and a weight of 200 g/m2.

[0032] Next, a thickness of approximately 50 μm is placed between the mat-like materials.
After sandwiching a high-density polyethylene film of MI30, needle punching was performed at 30 locations per 1 cm2 to integrate the sandwiched bodies. Then, MI5 high-density polyethylene films were laminated to a thickness of about 100 μm on both sides of this sandwich body to form a laminate.

[0033] Thereafter, the entire laminate was sandwiched between Teflon sheets and heated at 200 degrees Celsius for 3 minutes.
It was compressed with a press heated to 200 degrees Celsius under a pressure of 200 degrees Celsius, and then the Teflon sheet was expanded to 5 mm by vacuum suction from both sides at 200 degrees Celsius, and then cooled.

[0034] Various parts of different weights were taken from the obtained sample, and the bending strength and bending elastic modulus were measured.

The results are shown in Table 1.

[0036]

[Example 2] Length 40-200mm, diameter 9-13μm
The glass fibers were fed into a card machine, mixed and woven into a mat-like material, and needle punched at 30 locations per 1 cm2 to obtain two mat-like products having a thickness of 4 mm and a weight of 200 g/m2.

[0037] Next, a thickness of approximately 50 μm is placed between the mat-like materials.
After sandwiching a high-density polyethylene film (containing 10% by weight of the blowing agent azodicarbonamide) with a diameter of 1.5 mm and an MI of 30, needle punching was performed at 30 locations per 1 cm 2 to integrate the sandwiched bodies. Then, MI5 high-density polyethylene films were laminated to a thickness of about 100 μm on both sides of this sandwich body to form a laminate.

Thereafter, the entire laminate was sandwiched between Teflon sheets and heated at 170 degrees Celsius for 3 minutes, and then heated to 22 degrees Celsius.
It was compressed for 10 seconds at a pressure of 3 kg/cm2 in a press heated to 0 degrees Celsius, and then the Teflon sheet was expanded to 5 mm by vacuum suction from both sides while keeping the temperature at 200 degrees Celsius, and then cooled.

[0039] Various parts having different weights were taken from the obtained sample, and the bending strength and bending elastic modulus were measured.

The results are shown in Table 1.

[0041]

[Example 3] Instead of the high-density polyethylene film containing a blowing agent inserted between the mat-like materials, high-density polyethylene resin powder containing 10% by weight of a blowing agent (azodicarbonamide) was used in an amount of 50 g/m2. The process is the same as in Example 2 except that the layers are laminated.

[0042] Various parts having different weights were taken from the obtained sample, and the bending strength and bending elastic modulus were measured.

The results are shown in Table 1.

[0044]

[Comparative Example] The same as Example 1 except that the high-density polyethylene film was not sandwiched between the mat-like materials and the thickness of the high-density polyethylene film laminated on both sides was about 125 μm.

[0045] Various parts having different weights were taken from the obtained sample, and the bending strength and bending elastic modulus were measured.

The results are shown in Table 1.

[0047]

[Table 1]

[0048]

Effects of the Invention As described above, according to the present invention, the ability to impregnate thin parts of the mat-like material is improved, and the decrease in strength of that part is alleviated, so that fiber composites with more uniform strength can be produced. You can get a body.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the process of manufacturing a sandwich body in the method for manufacturing a fiber composite according to the present invention.

FIG. 2 is a cross-sectional view showing the process of manufacturing a laminate in the method for manufacturing a fiber composite according to the present invention.

[Explanation of symbols]

1. Mat-like material 2 Thermoplastic resin 3 Sandwiching body 4 Thermoplastic resin film 5 Laminated body

Claims (2)

[Claims] 1. A method for producing a fiber composite in which a thermoplastic resin is impregnated into a mat-like material mainly composed of inorganic fibers, the thermoplastic resin being sandwiched between the mat-like materials, A lamination step in which a thermoplastic resin film is laminated on at least one side of the sandwiched body obtained in this way to form a laminate, and the laminate is heated at a temperature higher than the melting temperature of the resin component. a heating step of heating to melt the resin component, a compression step of compressing the laminate in this molten state, and expanding the laminate with the resin component in the molten state to increase the thickness of the laminate. 1. A method for manufacturing a fiber composite, comprising sequentially performing an expanding step of expanding the laminate, and a cooling step of cooling the expanded laminate. 2. A method for producing a fiber composite in which a thermoplastic resin is impregnated into a mat-like material mainly composed of inorganic fibers, the thermoplastic resin containing a foaming agent between the mat-like materials. a lamination step in which a thermoplastic resin film is laminated on at least one side of the sandwiched body obtained in this way to form a laminate; A heating step in which the resin component is melted by heating to a temperature higher than the melting temperature and lower than the decomposition temperature of the blowing agent, a compression step in which the laminate is compressed at a temperature higher than the decomposition temperature of the blowing agent, and the resin component is A fiber composite comprising: expanding the laminate in a molten state to increase the thickness of the laminate; and cooling the expanded laminate. Production method.