JPS60129246A - Manufacture of three-dimensional fiber-reinforced expanded material - Google Patents

Abstract

PURPOSE:To obtain a three-dimensional fiber-reinforced expanded material having excellent compressive strength by a method in which many Z-axis-directed holes are drilled in a two-dimensional fiber-reinforced expanded material having plural X and Y-two-dimensional fibrous layers and Z-axis-directed fibers are inserted into and fixed to each hole. CONSTITUTION:A two-dimensional fiber-reinforced expanded material having plural layers of X-axis directed fiber groups (a)... and Y-axis-directed fiber groups (d)... is formed, and holes (d) are drilled from the upside of the X and Y axis to the Z axis. Z-axis directed fibers (e) coated with an expandible raw liquid are inserted into each of the holes (d) and the expandible raw liquid is expanded and hardened to obtain a given three-dimensional fiber-reinforced expanded material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for manufacturing three-dimensional fiber-reinforced foams.

Foamed plastic bodies, especially urethane foam, reinforced with a three-dimensional fiber structure consisting of X-axis fibers, X-axis fibers, and Useful as an insulating layer to insulate tanks.

Conventionally, various methods have been proposed for manufacturing such three-dimensional fiber-reinforced foams, for example, an X-axis fiber layer in which X-axis fibers are arranged at intervals in the X-axis direction;
A three-dimensional fiber lattice is created by inserting a large number of Z-axis fibers, for example, by air blowing, into a multilayer fiber layer consisting of a Y-axis fiber layer in which axial fibers are arranged at intervals in the X-axis direction. Therefore, it has been proposed to fill this three-dimensional lattice with a foam, such as hard urethane (Japanese Patent Laid-Open No. 52-5726).
2su Publication). In all conventional methods, a three-dimensional fiber lattice in which the Z-axis fibers are free is filled with foam, and the gas pressure when filling the foam bends the Z-axis fibers. There is a possibility of overcrowding due to movement or displacement of the dog. However, in order for the Z-axis fibers of the three-dimensional fiber-reinforced foam to act as an ideal reinforcing element against the Z-axis load, it is necessary to distribute the load as evenly as possible to each Z-axis fiber. It is necessary to keep the density of the fibers, that is, the fiber spacing constant,
In particular, the strength against compressive loads in the Z-axis direction depends on the buckling strength of the fibers in the X-axis direction, so it is necessary to hold the fibers straight.

Therefore, conventional methods in which bending and coarsening of the fibers in the X-axis direction are unavoidable have problems in terms of the mechanical properties of the resulting three-dimensional fiber-reinforced foam.

In view of the above, the present invention provides a method for producing a three-dimensional fiber-reinforced foam that can eliminate these disadvantages.

That is, the method for producing a three-dimensional fiber-reinforced foam according to the present invention involves molding a two-dimensional fiber-reinforced foam having a plurality of XY two-dimensional fiber layers, and piercing the molded product with a large number of holes in the Z-axis direction. This method is characterized by inserting and fixing the X-axis direction fibers into the can.

In the present invention, the fiber layer of the two-dimensional fiber-reinforced foam having a plurality of XY two-dimensional fiber layers includes
A group of axial fibers arranged alternately at a fixed interval (interval in the Z-axis direction), or a group of 2 to 3 fibers arranged alternately, a group of X-axis fibers and a group of Y-axis fibers In this case, the paired Y-axis fiber group and the X-axis fiber group are woven with satin weave, twill weave, etc. ,
(Usually roving is used for each fiber), short fibers are
A nonwoven fabric arranged randomly in the Y plane, a chopped strand mat arranged at regular intervals, etc. can be used. For reinforcing the foam material, use fibers that have lower tensile strength and elastic modulus and lower elongation than the foam material, such as inorganic fibers, metal fibers,
Synthetic fibers can be used. In particular, glass fibers, carbon fibers, or these fibers impregnated with resin can be used.

As the foamable material, undiluted solutions of urethane foam, epoxy foam, incyanurate foam, etc. can be used.
Advantageously, the urethane foam stock solution has a low viscosity that allows it to penetrate the fiber layer in the Z-axis direction, and a high reaction rate.

Both batch and continuous molding methods can be used to mold two-dimensional fiber-reinforced foams.The continuous molding method involves running multiple sheets of woven fabric or non-woven fabric in parallel at equal intervals. As shown in Fig. 1, a plurality of fiber layers P, P are placed on a belt conveyor 1.
. . . It is possible to use a method of running the conveyor in synchronization with the conveyor 1 and blowing the foaming stock solution through the nozzle 2.

The Z-axis holes penetrating the two-dimensional fiber-reinforced foam are preferably provided so that the pieces formed by the X-axis fibers and the X-axis fibers pass through the y center (therefore, the - (one biaxial hole corresponds to the sub-axis).

In order to fix the X-axis fibers by inserting the X-axis fibers into the cans of the Z-axis holes provided in a number of holes in the two-dimensional fiber-reinforced foam, insert the fibers coated with a foamable stock solution. The pores may be sealed by foaming the stock solution, and the pore-sealed foam may be integrated into the two-dimensional fiber-reinforced foam. In this case, the cross-sectional area of the pores is 1.2 to 10 times the fiber cross-sectional area, in particular 1.5 to 5
It is preferable to approximately double the amount. It is preferable to use the same material as the fiber layer for the X-axis direction fibers, and in particular,
Resin-impregnated low pink is advantageous in the insertion process as well as in the strength of the three-dimensional fiber-reinforced foam. It is advantageous to use the same foaming solution for the three-dimensional fiber-reinforced foam as the foaming solution to be applied to the fibers, in order to achieve a uniform heat insulating effect.

The present invention can be implemented in the following manner.

First, as shown in FIG. 2A, the X-axis direction fiber groups a, a,
A two-dimensional fiber-reinforced foam C having multiple layers of ... and Y-axis direction fiber groups b, ... is molded, and then the Z-axis direction from the xy upper surface of this foam C is shown in FIG. direction hole d,
d, . , the fiber end portions e', . . . protruding from each hole in the second drawing, and the lily foam f', .

The above-mentioned perforation is performed using needles provided at regular intervals from front to back as well as from left to right. On the other hand, the holes in the Z-axis direction can be equally spaced, and therefore the fibers in the X-axis direction can also be provided with a uniform density. Furthermore, the holes can be provided straight, and therefore the X-axis direction fibers can be provided straight.

Examples of the present invention will be described below in comparison with comparative examples.

Example: A 200 cm3 container was prepared using a metal plate, and holes with an outer diameter of 1.1 m were drilled in the sides at 10 cm intervals in both the vertical and horizontal directions, and rod-shaped materials were inserted into the holes. At the same time, the rod-shaped materials were parallel to the bottom surface of the container, and the rods inserted into adjacent surfaces were shifted by five positions so as not to touch each other. This metal container with holes drilled on its side is treated with fluorine for mold release.
After that, glass fiber reinforced plastic (outer diameter 1.0 mm,
A Nitto Denko membrane (hereinafter referred to as FRP rod) was inserted into the hole to penetrate the container.

In the above container, put a two-component rigid urethane foam stock solution (resin premix/isocyanate-1 system, use simmeryl diisocyanate as incyanate, foam density 7)
2 kq/m', made by Mitsui Nippon 11 urethane) was stirred for 60 seconds at a mixing ratio of resin premix 658 J/incyanate 700 N, and after curing, the container was opened and taken out, and it was mixed in two directions with an FRP rod. A reinforced foam was obtained.

A metal plate having a length of 230 mm and an outer diameter of 3.0 mm with sharp metal rods fixed at intervals of 0 mm was prepared, and an air cylinder was lowered by air pressure to push down the metal plate and remove the reinforced foam material. The above operation was repeated nine times to form holes at 10 mm intervals over the entire surface.

Subsequently, the above-mentioned FRP rod was passed through the foamable stock solution stirred at the above-mentioned mixing ratio, and the operation of immediately inserting the cutting into the through hole was repeated, and the urethane stock solution was foamed and hardened to obtain a three-dimensional fiber-reinforced heat insulating material.

The FRP rods in this insulation material were perpendicular to the FRP rods in the other two directions.

The density of this three-dimensional fiber-reinforced insulation material was 90 kg/m,', and the load giving 1% strain was 4.2 kg/i.

(Test Method J I S A -9514-'1979 Rigid Urethane Foam Heat Insulating Material) Comparative Example A container with holes made in the same manner as in the example was tested from two directions using FRP.
The rod was inserted. Next, a length of j 200 m was inserted into the opening of the lattice formed by the FRP rods from both sides of the container.
A cut FRP rod was dropped.

Next, a foaming stock solution with the same composition as in the example was poured, the lid was covered with a metal plate, and the FRP Rondo was pressed to one side so that it did not move, and the three-dimensional fiber-reinforced foam was moved.

When this foam was tested in the same manner as in the example, the density was 90 kg/m', and the load giving 1% strain was 3.8 to 8/m'.
It was d.

As is clear from the comparison between the above examples and comparative examples, according to the method for producing a three-dimensional fiber-reinforced foam according to the present invention,
Straightening and uniform density of axial fibers can be ensured, and a three-dimensional fiber-reinforced foam with excellent compressive strength can be obtained.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of the method of molding the two-dimensional line 8-1 reinforcing foam used in the present invention, FIG. 2 A1, FIG. 2 B1, FIG. FIG. 2A is an explanatory diagram showing a method for manufacturing a base fiber-reinforced foam; FIG. 2A shows the state before the Z-axis direction hole is punched, FIG. 2B shows the state after the hole is punched, and FIG. 2C
The figure shows the fiber insertion in the X-axis direction, and the second figure shows the fiber insertion in the ZIIilII direction. 4? 'r people are shown respectively. In the figure, a, a・ are fibers in the X-axis direction, b, b・・ are Y fibers
Axial fibers, C are two-dimensional fiber-reinforced foams, d, d... are Z-axis holes, e, e... are X-axis fibers. a? Tuft A 72zβ T2/1lc -”!'2fjD

Claims (2)

[Claims] (1) A two-dimensional fiber-reinforced foam made of multiple XY two-dimensional fiber layers is molded, a large number of holes are formed in the Z-axis direction, and the Z-axis fibers are inserted and fixed into the holes. A method for producing a three-dimensional fiber-reinforced foam. (2) A method for producing a three-dimensional fiber-reinforced foam according to claim 1, characterized in that the Z-axis direction fibers are coated with an unfoamed foaming solution.