JP2002127263A - Method for manufacturing thick pultruded item - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a thick pultruded item which can effectively produce a thick pultruded item showing no swell in the thickness direction and having uniform thickness. SOLUTION: A method for manufacturing a thick pultruded item comprises a step of shaping and heating a forming material 3 obtained by impregnating a fiber base material with an uncured thermosetting resin by making the forming material 3 pass through a forming aperture 211 of a pultruding die 21 having a cross sectional inner shape corresponding to a cross sectional outer shape of the thick pultruded item to be formed and continuously pultruding the thick pultruded item 4 having a cured outer layer portion and a half-cured central portion and a step of clamping the thick pultruded item 4 in its thickness direction for a predetermined period with a pressure holding die 221 to keep the thickness of the formed item immediately after being pultruded from the die, moving it in the pultruding direction and curing its central portion by use of an pressure holding apparatus 21 having the pressure holding die 221 moving in the pultruding direction in liaison with the pultruding velocity and thereafter removing the pressure holding die 221.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a thick pultruded product.

[0002]

2. Description of the Related Art Conventionally, when a fiber reinforced resin (FRP) molded product is manufactured by a pultrusion method, an uncured thermosetting resin-impregnated reinforced fiber material is generally provided with a molding hole having a predetermined cross-sectional shape. While passing through the forming hole of the pultruding mold, the pultruding was performed through the steps of shaping, heating, and holding pressure. The heating at this time is sequentially conducted from the surface of the uncured molded body formed from the inner surface of the molding hole to the center, the curing reaction proceeds, and the curing is completed in the pressure holding step.

However, when a thick pultruded product is manufactured by such a conventional pultrusion method, a large difference occurs between the hardened state of the outer layer portion and the center portion of the formed body in the heat hardening step. Although the part is hardened, the central part passes through the pressure-holding step in an uncured or semi-cured state and comes out of the pultrusion mold. Outside the pultrusion mold, the uncured or semi-cured resin at the center is cured in the direction perpendicular to the drawing direction in which the reinforcing fibers are not oriented, that is, expanded in the thickness direction by the resin pressure and cured. Therefore, there is a problem that only a thick-walled pultruded product having a wall thickness larger than the inner shape of the pultruding mold and having an extremely poor molding state can be obtained.

As a countermeasure, a method of reducing the drawing speed to complete the hardening of the resin in the central portion in the pressure holding step in the pultrusion mold can be considered. Since the molding speed is extremely slow, there is a problem that production efficiency and economic efficiency are deteriorated.

[0005] Another method is to lengthen the pultrusion mold and lengthen the convection time of the molded body in the pultrusion mold to complete the curing of the resin at the center in the pressure-holding step. Although it is conceivable, in addition to the large manufacturing equipment, the length of the pultruding mold affects the pulling force, and the length of the pultruding mold that can be pultruded by itself is restricted from the drawing ability, Not a big improvement.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and to provide a thick pultruded product having a uniform thickness without swelling in the thickness direction with high productivity. The purpose of the present invention is to provide a method for producing a thick-walled pultruded product which can be manufactured as follows.

[0007]

The invention according to claim 1 of the present application (Invention 1) is a method of forming a molding material obtained by impregnating a fibrous base material with an uncured thermosetting resin into a drawing mold. Forming and heating while passing through a molding hole having an internal cross-section corresponding to the cross-sectional outer shape of the thick-walled drawn product to be formed, the outer layer is cured and the central portion is uncured or semi-cured. A step of continuously drawing out the molded body, and using the pressure-holding device having a pressure-holding type that moves the thick-walled drawn-out molded body in the drawing direction in conjunction with the drawing speed, and using the pressure-holding mold to form the thick-walled drawn-out molded body. The thickness direction of the thick-walled pultruded molded product comprising the steps of: moving in the pulling-out direction while being held for a predetermined time so as to maintain the thickness immediately after the die is drawn out, and hardening the central portion, and then removing the pressure-holding mold. It is a manufacturing method.

The invention described in claim 2 of the present application (Invention 2)
Is a method of manufacturing a thick-walled pultruded product according to the first aspect of the present invention, in which a thick-walled pultruded body pulled out from a molding hole of the pultruding-molding die is clamped by the pressure-holding mold in a pressurized state.

In the present invention, as the fiber base material, for example, roving, chopped strand mat, continuous mat, roving cloth, interdigital cloth made of glass fiber, carbon fiber, aramid fiber, vinylon fiber or a combination thereof. Cloth and the like can be mentioned, and these can be used alone or in combination. In the present invention, as the thermosetting resin, an unsaturated polyester resin, an epoxy resin, a vinyl ester resin, a phenol resin or the like is suitably used.

[0010] The interval until the thick-walled pultruded product drawn out of the molding hole of the pultruding mold is clamped by the pressure-holding mold of the pressure-holding device is preferably as short as possible. Can be demonstrated.

The thickness holding force of the thick pultruded product in the thickness direction of the thick pultruded product in which the outer layer portion is hardened and the center portion is uncured or semi-cured by the pressure-holding die of the pressure holding device is 0 with respect to the thickness of the thick pultruded product. .0
The pressure is preferably set to 3 to 0.07 MPa / mm.

[0012]

The method of manufacturing a thick pultruded product of the present invention comprises the steps of: forming a molding material obtained by impregnating a fibrous base material with an uncured thermosetting resin; Shaping while passing through the inside of a molding hole with an inner shape corresponding to the outer shape
Heating, the outer layer is hardened and the central part is continuously hardened or unhardened or semi-hardened.The process of continuously drawing out the thick-drawing molded body, and the thick-drawing molded body is moved in the drawing direction in conjunction with the drawing speed. Using a pressure-holding device having a pressure-holding die, the thickness direction of the thick-walled pultruded molded product is moved by the pressure-holding die in the pull-out direction while being held for a predetermined time so as to maintain the thickness immediately after the die is drawn. Curing, and then removing the pressure-holding mold, so that even if the drawing speed is high, the thickness direction of the thick-walled pultruded molded article is maintained by the pressure-holding mold so as to maintain the thickness immediately after the mold is drawn. Since the central portion hardens while being moved in the pulling direction while holding for a time, even if the fiber base material oriented in the thickness direction does not exist, swelling in the thickness direction is no longer caused when the holding mold is detached. And has a uniform thickness.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an example of a thick pultruded product manufactured by the method for manufacturing a thick pultruded product of the present invention. This thick pultruded product is an insulating joint plate for a track which is disposed between end side surfaces of adjacent tracks and is connected by a fastener such as a bolt.

As shown in FIG. 1, the track insulating joint plate 1 is formed in a horizontally long and thick flat plate shape having a thickness A, and is applied to a fiber base made of glass roving GL or glass mats GM. Each is made of an integrally cured molded product manufactured by a pultrusion molding method using a molding material impregnated with an uncured thermosetting resin. A fiber base material,
In particular, the glass rovings GL are arranged along the longitudinal direction which is the drawing direction, but are not oriented in the thickness direction A which is a direction orthogonal to the drawing direction.

On the inner surface 11 which is the side surface of the raceway insulation seam plate 1, a raceway head contact surface 111 which has a curved surface which is in contact with the lower surface of the raceway head along the longitudinal direction on one side. A track bottom contact surface 112 is provided on the other side and in contact with the upper surface of the track bottom along the longitudinal direction. A curved bottom contact surface 112 is provided, and a substantially flat surface is provided between both contact surfaces 111 and 112. The shape is such that it does not directly contact the track.
At the approximate center of the outer surface 12 opposite to the track side,
A recess 121 is provided along the longitudinal direction. The recesses 121 are provided for inserting the heads of bolts to be fastened to prevent rotation when the insulating seam plate 1 for a track straddles between end side surfaces of adjacent tracks.

FIG. 2 is a front view for explaining a process of manufacturing the track insulating joint plate 1 shown in FIG. 1 by the method for manufacturing a thick pultruded product of the present invention. As shown in FIG. 2, the method for manufacturing a thick-walled pultruded product includes a pultrusion mold 21 and
The device 2 including the pressure holding device 22 is used.

The pultrusion molding die 21 is provided with a molding hole 211 having an inner shape in cross section corresponding to the outer shape of the cross section of the insulating joint plate 1 for a track to be formed, and heats a molding material passing through the forming hole 211. Heating means (not shown) is incorporated.

When the mold is closed, the pressure-holding device 22 has an upper press frame 221a and a lower press frame 221b in which an inner shape corresponding to the cross-sectional outer shape of the track insulating seam plate 1 to be formed is formed.
Are provided. A plurality of upper press frames 221a,... Forming one of a plurality of pairs of pressure-holding dies 221 are serially mounted on an upper endless belt 222 that circulates between the drive rolls 223 and 223. A plurality of lower press frames 221b,...
225 is connected in series to a lower endless belt 224 that goes around.

The pressure-holding device 22 is provided with the endless belts 222 and 224 at the outlet side of the molding hole 211 of the pultrusion molding die 21 over a pressure-holding section where it is necessary to maintain the pressure-holding state immediately thereafter. By turning, upper press top 221a
And the lower press frame 221b are closed to form a plurality of pairs of pressure-holding dies 221. The continuous pressing machine 226 maintains the pressure-pressed state of the plural pressure-holding dies 221 while interlocking with the drawing speed. After moving in the pulling-out direction and passing through the pressure holding section, the upper press frame 221a and the lower press frame 221b are in an open state, and return to the original position by the rotation of the endless belts 222 and 224 mounted respectively. It has a mechanism. The circumference of the rotating pressure-holding mold 221 is surrounded by a pressure-holding chamber 227, and the inside of the pressure-holding chamber 227 can be heated.

Next, the steps of the method for manufacturing a thick pultruded product will be described with reference to FIG. First, in the first half of the process, the molding material 3 in which the fiber base material is impregnated with the uncured thermosetting resin is shaped and heated while passing through the molding hole 211 of the pultrusion mold 21 to form an outer layer. The thick pultruded molded body 4 whose part is cured and whose central part is uncured or semi-cured is continuously pulled out.

In the subsequent second half step, the thick pultruded molded body 4 is held by a plurality of pairs of pressure-holding dies 221 of the pressure-holding device 22.
In a state where the upper press frame 221a and the lower press frame 221b are closed, the upper press frame 221a and the lower press frame 221b are successively sandwiched so as to maintain the thickness immediately after the mold is drawn out. Immediately after the exit of the molding hole 211 of the mold 21, the mold 21 is moved in the pulling direction over a certain section (pressure holding section). As a result, the central portion is cured. Then, after passing through the pressure holding section, a plurality of pairs of the pressure holding molds 221 have an upper press frame 221a and a lower press frame 221b.
By removing the mold in a state where the gaps are sequentially opened, a thick-walled pultruded product 5 is obtained, and this is cut into a required length to obtain a thick pultruded product 5 as shown in FIG.
And a track insulation seam plate 1 as a product shown in FIG.

Even if the drawing speed is high, the insulating joint plate 1 for a track manufactured through such a process has a thickness just after the die is drawn by pressing the thick-walled drawn product in a thickness direction by a pressure-holding die. The center is hardened while being moved in the drawing direction while holding for a predetermined time so as to maintain the thickness direction when the holding mold is detached even if the fiber base material oriented in the thickness direction does not exist. Swelling does not occur and has a uniform thickness.

The pressure-holding type is not limited to the one described above. For example, as shown in FIG.
A plurality of pairs of an upper frame 228a and a lower frame 228b, which form an inner cross-section corresponding to the cross-sectional outer shape of the track insulating seam plate 1 to be formed, can be fastened to form a thick-drawing molded body immediately after the mold is drawn. The thickness direction may be such that the thickness can be maintained immediately after the mold is drawn out. In particular, it is not an essential condition that the pressed state is maintained.

As shown in FIG. 4, when the mold is closed, the upper press frame 221a 'having a press surface corresponding to the outer shape of the central portion along the longitudinal direction on the inner surface 11 side of the insulating seam plate 1 for tracks.
And a lower press frame 221b 'having a press surface corresponding to the outer shape of the central portion along the longitudinal direction of the outer surface 12 side (see FIG. 1).

(Examples) Hereinafter, the present invention will be described with reference to examples. Example 1 As a fiber base material, glass roving (Asahi Fiber Co., # 4450), continuous strand mat (Asahi Fiber Co., # 450), and glass cloth (Nippon Glass Co., Ltd., # 560) were used. As an uncured thermosetting resin, a curing agent [organic peroxide (t
-Butylperoxybenzoate)] was used.

As shown in FIG. 2, a molding material 3 obtained by immersing the above-mentioned fiber base material in an uncured thermosetting resin mixed with the above-mentioned curing agent is passed through a molding hole 211 of a pultrusion mold 21. By shaping and heating while passing, the thick pultruded molded body 4 in which the outer layer was cured and the center was uncured or semi-cured was continuously pulled out at a speed of 0.25 m / min.

Next, the thick pultruded molded product 4 is pressed by a plurality of pairs of pressure-holding dies 221 of a pressure-holding device 22 on the upper press frame 2.
The press-molding die 21a and the lower press frame 221b are sequentially clamped in a closed state, and a continuous press machine 226 holds a pressurized state of 0.05 MPa / mm per thickness in a thickness direction, while forming a die for pultrusion molding. 21 immediately after the exit of the forming hole 211, a drawing speed of 0.25 m in the drawing direction over a certain section.
/ Min. This allows
The center was in a cured state.

The interval between the molding hole 211 of the pultruding mold 21 and the thick pultruded molded body 4 being clamped by the pressure-holding mold 221 of the pressure-holding device 22 is 50 mm. Is 1.5 m. After passing through the pressure holding section, the upper press frame 221a and the lower press frame 221b of a plurality of pairs of the pressure holding molds 221 are sequentially opened to remove the mold, and are cut to a required length.
An insulated rail joint plate 1 having dimensions of 560 mm in length, 105 mm in height and 42 mm in thickness as shown in FIG. 1 was obtained.

Dimensional stability (standard deviation of thickness, difference between average value of thickness of insulating seam plate for track and die size) and process capability (process capability index, coefficient of variation) of obtained raceway insulating seam plate 1 ) Was evaluated. Table 1 shows the results. The method of measuring and calculating the thickness standard deviation, the difference between the average thickness of the track insulation seam plate and the mold dimensions, the process capability index, and the coefficient of variation are as follows. Standard deviation (σ): Variation of data represented by the following equation was obtained for data at n points.

[0030]

(Equation 1)

Difference between the average thickness of the insulated seam plate for the track and the mold dimensions: Measured with a caliper. Process capability index (Cp): The range of tolerance / 6σ was determined. This process capability index has a significance of evaluating whether the process capability is sufficient for the size of the standard tolerance range. Coefficient of variation: Obtained from the relational expression shown below.

[0032]

(Equation 2)

This variation coefficient has a significance of evaluating the degree of variation of data.

Embodiment 2 As a dwelling type, an upper frame 228a and a lower frame 2 shown in FIG.
28b, using a plurality of pairs,
In the pressure-holding section, the two parts are fastened at the time of closing the mold so that the thickness direction of the thick-walled drawn molded body immediately after the die drawing is maintained at the thickness immediately after the die drawing, the drawing speed of the thick-walled drawn molded body 4 and The moving speed of the pressure-holding mold 22 in the drawing direction is 0.20 m / min.
In the same manner as in Example 1, except for the above, an insulated rail joint plate having the same dimensions as in Example 1 was obtained. About the obtained insulating joint plate 1 for tracks, the same dimensional stability and process capability as in Example 1 were evaluated. The results are shown in Table 1.

Example 3 As a pressure-holding type, a plurality of pairs of an upper press frame 221a 'and a lower press frame 221b' shown in FIG. 4 were used.
Pa, in the state of applying a holding pressure of 0.05 MPa per thickness, moved in the drawing direction, the drawing speed and the moving speed of the holding mold in the drawing direction were set to 0.20 m / min. A track having the same dimensions as in Example 1 according to Example 1, except that the interval between the molding hole 211 of the mold 21 and the thick-drawing molded article 4 being clamped by the holding mold was set to 150 mm. An insulating joint plate was obtained. The obtained insulating joint plate for track was evaluated for the same dimensional stability and process capability as in Example 1. The results are shown in Table 1.

Comparative Example The steps of shaping, heating and holding pressure while passing the uncured thermosetting resin-impregnated reinforcing fiber material through the molding holes of a pultrusion mold having molding holes having a predetermined cross-sectional shape. After that, pultruding was performed to obtain a track insulating joint plate having the same dimensions as in Example 1. The obtained insulating joint plate for track was evaluated for the same dimensional stability and process capability as in Example 1. The results are shown in Table 1.

[0037]

[Table 1]

As is clear from Table 1, the standard deviation of the thickness dimension is remarkably reduced in each of the examples of the present invention as compared with the comparative example, and the process capability index (Cp) is 1 or more. And has a stable process capability against tolerances.
It was possible to increase the molding speed, and it was possible to realize approximately twice the production capacity.

[0039]

The method for producing a thick pultruded product of the present invention is as follows.
With the above configuration, a thick pultruded product having a uniform thickness without swelling in the thickness direction can be manufactured with high productivity.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a thick pultruded product manufactured by the method for manufacturing a thick pultruded product of the present invention.

FIG. 2 shows the steps of the method for producing a thick pultruded product of the present invention.
It is explanatory drawing shown with the apparatus used.

FIG. 3 is an explanatory view showing another example of a pressure holding type used in the present invention.

FIG. 4 is an explanatory view showing still another example of a pressure holding type used in the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 track insulation seam plate (thick pultruded product) 2 device 3 molding material 4 thick pultruded product 5 thick pultruded product 21 pultruding mold 22 pressure-holding device 221 pressure-holding die 226 press device 221a, 221a ' Upper press frame 221b, 221b 'Lower press frame 228a Upper frame 228b Lower frame

Claims (2)

[Claims] 1. A molding hole having a cross-sectional inner shape corresponding to a cross-sectional outer shape of a thick-walled pultruded product to be molded in a pultruding mold by molding a fibrous base material impregnated with an uncured thermosetting resin. Shaping and heating while passing through the inside, a step of continuously drawing out a thick-drawing molded body in which the outer layer is hardened and the center is uncured or semi-cured, and the drawing speed of the thick-drawing molded body is increased. Using a pressure-holding device having a pressure-holding die that moves in the pull-out direction in conjunction with the above, while holding the thickness direction of the thick-drawing molded body by the pressure-holding die for a predetermined time so as to maintain the thickness immediately after the die is drawn. Moving the resin in the pulling direction to harden the central portion, and then removing the pressure-holding mold. 2. The thick-walled pultrusion according to claim 1, wherein the thick-walled pultruded body pulled out from a molding hole of the pultruding-molding die is clamped by the pressure-holding mold in a pressurized state. Product manufacturing method.