JP2006188597A - Method for producing fiber-reinforced plastic - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a fiber-reinforced plastic with which the fiber-reinforced plastic is produced with sheets ensuring the strength by the whole sheets when long fiber-reinforced resin sheets having an optional desired angle as the fiber direction are produced by using a unidirectional prepreg raw fabric. <P>SOLUTION: The fiber-reinforced plastic having a structure in which each fiber direction 1 of mutually adjacently laminated sheets obtained by laminating the fiber-reinforced resin sheets 3, 4', 5' and 6' composed of unidirectional continuous fibers impregnated with a resin intersects is produced. In the process, long continuous fibers 3 having the longitudinal direction 2 coincident with the fiber direction 1, i.e. the unidirectional prepreg raw fabric 3 is used as the fiber-reinforced resin sheet raw fabric 3 to successively carry out the following steps: a first step of cutting the raw fabric 3 at a prescribed angle relatively to the fiber direction 1 using the nearly same length W as the width of the long continuous fibers 3 as a cutting interval, a second step of successively placing raw fabric small pieces 4 composed of the cut raw fabric 3 in a state of each arranged fiber direction 1 and the cutting interval coincident with the width W of the continuous length on the long continuous fibers 3 having the different fiber directions 1 and a third step of heating and pressurizing the material of the continuous length composed of the successively placed raw fabric small pieces 4 together with the underlying long continuous fibers 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a fiber reinforced plastic, and in particular, when a fiber reinforced resin sheet (prepreg) raw material constituting the fiber reinforced plastic is provided in a long shape such as a winding type, a plurality of the raw materials are used. The present invention relates to a method for producing a fiber-reinforced plastic formed by lamination.

  The fiber reinforced plastic is a material reinforced with various fibers such as carbon fiber and glass fiber using an epoxy resin, polycarbonate resin, unsaturated polyester resin, vinyl ester resin, polypropylene resin or the like as a matrix (base material). Since this fiber reinforced plastic has high specific strength and specific rigidity, it is widely used for automobile parts, aircraft parts, electrical equipment parts and the like that are required to be lightweight and have high strength.

  As a method for producing fiber reinforced plastic, for example, a reinforcing material such as glass cloth is uniformly impregnated with a thermosetting resin or a thermoplastic resin, and a dried fiber reinforced resin sheet (prepreg) is manufactured, and a plurality of these are laminated. After that, a lamination molding method is known in which it is heated under pressure and integrated into a required shape.

  In such a fiber reinforced plastic, when continuous fibers are used as a reinforcing material, the strength and toughness in the longitudinal direction of the continuous fibers are high, so that they are used for members that require higher strength and light weight. On the other hand, in the direction orthogonal to the longitudinal direction of the continuous fiber, it can be said that the strength and toughness are low and the mechanical properties are anisotropic. In order to alleviate such anisotropy, a laminate in which three or more fiber reinforced resin sheets having different fiber directions are laminated in a symmetrical arrangement across a virtual center plane is known (for example, (See Patent Document 1).

  In addition, in order to reliably and easily laminate fiber reinforced resin sheets, a hot roller or a cold roller is used, and a plurality of sheets are laminated together regardless of the fiber direction (for example, , See Patent Document 2).

  By the way, as described in Patent Document 3 and the like, the fiber reinforced resin sheet original fabric currently provided as a commercial product is a long unidirectional prepreg in which the longitudinal direction matches the fiber direction. There is also a so-called cross prepreg in which the fiber directions intersect each other. That is, the fiber direction angle is limited to 0 °. For example, there is no original fabric product in which the fiber direction is oriented at 45 ° with respect to the longitudinal direction (longitudinal direction). Therefore, when this is necessary, it is necessary to cut the original unidirectional prepreg into small pieces having a desired fiber direction angle, and to align the pieces in the fiber direction angle and rearrange them so that the pieces are bonded to each other. Become.

The device shown in Patent Document 3 automates this work, but is small in the force acting in the longitudinal direction because the pieces are continuously joined by bonding and reproduced as long continuous fibers. The problem remains.
Japanese Patent Publication No. 56-54207 (Fig. 2 (f), Fig. 4-6) Japanese Patent Laid-Open No. 2001-293790 (FIG. 1, page 2) Japanese Patent No. 2876244 (Fig. 1-4)

  In view of the above problems, the present invention ensures the strength of the entire sheet when using a prepreg raw fabric and manufacturing a long fiber reinforced resin sheet with an arbitrary desired angle in the fiber direction. An object of the present invention is to provide a method for producing a fiber-reinforced plastic using a sheet.

  In order to solve the above problems, the present invention has a structure in which a plurality of fiber reinforced resin sheets including unidirectional continuous fibers impregnated with a resin are laminated, and the respective fiber directions of the sheets laminated adjacent to each other intersect. When manufacturing fiber reinforced plastics, use long continuous fibers with the same length and fiber direction as the fiber reinforced resin sheet, and cut the length approximately the same as the width of the long continuous fibers. As the interval, the first step of cutting the original fabric at a predetermined angle with respect to the fiber direction and the original raw piece made of the cut original fabric are aligned in the fiber direction and the cutting interval is made to match the long width. In this state, temperature control is performed on the long body composed of the second continuous step and the continuously placed raw small piece on the continuous continuous fiber having different fiber directions together with the continuous long continuous fiber. The third step to pressurize in order It was assumed to be performed.

According to this, long continuous fibers in which the longitudinal direction coincides with the fiber direction, that is, a unidirectional prepreg is used as a common raw fabric, and the following steps are performed.
First step: At a predetermined angle with respect to the fiber direction at a cutting interval of substantially the same length as the width of the long continuous fiber
By cutting the raw fabric, a large number of fibers aligned in the fiber direction other than the fiber direction angle of 0 °
A raw piece is produced.
Second step: While aligning the fiber direction of each raw fabric piece and matching the cutting interval with the long width,
Each piece of raw fabric is spliced on a continuous continuous fiber with different fiber directions adjacent to each other.
By placing them continuously, the aggregate of the raw fabric pieces has the same fiber direction.
It has a long body shape. At this point, however,
They only abut against each other and remain in a separate configuration.
Third step: A long body composed of each piece of raw fabric is temperature-controlled and pressed together with the continuous long continuous fiber, so that the contact portion of the piece of raw fabric is crimped and integrated continuously in the longitudinal direction.
In this state, lamination with the base fiber sheet is completed. In addition, this process is next
The content focuses only on the lamination with the base sheet that comes into contact, but the entire long body is placed.
Also included are long substrates and laminated sheets on the substrate that are temperature controlled and pressurized.
The In addition, as a long base, it is possible to use a unidirectional prepreg original as it is.
It is common.

  Furthermore, when there are a plurality of fiber reinforced resin sheets, the first to third steps are repeated as a process cycle for each sheet after making the cutting angle of the first step different between a pair of adjacent sheets. . As a result, the fiber directions of the fiber reinforced resin sheets laminated adjacent to each other cross each other, and further, a plurality of fiber reinforced resin sheets are laminated in a state where each sheet is accurately aligned with a sufficient length in the width direction. The structure is completed.

  The resin used for the fiber reinforced resin sheet may be either a thermosetting resin or a thermoplastic resin. However, when a sheet impregnated with a thermosetting resin is used, it usually has an adhesive property at room temperature. Have. When using this type of original fabric, when the original pieces are cut in the first step or when the original pieces are continuously placed in the second step, if the pieces come into contact with each other, they will adhere to each other at the contact point. And there is a risk of hindering the placement work.

  Therefore, when a thermosetting resin is used, a cooling step for cooling the original fabric or the original web piece is added before the above-described second step so that the original fabric or the original web piece can be handled without stickiness. Then, work efficiency improves.

  According to the present invention, a unidirectional prepreg is used as a common raw material, and in the first step, a large number of raw fabric pieces aligned in the fiber direction other than the fiber direction angle of 0 ° are produced. The assembly of small pieces forms a long body having the same fiber direction, and in the third step, the contact portions of the raw small pieces are pressure-bonded and continuously integrated in the longitudinal direction, and laminated with the underlying fiber sheet. Is completed. And after making the cutting angle of a 1st process different in a pair of sheet | seat which should be adjacent, a 1st thru | or 3rd process is repeated as a process cycle for every sheet | seat.

  This includes a structure in which the fiber directions of the fiber reinforced resin sheets laminated adjacent to each other cross each other, and in addition, the plurality of fiber reinforced resins in a state where each sheet is accurately aligned in the width direction length. A laminated structure of sheets is completed.

  As described above, the method for producing a fiber-reinforced plastic according to the present invention includes a first step of cutting a unidirectional prepreg raw material composed of continuous fibers impregnated with a resin, and a raw material in which the fiber directions are aligned. It comprises a second step of continuously placing the anti-small pieces and a third step of controlling and pressurizing the long body of the continuously placed original small pieces. 1 shows the first step, FIG. 2 shows the second step, FIG. 3 shows the third step, and FIG. 4 is a completed drawing of the fiber reinforced plastic obtained through the first to third steps. Indicates.

  The first step of the method of the present invention will be described with reference to FIG. In FIG. 1 (a-1), a unidirectional prepreg raw fabric 3 having a long width W in which the fiber direction 1 coincides with the longitudinal direction 2 is used, and this is 135 ° (−45 ° with respect to the fiber direction 1). ) Cut at an angle. The cutting interval at this time is made substantially the same as the long width W. By continuously performing this cutting operation, a plurality of identical prepreg raw fabric pieces 4 having a fiber direction angle of −45 ° and a height W as shown in FIG. 1 (a-2) are obtained.

  Similarly, in FIGS. 1 (b-1) and (b-2), a prepreg raw fabric piece 5 having a fiber direction angle of 45 ° and a height W is obtained, and FIGS. 1 (c-1) and (c−) are obtained. In 2), the prepreg raw fabric pieces 6 having a fiber direction angle of 90 ° and a height W are obtained.

  In the next second step, the prepreg raw fabric pieces 4, 5, 6 thus obtained are placed on the prepreg raw fabric 3, which is a long substrate, for each type classified in the fiber direction. That is, as shown in FIG. 2, the height W of the original fabric piece 4 having a fiber direction angle of 135 ° (−45 °) is matched with the width W of the prepreg original fabric 3 directly below the original fabric 3. Place. At this time, the distance between both side lines is restricted to the length W along both side lines of the prepreg original fabric 3 so that the height W of the original fabric piece 4 and the width W of the prepreg original fabric 3 are surely matched. Guides 7 and 7 are installed. That is, the position for placing the original web piece 4 is between the guides 7 and 7.

  In addition, the prepreg original fabric 3 as the base is continuously fed out in the longitudinal direction in the right direction on the paper surface, and the raw piece 4 placed on the prepreg original fabric 3 is the same as the original fabric 3 is fed out. Move in the direction. Then, at the point of time when the original web piece 4 is moved by one piece with respect to the guides 7 and 7, the next original web piece 4 is placed on the prepreg original fabric 3 with the fiber directions aligned. Thereby, the raw fabric pieces 4 and 4 are joined together without generating a gap between them. By continuously performing this mounting operation, an elongated body in which the aggregates of the raw fabric pieces 4, 4, 4,... Are aligned in the fiber direction is formed.

  In addition, the same placement operation is performed on the raw fabric pieces 5 and 6. That is, in the guides 8 and 8 positions, the raw fabric pieces 5, 5, 5... Having a fiber direction angle of 45 ° are aligned on the prepreg original fabric 3 on which the raw fabric pieces 4 are placed. In addition, on the prepreg raw fabric 3 on which the raw fabric pieces 4 and 5 are placed, the raw fabric pieces 6, 6, 6. Place continuously in an aligned state. By performing these placing operations in parallel for each of the raw fabric pieces 4, 5 and 6, four types of fibers in a state where the fiber directions of the adjacent prepreg raw fabrics 3, 4, 5 and 6 cross each other. A four-layer laminate consisting of elongated bodies in the direction is obtained. However, at this stage, the raw fabric pieces 4, 5, and 6 are merely brought into contact with each other by seaming and remain in a separate configuration.

  Therefore, in the third step, the four-layer laminate is subjected to temperature control and pressurization, whereby the original pieces 4, 5, 6 are pressure-bonded to form an integrated configuration continuous in the longitudinal direction. FIG. 3 is a schematic view of an apparatus for performing the third step. This apparatus is provided with guides 7, 8, and 9 sandwiching the prepreg original fabric 3 fed from the roll original 3 'by the conveying roller 10, and pressure rollers 11, 12, and 13 for laying the original fabric 3. ing. In addition, a cooling mechanism 14 and a heating mechanism 15 are installed before and after the placement positions of the raw fabric pieces 4, 5, 6 near the guides 7, 8, 9.

  The cooling mechanism 14 may be diverted from a cold air blower or a refrigerator, and reduces the adhesiveness when the impregnating resin of the prepreg raw fabric 3 is a thermosetting resin. That is, it is installed for the purpose of reducing the adhesiveness of the original small piece 4 and improving the work efficiency before work. On the other hand, the heating mechanism 15 may be a halogen heater, an infrared heater or the like, and thereby heats the raw fabric piece 4 and the prepreg raw fabric 3 on which it is placed.

  Then, as shown in FIG. 3A, while the prepreg original fabric 3 is continuously fed out by the conveying roller 10, the original fabric pieces 4 are continuously placed in the vicinity of the guide 7 (see the second step). The original piece 4 is placed on the prepreg original 3 with no gap. In this state, the prepreg original fabric 3 on which the original fabric pieces 4, 4, 4,. At this time, the joined portions of the raw fabric pieces 4, 4, 4,... Are pressure-bonded to be modified into long continuous fibers 4 ′ that are continuously integrated in the longitudinal direction. Then, after the pressure roller 11, the lamination of the long continuous fiber 4 ′ and the prepreg original fabric 3 having different fiber directions is completed.

  FIG. 3A shows a state in which the long continuous fiber 4 ′ drawn out by the conveying roller 10 and placed on the prepreg original fabric 3 has reached the vicinity of the guide 8. Next, FIG. 3B shows a state in which the raw fabric pieces 5 are continuously placed on the long continuous fiber 4 ′ in the vicinity of the guide 8 in this state (see the second step), and the prepreg raw fabric 3 is placed. And the state which performs the operation | work which mounts the raw fabric piece 5 on the elongate continuous fiber 4 'without a gap is shown. The purpose of installing the cooling mechanism 16 and the heating mechanism 17 before and after placing the original small piece 5 is the same as that of the cooling mechanism 14 and the heating mechanism 15 in the vicinity of the guide 7.

  Then, as shown in FIG. 3C, in this state, the prepreg original fabric 3 on which the original fabric small pieces 5, 5, 5,. At this time, the seam pieces 5, 5, 5,... Are joined to each other so that they are crimped and reformed into a long continuous fiber 5 ′ continuously integrated in the longitudinal direction. Then, after the pressure roller 12, the lamination of the long continuous fibers 4 'and the long continuous fibers 5' having different fiber directions is completed.

  FIG. 3C shows a state in which the long continuous fiber 5 ′ drawn out by the transport roller 10 and placed on the prepreg original fabric 3 has reached the vicinity of the guide 9. Next, FIG. 3D shows a state in which the raw fabric pieces 6 are continuously placed on the long continuous fiber 5 ′ in the vicinity of the guide 9 in this state (see the second step), and the prepreg raw fabric 3 is placed. The state which performs the operation | work which mounts the raw fabric piece 6 on the elongate continuous fiber 4 'and the elongate continuous fiber 5' without a gap is shown. The purpose of installing the cooling mechanism 18 and the heating mechanism 19 before and after placing the original small piece 6 is the same as that of the cooling mechanism 14 and the heating mechanism 15 in the vicinity of the guide 7.

  Then, as shown in FIG. 3C, the prepreg original fabric 3 on which the original fabric small pieces 6, 6, 6... Are pressed with the pressure roller 13 in this state. At this time, the seam pieces 6, 6, 6... Are joined together by pressure bonding and reformed into a continuous continuous fiber 6 'continuously integrated in the longitudinal direction. Then, after the pressure roller 13, the lamination of the long continuous fibers 5 ′ and the long continuous fibers 6 ′ having different fiber directions is completed.

  In FIG.3 (d), the 2nd process which mounts the raw fabric pieces 4,5,6 continuously in the vicinity of the guides 7,8,9, respectively, and the heating fabrics 15,17,19 respectively, In addition, a state in which the third step of heating and pressing using the pressure rollers 11, 12, and 13 is performed in parallel is shown. Then, through these steps, as shown in FIG. 4, the fiber directions of those laminated adjacent to each other in the prepreg sheets 3, 4 ′, 5 ′, 6 ′ intersect, In 4 ′, 5 ′, and 6 ′, the laminated structure constituting the fiber reinforced plastic is completed in a state where the width direction length W is accurately and accurately aligned.

  By the way, in the above, a thermosetting resin is used as the impregnating resin, and the cooling mechanism 14, 16, 18 is installed in the apparatus shown in FIG. When a plastic resin is used, a cooling mechanism can be dispensed with. Unlike the thermosetting resin, the thermoplastic resin is easy to handle at room temperature and has no problem in workability. Therefore, by using a simple apparatus (for example, see FIG. 5) from which the cooling mechanism is removed, Similarly, a laminated structure of fiber reinforced plastic is completed.

  3 and 5, the third process of heating and pressurization is performed after each of the original fabric pieces 4, 5, 6 is placed. The same laminated structure can be obtained by using a simple method in which the subsequent mounting is completed first, and then the prepreg raw fabric 3 on which these are mounted is heated and pressurized. A heating mechanism may be provided for each pressure roller. In addition, the fiber direction angle and the mounting order of the raw fabric pieces 4, 5, and 6 are not limited to this, and may be changed as necessary.

  Using the prepreg original fabric 3 impregnated with any one of epoxy resin, unsaturated polyester resin, and epoxy acrylate resin by the apparatus shown in FIG. 3, the fiber direction angle is 0 ° (prepreg original fabric 3), − A four-layer laminate was manufactured at 45 ° (raw piece 4), 45 ° (raw piece 5), and 90 ° (raw piece 6). At this time, the cooling mechanisms 14, 16, and 18 were cooled at about 10 ° C. (corresponding to a temperature at which the thermosetting resin does not exhibit adhesiveness) using a cold air blower or a refrigerator. In addition, a halogen heater, an infrared heater, or the like is used for the heating mechanisms 15, 17, and 19, and heating is performed at about 45 ° C. to 50 ° C. (corresponding to a temperature at which the thermosetting resin exhibits adhesiveness and below a curing temperature). It was. Further, a pressure load of about 1 MPa or less was applied to the pressure rollers 11, 12, and 13. As a result, as shown in FIG. 4, the laminated fiber structure in which the fiber directions of the prepreg sheets laminated adjacent to each other intersect each other, and the lengths in the width direction of each sheet are accurately aligned without excess or deficiency is obtained. It was.

  By using the prepreg original fabric 3 impregnated with a thermoplastic resin of any of polyolefin resins such as polypropylene and polyethylene, nylon resin, and polycarbonate resin by using the apparatus shown in FIG. 3, the fiber direction angle is 0 ° (prepreg original fabric 3), Four-layer laminates were produced at -45 ° (raw fabric piece 4), 45 ° (raw fabric piece 5), and 90 ° (raw fabric piece 6). At this time, the cooling mechanisms 14, 16, and 18 were cooled at about 100 ° C. (corresponding to the melting temperature of the thermoplastic resin or lower) using a cold air blower or a refrigerator. In addition, a halogen heater or an infrared heater was used for the heating mechanisms 15, 17, and 19, and heating was performed at about 150 ° C. to 220 ° C. (corresponding to the melting temperature of the thermoplastic resin or higher). Further, a pressure load of about 1 MPa or less was applied to the pressure rollers 11, 12, and 13. As a result, as shown in FIG. 4, the laminated fiber structure in which the fiber directions of the prepreg sheets laminated adjacent to each other intersect each other, and the lengths in the width direction of each sheet are accurately aligned without excess or deficiency is obtained. It was.

  INDUSTRIAL APPLICATION This invention can be utilized for manufacture of the fiber reinforced plastic using a unidirectional prepreg original fabric.

Process drawing showing the first step of the present invention (a-1) Schematic diagram (a-2) for cutting a raw fabric piece having a fiber direction angle of -45 ° (a-1) Fiber direction angle of -45 ° obtained by (a-1) Original fabric piece (b-1) Schematic diagram (b-2) obtained by cutting an original fabric piece having a fiber direction angle of 45 ° (b-1) Original fabric piece (c-1) fiber having a fiber direction angle of 45 ° obtained by (b-1) Schematic drawings (c-2) and (c-1) for cutting a raw fabric piece having a direction angle of 90 °. Process drawing showing the second step of the present invention (A)-(d) Process drawing which shows the 3rd process of this invention. Complete perspective view of a four-layer laminate structure according to the present invention Fiber reinforced plastic manufacturing equipment using thermoplastic resin

Explanation of symbols

1 Fiber direction 2 Longitudinal direction (long direction)
3 Prepreg original fabric 4 5 6 Original fabric piece 11 12 13 Pressure roller 14 16 18 Cooling mechanism 15 17 19 Heating mechanism W Long width, cutting interval

Claims (1)

A method for producing a fiber reinforced plastic comprising a structure in which a plurality of fiber reinforced resin sheets containing unidirectional continuous fibers impregnated with a resin are laminated, and the respective fiber directions of the sheets laminated adjacent to each other intersect. ,
As a fiber reinforced resin sheet raw fabric, in which the longitudinal direction and the fiber direction match, in which long continuous fibers are used,
A first step of cutting the raw fabric at a predetermined angle with respect to the fiber direction, with a length substantially the same as the width of the continuous continuous fiber as a cutting interval;
A second step of continuously placing the raw fabric pieces made of the cut raw fabric on the long continuous fibers having different fiber directions in a state where the fiber directions are aligned and the cutting intervals are matched to the long width. When,
A third step of controlling the temperature and pressurizing the long body composed of the continuously placed raw fabric pieces together with the continuous long continuous fibers;
A method for producing a fiber-reinforced plastic, comprising:

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