JP2005325191A - Method for producing unidirectional prepreg and apparatus for production - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing prepreg eliminating meandering of reinforcing fibers in especially opening and widening and affording the suitable prepreg when processing the reinforcing fibers into the prepreg and to provide an apparatus for production. <P>SOLUTION: The method for producing the prepreg comprises opening a plurality of unidirectionally doubled and running reinforcing fiber bundles and impregnating the resultant reinforcing fiber sheet with a resin. The method for producing the unidirectional prepreg is characterized as follows. The reinforcing fiber bundles are brought into contact with driving rollers arranged in the direction in which the central shafts intersect the reinforcing fiber sheet and rotating at a peripheral speed Vr in the same direction as the transporting direction of the reinforcing fiber sheet between an opening means for opening the reinforcing fiber bundles and a resin impregnating part. The peripheral speed Vr is within the range of 0<Vr/Vf≤0.9 based on the transporting speed Vf of the reinforcing fiber sheet. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method and an apparatus for producing a prepreg suitable for producing a unidirectional prepreg having a good quality and quality with little crack defect.

  As is well known, unidirectional prepregs are used for molding FRP (fiber reinforced plastic). Such a unidirectional prepreg, for example, aligns a plurality of reinforcing fiber bundles such as carbon fiber bundles in parallel in one direction, and opens and widens each reinforcing fiber bundle as necessary for reinforcement. After forming the fiber sheet, a release paper coated with a matrix resin such as a B-stage epoxy resin is superimposed on the reinforcing fiber sheet on the resin application surface, and the matrix resin on the release paper is transferred and impregnated into the reinforcing fiber sheet. In this method, the reinforcing fiber sheet is formed in such a manner that each reinforcing fiber bundle is spread and the resin is directly impregnated into a widened reinforcing fiber sheet. If it is non-uniform, the prepared prepreg will also be non-uniform, causing crack defects and poor smoothness, for example. It goes without saying that the FRP molded using such a non-uniform prepreg will of course have non-uniform characteristics.

  In particular, when each reinforcing fiber bundle is opened and widened, the reinforcing fiber bundle after opening and widening forms a bundle in order to unwind the form of the fiber reinforcing bundle by applying some force from the outside to the fiber reinforcing bundle. There is a case where the orientation of the single fibers is disturbed, and for example, the meandering of the reinforcing fibers occurs as a group of a plurality of single fibers of about 10 to 1000, which may cause the reinforcing fiber sheet to have an uneven shape. is there.

  As a method of opening and widening a reinforcing fiber bundle, conventionally, a method of sequentially contacting a plurality of reinforcing fiber bundles arranged in parallel in one direction with a plurality of vibration bars and vibration rollers arranged in multiple stages. In addition, a method has been proposed in which the filament is separated in the width direction by a suction airflow that passes in a direction orthogonal to the flow direction (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3). Among these, in the method of bringing the reinforcing fiber bundle into contact with the vibrating roller, the reinforcing fiber bundle is opened by repeating the contact and separation between the reinforcing fiber bundle and the vibrating roller. At this time, since the reinforcing fiber bundle repeats relaxation and tension, the orientation of the single fibers constituting the reinforcing fiber bundle is likely to be disturbed, and as a result, the reinforcing fiber may meander. Also, in the method of separating the filaments in the width direction by the suction airflow, the reinforcing fiber bundle is formed at the time of opening in order to give the airflow to the place where the filament is substantially in tension by adjusting the filament feed amount. The orientation of the single fibers constituting the structure is likely to be disturbed, and as a result, the reinforcing fibers may meander.

As described above, in the generally well-known method of opening and widening a reinforcing fiber bundle, meandering may occur in the reinforcing fiber bundle after opening and widening, and the quality of the prepreg is degraded. Had.
JP 2001-262443 A Japanese Patent Laid-Open No. 10-292238 Japanese Patent No. 3146200

  An object of the present invention is to solve the above-mentioned problems of the prior art, particularly to eliminate meandering of reinforcing fibers in the opening and widening, and to obtain a suitable prepreg when processed into a prepreg using them. The object is to provide a method and an apparatus for manufacturing a prepreg.

In order to solve the above problems, the present invention employs the following configuration. That is,
(1) A method for producing a prepreg in which a reinforcing fiber sheet obtained by opening a plurality of traveling reinforcing fiber bundles arranged in one direction is impregnated with a resin, wherein the reinforcing fiber bundle is opened. Between the fiber means and the resin-impregnated portion, the central axis is arranged in a direction intersecting the reinforcing fiber sheet, and is brought into contact with a driving roller that rotates at a peripheral speed Vr in the same direction as the conveying direction of the reinforcing fiber sheet. The method for producing a unidirectional prepreg, characterized in that the circumferential speed Vr is within a range of 0 <Vr / Vf ≦ 0.9 with respect to the conveying speed Vf of the reinforcing fiber sheet.

  (2) The method for producing a unidirectional prepreg according to (1), wherein a plurality of the driving rollers are arranged, and both surfaces of the reinforcing fiber sheet are brought into contact with the driving roller at least once.

  (3) The method for producing a unidirectional prepreg according to the above (1) or (2), wherein the means for opening the reinforcing fiber bundle is by applying vibration to the reinforcing fiber bundle or by fluid contact.

  (4) The method for producing a unidirectional prepreg according to (2) or (3), wherein the total contact length of the plurality of drive rollers and the reinforcing fiber sheet is 5 to 500 mm.

  (5) The method for producing a unidirectional prepreg according to any one of (1) to (4), wherein the reinforcing fiber bundle is a carbon fiber bundle.

  (6) A prepreg manufacturing apparatus for impregnating a reinforcing fiber sheet obtained by opening a plurality of traveling reinforcing fiber bundles aligned in one direction with a resin, wherein the reinforcing fiber bundle is opened. Between the fiber means and the resin impregnated portion, the central axis is arranged in a direction intersecting the reinforcing fiber sheet, and rotates at a peripheral speed Vr in the same direction as the conveying direction of the reinforcing fiber sheet. The driving roller is arranged so that the peripheral speed Vr of the driving roller is controlled within the range of 0 <Vr / Vf ≦ 0.9 with respect to the conveying speed Vf of the reinforcing fiber sheet. An apparatus for producing a unidirectional prepreg characterized by comprising:

  (7) The prepreg manufacturing apparatus according to (6), wherein the driving roller is a flat roller and has a satin surface having a surface roughness of 3 to 20S.

  (8) Unidirectionally produced by the prepreg production method according to any one of (1) to (5) or the prepreg production apparatus according to (6) or (7). Prepreg.

  According to the present invention, by eliminating the meandering of the reinforcing fibers in the opening and widening, the orientation disorder of the single fibers constituting the reinforcing fiber bundle is improved, and the quality with little crack defects while preventing the occurrence of crack defects A prepreg with good quality can be produced.

  Next, the present invention will be described in more detail.

  The present invention is a method for manufacturing a prepreg in which a reinforcing fiber sheet obtained by opening a plurality of traveling reinforcing fiber bundles arranged in parallel in one direction is impregnated with a resin, the reinforcing fiber bundle Between the opening means for opening the fiber and the resin impregnated portion, the central axis is arranged in a direction intersecting the reinforcing fiber sheet, and rotates at a peripheral speed Vr in the same direction as the conveying direction of the reinforcing fiber sheet. It is a manufacturing method of the unidirectional prepreg which makes it contact with a drive roller and makes this peripheral speed Vr in the range of 0 <Vr / Vf <= 0.9 with respect to the conveyance speed Vf of a reinforced fiber sheet.

  The reinforcing fiber bundle is generally drawn out from a package such as a plurality of bobbins, but the method is not particularly limited. Further, as the reinforcing fiber bundle in the present invention, a carbon fiber bundle is preferable from the viewpoint of weight reduction and strength enhancement of a fiber reinforcing member using the reinforcing fiber bundle. The reinforcing fiber bundle is composed of several thousand to several tens of thousands of single fibers, and is usually composed of about 1,000 to 48,000 single fibers. The diameter of the single fiber is usually about 4 to 10 μm.

  Also, in order to align the reinforcing fiber bundles in parallel and as uniformly as possible, a comb with pins arranged at equal pitch intervals or a roller having grooves at equal pitch intervals may be used. Although preferred, the means is not particularly limited.

  In the method of opening a reinforcing fiber bundle in the case of using a plurality of reinforcing fiber bundles for the production of a prepreg, the reinforcing fiber bundles are aligned in one direction and then sent to the opening means to open and widen the reinforcing fibers. A sheet. As a means for opening the reinforcing fiber bundle, a method of opening and widening by rubbing with a rubbing bar, a method of opening by opening a contact with a vibration roller and applying vibration, a fluid such as an air flow or a water flow is opened. There are methods such as fiber-spreading and widening, but the method of opening and widening by applying vibrations in particular, and the method of opening and widening by bringing fluid into contact with each other are suitable for the orientation of the single fibers constituting the reinforcing fiber bundle at the time of opening. Since disturbance is likely to occur, it is effective to make contact with the drive roller of the present invention described above.

  In the present invention, the reinforcing fiber sheet obtained by opening the reinforcing fiber bundle by the above opening means is the center axis between the opening means and the resin-impregnated portion and the running surface of the reinforcing fiber sheet. A driving roller disposed substantially in parallel and intersecting the reinforcing fiber bundle is brought into contact with the driving roll while rotating in the same direction as the reinforcing fiber bundle. More specifically, the reinforcing fiber bundle may be disturbed in the orientation of the single fibers constituting the reinforcing fiber bundle by receiving vibration imparting or fluid contact in the opening means. As shown in FIG. 1, the disorder of the orientation of the single fiber is shifted or meandering with respect to the longitudinal direction of the reinforcing fiber bundle. As a result, meandering occurs in the reinforcing fiber sheet itself, which may deteriorate the quality of the prepreg. The reinforcing fiber sheet in which the disorder of the orientation of the single fibers has occurred is brought into contact with a driving roller arranged in a direction in which the central axis is substantially parallel to the traveling surface of the reinforcing fiber sheet and intersects the reinforcing fiber bundle. Thus, it can be improved to a state in which the orientation of single fibers is uniform as shown in FIG. This is because single fibers with disordered orientation are locally low in tension compared to single fibers that are not disturbed, and this single fiber with low tension is almost equal to other single fibers by rubbing with a driving roller. It can be explained by the tension of. What is important here is that the peripheral speed Vr of the driving roller is within the range of 0 <Vr / Vf ≦ 0.9 with respect to the conveying speed Vf of the reinforcing fiber sheet, and the peripheral speed Vr of the driving roller is reinforced. A suitable effect can be obtained by controlling the conveyance speed Vf of the fiber sheet within this range. Furthermore, it is more preferable that the peripheral speed Vr of the drive roller is within a range of 0.05 ≦ Vr / Vf ≦ 0.75 with respect to the conveying speed Vf of the reinforcing fiber sheet. In the range of Vr / Vf> 0.05, although there is an effect of improving the disorder of the orientation of the single fiber, excessive abrasion between the reinforcing fiber sheet and the driving roller may occur, and scuffing due to abrasion may occur. On the other hand, even when the driving roller is set in the direction opposite to the direction in which the reinforcing fiber sheet is conveyed, there is a case where scuffing due to scratching may occur for the same reason. Further, in the range of Vr / Vf <0.75, the abrasion between the reinforcing fiber sheet and the driving roller is reduced, the effect of improving the disorder of the orientation of the single fiber is reduced, and further, Vr / Vf <0.9. In the range, rubbing between the reinforcing fiber sheet and the driving roller becomes too small, and the effect of improving the disorder of the orientation of the single fiber targeted by the present invention is hardly obtained.

  Moreover, in this invention, both surfaces of a reinforced fiber sheet can be made to contact a drive roller at least once or more by using two or more said drive rollers. Thereby, both surfaces of a reinforced fiber sheet can be rubbed evenly and disorder of the orientation of a single fiber can be improved as a whole. Usually, if the two or six drive rollers are brought into contact with one side of the reinforcing fiber sheet about 1 to 3 times and the other side about 1 to 3 times, the intended effect of the present invention is can get. Increasing the number of drive rollers more than necessary is not preferable in terms of equipment space and equipment costs.

  Furthermore, in this invention, it is preferable that the sum total of the contact length of the said several drive roller and a reinforced fiber sheet shall be 5-500 mm. The contact length here is the total length of the portions where the plurality of drive rollers and the reinforcing fiber sheet are in contact with each other, and the longer the contact length, the greater the friction between the drive roller and the reinforcing fiber sheet. The disturbance of the orientation of the single fiber by the above-mentioned fiber opening means is about several tens of μm to several millimeters, and the total contact length between the driving roller and the reinforcing fiber sheet is 5 to 500 mm, thereby disturbing the orientation of the single fiber. Can be suitably improved. If the total contact length is less than 5 mm, the improvement effect may be reduced when the orientation of the single fiber is largely disturbed. Further, when the total contact length exceeds 500 mm, the improvement of the improvement effect is not so much increased, and it is not preferable from the viewpoint of equipment space and equipment cost to increase the number of drive rollers more than necessary.

  By applying the above method, a suitable reinforcing fiber bundle sheet can be produced from a plurality of reinforcing fiber bundles, and a more preferred unidirectional prepreg can be produced.

  Next, a prepreg manufacturing apparatus suitable for the present invention will be described. The prepreg manufacturing apparatus of the present invention is a prepreg manufacturing apparatus including a fiber opening means for opening and widening a conveyed reinforcing fiber bundle, a resin-impregnated section, and a product winding section. Between the resin impregnated portion, the speed can be controlled by a motor, and the prepreg manufacturing apparatus includes one or more driving rollers that come into contact with the reinforcing fiber sheet. When rotating in the same direction at a peripheral speed Vr, the peripheral speed of the driving roller is Vr, and the conveying speed of the reinforcing fiber sheet is Vf, the range is 0 <Vr / Vf ≦ 0.9, more preferably 0. The conveying speed of the driving roller and / or the reinforcing fiber sheet is controlled within the range of 05 ≦ Vr / Vf ≦ 0.75.

  An example of the present invention is shown in FIG. As shown in FIG. 3, the prepreg manufacturing apparatus of the present invention widens reinforcing fiber bundles 5, 5,... Unwound from a large number of packages 4, 4,. Drive rollers 9, 10 which are provided with a spreading means 8 for opening the fiber, a resin impregnated part 15, and a product take-up part 16, and are in contact with the reinforcing fibers between the fiber opening means 8 and the resin impregnated part 15. It has. Here, when the reinforcing fiber bundle is introduced into the fiber opening means 8, a guide roller 6 and a comb 7 for equalizing the reinforcing fiber bundle pitch may be provided as necessary. Further, the opening means 8 is not particularly defined, but the opening means provided with a scraping bar, the opening means provided with a vibrating roller, the ejecting device for a fluid such as an air current or a water flow, or the opening means provided with a suction device. Is effective. A plurality of reinforcing fiber bundles 5, 5,... Are opened into a sheet shape by the opening means 8. Furthermore, the driving rollers 9 and 10 that come into contact with the sheet-like reinforcing fiber sheet can be controlled by a motor (not shown), and are metal rollers having an appropriate rigidity that is not bent by the reinforcing fiber sheet. If there exists, it is preferable from the surface of intensity | strength. The driving rollers 9 and 10 are preferably flat rollers because fuzz on the surface of the reinforcing fiber sheet can be suppressed, and the surfaces of the driving rollers 9 and 10 have a surface roughness (maximum height described in JIS B0601) of 3 to 3. A 20S satin surface is preferred because it prevents winding of the reinforcing fiber bundles constituting the reinforcing fiber sheet. The resin-impregnated portion 15 is composed of resin-impregnated rollers 13, 13,... And the reinforcing fiber sheet is sandwiched between release papers 12 coated with resin at the introduction position of the resin-impregnated portion, and the resin-impregnated rollers 13, 13,. A reinforced fiber sheet is impregnated with resin by pressing to obtain a prepreg product. Here, a metal heating roller is preferable as the resin impregnated roller, and the heating temperature may be any temperature at which the used resin is softened, and 60 to 150 ° C. is appropriate. The prepreg product is taken up by the product take-up unit 16, but the release paper 14 can be peeled off before taking up.

(Example 1)
Using the apparatus shown in FIG. 1, as reinforcing fiber bundles 5, 5,. Using fiber bundles ("Torayca" (registered trademark) T700SC-12K manufactured by Toray Industries, Inc.), 94 of them are arranged in a comb 7 so as to be parallel in one direction with a pitch of 10.6 mm and a total width of 1000 mm, 6 m / min Was fed to the opening means 8. As an opening means, the apparatus and method described in Example 1 of JP-A-10-292238 were used, and only the amplitude was changed to 10 mm.

  Two drive rollers 9 and 10 were installed behind the opening means 8. The drive rollers 9 and 10 each have a diameter of 50 mm, and a hard chrome plating roller processed on a satin surface having a surface roughness of 10S was used. Further, the driving roller 9 was placed in contact with the lower side of the reinforcing fiber sheet, and the driving roller 10 was brought into contact with the upper side of the reinforcing fiber sheet. The driving rollers 9 and 10 were connected to a commercially available motor via a belt, and the number of rotations of the motor was adjusted so that the peripheral speed was 2 m / min. At this time, Vr / Vf = 0.33 calculated from the peripheral speed Vr of the driving roller and the conveying speed Vf of the reinforcing fiber sheet.

  The reinforcing fiber sheet that passed through the driving roller 10 was uniform and good without the meandering or gaps of the reinforcing fibers.

The reinforcing fiber sheet after passing through the driving roller 10 and the guide roller 11 is sent to the resin-impregnated portion 15, and the resin-impregnated portion 15 has a width of B-stage epoxy resin on one side as release papers 12 and 12 coated with resin. The one coated with 1,005 mm and a basis weight of 22 g / m ² was used. The temperature of the resin-impregnated roller 13 was 100 ° C., and the linear pressure by the resin-impregnated roller was 58.8 kN / 1,000 mm (600 kgf / 1,000 mm). The obtained prepreg had a width of 1000 mm, a basis weight of 119 g / m ² and a fiber weight content of 63%, and the prepreg had no defects such as cracks caused by meandering reinforcing fibers and defective smoothness.

(Example 2)
A prepreg was produced in the same manner as in Example 1 except that the peripheral speed of the drive rollers 9 and 10 was changed to 5 m / min. At this time, Vr / Vf = 0.83 calculated from the peripheral speed Vr of the driving roller and the conveying speed Vf of the reinforcing fiber sheet.

  The reinforcing fiber sheet that passed through the driving roller 10 was slightly uniform in the meantime, although a slight meandering of the reinforcing fibers and a slight gap were observed.

  In addition, the obtained prepreg was slightly cracked, but was not so good as to deteriorate the quality of the prepreg and was good.

(Example 3)
As the reinforcing fiber bundles 5, carbon fiber bundles having an average single fiber diameter of 3 μm, the number of single fibers of 18,000, a fineness of 0.76 g / m, and a yarn width of 6 mm on the package (“TORAYCA manufactured by Toray Industries, Inc.” ”(Registered trademark) M30SC-18K), and 72 of them are aligned with a comb 7 so as to be parallel in one direction with a pitch of 13.9 mm and a total width of 1000 mm, and are spread to the opening means 8 at a speed of 5 m / min. Then, a prepreg was produced in the same manner as in Example 1. However, the frequency of the opening means 8 was set to 600 times / minute, and the peripheral speed of the drive rollers 9 and 10 was set to 2 m / minute. At this time, Vr / Vf = 0.40 calculated from the peripheral speed Vr of the driving roller and the conveying speed Vf of the reinforcing fiber sheet. The basis weight of the epoxy resin applied to the release papers 12 and 12 was 16 g / m ² . Other conditions were the same as in Example 1.

The reinforcing fiber sheet that passed through the driving roller 10 was uniform and good without the meandering or gaps of the reinforcing fibers. Further, the obtained prepreg had a width of 1000 mm, a basis weight of 88 g / m ² , and a fiber weight content of 63%, and the prepreg had no defects such as cracks caused by meandering reinforcing fibers and defective smoothness.

(Comparative Example 1)
A prepreg was produced in the same manner as in Example 1 except that the driving rollers 9 and 10 were removed.

  In the reinforcing fiber sheet that passed through the driving roller 10, meandering of the reinforcing fibers was partially seen, and there was a gap where the degree of meandering was large. In the obtained prepreg, cracks were observed at the locations where there were gaps in the reinforcing fiber sheet, which deteriorated the quality and quality of the prepreg.

(Comparative Example 2)
A prepreg was produced in the same manner as in Example 3 except that the driving roller was a fixed bar and Vr / Vf = 0 calculated from the peripheral speed Vr of the driving roller and the conveying speed Vf of the reinforcing fiber sheet.

  The reinforcing fiber sheet that passed through the driving roller 10 did not show any meandering or gaps in the reinforcing fiber, but a part of the reinforcing fibers damaged by the opening means 8 were excessively abraded by the driving rollers 9 and 10. The part which becomes a thread damage was seen. In the obtained prepreg, a large yarn damage portion was present as a defect, and the quality and quality of the prepreg were deteriorated.

It is the schematic which shows the example of the reinforcing fiber bundle from which the orientation of the single fiber shifted. It is the schematic which shows the example of the reinforcing fiber bundle with which the orientation of the single fiber was uniform. It is a schematic side view of the manufacturing apparatus of the prepreg which concerns on one form of this invention.

Explanation of symbols

1: reinforcing fiber bundle 2: single fiber constituting reinforcing fiber bundle 3: deviation of orientation of single fiber 4: package 5: reinforcing fiber bundle 6: guide roller 7: comb 8: fiber opening means 9: driving roller 10: driving Roller 11: Guide roller 12: Release paper coated with resin 13: Resin-impregnated roller 14: Recovery release paper 15: Resin-impregnated part 16: Product take-up part

Claims (8)

A prepreg manufacturing method in which a reinforcing fiber sheet obtained by opening a plurality of traveling reinforcing fiber bundles arranged in one direction is impregnated with a resin, and the opening means for opening the reinforcing fiber bundle; Between the resin impregnated portion, the central axis is arranged in a direction intersecting the reinforcing fiber sheet, and is contacted with a driving roller rotating at a peripheral speed Vr in the same direction as the conveying direction of the reinforcing fiber sheet. A method for producing a unidirectional prepreg, wherein the speed Vr is within a range of 0 <Vr / Vf ≦ 0.9 with respect to the conveying speed Vf of the reinforcing fiber sheet. 2. The method for producing a unidirectional prepreg according to claim 1, wherein a plurality of the driving rollers are arranged, and both surfaces of the reinforcing fiber sheet are brought into contact with the driving roller at least once. The method for producing a unidirectional prepreg according to claim 1 or 2, wherein the means for opening the reinforcing fiber bundle is by applying vibration to the reinforcing fiber bundle or by fluid contact. 4. The method for producing a unidirectional prepreg according to claim 2, wherein a total contact length of the plurality of driving rollers and the reinforcing fiber sheet is 5 to 500 mm. 5. The method for producing a unidirectional prepreg according to claim 1, wherein the reinforcing fiber bundle is a carbon fiber bundle. A prepreg manufacturing apparatus for impregnating a reinforcing fiber sheet obtained by opening a plurality of traveling reinforcing fiber bundles arranged in one direction with a resin, the opening means for opening the reinforcing fiber bundle; Between the resin impregnated portion, the central axis is arranged in a direction intersecting the reinforcing fiber sheet, and rotates at a peripheral speed Vr in the same direction as the conveying direction of the reinforcing fiber sheet to come into contact with the reinforcing fiber sheet. The drive roller is provided, and the drive roller is controlled so that the peripheral speed Vr of the drive roller is within a range of 0 <Vr / Vf ≦ 0.9 with respect to the conveyance speed Vf of the reinforcing fiber sheet. A unidirectional prepreg manufacturing apparatus. The prepreg manufacturing apparatus according to claim 6, wherein the driving roller is a flat roller and has a satin surface having a surface roughness of 3 to 20S. A unidirectional prepreg manufactured by the prepreg manufacturing method according to any one of claims 1 to 5 or the prepreg manufacturing apparatus according to claim 6 or 7.

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