JP7300698B2 - Prepreg manufacturing method and manufacturing apparatus - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method and apparatus for manufacturing a prepreg in which a plurality of reinforcing fibers extending in parallel in a predetermined direction are infiltrated into a thermoplastic resin sheet and integrated, and in particular, the degree of parallelism of the plurality of reinforcing fibers is determined by their extension. TECHNICAL FIELD The present invention relates to a method and apparatus for manufacturing prepregs that are uniformly maintained with respect to the direction in which they are present.

Conventionally, as a fiber reinforced plastic (FRP) material for application to structural materials such as automobiles and aircraft, so-called prepregs, in which reinforcing fibers are pre-impregnated with a thermoplastic resin matrix material to form a semi-solid state, have been widely used. ing. As a method for producing such a prepreg, a film stacking (FS) method is known, in which a fiber base material and a sheet-shaped resin film are laminated and pressed at high temperature and high pressure.

For example, in Patent Literature 1, a fiber bundle take-up section that sends out a spread fiber sheet in an expanded state, and a thermoplastic resin sheet that is supplied to the spread fiber sheet sent out in the spread state from the fiber bundle take-up section. a resin sheet supply unit that merges with the spread fiber sheet sent out from the fiber bundle take-up unit and superimposes a thermoplastic resin sheet on the surface of the spread fiber sheet; and a thermoplastic resin superimposed on the spread fiber sheet. A device for impregnating a spread fiber sheet with a thermoplastic resin, comprising: a resin heating and fusing mechanism that thermally melts the sheet and impregnates the melted thermoplastic resin between the fibers to form a prepreg sheet; and the device. is disclosed for producing a thermoplastic resin-impregnated prepreg sheet using In this impregnation device, the spread fiber sheet and the thermoplastic resin sheet are continuously supplied between the pair of press rolls from the fiber bundle supply mechanism and the resin sheet supply unit, respectively. and a thermoplastic resin sheet are superimposed to form a laminate. After that, the laminate is intermittently sent to the resin heating and fusing mechanism, and hot-pressed inside the resin heating and fusing mechanism so that the spread fiber sheets are evenly impregnated with the resin. ing.

Further, in Patent Document 2, a first supply roller that supplies a plurality of reinforcing fiber bundles to be opened, a second supply roller that supplies a resin film impregnated with the reinforcing fiber bundles, and the reinforcing fiber bundles A prepreg manufacturing apparatus is disclosed that includes a mechanism for applying ultrasonic vibrations and an impregnation device for heating and pressurizing a plurality of superimposed reinforcing fiber bundles and resin films. In this device, after applying ultrasonic vibration to a plurality of reinforcing fiber bundles to be supplied, resin is contained in the fibers by being heated and pressurized by an impregnation device equipped with a heating mechanism and a cooling mechanism inside. It is configured to be invaded.

JP 2005-29912 A JP 2016-130373 A

In a plastic reinforced by including fibers extending in one direction, the strength in the extending direction is higher when the included fibers are uniformly oriented (i.e., the "alignment degree" is high). . However, in the apparatus described in Patent Document 1, the superimposed spread fiber sheet and resin sheet are "intermittently" sent to the resin heating and fusing mechanism and are heat-pressed. It is conceivable that the fibers of the spread fiber sheet may be displaced by the applied pressure, and the intervals between a plurality of fibers may become uneven, or adjacent fibers may overlap, resulting in a decrease in the degree of alignment. On the other hand, in the device described in Patent Document 2, ultrasonic vibration is applied to a plurality of reinforcing fiber bundles before being sent to the impregnation device at a frequency of about 15 to 60 kHz in a direction perpendicular to the extending direction. It is described that the width of the reinforcing fiber bundle is widened and the thickness is reduced (see, for example, FIG. 3 of Cited Document 2), and the spacing between adjacent fibers becomes uneven or overlaps. It is inevitable that the degree of alignment decreases due to

In addition, in the devices described in Patent Documents 1 and 2, the resin of the resin sheet is once melted and "impregnated" between the reinforcing fibers. Even so, the shape stability decreases due to melting during impregnation. Moreover, since it melts once, it is inevitable that the properties of the resin sheet change before and after the impregnation.

The present invention has been made in view of the above circumstances, and its object is to increase the degree of alignment of a plurality of reinforcing fibers contained in a resin matrix, and to improve the alignment of the resin matrix before and after integration with the reinforcing fibers. An object of the present invention is to provide a prepreg manufacturing method and manufacturing apparatus capable of suppressing property changes.

According to the present invention, a method for manufacturing a prepreg in which a plurality of reinforcing fibers extending in parallel in a predetermined direction are infiltrated and integrated into a thermoplastic resin sheet includes integrating the plurality of reinforcing fibers with the thermoplastic resin sheet. At the time, it is characterized in that it is performed while applying tension in the predetermined direction to the plurality of reinforcing fibers. At this time, the plurality of reinforcing fibers and the thermoplastic resin sheet may be configured to be continuously supplied in the predetermined direction at the time of integration.

Further, according to the present invention, a prepreg manufacturing apparatus in which a plurality of reinforcing fibers extending in parallel in a predetermined direction are infiltrated into a thermoplastic resin sheet and integrated, includes a fiber supply mechanism that supplies the plurality of reinforcing fibers; A sheet supply mechanism that supplies the thermoplastic resin sheet, and an integration mechanism that integrates the plurality of reinforcing fibers into the thermoplastic resin sheet, wherein the fiber supply mechanism includes the plurality of reinforcing fibers. It is characterized by having a function of applying tension in the predetermined direction. At this time, the fiber supply mechanism includes a fiber unwinding mechanism that unwinds the plurality of reinforcing fibers, and a fiber guide mechanism that guides the plurality of reinforcing fibers unwound from the fiber unwinding mechanism to the integration mechanism. , may be provided.

According to this invention, when the plurality of reinforcing fibers are integrated with the thermoplastic resin sheet, tension is applied to the plurality of reinforcing fibers in the extending direction. Even if it comes into contact with tools or the like, the positional relationship between the fibers is maintained by tension, and the degree of alignment of the reinforcing fibers is maintained uniformly. In addition, since the resin is not melted and “impregnated” between the fibers, but the reinforcing fibers are integrated in a manner that “infiltrates” into the thermoplastic resin, the resin matrix before and after integration with the reinforcing fibers. It is possible to suppress the property change.

1 is a partial perspective view showing an outline of a prepreg manufactured by the manufacturing method of the present invention; FIG. 1 is a side view showing an outline of a prepreg manufacturing method according to a first embodiment of the present invention; FIG. FIG. 2 is a cross-sectional view schematically showing a prepreg manufacturing apparatus according to a second embodiment of the present invention; FIG. 4 is a partial cross-sectional view showing the outline of the main part of the guide mechanism shown in FIG. 3;

A prepreg manufacturing apparatus and a manufacturing method using the same as one embodiment of the present invention will be described below with reference to FIGS. 1 to 4. FIG.

FIG. 1 is a partial perspective view showing an outline of a prepreg manufactured by the manufacturing method of the present invention. As shown in FIG. 1 , the prepreg 10 is constructed in such a manner that a plurality of reinforcing fibers 14 extend in one direction X inside a thermoplastic resin sheet 12 .

The thermoplastic resin sheet 12 applied to the present invention is a sheet-shaped member that is preformed to a predetermined width and thickness according to the application. General-purpose resin materials such as PVC), polyurethane (PUR), polyethylene terephthalate (PET) can be exemplified. On the other hand, the reinforcing fibers 14 can be exemplified by bundles of general-purpose carbon fibers such as PAN or pitch. Here, FIG. 1 exemplifies a plurality of reinforcing fibers 14 aligned in the X direction at predetermined intervals. It can also include the state in which the fibers 14 are in contact with each other.

FIG. 2 is a side view showing the outline of the prepreg manufacturing method according to the first embodiment of the present invention, FIG. 2(a) showing the state of the reinforcing fiber preparation process, and FIG. 2(c) shows the state of the integration process, and FIG. 2(d) shows the prepreg after manufacturing. In the prepreg manufacturing method according to Example 1, as shown in FIG. 2(a), first, a plurality of reinforcing fibers 14 are arranged on the upper side of the lower mold 120 along the X direction (see FIG. 2(d)). (Reinforcing fiber preparation step). At this time, one end of the reinforcing fiber 14 is held by the one end clamp 110 and the other end is held by the other end clamp 112, and both clamps are moved so that the distance between them is separated in the X direction. A tensile force T1 in the X direction is applied to the reinforcing fibers 14 .

Next, as shown in FIG. 2(b), a lower sheet 12a and an upper sheet 12b made of a thermoplastic resin matrix are laminated on a lower mold 120 so as to overlap each other with the plurality of reinforcing fibers 14 interposed therebetween. (Lamination process). Subsequently, as shown in FIG. 2C, an upper mold 122 is placed above the upper sheet 12b, and the lower sheet 12a, the reinforcing fibers 14, and the upper sheet 12b laminated by the lower mold 120 and the upper mold 122 are laminated. are integrated by applying pressure P while heating (integration step). At this time, the reinforcing fiber 14 maintains a state in which the tension T1 is applied by the one end clamp 110 and the other end clamp 112 . Due to such an operation, the plurality of reinforcing fibers 14 positioned under tension "invade" into the lower sheet 12a and the upper sheet 12b, which have been semi-melted by heating, from the opposite surfaces. (i.e., “penetrating from the surface”). Then, as shown in FIG. 2(d), when the heat and pressure are released, the prepreg 10 having a plurality of reinforcing fibers 14 extending in the X direction is formed inside the thermoplastic resin sheet 12. As shown in FIG.

According to the prepreg manufacturing method according to the first embodiment of the present invention described above, the plurality of reinforcing fibers 14 are heated and pressed while the tension T1 in the X direction is maintained, whereby the reinforcing fibers 14 are can ensure a uniform degree of alignment. A lower mold 120 and an upper mold 122 heat-press the laminated lower resin sheet 12a and upper resin sheet 12b by one end clamp 110 and the other end clamp 112 that apply a tension T1 to the plurality of reinforcing fibers 14. Therefore, when the semi-molten resin sheets 12a and 12b are pressurized, it is possible to prevent the reinforcing fibers 14 from being displaced or deformed to lower the degree of alignment. Furthermore, since it is not necessary to heat the resin sheets 12a and 12b to a completely melted state, it is possible to maintain the shape and material of the resin sheets 12a and 12b before and after the integration.

FIG. 3 is a sectional view schematically showing a prepreg manufacturing apparatus according to a second embodiment of the present invention. The cross-sectional view shown in FIG. 3 shows a cross-section along the feed direction of the manufactured prepreg in the prepreg manufacturing apparatus according to the second embodiment, as seen from a side orthogonal to the cross-section. there is As shown in FIG. 3, a prepreg manufacturing apparatus 200 according to the second embodiment includes a supply mechanism 210 that continuously supplies a resin sheet 12 made of a thermoplastic resin matrix and a plurality of reinforcing fibers 14, and the supply mechanism 210. An integration mechanism 220 that integrates the resin sheet 12 and the reinforcing fibers 14 sent from 210 into the prepreg 10, and a recovery mechanism 230 that winds up and recovers the prepreg 10 after manufacturing.

The supply mechanism 210 includes a first reel 212 that holds the plurality of reinforcing fibers 14 in a wound state and continuously unwinds and supplies them, and a resin sheet 14 that holds the resin sheet 14 in a wound state and continuously winds it. A second reel 214 to be drawn out and supplied, and a guide mechanism 216 arranged downstream of the first reel 212 to guide the plurality of reinforcing fibers 14 and supply them to an integration mechanism 220 located further downstream. and including. Here, FIG. 3 illustrates a case where only one first reel 212 is provided for ease of illustration, but a plurality of reels 212 are provided according to the number of supplied reinforcing fibers 14 . A first reel 212 may be provided, each feeding into a guide mechanism 216 . Further, the second reel 214 is also exemplified in the case where the continuously supplied reinforcing fibers 14 are supplied from above, but the second reel may be arranged below, or may be arranged from both above and below. The two resin sheets may be configured to be continuously supplied. Details of the guide mechanism 216 will be described later. A fiber supply mechanism is formed by the first reel 212 and the guide mechanism 216 shown in FIG. 3, and a sheet supply mechanism is formed between the second reel 214 and the integrated mechanism 220 .

The integration mechanism 220 includes a body portion 222 and a pair of pressure rollers 223a and 223b rotatably attached to the side surface of the body portion 222. As shown in FIG. A pair of pressure rollers 223a and 223b are attached to the body portion 222 so that the centers of the rollers 223a and 223b can approach or separate from each other. As a result, the integration mechanism 220 can handle any thickness of the resin sheet 12 that is sent, and has a function of applying a pressure force when integrating the resin sheet 12 and the reinforcing fibers 14 . Further, as one aspect of the second embodiment, the pair of pressure rollers 223a and 223b are provided with a heating means such as a heater inside to pressurize the resin sheet 12 and at the same time perform necessary heating to integrate them. It has a function of softening the resin sheet 12 to such an extent that the reinforcing fibers 14 can easily enter inside in the process. The heating means for heating the resin sheet 12 only needs to be sufficiently heated when the resin sheet 12 is sandwiched between the pair of pressure rollers 223a and 223b. It may be arranged in the middle of the transport path from the reel 214 to the integration mechanism 220 .

The recovery mechanism 230 includes a recovery reel 232 on which the prepregs 10 manufactured by the integration mechanism 220 and continuously fed are wound and held, and a buffer section 234 arranged between the integration mechanism 220 and the recovery reel 232. and first to third transport rollers 235 a to 235 c provided on the side surface of the buffer section 234 . In the second embodiment, the first and second transport rollers 234a and 235b are arranged so as to sandwich the prepreg 10 sent from the integration mechanism 220 from above and below. On the other hand, the third conveying roller 235 c is arranged downstream of the first and second conveying rollers 235 a and 235 b and is arranged to change the conveying direction of the prepreg 10 toward the recovery reel 232 . A transport path for the prepreg 10 is formed by these first to third transport rollers 235a to 235c. Here, the third transport roller 235c is provided according to the position such as the height of the recovery reel 232 with respect to the buffer section 234, and may be omitted if not particularly required.

FIG. 4 is a partial cross-sectional view showing the outline of the essential parts of the guide mechanism shown in FIG. In the second embodiment, the guide mechanism 216 provided in the supply mechanism 210 is provided with a direction change roller 216a and a tensioning mechanism 217 arranged downstream of the direction change roller 216a on each side. there is The tensioning mechanism 217 includes a pair of guide rollers 217a and 217b arranged vertically. A conveying path for the reinforcing fibers 14 is formed by the direction changing roller 216a and the first and second guide rollers 217a and 217b. In addition, as described above, when a plurality of first reels 212 are provided for a plurality of reinforcing fibers 14, it is preferable that a plurality of direction changing rollers 216a corresponding thereto are also arranged.

In addition, as shown in FIG. 4, the direction-changing roller 216a is applied with tension so as to intentionally bend the conveying direction of the conveying path of the reinforcing fibers 14 from the pair of guide rollers 217a and 217b to the integrating mechanism 220. It is arranged below the application mechanism 217 . On the other hand, as shown in FIG. 4, the tensioning mechanism 217, including the pair of guide rollers 217a and 217b, is arranged in the left-right direction Y (that is, the transport direction F shown in FIG. 4) with respect to the main body of the guide mechanism 216. It has a structure that allows it to move in parallel relative to As a result, the reinforcing fibers 14 sent from the first reel 212 and transported from the direction changing roller 216a are transported while being bent by the guide rollers 217a when sandwiched between the pair of guide rollers 217a and 217b. . At this time, the tension applying mechanism 217 moves away from the integrating mechanism 220 (in the direction of arrow Y in FIG. 4), so that the tension T2 in the direction opposite to the conveying direction F is applied to the reinforcing fibers 14 . is loaded.

Next, with reference to FIGS. 3 and 4, the outline of the prepreg manufacturing method according to the second embodiment of the present invention will be described. First, as shown in FIGS. 3 and 4, in the supply mechanism 220, a plurality of reinforcing fibers 14 are unwound from the first reel 212 to the guide mechanism 216 and supplied to the guide mechanism 216 via the tensioning mechanism 217 of the guide mechanism 216. It is supplied to a pair of pressure rollers 223a and 223b of the integration mechanism 220 (reinforcing fiber preparation step). At the same time, the resin sheet 12 is unwound from the second reel 214 and supplied to the pair of pressure rollers 223a and 223b (lamination step).

Subsequently, the resin sheet 12 and the reinforcing fiber 14 sandwiched between the pair of pressure rollers 223a and 223b are pressed while the resin sheet 12 is heated to a predetermined temperature and softened. At this time, the continuously supplied reinforcing fibers 14 are sandwiched between the pair of pressure rollers 223a and 223b, and the tension applying mechanism 217 is driven to apply tension T2 in the direction opposite to the conveying direction F. Stay loaded. As a result, the plurality of reinforcing fibers 14 positioned under tension are integrated in such a manner that they “invade” inside from the surface of the resin sheet 12 which has been in a semi-molten state by heating (integration step). . Then, the prepreg 10 that has passed through the integration mechanism 220 is wound up on the recovery reel 232 via the buffer section 234 of the recovery mechanism 230 and recovered.

According to the prepreg manufacturing method and manufacturing apparatus according to the second embodiment of the present invention described above, while maintaining the state in which the tension T2 in the X direction is applied to the plurality of reinforcing fibers 14 that are continuously supplied, Since the integration step with the resin sheet 12 is performed, the prepreg can be continuously formed while ensuring uniform alignment of the reinforcing fibers 14, as in the first embodiment. Moreover, since the resin sheet 12 is heated and pressurized in a short time, it is possible to continuously manufacture prepreg while maintaining the shape and material of the resin sheet 12 before and after the integration.

Although the embodiments according to the present invention and modifications based thereon have been described so far, the present invention is not necessarily limited to these examples. Also, those skilled in the art will be able to find various alternatives and modifications without departing from the spirit of the invention or the scope of the appended claims.

10 prepreg 12 resin sheet 14 reinforcing fiber 110 one end side clamp 112 other end side clamp 120 lower mold 122 upper mold 210 supply mechanism 212 first reel 214 second reel 216 guide mechanism 217 tension applying mechanism 220 integration mechanism 230 recovery mechanism 232 collection reel 234 buffer unit

Claims (4)

A method for producing a prepreg in which a plurality of reinforcing fibers are provided inside a thermoplastic resin sheet so as to extend parallel to each other in the longitudinal direction of the thermoplastic resin sheet, comprising:
The thermoplastic resin sheet in a semi-molten state and the plurality of reinforcing fibers extending parallel to each other are superimposed and continuously supplied between a pair of pressure rollers to form the plurality of reinforcing fibers on the thermoplastic resin sheet. When the plurality of reinforcing fibers extending parallel to each other are sandwiched between a pair of guide rollers upstream of the pair of pressure rollers, the pair of pressure rollers are sandwiched between the pair of pressure rollers. A method of manufacturing a prepreg, characterized in that the prepreg is integrated while being moved in a direction away from the pressure roller to apply tension. 2. The method of manufacturing a prepreg according to claim 1, wherein the plurality of reinforcing fibers are bent and sandwiched by one of the pair of guide rollers. A prepreg manufacturing apparatus in which a plurality of reinforcing fibers are provided inside a thermoplastic resin sheet so as to extend parallel to each other in the longitudinal direction of the thermoplastic resin sheet,
A fiber supply mechanism that supplies the plurality of reinforcing fibers, a sheet supply mechanism that supplies the thermoplastic resin sheet, and an integration that integrates the plurality of reinforcing fibers by penetrating from the surface of the thermoplastic resin sheet into the interior. comprising a mechanism and
The integration mechanism includes a pair of pressure rollers, and between the pair of pressure rollers , the thermoplastic resin sheet and the plurality of fibers extending parallel to each other from the sheet supply mechanism and the fiber supply mechanism, respectively. The reinforcing fibers are continuously supplied in an overlapping manner, and the plurality of reinforcing fibers are made to penetrate into the inside from the surface of the thermoplastic resin sheet in a semi-molten state to be integrated ,
The fiber supply mechanism includes a pair of guide rollers that sandwich the plurality of reinforcing fibers extending parallel to each other upstream of the pair of pressure rollers, and the pair of guide rollers is moved from the pair of pressure rollers. The thermoplastic resin sheet and the plurality of reinforcing fibers extending parallel to each other are integrated by the integrating mechanism by applying tension to the plurality of reinforcing fibers extending parallel to each other by moving in a direction separating them. A prepreg manufacturing apparatus characterized by: The fiber supply mechanism includes a fiber unwinding mechanism that unwinds the plurality of reinforcing fibers, and a plurality of reinforcing fibers unwound from the fiber unwinding mechanism that are bent and sandwiched by one of the pair of guide rollers. 4. The prepreg manufacturing apparatus according to claim 3, further comprising a direction changing roller that causes the prepreg to rotate.

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