JPH0442168B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method and apparatus for manufacturing a fiber-reinforced sheet prepreg in which a resin sheet is reinforced with fibers. The fiber-reinforced sheet-like prepreg of the present invention is used, for example, as an industrial material such as a laminated material. [Prior Art] A method for producing a fiber reinforcing composition by impregnating fibers with a thermoplastic resin is disclosed in Japanese Patent Application Laid-Open No. 61-229534.
As described in JP-A No. 61-229535 and JP-A No. 61-229536, fiber sheets (such as warp only, woven fabric consisting of warp and weft, etc.) are coated with thermoplastic resin. The thermoplastic resin coated on the surface of the coating roll is transferred to the fiber sheet by guiding it to a coating roll whose surface is coated as a film, and then the front and back surfaces of the fiber sheet are brought into contact with a heating roll. , a method of increasing the degree of resin impregnation is known. [Problems to be Solved by the Invention] In the apparatus according to the above-described conventional method, there is no air shielding member such as a belt on the back surface of the fiber sheet that contacts the coating roll, and the fiber sheet is in an open state. In addition, since the application roll and each heating roll adjacent to it are arranged horizontally in parallel with a space between them,
The resin immediately after extrusion is continuously supplied to the application roll, and is transferred to the adjacent heating roll by continuously applying the resin to the fiber sheet. For this reason, the deterioration of the resin on the surface of the applicator roll appears to be continuous and is apparently small, but the transfer of the resin to the surface of the heating roll adjacent to the applicator roll immediately after extrusion is caused only by the fiber sheet. The amount is extremely small. For the above-mentioned reason, the resin transferred to the surface of the heating roll remains as it is without almost transferring to the adjacent heating roll. Therefore, the resin transferred to the surface of the heating roll is not replaced with the resin immediately after extrusion, but remains on the heating roll at a high temperature and in contact with air. Since it is extremely difficult to completely remove the resin transferred to the heating roll, the stagnant resin will progress to crosslinking and gelation due to thermal deterioration and oxidative deterioration of the resin over time, making operation impossible. There is a problem that. Further, since the resin in the obtained sheet has undergone thermal and oxidative deterioration as described above, it does not maintain sufficient strength and physical properties, leading to problems such as deterioration of sheet performance. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method and apparatus for manufacturing a high-performance fiber-reinforced sheet prepreg that allows stable continuous operation and less resin deterioration. [Means for Solving the Problems] The above objects of the present invention are achieved by the inventions set forth in claims 1 to 17. That is, the main feature of the present invention is that the fiber sheet is passed between a pair of belts that are heated above the softening point of the thermoplastic resin, have a coating film of the thermoplastic resin, and are welded by surface pressure to a heating roll. It is in. [Function] The pair of belts are continuous, and when the impregnated fiber sheet separates from the belt at the outlet of the impregnated section, some resin is transferred to the belt surface, and even if it is cooled and solidified, the belt When the transfer resin returns to the entrance of the impregnating section, the solidified transfer resin is reheated and melted, and is fused with a large amount of resin immediately after extrusion, so that the resin does not remain between the belts. Therefore, there is no problem of operating time, thermal deterioration, oxidative deterioration, or gelation of the resin, which was a problem with conventional roll coating, and long-term continuous operation is possible. Further, as described above, since thermal deterioration, oxidative deterioration, etc. are not caused, a high-performance sheet can be obtained. [Structure of the Invention] In the application of the present invention, fiber sheets to be impregnated with resin include those arranged in a sheet shape using only warp threads, woven fabrics woven using warp threads and weft threads, and the like. In the present invention, the plurality of continuous fibers constituting the fiber sheet refers to the use of a plurality of fibers known as rovings, yarns, and tows, which are aggregates of filaments constituting the fibers, and the filaments are long enough. and has sufficient strength to be pulled against a molten thermoplastic resin coating under the conditions of use. Preferred materials include glass fibers, carbon fibers, and highly elastic synthetic resin fibers, but inorganic silicon carbide fibers, alumina fibers, titanium fibers, boron fibers, and metal fibers such as stainless steel can also be used. The synthetic resin fibers are preferably surface-treated to have adhesive properties with the thermoplastic resin to be impregnated, and further, it is necessary that the properties such as strength do not change at the melting temperature of the thermoplastic resin used.
Examples of synthetic resin fibers include aramid fibers (registered trademark "Kevlar", etc.). The glass fibers and carbon fibers are preferably coated with a surface treatment agent such as a silane-based or titanium-based coupling agent on the fiber surface in order to improve adhesion with the thermoplastic resin used. Further, a sizing agent can be used to prevent the roving or tow from unraveling during handling within a lifetime during impregnation. The above-mentioned continuous fibers are arranged in parallel in one direction, for example, in the machine direction, spread in the width direction while being controlled so as not to cross each other, and adjusted to an appropriate thickness to form a sheet like the warp of a loom. formed into a shape. Specifically, continuous fibers are wound around multiple bobbins, and the fibers are fed out from each bobbin while applying an appropriate tension, and are arranged in a line with an appropriate width in the machine direction in a sieve-like shape. Preferably, they are arranged in a sheet through the container. The thickness of the sheet depends on the thickness of the fibers (rovings and tows) used, but can be controlled by the arrangement and density of the rovings and tows in the width direction. Since the thickness accuracy affects the variation in the impregnated state, it is preferably within ±10% of the target thickness. There is no particular limit to the thickness, but if the thickness is greater than 10 μm, fiber breakage can be prevented, while if it is thinner than 1000 μm, the degree of resin impregnation will be high, there will be few voids, and no molding defects will occur. When arranging fibers into a sheet, it is effective to increase the humidity of the working environment in order to prevent the fiber filaments from breaking due to friction when they pass through guide rollers or aligners. In the sheet thus obtained, it is necessary that a uniform tension be applied to each roving or tow so that the rovings or tows do not cross each other. The above-mentioned fiber sheet may be made by aligning a plurality of continuous fibers as shown in the examples below, but it is also possible to use a so-called beamed yarn in which a required number of continuous fibers are wound in advance around a warp beam in one direction like a warp. be. The beamed yarns mentioned above are widely used as warp yarns when making continuous fibers into woven fabrics. In the present invention, a woven fabric refers to a fabric processed into a fabric using the above-mentioned continuous fibers, and the weaving method of the fibers is arbitrary. Therefore, the woven fabrics used in the present invention include those obtained by weaving methods generally called plain weave, satin weave, twill weave, and herringbone weave, as well as mat-like nonwoven fabrics and needle-woven fabrics in the mat-like nonwoven fabrics. Including punched products. In impregnating the fiber sheet with a thermoplastic resin, the thermoplastic resin used is polystyrene, polyvinyl chloride, high-density polyethylene, polypropylene, nylon, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, etc., but is limited to these. Not done. In addition, when using the resin sheet (prepreg) obtained by the present invention for applications that require structural strength, it is preferable that the resin has a high elastic modulus and high tensile strength. High grade engineering resins such as , polysulfone, polyphenylene sulfide, thermoplastic polyimide, polyetherimide (trademark "ULTEM"), polyetheretherketone, etc. are suitable. When using these resins, it is preferable to dry them in advance, and it is more preferable to add a titanium-based coupling agent or the like to the resin for the purpose of improving adhesion to fibers. The thermoplastic resin is melted in, for example, an extruder, extruded from a die provided at the tip of the extruder, and applied to a previously heated surface of, for example, a lower belt. The resin temperature is set so that a uniform resin coating is formed.
It is determined according to the characteristics of each resin.
The width of the resin coating film may be equal to or greater than the width of the fiber sheet, and the thickness of the coating film is adjusted to an appropriate thickness corresponding to the thickness of the fiber sheet. This thickness is a value determined experimentally based on the set target value of the resin content in the fiber-reinforced sheet finally obtained. The coating film thickness is preferably 10 to 1000 μm, more preferably
It is 20 to 200 μm. On the other hand, since the thickness accuracy greatly affects the resin content in the width direction, it is preferably within ±10% of the set thickness, and more preferably within ±5%. As a coating method for improving the thickness accuracy of the coating film in this way, a conventional method can be used. In this way, the fiber sheet was given a resin coating,
For example, the fibers are pressed against a roll via a lower belt, and impregnation of the fibers with resin is started. Impregnation is achieved when the resin coating passes between the filaments constituting the fiber sheet and reaches the back side of the fiber sheet, so the contact pressure of the fiber sheet to the belt and eventually to the roll is determined by the resin coating of the fiber sheet. It is sufficient that the membrane can be pushed apart to reach the lower belt surface, and this contact pressure is adjusted by the tension applied to the fiber sheet. If this tension is too strong, the resin coating will not pass between the filaments of the fiber sheet and will be pushed apart in the width direction of the fiber sheet, so the tension must be determined depending on the viscosity of the resin used. In the present invention, the viscosity of the resin is preferably 500 to 50,000 poise, more preferably 1,000 to 5,000 poise. Further, in the present invention, the tension applied to the fiber sheet (or woven fabric) is preferably 1 to 10,000 g/sheet, more preferably 10 to 5,000 g/sheet.
In the case of woven fabric, the tension is preferably 5 to 100,000 g/cm width, more preferably 50 to 20,000 g/cm width. The resin-coated fiber sheet is then conveyed while being sandwiched between upper and lower belts, and is pressed against, for example, one or more heating rolls,
After improving the impregnation efficiency, it is cooled and collected. The temperature of these heating rolls is above the softening point of the resin to be impregnated. In this specification, the softening point refers to the lowest temperature that can be measured using a melt index measuring device under a load of 5 kg. If the surface of the fiber sheet that first comes in contact with the lower belt is the front side, then the next heating roll will have the back side through the upper belt, and the next heating roll will have the front side through the lower belt. , while alternately pressing the front and back sides against the roll via the lower and upper belts,
The fiber sheet is passed through the belt such that the resin present on the front or back side flows between the filaments of the fiber sheet in alternating directions from the front side to the back side and then from the back side to the front side by the plurality of rolls via the lower or upper belt. It is preferable to press it against a roll, and by doing so, the degree of impregnation can be improved. In the present invention, the number of rolls should be determined by the characteristics of the resin used, and it is an extremely effective means to adjust the number of heated rolls to the required number depending on the type of resin used. In the application of the present invention, it is preferable to remove the resin adhering to the belt surface with a doctor plate or the like, since this has the effect of adjusting the resin content and smoothing the surface of the fiber sheet. Further, the resin can be removed in either a molten or solidified state, but the state should be determined depending on the characteristics of the resin. Next, regarding cooling of fiber sheets impregnated with resin, especially in the case of crystalline resins, the crystallinity and crystal grain size are affected by the cooling rate, so by adjusting the cooling rate depending on the resin used, the fiber sheet It is preferable to control the crystallinity and crystal grain size of the resin within. The cooling rate can be adjusted by providing a heating zone between the impregnating section and the drawing machine and creating a temperature gradient in the heating zone to gradually cool the material.
Alternatively, a method of rapidly cooling the fiber sheet by directly spraying a cooling medium such as cooling air onto the fiber sheet may be adopted. On the other hand, when the fiber sheet is separated from the impregnated part with the impregnated resin in a molten state as described above, depending on the type of the impregnated resin, it may be
The resin part may deteriorate. In this case, it is more preferable to provide a cooling device in the resin-impregnated portion to cool the belt to below the softening point of the thermoplastic resin. In this case, the fiber sheet impregnated with the thermoplastic resin is then cooled to below the softening point of the resin while being held between the belts, and then taken to the take-off section. Examples of the cooling method include slow cooling in the atmosphere, and forced cooling of the upper and lower belts by air injection, water, and the like. During the cooling, cooling the fiber sheet under pressure, for example, by sandwiching the upper and lower belts between one or more pairs of cooling nip rolls and applying pressure to the fiber sheet via the upper and lower belts, improves the appearance of the fiber sheet and defoams. This is preferable from the viewpoint of this, and also contributes to improving the releasability of the fiber sheet from the belt. It is particularly preferable to perform mold release treatment on the belt surface before or during operation, from the viewpoint of improving the mold releasability of the fiber sheet. Next, details of the present invention will be explained with reference to representative embodiments shown in the drawings. First, an example in which the present invention is applied to a fiber sheet made of a plurality of continuous fibers will be described. As shown in FIG. 1, the manufacturing apparatus for carrying out the method of the present invention comprises a fiber delivery section 1, a supply section 2, a resin impregnation section 3, and a take-off section 4. Feeding Section The fiber feeding section 1 has means for supplying a plurality of continuous fibers, such as a plurality of bobbins 6, and a mechanism for adjusting tension during feeding of the fibers, such as a tension adjusting brake belt 64 shown in FIG. 2. In the fiber delivery section 1, continuous fibers 7 wound around a plurality of bobbins 6 attached to a pedestal 5 are delivered in a required number of fibers. As shown in FIG. 2, the bobbin 6 has a bobbin main body 61 fixed to a shaft 62, and the shaft 62 rotatably attached to a bearing 63.
A tension adjustment brake belt 6 is attached to the shaft 62 to adjust the tension at which the fibers are fed out from the bobbin 6.
4 is installed. Supply Unit The supply unit 2 has the function of arranging the continuous fibers 7 fed out from the bobbin body 61 horizontally with a guide roll 8 and arranging them with an arbitrary fiber interval and arbitrary width using an aligner 9 to form a fiber sheet 10. have As shown in FIGS. 3 and 4, the aligner 9 is a frame-like frame with a large number of steel wires 91 stretched, and the continuous fibers 7
are aligned by passing through the gaps between the steel wires 91 one by one. The aligner 9 has a bearing 92 and has a structure that allows the angle to be changed in the direction of the arrow as shown in FIG. Width and thickness can be adjusted. Reference numeral 93 is a set screw for fixing the aligner 9 after selecting an arbitrary angle. Next, the tension of the fiber sheet 10 is controlled to be uniform over the entire width by a tension adjustment roll 11 having a brake 12, and the fiber sheet 10 is supplied to the resin-impregnated section 3. The surface of the tension adjustment roll 11 is preferably made of rubber or the like so that the tension can be easily adjusted by frictional resistance. There are no particular restrictions on the tension, and the fiber sheet 1
0 is sufficient as long as there is no disturbance between the fibers during the impregnation process of the resin-impregnated portion 3. Note that the tension adjustment roll 11 may not be used as long as it is possible to uniformly adjust the tension of all the bobbins 6 in the feeding section 1. Resin-impregnated section The resin-impregnated section 3 has a pair of belts, that is, an upper belt 14 and a lower belt 15, and a first heating roll (entrance heating roll) 17, a first heating roll (inlet heating roll) 17, a first heating roll (inlet heating roll) Two heating rolls 18 and a lower pull roll (exit roll) 19 are arranged in parallel. A first nip roll 20 is arranged above the first heating roll 17, and an upper pull roll 22 is arranged above the lower pull roll 19. 21 is an upper belt tension adjustment roll, 23 is a heated resin supply roll, and 24 is a lower belt tension adjustment roll.
13 is a resin supply die, and 16 is a drive motor. As the belt heating means, a method is used in which the heat of the heated rolls 17, 18, 19, 22, and 23 is conducted to the belt that is in surface pressure contact with these rolls. By adjusting the distance between the exit rolls 19 and 22, it is possible to adjust the thickness of the resulting fiber-reinforced sheet prepreg. Note that it is preferable that the upper and lower belts 14 and 15 be provided with scrapers (not shown) for scraping off the resin coating film attached to the surfaces, so that both belts always contact the resin and fiber sheet 10 with clean surfaces. It is preferable that the amount of resin impregnated into the fiber sheet 10 does not vary. When the fiber sheet 10 enters the resin-impregnated section 3 having the above structure, a thermoplastic resin plasticized by an extruder (not shown) is passed through the die 13 and a thin film of the resin is coated on the surface. It comes into contact with the belt 15 and is impregnated with the resin by being pressed against the heating roll 17 via the belt 15, and then transferred to the heating roll 18 via the upper belt 14, and then to the pull roll (heating roll) via the lower belt 15. 19.
In this way, sufficient resin impregnation is achieved. The resin-impregnated portion of the present invention can be improved as shown in FIG. 6 from the viewpoint of improving the impregnation effect under high speed conditions. Note that the embodiment shown in FIG.
A third heating roll 50 and a fourth heating roll 51 are added to the resin-impregnated portion in the figure. First of all, the first improvement is that a first
A resin impregnation accelerator roll 30 is provided. The position where the roll 30 is provided is preferably a position where the fiber sheet is more strongly pressed against the first heating roll 17, and the position may vary depending on the viscosity of the resin, the tension direction between the first heating roll 17 and the second heating roll 18, etc. The preferred location can then be determined. In the illustrated embodiment, the first heating roll 1
7, and with the first heating roll 17 as the center, the side where the roll 30 is provided is downward to the left in the drawing, and the side where the second heating roll 18 is provided is downward to the right in the drawing. The structure is such that each tension acts. Although the distance between the centers of the roll 30 and the first heating roll 17 is not particularly limited, it is preferable that they be close to each other as shown in the drawing. When the roll 30 and the first heating roll 17 are provided a little apart, another roll that exhibits a cooperative action with the roll 30 may be interposed between the rolls 30 and 17.
Preferably, the roll 30 is provided with a roll position adjustment mechanism for moving it closer to or away from the first heating roll 17. The direction in which the fiber sheet 10 is introduced into the impregnated section 3 is usually the horizontal direction as shown in the figure, but it is not limited to this, and may be in any direction such as upward or downward while maintaining the horizontal direction. If the sheet 1
It goes without saying that a plurality of guide rolls may be interposed in the roller 0 to the extent that the effects of the present invention are not impaired. Further, when the sheet 10 is introduced in a forward upward direction, the inclination of the sheet 10 between the roll 30 and the roll 17 may be the same or approximately the same, in which case the roll 30 is
It is also possible that the rollers act cooperatively with the guide rolls interposed between them. Note that the diameter (size) of the roll 30 is not limited. By providing the first resin impregnation accelerating roll 30 as described above, it is possible to promote resin impregnation into the fiber sheet 10 even under high-speed conveyance, and the air inside the fibers can be degassed at the initial stage of impregnation, resulting in high quality. You can get the product. The second improvement is to provide an outlet impregnation accelerator roll 31 at the outlet of the resin impregnated section 3. In the illustrated embodiment, the roll 31 is preferably located at a position below the upper end of the exit roll (lower pull roll) 19 and at a position where the fiber sheet 10 can be pressed against the exit roll 19. The roll 31
It is preferable that a roll position adjustment mechanism for moving the roll 19 closer to or farther away from the roll 19 is provided. The roll 31 and the exit roll 19 only need to be close to each other, and the distance between their centers is not particularly limited, but it is preferable that they be close to each other as shown in the drawing. If the roll 31 and the exit roll 19 are provided a little apart, another roll that cooperates with the roll 31 may be interposed between the roll 31 and the exit roll 19. The direction in which the fiber sheet 10 is led out from the impregnated portion 3 is as follows:
Normally, the direction is horizontal as shown in the figure, but it is not limited to this, and depending on the winding position, it may be up in the front or down in the front, etc. In that case, the sheet 1
It goes without saying that a plurality of guide rolls may be interposed in the roller 0 to the extent that the effects of the present invention are not impaired. In addition, when the sheet 10 is led out from the exit roll 19 in a forward downward direction, the lead-out slope is such that the sheet 10 between the roll 31 and the exit roll 19
The inclination of the roll 31 may be the same or approximately the same as the inclination of the roll 31, and in that case, the roll 31 may cooperate with other guide rolls interposed in the sheet 10. Note that the shape of the roll 31 is not limited to a flat type, but may be a curved cross-section type, and the diameter (size) of the roll 31 is also not limited. When the exit impregnation accelerating roll 31 as described above is provided, it is effective in eliminating variations in the degree of resin impregnation even at high speeds and preventing the occurrence of cracks (so-called splits) in the fiber direction between the fiber sheets. The third improvement is to attach impregnation accelerator rolls 32, 33, and 34 to each of the second heating roll 18, third heating roll 50, and fourth heating roll 51 (referred to as intermediate heating rolls). . The second heating roll 18 and the fourth heating roll 51
In this embodiment, tension is applied upward, and the impregnation accelerating rolls 32 and 34 are each
It is also preferable that the heating rolls 18 and 51 be provided in contact with each other below the fourth heating rolls 18 and 51. Similarly, the impregnation accelerating roll 33 is preferably disposed above the third heating roll 50. The sizes of the impregnation accelerator rolls 32, 33, and 34 are not particularly limited. The positions at which the impregnation accelerator rolls 32, 33, and 34 are provided are not limited to directly below or directly above the heating rolls 18, 50, and 51, and may be slightly biased forward and backward (left and right). By providing the above impregnation accelerating rolls 32, 33, and 34, it is possible to increase the speed of conveyance, eliminate variations in resin impregnation into the fiber sheet 10, and adjust the product thickness. A fourth improvement is to provide meandering adjustment rolls 35 and 36 between rolls 21 and 22 and between rolls 19 and 24, respectively. The rolls 35 and 36 adjust the tension of the rolls 21 and 24 by moving up and down in the drawing, while the meandering of the belt is adjusted by moving only one end of the roll in the left and right directions in the drawing. do. The means for moving the rolls 35 and 36 in the left-right direction is not particularly limited, and various sliders or the like can be used, for example. Although not shown, the rolls 35 and 36 are provided at positions in contact with the outside of the belts 14 and 15,
The meandering may be adjusted by pressing the belts 14 and 15 from the outside, and in this case, the rolls 35,
The material of 36 is preferably a soft material such as aluminum. Further, the rolls 35 and 36 are the roll 2
0 and the roll 21, and between the roll 23 and the roll 24, respectively. Furthermore, in addition to the rolls 35 and 36, the roll 3
One or more rolls movable in the same direction or in a different direction from those of 5 and 36 may be added. Also, rolls 19, 22 or rolls 17, 20
The meandering adjustment function may be imparted to the rolls by moving only one end of each roll in the left-right direction. When the above meandering adjustment rolls 35 and 36 are provided,
It is possible to prevent the belt from meandering, which could occur if the tension roll were to run out. The fifth improvement is to provide a tension adjustment means T for making the tension of the belt Bx in front of the roll 51 one position before the exit roll 19 larger than the tension of the belt By behind the roll 51 one position before the exit roll 19. That's true. The tension adjustment means T includes, for example, a drive motor 16 directly connected to the exit roll 19, and a drive motor 16 directly connected to the exit roll 19.
Transmission 1 directly connected to roll 51 one position before roll 9
6A, and it is preferable to have a configuration in which the rotational speed of the roll 51 one position before the exit roll 19 is made different, that is, a configuration in which the driving force of the transmission 16A is transmitted to the roll 51. The transmission 16A may be of any type as long as it can be changed continuously or stepwise, and may be automatic,
It can be either semi-automatic or manual. Further, the speed change method may be, for example, a belt type, a gear type, or the like. Although the adjustment range of the transmission is not particularly limited, it is preferably 10 to 95% of the drive motor revolutions. In the present invention, it is preferable to adjust the speed change rate of the transmission 16A so as to speed up the rotation of the exit roll 19 and slow down the rotation of the roll 51 immediately before it. Upper and lower exit rolls (upper and lower pull rolls) 19 and 2
2, a drive gear 19A connected to the drive motor 16 is provided, and a gear 22A connected to the drive gear 19A is provided, and from the drive gear 19A to the exit roll 19, from the gear 22A It can be transmitted to the roll 22. In addition, the third heating roll 50 and the fourth heating roll 5
1, each gear 50A and 51A are meshed. As a result of each roll being connected to the drive source as described above, the rolls 50, 51, 19, and 22 function as drive rolls, and the rolls 17, 18, 20, and 2
1, 23, 24, 32, 33, 34, 35, 36
functions as a subordinate role. It is also possible to drive the rolls 35 and 36 slightly faster than the upper and lower exit rolls 19 and 22, and in this case, the above-mentioned meandering adjustment function can be further improved. This embodiment is characterized in that the tension of the belts before and after the roll 51 is changed by changing (including controlling) the rotation of the roll 51 one before the exit roll 19. be. As described above, by providing a drive source with a speed reduction mechanism that makes the rotations of the exit roll and the roll immediately before the exit roll different, the tension applied to the belt between each roll can be freely changed, and the belt tension If the pressure is gradually weakened from the outlet to the inlet, it is possible to prevent the belt from opening and prevent the resin from deteriorating due to the intake of outside air. Cooling Section The fiber sheet 10 impregnated with resin as described above is cooled to below the resin softening point while passing through the cooling device 26 provided in the cooling section. The inside of the cooling device 26 can be configured to be able to cool at a cooling rate depending on the resin used. As a method of controlling the cooling rate, it is preferable to create a temperature gradient from the inlet to the outlet of the cooling device using a heater, hot air, cold air, or the like. The cooling device 26 may be provided in the post-process of the resin-impregnated section 3 as shown in FIG. 1, but is not limited thereto, and may also be provided inside the resin-impregnated section 3 as shown in FIG. . According to FIG. 8 showing the details, the cooling device 26 shown in FIG. 7 includes one or more pairs of rolls 261.
The lower roll group 262 is composed of a water tank 26
It is cooled by water stored in 3. Further, the upper roll group 264 is cooled by water sprayed from the nozzle 265. From the viewpoint of cooling efficiency, it is preferable to attach a water-retentive material such as asbestos to the surface of these rolls. These cooled lower and upper roll groups 262, 26
4 cools the upper and lower belts 14, 15, thereby cooling the fiber sheet 10. The lower and upper roll groups 262 and 264 are bolted together as shown in FIG.
By tightening the nut 266, the nip force of the roll group can be adjusted as desired. If such cooling is performed within the resin-impregnated portion, contact with air can be eliminated even during the cooling, and oxidative deterioration can be completely prevented. In addition, when cooling is performed via the upper and lower belts, there is no need to worry about staining the fiber sheet or fabric due to the cooling medium, so it is also possible to use water cooling, which is cheaper.
It has the effect of high process versatility. Further improving the embodiment shown in FIG.
When constructed as shown in the figure, high-speed impregnation is possible as in the embodiment shown in FIG. Note that in FIGS. 7 and 10, portions with the same reference numerals as those shown in FIG. 1 or FIG. 6 have the same configuration, and therefore the description thereof will be omitted. In Figures 7 and 10, roll 50 is heated, but rolls 19 and 22 are not heated.
This is because heating after cooling is not preferable. Taking-off Section The fiber sheet 10 cooled in this way is taken off while applying tension by the take-up roll 27 of the taking-off section 4, and wound around the winding shaft 29. Note that 28 is a motor for the take-up roll 27 and the take-up shaft 29. The embodiments of the present invention have been described above, but
For example, the present invention is not limited to these, and for example, a beamed yarn is used as a fiber sheet setting section instead of the fiber feeding section 1 shown in FIG. It is also possible to perform similar processing below. In this case, it is preferable to control the rotation of the beamed yarn so that an appropriate tension is applied to the fibers. The above embodiments show the case where the present invention is applied to a fiber sheet obtained from a plurality of continuous fibers, but when the present invention is applied to a woven fabric (sheet), the present invention is applied to a woven fabric (sheet) as shown in FIG. A woven fabric original fabric setting part 1A is provided in the feeding part 1, a woven fabric original fabric is set in the woven fabric fabric setting part 1A, and the woven fabric is supplied to the resin impregnating part 3 through the woven fabric supplying part 2A, Impregnation can be performed in the same manner as in the above embodiment. Further, in the embodiments described above, the resin is supplied from the die 13 to the lower belt 15, but the present invention is not limited thereto, and the resin may be supplied from the die 13 to the upper belt 14. In that case, substantially the same effect can be obtained by inverting the roll arrangement and tension direction with respect to the center of the conveying system for the fiber sheet 10 in the illustrated example. Note that in FIG. 5, parts with the same reference numerals as those shown in FIG. Further, since the resin-impregnated part 3 and the take-off part 4 are the same as those in Example 1, illustration thereof is omitted. [Example] Hereinafter, the present invention will be explained with reference to Examples. Example 1 The specifications of each part of the device shown in Figure 1 are based on the number of bobbins.
100 pieces, extruder 30mmφ, width of rolls 17 to 24 400
The roll diameter was 240 mmφ, the thickness of the upper and lower belts 14 and 15 was 0.5 mm, and the width was 350 mm. The continuous fiber is carbon fiber (Besphite HTA-7
-3000) and polyetheretherketone (ICI, VICTREX PEEK) as the thermoplastic resin.
was used. The viscosity of this polyetheretherketone at a temperature of 380°C and a shear rate of 100sec ^-1 is:
It was worth 7000 poise. The continuous fibers fed out from the 100 bobbins were aligned to form a fiber sheet with a width of 15 cm. On the other hand, polyetheretherketone heated and melted at 380℃ in an extruder is passed through a coat hanger die.
A film thickness of 60 μm was applied to the lower belt moving at a speed of 50 cm/min on the 23rd roll heated to 400°C. The fiber sheet with a tension of 150 kg is sandwiched between upper and lower belts 14, 15 and rolled into rolls 17, 18, 19, 20, 22 heated to 400°C.
The polyetheretherketone in the fiber sheet is impregnated by passing through the fiber sheet in the state shown in FIG.
After being slowly cooled in a slow cooling furnace kept at 140°C, it was rolled up using a winding machine. The above operation was carried out continuously for 24 hours, and the operation was successful without crosslinking or gelation caused by heat or oxidative deterioration of the resin. The resulting sheet has a resin content of 35% by weight and a thickness of 0.13
mm, and the fibers were not disordered and there were no voids between the fibers. Further, the resin molecular weight retention rate in the obtained sheet was measured and was 95%. still,
The resin molecular weight retention rate referred to here is the relative molecular weight percent when the resin molecular weight before heating is set as 100. Comparative Example The sheet was obtained using the apparatus and manufacturing conditions shown in Example 1 of JP-A-61-229535. The resin on the rolls gelled due to thermal and oxidative deterioration as the operating time progressed, and after about 3 hours, the resin became difficult to flow, impregnation was impossible, and the fiber filaments were broken, making it impossible to operate. The resulting sheet had a resin content of 36% by weight and a thickness of 0.13.
It was warm in mm. Furthermore, although the fibers were undisturbed and there were no voids between the fibers, when the resin molecular weight retention in the sheet was measured, it was 80%, indicating that the resin had deteriorated during impregnation. Examples 2 to 4 Resin-impregnated sheets were obtained by changing the type of resin and operating conditions in Example 1 as shown in Table 1.

[Table] As is clear from Table 1, it can be seen that according to the present invention, a good impregnated sheet with almost no resin deterioration can be obtained regardless of which resin is used. Example 5 The specifications of each part of the apparatus shown in Figure 5 (see Figure 1 for omitted parts) are as follows: extruder 30mmφ, roll 17~
24 width 400mm, roll diameter 240mmφ, upper and lower belt 1
4.15 with a thickness of 0.5 mm and a width of 350 mm was used. The continuous fibers were made of carbon fiber plain weave fabric (Besphite W-1103) and were adjusted to a width of 200 mm. Moreover, the same polyether ether ketone as in Example 1 was used as the thermoplastic resin. The woven fabric was placed on top of the woven fabric set section 1A, and a tension of 30 kg was applied in the take-up direction using a tension adjustment roll. On the other hand, in an extruder, polyether ether ketone heated and melted at 380°C is transferred from the coat hanger die to the lower belt moving at a speed of 50 cm/min on the 23rd roll heated to 400°C with a coating thickness of 60 μm. Coated. The woven fabric 10 under tension is passed between the rolls 17, 18, 19, 20, 22 heated to 400°C while being sandwiched between the upper and lower belts 14, 15.
The woven fabric was impregnated with polyether ether ketone by passing it through the fabric under the conditions shown in , and after being slowly cooled in an annealing furnace kept at 140°C, it was wound up at a take-up section. The above operation was carried out continuously for 24 hours, and the operation was successful without any phenomenon of gelation due to heat or oxidative deterioration of the resin. The obtained fiber-reinforced resin sheet had a resin content of 35% by weight and a thickness of 0.13 mm, and the fibers were not disordered and there were no voids between the fibers. Furthermore, the resin molecular weight retention rate in the obtained fiber-reinforced resin sheet was measured and was 95%. Examples 6 to 15 The resin impregnated part in Fig. 1 was replaced with the equipment shown in Fig. 6. The specifications of each part were as follows: 100 bobbins, extruder 30 mmφ, rolls 17, 18, 19, 20, 2.
1, 22, 23, 24, 50, 51 width 400mm,
The roll diameter was 240 mmφ, the thickness of the upper and lower belts 14 and 15 was 0.5 mm, and the width was 350 mm. However, the rolls 30, 32, 33, 34, 35, 36, the exit impregnation accelerating roll 31, and the speed reducer 16A were changed as shown in Table 2. The impregnation accelerator roll 30 had a roll width of 400 mm and a roll diameter of 100 mm, and the impregnation accelerator rolls 32, 33, and 34 had a roll width of 400 mm and a roll diameter of 120 mm. The rotation speeds of the rolls 19 and 51 were set as shown in Table 2. Note that a powder clutch was used as the speed reducer 16A. The continuous fiber is carbon fiber (Besphite HTA-7
-3000), and the thermoplastic resins shown in Table 2 were used. The continuous fibers fed out from the 100 bobbins were aligned to form a fiber sheet with a width of 15 cm. On the other hand, the lower belt 1 moves the resin shown in Table 2 melted in an extruder from a coat hanger die on a heated roll 23 as shown in Table 2 at a speed of 75 cm/min.
No. 5 was coated with the coating thickness shown in Table 2. The fiber sheet with a tension of 150 kg is attached to the upper and lower belts 1.
Rolls 17, 18, 20, 50, 51, 1 heated as shown in Table 2 while being sandwiched between
9 and 22 in the state shown in FIGS. 1 and 6 to impregnate the fiber sheet with the resin shown in Table 2. After that, it was slowly cooled in a cooling device maintained at the temperature shown in Table 2, and then wound up in a take-up machine. The above operation was carried out continuously for 24 hours, and the operation went smoothly without any gelling phenomenon caused by heat or oxidative deterioration of the resin. Table 2 shows the above experimental conditions and results. Note that the * in the table is as follows. *3 If there is no reducer 16A, roll 17,
A drive motor for driving the motors 18, 50, and 51 is provided separately from the drive motor 16. *4 Void ratio: Value determined from the specific gravity of the resin-impregnated sheet and the weight percentage of fiber content.

【table】

[Table] Example 16 An experiment was carried out using an apparatus in which the feeding section 1 and the supplying section 2 of FIG. 1 were changed as shown in FIG. 5. Note that the specifications of the resin-impregnated portion were the same as in Example 6. The continuous fiber is carbon fiber plain woven fabric (Besphite W).
-1103) adjusted to a width of 200 mm was used. or,
The same polyetheretherketone as in Example 6 was used as the thermoplastic resin. The woven fabric was placed on top of the feeding section 1, and a tension of 30 kg was applied in the take-up direction using a tension adjustment roll. Next, after impregnation under the same conditions as in Example 6, the resin-impregnated sheet was obtained by slow cooling in an annealing furnace. The resulting resin-impregnated sheet has a thickness of 0.13 mm, a void rate of 0.4%, and a resin molecular weight retention rate.
It was 98%. Example 17 Impregnation, cooling, and winding were carried out in the same manner as in Example 1 using an apparatus in which the resin impregnation section and cooling device shown in FIG. 1 were modified as shown in FIG. 7. The above operation was carried out continuously for 24 hours, and the operation went smoothly without any gelling phenomenon caused by heat or oxidative deterioration of the resin. The resulting sheet has a resin content of 35% by weight and a thickness of 0.13
mm, and the fibers were not disordered and there were no voids between the fibers. Furthermore, the resin molecular weight retention rate in the obtained sheet was measured and was 97%. Examples 18-20 Resin-impregnated sheets were obtained by changing the type of resin and operating conditions in Example 17 as shown in Table 3.

[Table] Measures belt temperature.
As is clear from Table 3, it can be seen that according to the present invention, a better impregnated sheet with almost no resin deterioration can be obtained no matter which resin is used. Example 21 An experiment was carried out using an apparatus in which the feeding section 1 and the supplying section 2 of FIG. 1 were changed as shown in FIG. 5. Note that each specification of the resin-impregnated portion was the same as in Example 17. The continuous fiber is carbon fiber plain woven fabric (Besphite W).
-1103) adjusted to a width of 200 mm was used. or,
The same polyetheretherketone as in Example 17 was used as the thermoplastic resin. The woven fabric was placed on top of the feeding section 1A, and a tension of 30 kg was applied in the take-up direction using a tension adjustment roll. Next, after impregnation under the same conditions as in Example 17, the resin was slowly cooled in a slow cooling furnace to obtain a resin-impregnated sheet. The resulting sheet has a resin content of 35% by weight and a thickness of 0.13
mm, and the fibers were not disordered and there were no voids between the fibers. Furthermore, the resin molecular weight retention rate in the obtained sheet was measured and was 97%. [Effects of the Invention] According to the present invention, it is possible to provide a method and apparatus for producing a high-performance fiber-reinforced sheet prepreg that allows stable continuous operation and has little resin deterioration.

[Brief explanation of drawings]

Fig. 1 is a schematic side view showing one embodiment of the present invention, Fig. 2 is a sectional view showing the mounting structure of a bobbin wound with continuous fibers, and Fig. 3 is a fiber sheet formed by collecting and arranging continuous fibers. Front view of the aligner, No. 4
The figure is a plan view of the same as above (only half of the whole shows the fiber sheet), Figure 5 is a side view of the main part showing an example of applying the present invention to a woven fabric, and Figure 6 is an improved resin-impregnated part. Fig. 7 is a side view showing another example of the resin-impregnated part, Fig. 8 is a schematic cross-sectional view of the cooling device, Fig. 9 is a schematic side view, and Fig. 10 is the resin-impregnated part. It is a detailed diagram showing another example of the section.

Claims (1)

[Claims] 1. Applying the thermoplastic resin to at least one of a pair of belts heated above the softening point of the thermoplastic resin, and introducing the coating film between the pair of opposing belts, A method of producing a fiber-reinforced sheet prepreg by impregnating fibers with a thermoplastic resin by passing the sheet between the pair of belts. 2. The method for producing a fiber-reinforced sheet-like prepreg according to claim 1, wherein the fiber sheet is a sheet formed by aligning a plurality of continuous fibers in one direction like warp threads. 3. The method for producing a fiber-reinforced sheet prepreg according to claim 1, wherein the fiber sheet is a woven fabric. 4 After the fiber sheet passes between the pair of belts,
2. The method for producing a fiber-reinforced sheet prepreg according to claim 1, wherein the fiber-reinforced sheet prepreg is cooled. 5 After the fiber sheet is impregnated with resin between a pair of belts,
2. The method for producing a fiber-reinforced sheet prepreg according to claim 1, wherein the prepreg is cooled between the belts. 6. A means for supplying a fiber sheet, a pair of belts supported by a group of rolls having a heating roll heated to a temperature higher than the softening point of the thermoplastic resin, and a means for applying a thermoplastic resin coating to at least one of the belts. 1. An apparatus for manufacturing a sheet-like prepreg, comprising: a resin-impregnated section having a means for producing prepreg; and a take-off section that takes off the prepreg after passing through the resin-impregnated section. 7. Claim 6, characterized by comprising a fiber supply section having a plurality of bobbins for supplying fibers, a mechanism for adjusting tension during fiber feeding, and a mechanism for aligning fibers in one direction. An apparatus for producing the fiber-reinforced sheet prepreg described above. 8. The apparatus for manufacturing a fiber-reinforced sheet prepreg according to claim 6, further comprising means for setting a beamed yarn in which a necessary number of continuous fibers are wound in advance around a warp beam in one direction like a warp. 9. The fiber-reinforced sheet-like prepreg manufacturing apparatus according to claim 6, further comprising means for supplying the woven fabric. 10. The fiber-reinforced sheet prepreg manufacturing apparatus according to claim 6, further comprising a cooling section for cooling the thermoplastic resin to below the softening point of the resin between the resin impregnation section and the take-off section. 11. The fiber-reinforced sheet prepreg manufacturing apparatus according to claim 6, further comprising a cooling section in the resin-impregnated section for cooling the thermoplastic resin to below the softening point of the resin. 12. The production of the fiber-reinforced sheet-like prepreg according to claim 6, further comprising a resin impregnation accelerator roll which is provided near the entrance heating roll provided at the entrance of the resin-impregnated section and brings the fiber sheet into pressure contact with the entrance heating roll. Device. 13. The production of the fiber-reinforced sheet-like prepreg according to claim 6, further comprising a resin impregnation accelerator roll which is provided near the exit heating roll provided at the exit of the resin-impregnated section and brings the fiber sheet into pressure contact with the exit heating roll. Device. 14. The fiber reinforcement according to claim 6, further comprising a resin impregnation accelerator roll which is attached to an intermediate heating roll disposed between an inlet heating roll and an exit heating roll and presses the fiber sheet to the intermediate heating roll. Equipment for manufacturing sheet prepreg. 15. The fiber-reinforced sheet prepreg manufacturing apparatus according to claim 6, further comprising means for adjusting the tension of the pair of belts. 16 The tension adjusting means makes the tension (Bx) of the front belt of the plurality of rolls supporting the belt and the roll one roll before the exit roll larger than the tension (By) of the rear belt of one roll before the exit roll. 16. The apparatus for manufacturing a fiber-reinforced sheet prepreg according to claim 15, wherein the apparatus is a tension adjusting means. 17 A means for supplying a fiber sheet, a pair of belts supported by an inlet roll, an outlet roll, and an intermediate roll heated above the softening point of the thermoplastic resin, and a thermoplastic resin coating film applied to at least one of the belts. a resin impregnation section equipped with an extruder and a die for the process, a first resin impregnation accelerator roll provided near the inlet roll, a resin impregnation accelerator roll connected to the intermediate roll, and an exit roll. Tension adjustment means for making the tension of the front belt (Bx) of the exit impregnation promotion roll provided nearby and the roll one roll before the exit roll larger than the tension (By) of the rear belt of the roll one roll before the exit roll. An apparatus for manufacturing a fiber-reinforced sheet prepreg, comprising: a means for cooling a sheet impregnated with a thermoplastic resin; and a means for winding up a fiber sheet impregnated with a thermoplastic resin that has passed between the belts.