JP4187279B2 - Manufacturing method of filament winding molded product - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an improvement in a method for producing a fiber-reinforced composite material molded article by filament winding.
[0002]
[Prior art]
There are two methods for manufacturing filament winding molded products: a method in which reinforcing fiber tows not impregnated with resin are supplied to a filament winding molding machine, impregnated with resin in-line, and wound around a mandrel, and then impregnated with resin offline. There is a method in which the reinforced fiber tow is supplied to a filament winding molding machine and wound around a mandrel.
[0003]
In particular, in the former method, a reinforcing fiber tow is passed through a resin bath called a resin bath whose temperature is controlled, and excess resin adhering to the reinforcing fiber tow is scraped off by a doctor blade, a nip roll, etc. The resin impregnation is promoted with flat rolls, and finally, the resin is transferred to a transfer roll installed in contact with the resin in the resin bath by wrapping and molding on a mandrel, and the transfer resin is transferred to a doctor blade, etc. There is a known method of adjusting the amount of the resin, and then transferring the adjusted transfer resin to the reinforcing fiber tow again, and then accelerating the resin impregnation with several flat rolls, and finally winding and forming on the mandrel. It has been.
[0004]
[Problems to be solved by the invention]
In the reinforcing fiber tow used in the method for producing a filament winding molded product, when the resin is impregnated in-line, the resin content in the longitudinal direction varies with the variation of the winding speed around the mandrel. Resin excess portions and resin shortage portions tend to exist inside.
[0005]
Also, there is no problem with room temperature liquid resin, but when using a hot melt resin, the conventional method has a problem of stage up of the resin, and in terms of the resin impregnation speed to the reinforcing fiber tow relative to the filament winding winding speed, In the method, the rate of impregnation with several flat rolls is determined by the preheating of the transfer resin, the pressure conditions generated by the reinforcing fiber tow tension, and the life of the resin if it is a thermosetting resin. However, it is not necessary to simply reduce the viscosity by heating, and there are problems such as the length of the impregnation step, and there is a limit due to the resin impregnation rate in improving the production rate.
[0006]
In addition, in the case of using a solvent, a method of producing by lowering the viscosity with a solvent and impregnating and then volatilizing the solvent has been carried out for a long time, but this method has caused environmental problems due to volatilization of the solvent and filament winding molding. Voids generated due to foaming of the solvent during subsequent heating were a problem.
[0007]
Furthermore, when supplying the reinforcing fiber tow impregnated with resin to the filament winding molding machine, various devices for improving the handling of the supplied resin-containing reinforcing fiber tow, for example, optimization of resin and resin viscosity, It was necessary to attach a separate film, etc., the pre-process for supplying to the filament winding molding machine was complicated, and the type of resin used was also limited.
[0008]
The present invention solves the above-mentioned conventional problems, and provides a method capable of efficiently and uniformly impregnating a resin to produce a filament winding molded article having good productivity.
[0009]
[Means for Solving the Problems]
The present invention supplies resin at a fixed ratio to at least one side of a tow made of flattened reinforcing fibers, and simultaneously with or immediately after contacting the tow, the resin is infiltrated in the thickness direction of the tow so as to narrow the tow width. Filament winding molding characterized by uniformly impregnating the resin in the tow by lateral movement of the tow constituent filaments, which uses both the means having the means and the means having the function of widening the tow width, and then winding and molding on the mandrel The above-described problems are solved by a method for manufacturing a product.
[0010]
The reinforcing fiber in the present invention is a reinforcing fiber (bundle) made of long fibers and made of inorganic fibers, organic fibers, metal fibers, or a mixture thereof. As the inorganic fiber, carbon fiber, graphite fiber, silicon carbide fiber, alumina fiber, tungsten carbide fiber, boron fiber, glass fiber and the like are preferable. As the organic fibers, aramid fibers, high density polyethylene fibers, and other general organic fibers such as nylon and polyester are preferable. As the metal fiber, any fiber such as stainless steel or iron can be used if it has mobility.
[0011]
The diameter of the fiber is preferably 0.1 μm or more and 100 μm or less. If the thickness is less than 0.1 μm, the strength becomes small, and there is a possibility of cutting when the lateral movement occurs. On the other hand, if it exceeds 100 μm, it becomes too rigid and it becomes difficult to move laterally.
[0012]
As the resin, a thermosetting resin and a thermoplastic resin that are generally used for fiber-reinforced composite materials are used, and a thermosetting resin capable of reducing the viscosity by heating is preferable. As the thermosetting resin, epoxy resin, phenol resin, vinyl ester resin, epoxy acrylate resin, urethane acrylate resin, phenoxy resin, alkyd resin, urethane resin, etc. can be used. Resins are preferred. As the thermoplastic resin, super engineering plastics such as PEEK, PEI, polyarylate and polysulfone, engineer plastics such as nylon, polyester and ABS, and general-purpose plastics such as acrylic resin, polyethylene resin and polypropylene resin can be used.
[0013]
The property required for these resins is that they have fluidity at the temperature at the time of impregnation. The viscosity range as a measure of fluidity is preferably 1 CPS (centipoise) or more and 1 million CPS or less. Furthermore, the smaller the viscosity at the time of impregnation, the better, and ideally 1 CPS or more and 10,000 CPS or less. This is because at least the filament mobility must be high so that the filament movement and the resin movement associated therewith can be facilitated by the filament movement impregnation described below. That is, it is necessary to reduce the filament movement resistance by reducing the viscosity. There are few resins with viscosity levels below 1 CPS. If it exceeds 1 million CPS, the viscosity is high, and filament movement and accompanying resin movement are almost impossible. The presence or absence of an additive such as a filler is not a problem as long as the resin has fluidity during impregnation.
[0014]
It is desirable that the tow is flat in order to increase the contact area with the resin, and making the tow width constant is important in terms of making the contact area with the quantitatively supplied resin constant. In general, reinforcing fiber tows do not have a constant width and need to be widened. As a method of widening, it is possible to use processes such as rubbing with a cylindrical bar, applying vibration, and crushing. Before the resin comes into contact with the tow, it is only necessary that the tow is flattened. To that end, in the production process of the present invention, it is only necessary that the tow is widened more than the tow width when the resin comes into contact with the tow. . A commercially available tape-like tow is regarded as a tow widened off-line. The tow width of the widened tow is not stabilized, and there are variations in how it spreads. Therefore, in order to stabilize the contact area with the resin at the time of resin contact, it is effective to narrow and stabilize the toe width immediately before the resin contact or at the time of resin contact. As an example of the method, a method of forming a groove in the resin discharge port can be used to narrow the toe width.
[0015]
The tow preheating has a meaning of increasing the tow temperature in advance so that the resin temperature does not decrease during penetration into the tow after the resin contact. If the preheated tow temperature is equal to or higher than the resin temperature before contact, the tow temperature after contact between the tow and the resin will not be lower than the resin temperature before contact. As a heating method, a non-contact heating method such as direct contact heating or current heating, dielectric heating, infrared heating, or atmosphere heating can be used.
[0016]
The content of the resin impregnated in the reinforcing fiber tow is preferably 10% by weight to 80% by weight. If it is less than 10% by weight, it is difficult to impregnate uniformly, and if it exceeds 80%, a problem arises in the mechanical properties of the filament winding molded product. 30% by weight or more and 50% by weight or less is ideal for effectively expressing the performance of the mechanical properties.
[0017]
In the present invention, it is important to allow the resin to penetrate in the thickness direction of the tow at the same time as or immediately after the resin and the tow are brought into contact with each other in order to allow the resin supplied in a fixed amount to permeate and adhere to the tow without delay. . As a method for this, it is a good method to quickly scrape the toe surface side in contact with the resin. Here, rubbing means rubbing the tow on a rubbing body, for example, on an arc or an edge. Since the tow is pressed against the rubbing body at the time of rubbing, resin pressure in the tow thickness direction inevitably acts. As a result, the resin penetrates into the tow. Since the tow is pressed against the rubbing body, there is no gap between the rubbing body and the tow. In rubbing on the arc after the resin contact, the winding angle is desirably 1 ° or more and 90 ° or less. This is because if the angle is less than 1 °, the resin penetration effect is small, and if it exceeds 90 °, the tension increases due to the resistance caused by abrasion.
[0018]
When a rapid pressure is generated by rubbing as in the present invention, the state of penetration of the resin becomes non-uniform. However, the purpose here is not to impregnate uniformly, but to focus on ensuring resin adhesion. Therefore, the homogenization of the resin impregnation is an important issue in the subsequent impregnation step. The quantitative adhesion controllability of the resin of the present invention depends on the discharge accuracy of the resin discharge machine, and is to push the supplied resin into the tow quickly and without stagnation, allowing the tow to pass through a narrow space such as a clearance on the surface of the tow. It is not to form a resin film layer. Here, rubbing does not form a resin film layer on the tow surface, but acts as a function of quickly pushing the resin into the tow.
[0019]
In the impregnation process of the present invention, the lateral movement of the filament is a resin in which the external position is positively applied to the tow filament, the filament is moved in a direction perpendicular to the filament fiber direction, and the relative position of the filament is changed. This is characterized by increasing the opportunity of contact with the filament, simply pressurizing the resin, and improving the impregnation effect more than the impregnation effect by the wetting of the resin in the capillary phenomenon. It is characterized in that the impregnation effect is higher than the impregnation effect by the wetting of the resin in the capillary phenomenon by simply pressurizing the resin. Specifically, folding of the tape-like tow penetrated by the resin , expansion of the tow width, reduction of the tow width, twisting of the tow, etc. can be used. When these are used in combination, the effect of uniform impregnation is enhanced. These actions change the position of the filament in the tow, resulting in an increased chance of contact with the resin. Further, as a secondary action, a new flow of the resin is caused, which is advantageous for uniform impregnation. In addition, twisting produces the effect that the resin is pushed out of the tow.
[0020]
In these operations, folding, toe width reduction, and twisting tend to narrow the tow width. Therefore, when these actions and widening are used in combination, the effect of uniform impregnation is enhanced. However, even when used in combination, the effect of uniform impregnation is sufficient. In addition, since the tow has a property of converging when pulled, the tow can be naturally converged by increasing the interval of the rubbing action, and the impregnation can be made uniform by widening again by rubbing. However, it can be said that it is more effective to actively reduce the tow width as in the present invention because the filament can be moved in the lateral direction at a short distance.
[0021]
In the twisting action, the tow rotates and the filament positional relationship in the tow changes. Tow rotation belongs to this twisting action. The twisting may be performed at the time of resin impregnation, and if the intermediate material after impregnation needs to be untwisted, it may be twisted after impregnation. Moreover, if it is false twist, it is not necessary to untwist and is most desirable when a tow without twist is required. Further, if rubbing is applied simultaneously with or immediately after twisting, the tow width tends to increase, and the uniformity of impregnation increases due to movement in the thickness direction of the resin.
[0022]
In uniform impregnation of the transverse movement of the filament, rotating a rotating body such as a roll at a peripheral speed lower than the production speed is useful for fluff deposition, roll cleaning, and the like. Here, the peripheral speed less than the production speed may be that the tow is scraped on the surface of the rotating body. By doing so, the tow does not get tangled on the surface of the rotating body, and since it is scraped and rotated, the contact surface between the tow and the rotating body is always cleaned, which is useful for improving the manufacturing environment. . The peripheral speed of the rotating body only needs to be equal to or lower than the manufacturing speed, and may be rubbed in the direction opposite to the toe traveling direction.
[0023]
The tow uniformly impregnated in the present invention can be narrowed with a grooved roll or a roll provided with a clearance and simultaneously compressed to control the cross-sectional shape. The control position is preferably immediately before winding around the mandrel.
[0024]
As a method for supplying and attaching the resin to the reinforcing fiber tow, it is ideal to use a molten resin discharger. Plunger-type dispensers, gear pump-type dispensers, extruders, etc. can be used. In particular, it is ideal in terms of quantitative supply accuracy to use ultra-precision gear pumps or extruders. In the case of a thermosetting resin, when the resin life after resin mixing becomes a problem, it is more ideal if the curing agent and the main agent are extruded separately and supplied while being mixed with a static mixer or the like. What is necessary for adhesion is that the resin has a low viscosity and is likely to adhere to the tow.
[0025]
As a method of supplying a constant ratio using the above-described molten resin discharger, for example, a method of detecting the speed of the reinforcing fiber tow and converting it into an electric signal, and performing feedback by the electric signal with a motor for driving the molten resin In addition, the operation contents of the filament winding molding machine drive motor and the molten resin discharge machine drive motor can be programmed in advance in a computer, and the operation control can be performed. There is no problem with the control configuration.
[0026]
The present invention will be described with reference to the drawings. FIG. 1 is a side view showing an example of basic steps of a manufacturing method according to the present invention. In the figure, a tape-like tow is used for the reinforcing fiber wound around the bobbin and is pulled out from the creel 1 with a constant tension. The drawn-out reinforcing fiber tow 2 is passed through the widening roll 3 to be rubbed and widened. Resin is heated and held in the tank 4, and the resin is pushed out by the gear pump type resin discharge machine 5 and supplied to the discharge port 7 through the heating hose 6. At that time, the widened tow is brought into contact with the supplied resin with a narrow width at the discharge port and a constant width. Thereafter, the resin is infiltrated into the tow by the resin-penetrating scraping body 8. In order to narrow the tow width and to prevent the resin from overflowing when the resin permeates due to resin adhesion or abrasion, the tow passage band is grooved. Thereafter, a roll for reducing the tow width and a roll for increasing the width are uniformly impregnated by the filament lateral movement impregnation unit 9 arranged alternately. The uniformly impregnated tow 10 is wound around a mandrel 12 that rotates in the filament winding molding section 11 to form a molded body such as a tubular body.
[0027]
FIG. 2 is a side view showing an example of means for performing lateral movement of the filaments constituting the tow in combination with enlargement and reduction of the tow width, in which 15 is a roll for enlarging the tow width. 16 is a roll for reducing the toe width, and the toe width can be narrowed by inclining the roll.
[0028]
FIG. 3 is a side view showing an example of means for performing lateral movement of the filaments constituting the tow by using both tow twisting and tow width enlargement. In FIG. 3, 17 denotes a twisting tool. ing.
[0029]
FIG. 4 is a side view showing an example of means for using both the folding of the tow and the expansion of the tow width in the lateral movement of the filament constituting the tow. In FIG. 4, the tow 2 is gradually folded by the folding guide 19. Then, it is folded up completely with a pair of rolls 18 standing vertically.
[0030]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples.
[0031]
[Example 1]
A filament winding molded product was manufactured in the manufacturing process of FIG. Further, as the resin impregnation means by lateral movement of the filament, two units were used which were used in combination with expansion and reduction of the tow width shown in FIG. The reinforcing fiber used was one carbon fiber TR30G tow manufactured by Grafel, USA. The tow 2 is widened to 5 mm or more by the tow width expanding roll 3, narrowed to 4 mm width by the nozzle combining the resin discharge port 7 and the resin penetrating scraper 8, and at the same time, the resin is supplied to and contacted with one side of the tow 2. The resin was infiltrated into the tow 2 by the resin infiltrating scraper 8. The resin used was a resin composition in which Epicoats 1001 and 834 manufactured by Yuka Shell Epoxy Co., Ltd. were mixed at 50/50, and 4 parts of dicyandiamide was mixed with the mixture. The mixed resin was held at 65 ° C. in the tank 4 and discharged from the gear pump through the heating hose 6 at 120 ° C. from the discharge port 7.
[0032]
It was confirmed that there was no resin overflow or resin stagnation during resin contact and penetration, and that the resin discharged from the gear pump adhered to the tow without stagnation. Thereafter, the filament was moved laterally by reducing and expanding the tow width, and the resin was uniformly impregnated. The resin viscosity at that time was about 500 CPS. After expanding the tow width to about 5 mm with the last impregnation roll, it is wound on a mandrel in the filament winding molding section, and then cured in a heating oven at 130 ° C. for 4 hours to filament winding. A molded body was obtained. During the above manufacturing process, the tow travel speed is detected immediately before the resin discharge nozzle using the non-contact speed detection sensor E6B-CWZ3C manufactured by OMRON, and the speed signal is fed back to the gear pump motor for resin supply. Thus, the resin supply amount was controlled. The impregnation of the resin was good at a production rate of 5 to 50 m / min. The resin content was in the range of 35% ± 1% and was highly accurate.
[0033]
[Example 2]
Instead of detecting the tow traveling speed and feedback to the resin supply gear pump motor in Example 1, the resin discharge amount was controlled by programming the operations of the filament winding molding drive unit and the resin discharger drive unit in advance. The impregnation state of the resin was good and the resin content controllability was as good as in Example 1.
[0034]
[Example 3]
Using the same process as in Example 1 except for the tow width expanding roll 3, using the TR30GWD tape-like carbon fiber tow manufactured by Grafel, USA, the resin system is the same system as in Example 1, and the filament winding molded product is manufactured. went. A tow having a width of 4 mm or more was narrowed to 4 mm with a nozzle. The properties of the molded product were the same as in Example 1.
[0035]
[Example 4]
In the manufacturing process of Example 1, the number of twists was set to 10 times / m using 2 units of the tow twist and tow width expansion shown in FIG. A filament winding molded article was produced in the same manner as in Example 1 with the reinforcing fibers, resin, and production conditions. The impregnation state of the resin was good and the resin content controllability was as good as in Example 1.
[0036]
[Example 5]
In the production process of Example 1, two units of the means for combining tow folding and tow width expansion shown in FIG. 4 are used as the resin impregnation means by lateral movement of the filament, and the reinforcing fiber, the resin, and the production conditions are the same as in Example 1. Similarly, a filament winding molded product was produced. The impregnation state of the resin was good and the resin content controllability was as good as in Example 1.
[0037]
[Example 6]
In the manufacturing process of Example 1, five similar carbon fiber tows were used, and each tow was widened to 5 mm or more with a roll and then narrowed to 4 mm. The resin was allowed to pass through and the resin was infiltrated into contact from the toe side. After that, the tows are separated one by one, and the means shown in FIG. 2 is installed for each tow as a resin impregnation means by moving the filament in the lateral direction, and the resin is uniformly impregnated for each tow. Rolled up on a mandrel. The obtained filament winding molded product had the same performance as that obtained in Example 1.
[0038]
[Example 7]
A filament winding molded article was produced in the same manner as in Example 1 except that a preheating roll was installed in front of the resin contact and infiltration nozzles to preheat the tow. The tow was heated to 130 ° C. by contact heating to the roll. The temperature of the discharged resin was 110 ° C., but the tow temperature after the resin contact and penetration was about 120 ° C. Thereafter, it was impregnated uniformly, cooled and wound on a bobbin. In Example 1, the tow temperature after resin contact and infiltration was not pre-heated, so it was necessary to increase the tow temperature with the first impregnation roll, but this was achieved by increasing the tow temperature before resin contact. Improved tow heating efficiency.
[0039]
[Example 8]
A filament winding molded product was produced in the same manner as in Example 1 except that the filament transverse movement impregnation roll was rotated. In Example 1, since the roll of filament lateral movement impregnation was used in a fixed manner, fluff was deposited on the rear part of the roll, but in this example, the fluff was not deposited and workability was improved. The roll rotation speed was 20 revolutions per minute, the peripheral speed was about 2.5 m / min, and the toe running speed was 5 to 50 m / min.
[0040]
[Example 9]
In the manufacturing process of Example 1, after resin penetration, the cross-sectional shape is 4 mm wide by narrowing and compressing the tow width using a heating roll, a grooved roll, and a compression roll with a protrusion fitted in the groove. And then wound up. Tow orientation was improved because the tow cross-sectional shape was controlled.
[0041]
【The invention's effect】
According to the present invention, in the resin-containing reinforcing fiber tow used in the method for producing a filament winding molded product, the resin content in the longitudinal direction does not vary with respect to the variation in the winding speed around the mandrel, and the resin excess inside the filament winding molded product The presence of parts and resin-deficient parts can be prevented. In addition, not only room temperature liquid resin but also hot melt resin is used to precisely control the resin content, so that efficient uniform impregnation is possible and production efficiency is improved. Furthermore, regarding the resin impregnation rate to the reinforcing fiber tow with respect to the filament winding molding rate, the molding rate can be improved by improving the resin impregnation rate, and problems such as the length of the impregnation step are also solved.
[Brief description of the drawings]
FIG. 1 is a side view showing an example of a basic manufacturing process of the present invention.
FIG. 2 is a side view showing an example of a means for performing lateral movement of a filament constituting the tow by combining expansion and reduction of the tow width.
FIG. 3 is a side view showing an example of means for performing lateral movement of a filament constituting the tow by using both twisting of the tow and enlargement of the tow width.
FIG. 4 is a side view showing an example of means that uses both the folding of the tow and the enlargement of the tow width for lateral movement of the filament constituting the tow.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Creel 2 Reinforcement fiber toe 3 Tow width expansion roll 4 Resin tank 5 Resin discharge machine 6 Heating hose 7 Resin discharge port 8 Scraping body 9 Resin impregnation means 10 by filament lateral movement 10 Resin impregnated toe 11 Filament winding forming part 12 Mandrel 15 tow width expanding roll 16 tow width reducing roll 17 twisting tool 18 tow folding roll 19 tow folding guide

Claims (9)

  A means and a tow having a function of narrowing a tow width by supplying a resin at a fixed ratio to at least one side of a flattened reinforcing fiber and allowing the resin to permeate in the thickness direction of the tow at the same time or immediately after contacting the tow. A method for producing a filament winding molded article characterized by uniformly impregnating a resin in a tow by lateral movement of a tow-constituting filament in combination with means having a function of expanding the width, and then winding and molding on a mandrel . The method of manufacturing a filament winding molded article according to claim 1, wherein the resin discharge amount is controlled by supplying the resin to the tow with a resin discharger, and detecting the tow speed and feeding back to the resin discharger.   The filament winding molded product according to claim 1, wherein the resin is supplied to the tow by a resin discharger, and the operation of the filament winding molding drive unit and the resin discharger drive unit is programmed in advance to control the resin discharge amount. Production method.   The manufacturing method of the filament winding molded product of any one of Claims 1-3 using a plurality of reinforcing fiber tows.   The method for producing a filament winding molded article according to any one of claims 1 to 4, wherein the resin is permeated in a thickness direction of the tow by rubbing the tow using a scraping body.   The method for producing a filament winding molded article according to any one of claims 1 to 5, wherein the means having the function of narrowing the tow width includes toe folding or tow twisting.   The method for producing a filament winding molded article according to any one of claims 1 to 6, wherein the tow is preheated before the resin comes into contact with the tow.   In the manufacturing method of the filament winding molded product according to any one of claims 1 to 7, the tow width is narrowed at the time of resin contact with the tow after the tow width is widened more than regulated at the time of resin contact. A method of manufacturing a filament winding molded product.   9. The method of manufacturing a filament winding molded article according to any one of claims 1 to 8, further comprising the step of controlling the cross-sectional shape of the tow by compressing at the same time as reducing the tow width. Manufacturing method.

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