JP2015113393A - Method for manufacturing tow prepreg - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method capable of inexpensively manufacturing a tow prepreg which has a resin content appropriately controlled and is suitably used for manufacturing a fiber reinforced composite material by a filament winding method, an auto tape lay-up method, a drum winding method, and the like.SOLUTION: The manufacturing method of a tow prepreg comprises: forming a resin layer having a uniform thickness and consisting of a matrix resin composition on the surface of a cylindrical roll (a); transferring the resin layer on the surface of the cylindrical roll (b) controllable to a rotational speed different from that of the cylindrical roll (a); and supplying the matrix resin composition to a reinforced fiber bundle by contacting the resin layer transferred on the surface of the cylindrical roll (b) with the reinforced fiber bundle.

Description

  The present invention relates to a method for producing a tow prepreg which is preferably used for producing a fiber-reinforced composite material.

  Tow prepreg is an intermediate material formed by impregnating a reinforcing fiber bundle (tow) such as carbon fiber or glass fiber with a matrix resin composition such as a thermosetting resin composition. In the tow prepreg, since the resin content is a control factor for physical properties such as strength, elastic modulus, and thermal expansion coefficient of the composite material molded article, control of the resin content is extremely important.

  As a method for producing a tow prepreg, for example, (1) a method in which a reinforcing fiber bundle is immersed in a thermosetting resin and then the resin adhesion amount is adjusted with a drawing die (Patent Document 1), (2) a thermosetting resin is added (3) Heat discharged from the die, a method in which a part of a rotating drum having a doctor blade is immersed in an impregnation tank and a reinforcing fiber bundle is brought into contact with the resin made into a thin film with a doctor blade attached to the rotating drum. The method of providing curable resin to a reinforced fiber bundle is mentioned.

  (1) The initial investment can be kept low and maintenance is easy, but it is difficult to adjust the resin supply amount, and in particular, a tow prepreg with a low resin content (such as 30% by mass or less) is manufactured. Is difficult.

  In (2), the initial investment can be kept low and maintenance is easy, but it is difficult to adjust the resin supply amount. Specifically, fine adjustments can be made by adjusting the rotation speed of the rotating drum and the traveling speed of the reinforcing fiber bundle. However, to make significant changes, the clearance between the rotating drum and the doctor blade must be adjusted again. Don't be. Furthermore, when making a tow prepreg using a matrix resin composition exhibiting strong viscoelasticity, the thickness of the resin layer does not show a simple proportional relationship with the clearance between the rotating drum and the doctor blade, and a thin resin layer is formed. It will be very difficult to do. For this reason, the loss at the time of production at the time of adjusting the resin content is extremely large, and it becomes very difficult to produce a tow prepreg having a low resin content.

  As for (3), adjustment of the resin supply amount is easy as long as the accuracy of the pump used for discharging the resin is increased, but since it is necessary to use many pumps and dies for industrial production, an increase in initial investment is required. And there is a problem that it takes time and maintenance.

JP-A-9-176346

  The objective of this invention is providing the manufacturing method of the tow prepreg which can manufacture the tow prepreg by which resin content rate was adjusted at low cost.

  As a result of intensive studies, the present inventors have found the following method.

  That is, the present invention forms a resin layer having a uniform thickness made of a matrix resin composition on the surface of the cylindrical roll (a) and can be controlled at a rotational speed different from that of the cylindrical roll (a). After transferring the resin layer to the surface of (b), the resin layer transferred to the surface of the cylindrical roll (b) and the reinforcing fiber bundle are brought into contact with each other, whereby the matrix resin composition is made into the reinforcing fiber bundle. It exists in the manufacturing method of a tow prepreg characterized by supplying.

  By the method for producing a tow prepreg of the present invention, a tow prepreg having a controlled resin content can be produced at a low cost. The tow prepreg produced by the production method of the present invention can be suitably used for producing a fiber-reinforced composite material by a filament winding method, an auto tape layup method, a drum winding method or the like.

It is a schematic block diagram which shows an example of the tow prepreg manufacturing apparatus of this invention.

  The present invention combines a coating jig such as a doctor blade or a comma roll with a cylindrical roll (a), thereby forming a resin layer having a uniform thickness on the surface of the cylindrical roll (a). After the resin layer is transferred to the cylindrical roll (b) capable of controlling the rotational speed different from that of the cylindrical roll (a), the resin layer and the reinforcing fiber transferred to the surface of the cylindrical roll (b) A method for producing a tow prepreg, wherein the matrix resin composition is supplied to the reinforcing fiber bundle (tow) by contacting the bundle 2.

  First, the present invention will be described with reference to the drawings, but the present invention is not limited to this example.

  FIG. 1 is a schematic configuration diagram showing an example of a basic process for producing a tow prepreg.

  In the drawing, the reinforcing fiber bundle 2 is drawn out from a bobbin (core material) mounted on the creel 1 and widened by a fiber opening roll unit 3. The widened reinforcing fiber bundle 2 is restricted in yarn path by the groove roll 4. When the cylindrical roll 9 (that is, the cylindrical roll (b)) provided with a resin layer (not shown) made of the matrix resin composition 6 on the surface is in contact with the reinforcing fiber bundle 2, the matrix resin composition 6 is Supplied to the reinforcing fiber bundle 2.

  The reinforcing fiber bundle 2 supplied with the matrix resin composition 6 is sufficiently impregnated with the matrix resin composition 6 by passing through the impregnation roll unit 10, and then guided to the winder 12 through the godet roll 11 and wound up.

  The cylindrical roll 8 includes a resin reservoir 5 that stores the matrix resin composition 6 that has been heated and melted, and a resin layer (not shown) that is coated on the coating roll (cylindrical roll 8, that is, the cylindrical roll (a) in the present invention). A doctor blade 7 for adjusting the thickness of The cylindrical roll 8 and the cylindrical roll 9 are installed so that the cylindrical axis directions are parallel to each other, and are pressed against the cylindrical roll 8 so that the cylindrical roll 9 comes into contact therewith. Thereby, the resin layer having a uniform thickness formed on the surface of the cylindrical roll 8 is transferred to the cylindrical roll 9, and the thickness of the resin layer formed on the surface of the cylindrical roll 9 is changed by changing the speed ratio. It can be easily changed. Further, it is easy to reduce the thickness of the resin layer formed on the surface of the cylindrical roll 9. That is, it is easy to supply a desired amount of the matrix resin composition to the reinforcing fiber bundle 2, and in particular, since it is easy to form a thin resin layer, a tow prepreg having a low resin content is obtained. Is easy.

  Hereinafter, embodiments of the present invention will be described in more detail.

  It is preferable that the cylindrical roll 8 and the cylindrical roll 9 in FIG. 1 can be heated to a temperature at which the matrix resin composition 6 handled in the tow prepreg manufacturing method of the present invention has a viscosity of 1 Pa · s to 100 Pa · s. When the viscosity of the matrix resin composition 6 is greater than 100 Pa · s, it becomes difficult to supply the matrix resin composition 6 to the reinforcing fiber bundle 2, and the reinforcing fiber bundle 2 is reinforced when it leaves the surface of the cylindrical roll 9. The frequency with which the single yarn of the fiber bundle 2 adheres to the surface of the cylindrical roll 9 and the winding occurs increases. On the other hand, when the viscosity of the matrix resin composition 6 is less than 1 Pa · s, the cylindrical roll 8, the doctor blade 7, and a cylindrical roll or comma roll that may be used in place of the doctor blade 7 are applied for coating. It becomes difficult to accurately adjust the thickness of the resin layer only by the distance from the tool.

  It is preferable that the cylindrical roll 8 and the cylindrical roll 9 can be heated at different temperatures.

  When the temperature of the cylindrical roll 8 is set higher than the temperature of the cylindrical roll 9, it is preferable because the resin layer can be reliably transferred from the cylindrical roll 8 to the cylindrical roll 9. When the temperature of the cylindrical roll 9 is set higher than the temperature of the cylindrical roll 8, the surface of the resin layer transferred to the cylindrical roll 9 becomes smooth, and the pattern of the resin layer (coating unevenness etc.) is formed on the processed tow prepreg. It is preferable because it is not transferred.

  It is essential that the cylindrical roll 8 and the cylindrical roll 9 are controlled in rotational speed by driving and can be controlled to different rotational speeds. The resin layer formed on the surface of the cylindrical roll 9 without changing the thickness of the resin layer formed on the surface of the cylindrical roll 8 by changing the rotational speed of the cylindrical roll 9 relative to the rotational speed of the cylindrical roll 8 Thus, the amount of the matrix resin composition supplied to the reinforcing fiber bundle 2 can be adjusted. Here, in order to control the cylindrical roll 8 and the cylindrical roll 9 to have different rotational speeds, each may be driven by using a separate driving source, and the cylindrical roll 8 and the cylindrical roll may be driven using a common driving source. A mechanism capable of changing the speed ratio of the shape roll 9 may be separately provided.

  Moreover, even if the rotation direction of the cylindrical roll 8 and the cylindrical roll 9 is the forward direction (the roll surface moving direction at the closest position of both cylindrical rolls is the same direction), the reverse direction (the closest proximity of both cylindrical rolls) However, the reverse direction is preferable because the transfer from the cylindrical roll 8 to the cylindrical roll 9 is reliably performed.

  The diameters of the cylindrical roll 8 and the cylindrical roll 9 are preferably large as long as there are no restrictions on the location of the device or the device. Specifically, for example, when a fiber bundle made of carbon fibers is used as the reinforcing fiber bundle 2, the diameters of the cylindrical roll 8 and the cylindrical roll 9 are preferably 150 mm or more. When the diameter is smaller than 150 mm, depending on the length of the roll, the thickness of the resin layer formed on the surfaces of the cylindrical roll 8 and the cylindrical roll 9 is likely to vary depending on the location due to the deflection of the roll. When the reinforcing fiber bundle 2 comes into contact with the resin layer coated on the surface of 9, the resin layer moves greatly in the direction perpendicular to the longitudinal direction of the reinforcing fiber bundle 2, and the matrix resin composition 6 is moved into the reinforcing fiber bundle. 2 cannot be supplied well, and it may be difficult to accurately adjust the resin content of the tow prepreg to be produced.

  The contact length between the cylindrical roll 9 and the reinforcing fiber bundle 2 is preferably 10 mm to 300 mm. When the contact length is shorter than 10 mm, the matrix resin composition 6 cannot be supplied well to the reinforcing fiber bundle 2 and it may be difficult to accurately control the resin content of the tow prepreg to be produced. In addition, when the contact length is longer than 300 mm, the single yarn of the reinforcing fiber bundle 2 is carried on the surface of the cylindrical roll 9 and tends to increase the frequency of winding.

  The means for forming a resin layer having a uniform thickness on the surface of the cylindrical roll 8 is not particularly limited. For example, a coating jig such as a doctor blade, a comma roll, or a cylindrical roll may be used with a certain clearance. And a method of forming a resin layer having a thickness according to the interval on the surface of the cylindrical roll 8.

  The creel 1 in FIG. 1 preferably has a mechanism that can unwind the reinforcing fiber bundle 2 with the same tension even if the winding diameter of the reinforcing fiber bundle 2 wound around the core material changes.

  In order to enhance the impregnation property of the matrix resin composition 6, the reinforcing fiber bundle 2 may be opened by rubbing the reinforcing fiber bundle 2 with a heated roll before coming into contact with the cylindrical roll 9. preferable. Specifically, for example, each roll for fertilizing the opening roll unit 3 in FIG. 1 may be heated.

  In order to stabilize the process, there is preferably a guide having a groove in the yarn path. Any known guide that can regulate the position of the reinforcing fiber bundle 2 can be used as the guide. Specifically, a groove roll (groove roll 4 in FIG. 1) having grooves processed with a constant width and depth in the circumferential direction of the cylindrical roll surface, or a constant width and depth in the length direction. Examples include a plate having a processed groove. In order to suppress damage to the reinforcing fiber bundle 2 due to rubbing with the guide, the guide is preferably a groove roll 4 that rotates freely or at a peripheral speed similar to the conveying speed of the reinforcing fiber bundle 2.

  The impregnation roll for impregnating the reinforcing fiber bundle 2 with the matrix resin composition 6 (that is, the roll constituting the impregnation roll unit 10 in FIG. 1) is a cylindrical roll having a smooth surface. The impregnation roll may be freely rotated or driven by a motor or the like. The impregnating roll is preferably heated appropriately.

  As the winder 12 for winding the tow prepreg, a known winder can be used.

  The reinforcing fiber bundle 2 used in the present invention is a bundle of reinforcing long fibers (filaments) made of inorganic fibers, organic fibers, metal fibers, or a mixture thereof. Inorganic fibers include carbon fibers, graphite fibers, silicon carbide fibers, alumina fibers, tungsten carbide fibers, boron fibers, glass fibers, etc. Organic fibers include aramid fibers, high density polyethylene fibers, and other general organic fibers such as nylon and polyester. Etc. are preferably used. Among them, a reinforcing fiber bundle made of carbon fibers is particularly preferable.

  Moreover, in this invention, as the matrix resin composition 6 used for manufacture of a tow prepreg, the thermosetting resin and thermoplastic resin which are normally used as a matrix resin of a fiber reinforced composite material are used, for example, as a thermosetting resin, , Epoxy resin, phenol resin, vinyl ester resin, epoxy acrylate resin, urethane acrylate resin, phenoxy resin, alkyd resin, urethane resin and the like, and thermoplastic resins such as PEEK, PEI, polyarylate, polysulfone Super engineering plastics such as nylon, polyester, ABS and other engineering plastics, and acrylics, polyethylene resins, polypropylene resins and other general purpose plastics.

DESCRIPTION OF SYMBOLS 1 Creel 2 Reinforcing fiber bundle 3 Opening roll unit 4 Groove roll 5 Resin reservoir 6 Matrix resin composition 7 Doctor blade 8 Cylindrical roll (a) (Coating roll)
9 Cylindrical roll (b)
10 Impregnation roll unit 11 Godet roll 12 Winder

Claims (1)

  The surface of the cylindrical roll (b) in which a resin layer having a uniform thickness formed of a matrix resin composition is formed on the surface of the cylindrical roll (a) and can be controlled at a rotational speed different from that of the cylindrical roll (a). After transferring the resin layer to the cylindrical roll (b), the resin layer transferred to the surface of the cylindrical roll (b) is brought into contact with the reinforcing fiber bundle to supply the matrix resin composition to the reinforcing fiber bundle. A method for producing a tow prepreg.