JP2009220480A - Manufacturing method of notched sheet base material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a notched sheet base material which shows good fluidity and molding followability when used as a molding material and which shows a superior physical property when made of a fiber-reinforced plastic. <P>SOLUTION: The manufacturing method of the notched sheet base material comprises sending a sheet base material 3 containing a reinforcing fiber oriented in one direction and having a sheet thickness H in the range of 30 to 300 μm to a fiber arrangement direction 2, pushing a trimming die with a blade intermittently to the sheet base material, and advancing the blade into the sheet base material to insert disconnected notches therein. The four components Ws of the notches perpendicular to the fiber are in the range of 30 μm to 100 mm, and fiber length L of substantially all the reinforcing fibers is in the range of 10 to 100 mm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a cut sheet substrate that has good fluidity and molding followability, and exhibits excellent mechanical properties, low variability, and excellent dimensional stability when used as a fiber reinforced plastic. .

  Fiber reinforced plastic consisting of reinforced fiber and matrix resin is attracting attention in industrial applications because it has high specific properties, high specific modulus, excellent mechanical properties, weather resistance, chemical resistance, etc. The demand is increasing year by year.

  As a molding method of fiber reinforced plastic having high functional properties, a semi-cured intermediate base material impregnated with matrix resin is laminated on continuous reinforcing fiber called prepreg, and heated and pressurized in a high temperature and high pressure kettle. Autoclave molding in which a matrix resin is cured and a fiber reinforced plastic is molded is most commonly performed. In recent years, for the purpose of improving production efficiency, RTM (resin transfer molding) molding in which a continuous fiber base material previously shaped into a member shape is impregnated with a matrix resin and cured has been performed. The fiber reinforced plastics obtained by these molding methods have excellent mechanical properties because they are continuous fibers. Further, since the continuous fibers are regularly arranged, it is possible to design the mechanical properties required by the arrangement of the base material, and the variation in the mechanical properties is small. However, on the other hand, it is difficult to form a complicated shape such as a three-dimensional shape because it is a continuous fiber, and it is mainly limited to members close to a planar shape.

  As a molding method suitable for a complicated shape such as a three-dimensional shape, there is SMC (sheet molding compound) molding. SMC molding is performed by heating and pressurizing a semi-cured SMC sheet obtained by impregnating a chopped strand cut to about 25 mm with a matrix resin, which is a thermosetting resin, using a heating press. In many cases, before pressing, the SMC sheet is cut smaller than the shape of the molded body, placed on a mold, and stretched (flowed) into the shape of the molded body by pressing to perform molding. Therefore, it is possible to follow a complicated shape such as a three-dimensional shape by the flow. However, since SMC inevitably causes distribution unevenness and orientation unevenness of chopped strands in the sheeting process, the mechanical properties deteriorate or the variation of the values increases. Furthermore, due to uneven distribution and alignment unevenness of the chopped strands, warpage, sink marks and the like are likely to occur particularly in a thin member, which may be unsuitable as a structural material.

In order to fill in the drawbacks of the above-described materials, a base material is disclosed that can be made fluid and small in variation in mechanical properties by making intermittent cuts in a prepreg composed of continuous fibers and a matrix resin. (For example, Patent Documents 1 and 2). For example, Patent Document 1 discloses a method of placing a prepreg under a punching blade attached to a press and punching out the cut, but there is a problem that the base material cannot be manufactured continuously. For example, Patent Documents 1 and 2 disclose a method in which a blade is embedded in a rotating roller and pressed against a pair of rollers to continuously insert the incision, but the rotating roller is used to make intermittent incisions. There is a problem that it is difficult to accurately position and provide a plurality of blades corresponding to each cut on the curved surface.
Japanese Unexamined Patent Publication No. 63-247010 Japanese Patent Laid-Open No. 9-254227

  In view of the background of such prior art, the present invention has excellent fluidity, complicated shape followability, and exhibits excellent mechanical properties, low variation, and excellent dimensional stability when used as a fiber reinforced plastic. It is an object of the present invention to provide an efficient method for producing a cut sheet substrate or a cut prepreg substrate previously impregnated with a resin.

The present invention employs the following means in order to solve such problems. That is,
(1) A sheet base material including reinforcing fibers arranged in one direction, the sheet base material having a sheet thickness H in the range of 30 to 300 μm is sent in the fiber array direction, and a blade is disposed on the sheet base material. The cut die is pressed intermittently, the blade is intermittently entered into the sheet base material, intermittent cuts are inserted, and the fiber orthogonal component Ws of the cuts is in the range of 30 μm to 100 mm. The manufacturing method of the incision sheet base material which makes inside and the fiber length L of substantially all the reinforced fibers is in the range of 10-100 mm.

  (2) The part which makes the fiber orthogonal direction component Ws of the said incision into the range of 30 micrometers-100 mm is a part of the said blade, and penetrates a base material or inserts into a base material when inserting a notch Is a cut part, and the direction of pressing the punching die against the sheet base material is the pressing direction, and the fiber of the projection line A in which the ridge line of the cut part is projected onto the sheet base material in the pressing direction The method for producing a cut sheet base material according to (1), wherein the die is pressed against the sheet base material so that the orthogonal direction component Ws ′ falls within a range of 30 μm to 100 mm.

  (3) The means for setting the fiber length L of substantially all the reinforcing fibers within the range of 10 to 100 mm is part of the blade, and the base material is penetrated or inserted into the base material when inserting the cut. When the site to enter is a cut part, and the pressing direction is the direction in which the punching die is pressed against the sheet base material, the ridge lines of all the cutting parts included in the punching die are in the pressing direction. The sheet base material is pushed into the punching die so that the projection lines A projected onto the sheet base material are projected on the same fiber orthogonal plane in the fiber array direction and substantially all of the projection lines B are connected to each other. The manufacturing method of the cutting sheet base material as described in (1) or (2) which is to apply.

  (4) A portion that is a part of the blade and penetrates the base material or enters the base material when inserting a cut, and a cutting direction is a direction in which the punching die is pressed against the sheet base material. The angle θ between the projection line A obtained by projecting the ridge line of the cut portion on the sheet base material and the fiber arrangement direction in the pressing direction is in the range of 2 to 60 °. The manufacturing method of the cutting sheet base material in any one of (1)-(3) which presses a sheet base material on a type | mold.

  (5) The manufacturing method of the cutting sheet base material in any one of (1)-(4) which uses a plate-shaped sewing blade as said blade.

  (6) The cutting sheet base material according to (5), wherein the punching die is a flat plate and a plurality of the sewing machine blades are arranged in the punching die so as to be parallel to each other. Method.

  (7) A part of the sewing machine blade, which is a part that penetrates the base material or enters the base material when inserting a cut, and a distance between adjacent cut parts in the same sewing machine blade is a cut part The cutting according to (5) or (6), wherein the punching die is pressed against the sheet substrate so that the length W of the cut part and the distance b between the cut parts are constant when the distance b is set. A manufacturing method of a sheet base material.

  (8) Each time the projection lines B are connected to each other only at the ends and the sheet base material is moved 10 to 100 mm in the fiber array direction, the punching die is pressed against the sheet base material. )-(7) The manufacturing method of the cutting sheet base material in any one of.

  (9) The ratio (W / b) of the length W of the cut portion to the distance b between the cut portions is in the range of 1 to 1.5, and the projection lines B are connected to each other only at the end portions. Thus, whenever the said sheet | seat base material is moved 10-100 mm in the fiber arrangement | sequence direction, the said cutting die is pressed against the said sheet | seat base material, The manufacturing method of the cutting sheet base material as described in (8).

  (10) The method for manufacturing a cut sheet substrate according to (9), wherein the sewing blades are separated from each other by 1.5 times or more of the fiber length L of the reinforcing fibers in the fiber arrangement direction and arranged in a punching die.

  (11) The manufacturing method of the cut sheet base material in any one of (1)-(10) whose said sheet base material is a prepreg base material which consists of a reinforced fiber and matrix resin.

  (12) Using the prepreg base material gripped by the tape-shaped support, the punching die is pressed against the prepreg base on the opposite side of the tape-shaped support, penetrates the prepreg base, and The method for producing a cut sheet base material according to (11), wherein the cut that penetrates only a part of the tape-like support is inserted.

  According to the present invention, a cut sheet that has good fluidity, molding conformability of a complicated shape, and exhibits excellent mechanical properties, low variation, and excellent dimensional stability when made into a fiber reinforced plastic. A base material can be manufactured efficiently.

  In the present invention, the above-described problem, that is, an efficient manufacturing method for a cut sheet base material, is studied earnestly, and a cutting die provided with a blade is intermittently provided on a sheet base material made of reinforcing fibers aligned in one direction. The present invention has been clarified to solve such a problem at a stroke by manufacturing the cut sheet base material by pressing it and inserting a cut into the sheet base material. According to the present invention, a cut sheet base material having good fluidity, molding conformability of complicated shapes, and excellent mechanical properties, low variation, and excellent dimensional stability when made into a fiber reinforced plastic. Can be produced in large quantities and stably in a short time.

  The sheet base material used for producing the cut sheet base material of the present invention may be anything as long as it contains reinforcing fibers arranged in one direction, and the reinforcing fibers are woven and arranged across the fibers not intended for reinforcement. It may be integrated by means such as bonding or heat fusion, or may be integrated by spraying a resin such as tackifier and performing point fusion. Further, it may be a resin semi-impregnated base material (semi-preg) integrated in a state where the resin is not completely impregnated between the reinforcing fibers, or a prepreg in which the resin is completely impregnated between the reinforcing fibers. After inserting a predetermined cut into the sheet base material and manufacturing the cut sheet base material, the resin is applied by arranging a new resin sheet or nonwoven fabric on the cut sheet base material during lamination. Alternatively, they may be arranged on the cut sheet substrate at the time of molding, and excellent molding followability and fluidity are exhibited by applying a resin to the cut sheet substrate. In the present specification, unless otherwise specified, in the term including fiber or fiber (for example, “fiber direction” or the like), the fiber represents a reinforcing fiber.

  In the sheet base material 3 used in the present invention, the reinforcing fibers 1 are arranged in one direction, and the thickness H is in the range of 30 to 300 μm. In the present invention, as shown in FIG. 1, the sheet base material 3 is fed in the fiber array direction 2, and a punching die 7 in which a blade 6 is arranged is intermittently pressed to the sheet base material 3, and the blade 6 is Intermittent cuts 8 are inserted by intermittently entering the sheet base 3. At this time, the fiber orthogonal direction component Ws54 of the notch 8 shown in FIG. 3 (A) is in the range of 30 μm to 100 mm, and the fiber length L (34) of all the reinforcing fibers 1 is 10 to 100 mm. A cut sheet base material within the range is manufactured. When the cut sheet base material laminate thus obtained contains the resin, the laminate of the cut sheet base material obtained in this way can be used by giving the laminate alone or further the same or different resin. When the cut sheet base material is a dry base material that does not contain a resin, high fluidity can be exhibited when molding using press molding or the like by applying resin to the laminate. The fiber reinforced plastic obtained by molding can exhibit higher elastic modulus and strength than conventional SMC materials. In the present invention, “substantially all the reinforcing fibers have a fiber length L within the range of 10 to 100 mm” means that among the reinforcing fibers included in the cut sheet substrate, the fiber length L is 10 It shows that the number of fibers within the range of ˜100 mm is 90% or more of the ratio of the entire cut sheet substrate. Further, the “cutting fiber orthogonal direction component Ws” is an enlarged view of the cutting in the cutting sheet base material shown in FIG. Is a projection plane, and refers to a length 54 when projected from the notch 8 perpendicularly to the projection plane (fiber arrangement direction 2).

  The thickness H of the sheet base material used in the present invention needs to be in the range of 30 to 300 μm. Since the present invention has a cut, the larger the layer thickness of the sheet substrate to be divided, the larger the size of the cut portion, that is, the defect, and the strength tends to decrease. Therefore, if it is assumed to be applied to a structural material, H needs to be 300 μm or less. On the other hand, it is difficult in terms of process to stably manufacture an extremely thin sheet base material in which H is smaller than 30 μm. Therefore, in order to obtain the effects of the present invention at a low cost, it is necessary to be 30 μm or more. In view of the relationship between mechanical properties and cost, it is more preferably in the range of 50 to 150 μm.

  In the present invention, intermittent cuts are inserted into the entire surface of the sheet base material, and in manufacturing the cut sheet base material, the fiber length L of substantially all the reinforcing fibers in the cut sheet base material is 100 mm. By making the following, the fibers can flow at the time of molding, in particular, the fibers can flow in the arrangement direction of the fibers, and the molding followability of complicated shapes is excellent. When there is no notch, that is, when only continuous fibers are used, a complicated shape cannot be formed because the fibers do not flow in the fiber arrangement direction. On the other hand, when the fiber length L is less than 10 mm, the fluidity is further improved. However, even if other requirements are satisfied, high mechanical properties necessary as a structural material cannot be obtained. Preferably, the area in which fibers of 10 mm or less are arranged is smaller than 5% of the ratio of the sheet base material area. Considering the relationship between fluidity and mechanical properties, it is more preferably in the range of 20 to 60 mm.

  In the present invention, the fiber bundle end generated by the cut inserted into the sheet base material is highly likely to become a starting point of fracture in the fiber reinforced plastic when stress is applied when a load is applied. Therefore, it is advantageous in strength that the reinforcing fiber is not divided as much as possible. When the cut fiber orthogonal direction component Ws is larger than 100 mm, the strength is constant. From the viewpoint of mechanical characteristics, preferably, when Ws is 1.5 mm or less, the strength is significantly improved. On the other hand, when Ws is smaller than 30 μm, the fibers easily escape from the blade when the punching die is pressed against the sheet base material, and it is difficult to control the cutting position. It is difficult to ensure that the length L is 10 to 100 mm. That is, if there is a fiber that is not divided as designed, the fluidity of the base material is remarkably lowered, but if the cut length is excessively long, there are many problems that the fiber length L is less than 10 mm. There is a point. Preferably, by setting Ws to 1 mm or more, it is possible to insert the cut with a simple device. On the contrary, when Ws is larger than 10 mm, the strength is almost constant. That is, when the fiber bundle end becomes larger than a certain value, the load at which breakage starts becomes substantially equal. When Ws is 1.5 mm or less, the strength improvement is significantly more preferable. That is, Ws is preferably 1 to 10 mm from the viewpoint that the cutting can be inserted with a simple device. On the other hand, in view of the relationship between the ease of controlling the cutting and the mechanical characteristics, Ws Is preferably 30 μm to 1.5 mm, more preferably in the range of 50 μm to 1 mm.

  The following three methods can be considered as typical methods for inserting intermittent cuts into the sheet base material. The first is to insert a cut manually using a single blade such as a cutter knife, or an automatic cutting machine (moving the cutting blade or round blade along the specified CAD drawing to cut the substrate) This is a cutter method in which a notch is inserted into a sheet base material using an apparatus that performs such a process. The second is a rotary blade method in which a cut is inserted into a sheet base material by continuously pressing the sheet base material against a rotary roller on which a blade is previously arranged. The third is a pressing method in which a notch is inserted into the sheet base material by pressing a punching die having a blade disposed on the sheet base material using a press machine (elevator). The cutter method is suitable for making a cut in a sheet base material in a simple manner. However, the larger the number of cuts, the longer the time required for the insertion of the cut, and it is not suitable for mass production. In the rotary blade method, the insertion speed of the cut can be set fast, but in order to make intermittent cuts, it is necessary to accurately position and provide blades corresponding to each cut on the curved surface of the rotary roller. Have difficulty. On the other hand, the press-cutting method has a high production efficiency such as being able to insert a large amount of cuts into the sheet base material at a time by one press, and the punching process is easy, so the sheet base material is intermittent. It is the best way to insert a notch. In addition, as a method of attaching the punching die to the press machine in the press-cutting method, for example, it is preferable to embed the blade in a wooden mold as a base and attach it to the press machine as a punching die. If this method is used, it is easy to produce a punching die, and the amount of protrusion of the blade can be easily adjusted. The present invention uses this pressing method.

  The present invention inserts a cut into a sheet base material by feeding the sheet base material in the fiber array direction and intermittently pressing a die having a blade disposed on the sheet base material. By feeding the sheet base material in the fiber array direction, the sheet base material can be conveyed by applying tension to the fibers, and the sheet base material can be handled stably. Moreover, a cutting sheet base material can be manufactured continuously by intermittently pressing the punching die against the sheet base material while feeding the sheet base material in the fiber array direction. Here, when the punching die is pressed against the sheet base material intermittently, the sheet base material may always move, or is stopped only when the blade and the base material are in contact with each other, and at other times the sheet Means for moving the substrate may be taken. The former has an advantage that the cutting speed can be set high although the load applied to the blade during cutting becomes large. The latter has the merit that the cutting speed is slow, but the burden on the blade can be reduced, and the cut sheet base material can be stably mass-produced.

  Furthermore, as an epoch-making effect achieved by using the manufacturing method of the present invention, the amount of cuts inserted at a time can be reduced by pressing the punching die intermittently, and the insertion of the cuts There is a point that the load necessary for the can be kept small. As an example, let us consider a case where notches 8 having a pattern as shown in FIG. Temporarily, when it is going to insert the notch 8 of this pattern only by pressing a die once on the sheet | seat base material 3 (henceforth "press"), since there is much quantity of the notch 8 inserted at once. A large load is required to break the fiber. Therefore, if it is going to introduce the press machine which can load sufficient load to insert a notch at a stretch, a press machine will enlarge, production cost will rise, and raising / lowering speed will fall. However, instead of inserting all the cuts at a time, the first press presses the solid line portion 10 in FIG. 4B and the second press cuts the dotted line portion 11 in one press. If the number of the cuts 8 to be inserted is reduced and the cuts 8 are inserted by a plurality of presses, the amount of the cuts 8 to be inserted at one time is reduced, and the load load required for the press machine can be kept small. . Along with this, the press used to insert the cut 8 can be made smaller, leading to a reduction in production cost, increasing the lifting speed, and improving the production speed of the cut sheet base material. Moreover, although the sheet | seat base material to supply may be 1 sheet | seat, a several sheet | seat base material can be manufactured at a stretch by laminating | stacking several sheet | seat base materials.

  Further, as an advantage of inserting the cut by intermittently pressing, the density of the blades arranged in the punching die can be kept low. For example, when the cuts simultaneously inserted by one press are dense like the solid line part of FIG. 4 (B), an attempt is made to arrange independent blades in the punching die so as to correspond to the respective cuts. Then, since the distance between each blade is short, the operation | work which arrange | positions a blade may become difficult. In such a case, it is preferable that the cuts to be inserted at a time are not concentrated in a narrow area as shown in FIG. 4B, but preferably the cuts to be inserted at a time like the solid line part in FIG. It is better to design the punching die so that it is not crowded. 4 (B) and 4 (C) are examples in which the notches 8 are inserted using different punching dies, but any of the punching dies can be used by moving the sheet base material 3 by the amount of the arrow 12. Even in the case where it has occurred, it becomes possible to insert the notch of the pattern shown in FIG. By designing the punching die in this way, it becomes possible to produce the punching die more easily and at a low cost. Thus, the point that the blade density can be kept low is one of the epoch-making effects achieved by the present invention.

  As the punching die used in the present invention, an independent blade may be arranged for each notch to be inserted, but it is preferable to use a blade in which a plurality of cut portions are integrated. Here, the “cut portion” is an area of the blade 6 provided in the punching die 7 as shown in FIG. 2B), and enters the sheet base 3 when inserting the cut into the sheet base 3. Or a region penetrating the sheet substrate 3. Although the sheet | seat base material and blade at the time of cutting insertion were typically shown in FIG. 2, the cut part defined to this invention corresponds to the shaded part of FIG. When an incision to be inserted into a sheet base material is to be produced with independent blades, it is necessary to arrange a large number of blades in a punching die, and it takes time to attach the blades. Further, in the cut sheet base material, the position accuracy of the cut greatly affects the fluidity at the time of molding and the mechanical strength of the molded product. Therefore, it is important to accurately arrange the blades in the die. Therefore, as the number of blades to be attached increases, it takes more time to adjust the blade position with high accuracy. On the other hand, if a blade in which a plurality of cut portions are integrated in advance is used, the number of times of attaching the blade to the punching die can be greatly reduced. Examples of blades in which a plurality of cut parts are integrated include engraving blades obtained by cutting a plurality of sharp protrusions from a metal lump by cutting, corrosion blades obtained by etching the metal lump, and then machining, etc. And a sewing blade having a plurality of sharp protrusions at its end.

  In the present invention, the following two methods are effective as means for inserting a cut of a desired pattern into the sheet base material. Here, FIGS. 23 (A) and (B) show an example of the manufacturing method of the cut sheet substrate in the present invention, and FIGS. 23 (C) and (D) show the respective methods. An example of the cut sheet base material produced by using is shown. First, as a first means, a projection line obtained by projecting a ridge line of the blade edge of the blade included in the punching die onto the sheet base material 3 in a direction in which the punching die is pressed against the sheet base material (hereinafter referred to as a pressing direction). Is the projection line O (59), as shown in FIG. 23C, the projection line O (59) matches the desired cutting pattern, and as shown in FIG. In this method, the blade is disposed in the punching die so that the side surface of the blade is parallel to the pressing direction. By pressing the punching die thus produced against the sheet base material, a desired pattern of cuts can be inserted into the sheet base material. Second, as shown in FIG. 23 (D), the desired notch pattern is on the projection line O (59) and, as shown in FIG. 23 (B), tapers toward the cutting edge. The blade is arranged in a punching die, and the punching die is pressed against the sheet base material until a desired pattern of cuts is inserted. The former has an advantage that the amount of pressing the punching die can be arbitrarily set as long as the blade tip penetrates the sheet base material. On the other hand, in the latter case, it is necessary to control the amount of pressing the die against the sheet base material, but the blade deteriorates while the base material is cut, so that the continuous fiber remains without properly cutting the sheet base material. In this case, there is an advantage that the base material can be cut without leaving continuous fibers only by increasing the amount of pressing the punching die against the sheet base material. 23C and 23D, when the projection line A is a projection line obtained by projecting the ridge lines of all the cut portions included in the punching die onto the sheet base material 3 in the pressing direction. In any case, the projection line A coincides with the notch.

  In the present invention, as a means for setting the fiber orthogonal direction component Ws of the incision within the range of 30 μm to 100 mm, the die cutting is performed so that the fiber orthogonal direction component Ws ′ of the projection line A is within the range of 30 μm to 100 mm. Is preferably pressed against the sheet substrate. In the present invention, the base material is not greatly deformed when the base material is cut, and the base material is fed in the direction in which the reinforcing fibers are arranged. Therefore, in the manufacturing method of the present invention, the pattern of the projection line A has the shape of the notch 8 as it is, as in the relationship between FIG. 3 (A) and FIG. 3 (B). Therefore, by setting the value of the fiber orthogonal component Ws ′ of the projection line A within the range of 30 μm to 100 mm, it becomes possible to simultaneously set the fiber orthogonal component Ws of the cut within the range of 30 μm to 100 mm.

  Furthermore, in the present invention, the following method is preferable as a specific means for setting the fiber length L of substantially all the reinforcing fibers within the range of 10 to 100 mm. That is, as shown in FIG. 5 (A), the projection lines B (13) obtained by projecting the projection line A (47) onto the same fiber orthogonal plane 48 in the fiber arrangement direction 2 are substantially equal. It is preferable to press the punching die against the sheet base so that all are connected. 5A and 5B show the projection line A (47) and the projection line B (13) obtained by projecting the projection line A (47) onto the same fiber orthogonal plane 48 in the fiber arrangement direction 2. FIG. . As shown in FIG. 5 (A), when the blade is arranged on the punching die so that all the projection lines B (13) are connected, and the punching die is pressed against the sheet base material, the sheet base material 3 is made of fiber. When sending in the arrangement direction 2, the cut portion is pressed against the sheet base material 3 in the arrangement direction 2 of the reinforcing fibers at intervals of 10 to 100 mm, thereby dividing the reinforcing fibers in the sheet base material 3 into the range of 10 to 100 mm. Is possible. On the other hand, even if some of the projection lines B (13) are not connected, as in the case where all of the projection lines B (13) are connected, they may fall within the scope of the present invention. The case is as described below. That is, as shown in FIG. 5 (B), when the unconnected portion 14 is present in the projection line B (13), the fiber passing through the portion is no matter how many times the punching die is pressed against the sheet base material 3. It exists as a continuous fiber without being cut. As a result, the cut sheet base material cannot exhibit sufficient fluidity. However, the cut sheet base material can exhibit good fluidity if the width 15 of the non-connected portion is 0.5 mm or less and some continuous fibers remain. That is, “substantially all the projection lines B are connected” in the present invention means that there is no gap larger than 0.5 mm when all the projection lines B are overlapped. Preferably, the width 15 of the unconnected portion is 0.1 mm or less, and more preferably, the unconnected portion is completely absent, that is, it is best that there is no continuous fiber.

  As described above, as shown in FIG. 3 (A), the cut fiber orthogonal direction component Ws (54) indicates the amount of fiber cut by the cut 8 in the cut sheet substrate 3, and preferably When Ws is 1.5 mm or less, the strength is significantly improved. As a means for reducing Ws, that is, for reducing the fiber orthogonal direction component Ws ′ (5) of the projection line segment A (47), first, a method of reducing the length W (19) of the cut portion is conceivable. Here, the length W (19) of the cut portion is the length of the projection line segment A (47) obtained by projecting the ridge line 9 of the cut portion onto the sheet base material 3 in the direction in which the punching die is pressed against the sheet base material. In the case of a curve, the length along the projection line A is shown as shown on the right side of FIG. However, if the length W of the cut portion is extremely small, the blade becomes fine and durability is lowered, and the blade is easily damaged during cutting. In order to suppress breakage of the blade during cutting, it is preferable that the length W of the cut portion is 100 μm or more. As another means for reducing Ws, when the angle (absolute value) formed between the projection line A and the fiber arrangement direction is θ, the blade is pressed against the sheet substrate so that θ is an acute angle. There is a way. In the present invention, as shown in FIG. 3B, when the projection line A is a curve, the angle at the point where the angle formed with the fiber arrangement direction at the point on the projection line A is the maximum is θ. To do. As a result, even if the length W of the cut portion is the same, the value of Ws (Ws ′) can be kept small by reducing θ. As a result, the mechanical strength of the fiber reinforced plastic molded using this cut sheet substrate is also improved.

  Moreover, the resin rich part in the molded article of a cut sheet base material can also be made small by pressing a blade against the sheet base material so that θ becomes an acute angle. FIG. 6 (A) shows a schematic diagram of the cut sheet base material when θ is 90 °, and FIG. 6 (B) shows a part of the molded body of the cut sheet base material obtained by press molding. . When the cut sheet base material 3 is press-molded, first, the cut 8 in FIG. 6A is opened, and the fibers try to move in the arrangement direction 2 of the reinforcing fibers. Further, the resin flows into the opening with the opening of the notch 8, and at the same time, the reinforcing fibers adjacent to the opening and the fiber orthogonal direction 4 also slightly flow into the opening. As a result, as shown in FIG. 6 (B), a region not containing fibers, that is, a resin rich portion 16 is generated in the vicinity of the fiber end portion. In the fiber reinforced plastic, since the fiber bears most of the applied load, stress concentration occurs in the vicinity of the resin-rich portion, which tends to be a starting point of fracture. On the other hand, a schematic diagram of the cut sheet base material when θ is an acute angle is shown in FIG. 7A, and a part of the cut sheet base material obtained by press molding is shown in FIG. 7B. FIG. 7C shows an enlarged view of the opening of the molded body. When the cut sheet base material 3 having an acute angle θ is press-formed, first, the cut part 8 tends to open like a molded product of θ = 90 °. However, when θ is an acute angle, the length 17 of the opening in the fiber arrangement direction 2 becomes large when the incision is opened, so that fibers easily flow into the opening from the fiber orthogonal direction 4. Furthermore, the length (Ws) in the fiber orthogonal direction 4 of the opening is also reduced, and the area of the resin rich portion 16 is reduced. Furthermore, by pressing the blade against the sheet substrate so that θ is an acute angle, the reinforcing fiber is difficult to escape from the blade when the punching die is pressed against the reinforcing fiber, and the production stability is increased. That is, the reinforcing fibers contained in the sheet base material hardly deform in the fiber arrangement direction, but easily meander in the fiber orthogonal direction and try to escape from the blade, so that the orthogonal direction of the projection line A and the reinforcing fibers are aligned. In this case, cut mistakes are likely to occur.

  As described above, pressing the blade against the sheet base material so that θ is an acute angle is convenient both from the viewpoint of the mechanical properties of the obtained cut sheet base material and from the viewpoint of the manufacturing process. In particular, if θ is 60 ° or less, the reinforcing fibers are difficult to escape from the blade. Further, considering the strength aspect, θ is preferably 45 ° or less, more preferably 30 ° or less. On the other hand, even if θ is smaller than 2 °, sufficient fluidity and mechanical properties can be obtained, but it is difficult to insert the cut stably. That is, when the incision lies on the fibers, the blades easily break between the fibers. Further, in order to set the fiber length L to 100 mm or less, when θ is smaller than 2 °, at least the shortest distance between the cuts becomes smaller than 1.8 mm. By inserting a large number of cuts, the cut sheet base material is difficult to maintain its shape, and the handleability may be lacking.

  As described above, by the two means of shortening the length W of the cut portion and arranging the blade in the die so that the projection line A is inclined with respect to the substrate arrangement direction, The fiber orthogonal direction component Ws can be reduced, and the molded body using the cut sheet base material can be increased in strength. However, as described above, when the length W of the cut portion is extremely short or the angle θ between the projection line A and the fiber arrangement direction is too small, the production stability may be lacking. In that case, it is preferable to perform these two means at the same time, whereby the value of the cut fiber orthogonal direction component Ws can be further reduced and the strength can be further improved.

  In the manufacturing method of the present invention, as described above, various blades such as engraving blades, corrosion blades, and sewing blades can be arranged in the punching die. Among these, it is particularly preferable to use a sewing blade. Generally, the sewing machine blade is used when inserting a broken line-like cut into paper or the like. At this time, the broken line-shaped cut is designed so that it can be easily cut by hand along a designated line. Focusing on the shape of this sewing blade, one of the major features of the present invention is that it is used as a cut portion for inserting intermittent cuts into a sheet base material including reinforcing fibers in which the sewing blades are arranged in one direction. It is. The sewing blade can be manufactured industrially at a lower cost than the corrosion blade and the engraving blade. In addition, high-hardness materials cannot be used with corrosion blades due to manufacturing reasons, but higher-hardness materials can be used because sewing blades can also be obtained by cutting into forging blades. And has excellent durability.

  More preferably, the present invention uses a flat sewing blade. If the sewing blade is disposed obliquely with respect to the fiber arrangement direction (the projection line A is inclined with respect to the fiber arrangement direction), or the sharp protrusions are reduced in size and spacing, the fibers can be effectively cut. The orthogonal direction component Ws can be reduced, and a die can be produced very easily and inexpensively. If the sewing blade is applied to the rotating blade method, the rotating roller to which the blade is attached is curved, so that the cutting fiber can be obtained simply by arranging the sewing blade obliquely with respect to the fiber arrangement direction as in the present invention. The orthogonal direction component Ws cannot be reduced. Therefore, in the rotating blade method, the blade must be provided on the roller by a method such as cutting or etching, and the manufacturing cost is increased.

  Here, an example of a sewing machine blade suitably used in the present invention is shown in FIG. For example, the sewing blade is a flat sewing blade as shown in FIG. 8A, and the grooves are preferably cut out at a predetermined pitch. In addition, as shown in FIG. 8 (B), it is a flat plate-like sewing blade, and the cutting edge has a wave shape of a mountain, a valley, a mountain, a valley, as shown in FIGS. 8 (C) and (D). A blade having a wave shape in the out-of-plane direction is preferable. Although any blade can be used to carry out the present invention, the plate-like sewing blade shown in FIG. 8A is most suitable in view of ease of processing and cost. In addition, as a specific method for producing a sewing machine blade, a method of pressing a knurl against a continuous blade or an etching blade (continuous blade) obtained by machining the blade edge, or a continuous blade obtained by machining the blade edge using a machine tool There is a method of dividing at a predetermined pitch.

  As described above, the mechanical strength of the molded body using the cut sheet base material of the present invention strongly depends on the angle θ between the projection line A and the fiber arrangement direction. Therefore, when θ differs depending on the location, the mechanical properties are non-uniform and the design becomes difficult. Therefore, it is preferable that the sewing machine blade is flat and the sewing machine blades are arranged in a punching die in parallel with each other.

  Further, a part that is a part of the sewing machine blade and penetrates the base material or enters the base material when inserting a cut is defined as a cut part, and a distance between adjacent cut parts in the same sewing machine blade is defined between the cut parts. When the distance b is set, it is preferable that the punching die is pressed against the sheet substrate so that the length W of the cut portion and the distance b between the cut portions are constant. Even when the length W of the cutting part of the sewing blade and the distance b between the cutting parts are different from place to place, the cutting length in the cut sheet base material is different from place to place. Change. Therefore, it is preferable that the length W of the cut portion and the distance b between the cut portions are constant. As a result, the mechanical properties are uniform and the design is facilitated. In addition, as shown in FIG. 9, the said distance between cut parts b in this invention points out the minimum linear length b (20) between the cut parts 46 adjacent in the sewing machine blade 18. As shown in FIG.

  In the present invention, the projection lines B obtained by projecting the projection line A onto the same fiber orthogonal plane in the fiber array direction in the direction in which the punching die is pressed against the sheet base material are connected to each other only at the ends. It is preferable to press the punching die against the sheet base material and cut the sheet base material every time the sheet base material is moved 10 to 100 mm in the fiber array direction. Thereby, there is no place where the cut portion overlaps in the fiber arrangement direction in the punching die, and the amount of blades used for cutting the substrate can be minimized. Furthermore, by moving the sheet base material in the fiber array direction by the fiber length L of the reinforcing fiber contained in the cut sheet base material to be designed, the predetermined fiber is pressed against the sheet base material. The length L can be obtained. As described above, by reducing the amount of blades arranged in the punching die, the amount of cuts inserted at a time is reduced, and the load required for inserting the cuts can be kept small. In the present invention, “projection lines B are connected to each other only at their ends” means that an arbitrary projection line B is a projection line B1, the length of the line segment is Ws1, and a projection line B adjacent thereto is projected. When the line is B2 and the length of the line segment is Ws2, it indicates that the length of the common part of both line segments is (Ws1 + Ws2) × 0.1 or less.

  As a more preferable means, the ratio (W / b) of the length W of the cut part to the distance b between the cut parts (W / b) is within the range of 1 to 1.5 when the flat sewing blade is arranged in parallel with the punching die. It is preferable to press the punching die against the sheet base material every time the sheet base material is moved 10 to 100 mm in the fiber array direction so that the projection lines B are connected to each other only at the ends. . As an example, FIG. 10 (A) shows a punching die, and FIG. 10 (B) shows a cut sheet substrate produced using the punching die. At this time, the feed amount of the sheet base material corresponds to the fiber length L of the reinforcing fiber. Thereby, the fiber length of the reinforcing fiber of the sheet base material can be made constant, and the amount of blades to be used can be minimized. From the viewpoint of reducing the number of the reinforcing fibers having the designed fiber length L or less as much as possible, the ratio of the length W of the cut part to the distance b between the cut parts is preferably in the range of 1 to 1.1. Good.

  More preferably, the fiber length L of all the reinforcing fibers contained in the cut sheet base material is constant, and the sewing blades are spaced apart from each other by 1.5 L or more in the fiber arrangement direction and arranged in the punching die. When the straight cuts 8 inclined from the fiber arrangement direction as shown in FIG. 10B are inserted using a sewing machine blade, the straight cuts 8 are inserted at a time (that is, inserted at a time by the sewing machine blade). There is a tendency that the distance between each other) becomes smaller. As shown in FIG. 10A, when the sewing blades 18 are prepared so as to correspond to the rows of cuts arranged in a straight line, the distance between the sewing blades 18 is reduced, and the sewing blades 18 are arranged on the punching die. It becomes difficult. Further, when the punching die is pressed against the sheet base material, the punching die tends to be inclined because the load is localized. While intermittently inserting the notches 8 while feeding the sheet base material L by L in the fiber arrangement direction, the sewing machine blades are shifted by (0.5 + n) L (where n is an integer of 0 or more) in the fiber arrangement direction. By arranging in the punching die, it is possible to insert a cut as shown in FIG. Therefore, n is a natural number, that is, the sewing blades are arranged in the punching die with 1.5L or more in the fiber arrangement direction, so that the sewing blade can be easily placed in the punching die and the punching die can be easily balanced. It can be pressed against the material.

  In the present invention, when the sewing blades are provided to be inclined with respect to the fiber arrangement direction, as shown in FIG. 10 (A), it is possible to carry out with a minimum of two sewing blades. It is not economical because it becomes large and the punching die becomes considerably long at the same time. Therefore, as shown in FIG. 11, it is preferable to divide the sewing machine blade of FIG. 10A into a plurality of parts and to dispose them in the direction perpendicular to the fiber. Thereby, the length of the punching die in the substrate feeding direction can be kept small, the required press machine (elevating machine) is also reduced, the production cost can be reduced, and the elevating speed is also improved.

  Examples of the reinforcing fiber used for the cut sheet substrate of the present invention include organic fibers such as aramid fibers, polyethylene fibers, polyparaphenylene benzoxador (PBO) fibers, glass fibers, carbon fibers, silicon carbide fibers, and alumina. Inorganic fibers such as fiber, Tyranno fiber, basalt fiber, ceramics fiber, metal fiber such as stainless steel fiber and steel fiber, etc., boron fiber, natural fiber, modified natural fiber, etc., and a mixture of two or more of them Can be mentioned. Among them, carbon fiber is particularly lightweight among these reinforcing fibers, and has particularly excellent properties in specific strength and specific modulus, and is also excellent in heat resistance and chemical resistance. It is suitable for members such as automobile panels that are desired to be made. Among these, PAN-based carbon fibers that can easily obtain high-strength carbon fibers are preferable.

  As the sheet substrate used in the present invention, it is preferable to use a prepreg substrate composed of reinforcing fibers and a matrix resin. In the case where the sheet base material is composed only of reinforcing fibers, the base material is likely to be scattered at the time of cutting, and it may be difficult to perform stable cutting. If it is a prepreg base material, since the circumference | surroundings of the reinforced fiber are satisfy | filled with resin, it becomes possible to produce a cutting sheet base material stably, without a reinforced fiber separating at the time of base material cutting. When the fiber volume content Vf is 65% or less as the amount of the resin of the prepreg base material, sufficient fluidity can be obtained. The lower the Vf, the better the fluidity. However, if Vf is less than 45%, the high mechanical properties required for the structural material cannot be obtained. Considering the relationship between fluidity and mechanical properties, it is more preferably in the range of 50 to 60%.

  Examples of the matrix resin used for the prepreg base material used in the present invention include epoxy resins, unsaturated polyester resins, vinyl ester resins, phenol resins, epoxy acrylate resins, urethane acrylate resins, phenoxy resins, alkyd resins, urethane resins, and maleimides. Thermosetting resins such as resin and cyanate resin, polyamide, polyacetal, polyacrylate, polysulfone, ABS, polyester, acrylic, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene, polypropylene, polyphenylene sulfide (PPS) ), Polyether ether ketone (PEEK), liquid crystal polymer, vinyl chloride, polytetrafluoroethylene and other fluororesins, silicone and other thermoplastic resins And the like. Among these, it is particularly preferable to use a thermosetting resin. Since the matrix resin is a thermosetting resin, the cut prepreg base material has tackiness at room temperature, so when the base material is laminated, it is integrated with the upper and lower base materials by adhesion, It can shape | mold, keeping the laminated structure as it was.

  Furthermore, since the cut prepreg base material composed of the thermosetting resin produced according to the present invention has excellent drapability at room temperature, for example, when it is molded using a mold having a concavo-convex part, It is possible to easily perform preliminary shaping along the line. This pre-shaping improves moldability and facilitates flow control.

More preferably, among the thermosetting resins, an epoxy resin, an unsaturated polyester resin, a vinyl ester resin, a phenol resin, an acrylic resin, or a mixed resin thereof is preferable. The resin viscosity at normal temperature (25 ° C.) of these resins is preferably 1 × 10 ⁶ Pa · s or less, and if within this range, a prepreg base material having tackiness and draping properties satisfying the present invention is used. Obtainable. Among them, the epoxy resin is most excellent in mechanical properties as a reinforced fiber composite material obtained in combination with carbon fiber.

  The cut prepreg base material is more likely to be deformed as the number of cuts increases and the longer the cut, the lower the rigidity of the cut prepreg base material. Accordingly, when the cut prepreg base material is lifted during the laminating operation, handling becomes difficult, for example, the shape of the cut prepreg base material is broken. In order to avoid such a problem, as shown in FIG. 12, the opposite side of the prepreg base material 28 from which the die 7 is pressed is gripped by a tape-like support 29, and the tape-like support 29 is removed. It is preferable to carry out a so-called half cut in which only the prepreg base material 28 is cut while remaining. Thereby, even if there is much amount of cutting, since a tape-shaped support body suppresses a deformation | transformation of a cutting prepreg base material, the handleability of a base material improves significantly. Here, the tape-like support includes papers such as kraft paper, polymer films such as polyethylene / polypropylene, metal foils such as aluminum and the like, and in order to obtain releasability from the resin, silicone. A surface or “Teflon (registered trademark)” type release agent, metal vapor deposition, or the like may be applied to the surface. At this time, the amount of the tip 30 of the cut portion 46 entering the prepreg base material 28 may be the depth at which the tip 30 of the cut portion 46 enters just the prepreg base material 28, In this case, if the cut portion 46 is worn due to many cuttings, there is a possibility that uncut portions frequently occur. It is preferable that the cut portion 46 penetrates the prepreg base material 28 and only a part of the tape-like support 29 enters. Further, as the thickness of the tape-shaped support 29, a large thickness is not economical because the material cost increases. However, if the thickness is too thin, it is difficult to keep the tip 30 of the cut portion 46 inside the tape-shaped support 29 when the punching die 7 is pressed against the prepreg base material 28. As a result, when the tip 30 of the cut portion 46 completely penetrates the tape-like support 29, the handleability of the cut prepreg base material was lowered, and the tip of the cut portion did not reach the tape-like support. In some cases, the fibers cannot be cut, and continuous fibers remain in the cut prepreg base material, resulting in a decrease in fluidity during molding. Therefore, the thickness of the tape-shaped support 29 is preferably 30 to 300 μm, more preferably 50 to 200 μm.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the inventions described in the examples.

<Comparison of the number of blades (Examples 1-2)>
(Example 1): Each cut part in a cutting die was configured with an independent blade. A cutting sheet base was manufactured using a cutting die configured with all independent blades.

The used base material is a prepreg base material obtained by the following procedure. Epoxy resin ("Epicoat (registered trademark)" 828: 30 parts by weight, "Epicoat (registered trademark)" 1001: 35 parts by weight, "Epicoat (registered trademark)" 154: 35 parts by weight, manufactured by Japan Epoxy Resin Co., Ltd. Then, 5 parts by weight of thermoplastic resin polyvinyl formal ("Vinylec (registered trademark) K" manufactured by Chisso Corporation) was kneaded with a kneader to uniformly dissolve the polyvinyl formal, and then the curing agent dicyandiamide (Japan Epoxy Resin Co., Ltd.) ) DICY7) 3.5 parts by weight and 4 parts by weight of curing accelerator 3- (3,4-dichlorophenyl) -1,1-dimethylurea (Hodogaya Chemical Co., Ltd. DCMU99) were kneaded in a kneader. Thus, an uncured epoxy resin composition was prepared. This epoxy resin composition was applied onto a release paper having a thickness of 100 μm that had been subjected to silicone coating using a reverse roll coater to prepare a resin film. Next, a resin film is laminated on both sides of carbon fibers arranged in one direction (tensile strength 4,900 MPa, tensile elastic modulus 235 GPa), and the resin is impregnated by heating and pressing, so that the carbon fiber weight per unit area is increased. A prepreg base material having a thickness of 125 g / m ² , a fiber volume content Vf of 55%, and a thickness of 0.125 mm was produced.

  A prepreg base material having regular cuts at regular intervals is inserted into the prepreg base material obtained by the above means by continuously inserting cuts as shown in FIG. 13 by the production method of the present invention. Obtained. FIG. 13 shows a cutting pattern of one region of the cutting prepreg base material. The cutting direction is the fiber orthogonal direction 4, the cutting length W (33) is 5 mm (that is, the cutting fiber orthogonal direction component Ws = 5 mm), and the interval L (fiber length) 34 is 30 mm. . Further, the adjacent cut rows 35a and 35b are geometrically equivalent when moved 5 mm in the fiber orthogonal direction. In addition, there are pairs of cuts 35a and 35c, and 35b and 35d in the cut rows that are paired in the fiber longitudinal direction, and there are two patterns of cut rows. As shown in FIG. 14, the punching die used in the present invention is based on a veneer plate 36 of 500 mm × 500 mm × 15 mm, and a region 37 of the center 300 mm × 300 mm of the plywood plate has a width of 5 mm shown in FIG. A projection line in which a ridge line of the blade is projected onto the sheet base material in a direction (perpendicular to the sheet base material) in which the cutting blade and the cutting die shown in FIG. Arranged so that the minutes A coincided. At this time, the protruding amount of the blade from the plywood plate was 5 mm. The total number of blades used was about 600, and the total length of the ridge lines was about 3 m. FIG. 14B shows a schematic diagram of the punching die. Attach this punching die to a hydraulic press machine and push the punching die vertically from the side opposite to the release paper to the prepreg base at a speed of 30 times per minute while feeding the base by 300 mm per press. A cut prepreg base material was produced. At this time, the prepreg base material was supplied to the press machine at a constant speed of 9 m / min so that the feeding direction of the base material and the arrangement direction of the reinforcing fibers coincided. Thereby, the cutting prepreg base material can be produced at a speed of 9 m / min, and it was confirmed that this method can exhibit a sufficient production speed for mass-producing the cutting sheet base material.

  The produced cut prepreg base material was cut into a rectangular shape of 11 cm in the fiber arrangement direction shown in the dotted line part of FIG. 15 and 2 cm in the fiber orthogonal direction, and this was immersed in an NMP solution (N-methyl-2-pyrrolidone). The resin part was dissolved. At this time, the said strip-shaped base material was cut out so that the edge part of a notch may be located in the center of a strip-shaped base material. After 1 hour, the strip-shaped substrate was taken out of the NMP solution, the strip-shaped substrate was arranged in a plane on a fine paper, carbon fiber images were taken with an optical microscope, and the number of fibers was counted. As a result, about 2600 continuous fibers were confirmed. The same test was performed on a prepreg base material containing no notches at all, but the number of fibers at that time was approximately 38000. As a result, the ratio of continuous fibers is about 7%, and the remaining 93% of the fibers can be cut so that the fiber length is 100 mm or less. By this study, substantially all the reinforcing fibers are cut. It was confirmed that In addition, it is considered that the reason why the continuous fibers remained slightly is that the total length of the blades pressed against the prepreg base material at a time is long, resulting in insufficient pressure, and thus a slight uncut portion.

The cut prepreg base material thus produced was cut into a size of 250 × 250 mm in the fiber array direction and in a direction shifted by 45 degrees from the fiber array direction. The cut prepreg base material is laminated in a 16-layer pseudo-isotropic ([45/0 / −45 / 90] _2S ), placed on a 300 × 300 mm mold, and then heated by a 6 MPa Curing was performed under the conditions of 150 ° C. × 30 minutes under pressure to obtain a plate-like molded body of 300 × 300 × 1.7 mm. The fiber reinforced plastic had no fiber undulation, and the fibers were flowing evenly to the end. Although a continuous fiber was slightly present in a part of the cut prepreg base material, a streak pattern was observed along the fiber orientation direction at the end of the cut, but this continuous fiber hindered flow. There was no spot. Further, the cut portion was opened with a width of about 5 mm and a length of about 5 mm to form a resin rich portion, and the reinforcing fibers of the inner layer could be observed from the opening.

  A tensile strength test piece having a length of 250 ± 1 mm and a width of 25 ± 0.2 mm was cut out from the obtained flat molded body. According to the test method specified in JIS K-7073 (1988) “Tensile test method for carbon fiber reinforced plastic”, the tensile strength was measured at a crosshead speed of 2.0 mm / min with a distance between the gauge points of 150 mm. In this example, an Instron (registered trademark) universal testing machine 4208 type was used as a testing machine. The number of test pieces measured was n = 5, and the average value was the tensile strength. As a result of the tensile test, the tensile strength was 430 MPa and the elastic modulus was 44 GPa, which was very high.

(Example 2)
Compared with Example 1, the amount of blades attached to the punching die was reduced, and a cut prepreg base material was produced. Specifically, the area 37 for attaching the blade to the punching die was set to 300 mm × 30 mm as shown in FIG. Further, the die was pressed against the prepreg substrate at a speed of 90 times per minute while feeding the substrate by 30 mm per press. Other conditions were the same as in Example 1, and a cut prepreg base material was produced. Thus, a cut prepreg base material was produced at a speed of 2.7 m / min. The total number of blades used at this time was about 60, and the total length of the blades was about 0.3 m.

  The produced cut prepreg base material was immersed in the NMP solution in the same manner as in Example 1, and the number of reinforcing fibers exceeding 10 cm was counted. As a result, the number of reinforcing fibers longer than 10 cm contained in the strip-shaped base material is 1800 (about 5%), and it can be confirmed that substantially all the carbon fibers are divided to 100 mm or less. It was. Further, the amount of uncut residue is smaller than in Example 1, but this is considered to be due to the fact that the pressure applied to each blade is increased by reducing the number of blades.

  The cut prepreg base material thus obtained was molded in the same procedure as in Example 1 to obtain a flat fiber reinforced plastic. Compared to Example 1, the amount of continuous fibers at the cut end was reduced, and no streak pattern was observed, and the surface quality better than Example 1 was maintained.

<Examination of blade form (sewing blade: Example 3)>
(Example 3)
A cut prepreg base material was prepared and evaluated by the same procedure as in Example 2 except that the blade disposed in the punching die was a sewing blade having a cut portion length W5 mm and a cut portion distance b5 mm. A schematic diagram of the sewing machine blade used in Example 3 is shown in FIG. As a punching die, as shown in FIG. 17 (B), the sewing machine blades are arranged in the direction perpendicular to the fiber and separated by 15 mm, and the phase of each sewing machine blade (the length W of the cut part or the distance b between the cut parts) is set. What was arrange | positioned so that a half phase (length W of a cut part or the half length of the distance b between cut parts) may shift | deviate in the fiber orthogonal direction was used. Compared to the need to attach 60 blades to the punching die in Example 2, in Example 3, it is only necessary to install two sewing blades in the punching die, and the time required for making the punching die is greatly reduced. I was able to.

  The produced cut prepreg base material was immersed in the NMP solution in the same manner as in Examples 1 and 2, and the number of reinforcing fibers exceeding 10 cm was counted. As a result, the number of reinforcing fibers longer than 10 cm contained in the strip-shaped base material is 1400 (about 4%), and it can be confirmed that substantially all the carbon fibers are divided to 100 mm or less. It was. In addition, the amount of uncut residue is smaller than that in Example 2, which is considered to be due to the fact that the cut portion can be arranged with higher accuracy by using the sewing machine blade.

<Examination of Projection Length Ws (Examples 4 to 7)>
(Examples 4 to 7)
In Examples 4 to 7, a cut prepreg base material was produced and evaluated in the same manner as in Example 3 except that the length W of the cut part of the sewing machine blade and the distance b between the cut parts were changed. Specifically, the length W of the cutting portion of the sewing machine blade and the distance b between the cutting portions are set to 1: 1, and these lengths are 10 mm in Example 4, 2.5 mm in Example 5, and 1 in Example 6. 3 mm, and 0.63 mm in Example 7. Here, in Examples 4-7, since the incision and the fiber orthogonal direction coincide with each other, the length W of the incision coincides with the fiber orthogonal direction component Ws of the incision.

  The cut prepreg base material produced in each example was immersed in the NMP solution in the same manner as in Examples 1 and 2, and the number of reinforcing fibers exceeding 10 cm was counted. As a result, the number of reinforcing fibers longer than 10 cm contained in the strip-shaped base material was 1400 (about 3%) in Example 4, 1500 (about 3%) in Example 5, and in Example 6 1500 (about 3%), and in Example 7, it was 1600 (about 4%). Therefore, it was confirmed that substantially all the carbon fibers were divided to 100 mm or less.

  The produced cut prepreg base material was molded according to the above procedure, and a flat fiber-reinforced plastic was obtained in the same manner as in Examples 1 to 3. The appearance quality and the size of the resin rich portion were almost the same as those of Examples 1 to 3 in Examples 4 to 7. As shown in Table 2, the tensile strength is 410 MPa in Example 4, 460 MPa in Example 5, 520 MPa in Example 6, 560 MPa in Example 7, and the strength is improved as the cut length W is reduced. Was shown to do. The elastic modulus is as shown in Table 2, but all the levels were around 43 GPa.

<Examination of Cutting Angle θ (Examples 8 to 10)>
(Examples 8 to 10)
In Examples 8 to 10, a cut prepreg base material was produced and evaluated in the same manner as in Example 4 except that the sewing machine blade of Example 4 was inclined with respect to the fiber arrangement direction. As shown in FIG. 18, the punching die used is that the cutting blade length W and the distance b between the cutting portions are both 10 mm, and they are inclined by θ (39) with respect to the arrangement direction of the reinforcing fibers as shown in FIG. Are arranged. In FIG. 18, the sewing blades 21 arranged on the upper side or the sewing blades 22 arranged on the lower side are in phase with each other (the coordinates in the fiber arrangement direction of the cut portion are the same), and are adjacent in the fiber arrangement direction. The sewing blades (21 and 22) are shifted from each other by a half phase (half the fiber orientation direction component of the cut portion) in the fiber orthogonal direction. The sewing blades arranged in the punching die are classified into those 21 having the same phase in the direction perpendicular to the fiber and those 22 having the same phase in the direction perpendicular to the fiber, and the assembly 21 of the sewing blade and the assembly 22 of the sewing blade have a fiber arrangement with each other. 15 mm away in the direction. The length of each sewing blade in the direction perpendicular to the fiber is 50 mm. Regarding the angle θ, θ = 60 ° in Example 8, θ = 30 ° in Example 9, and θ = 10 ° in Example 10.

  The cut prepreg base material produced in each example was immersed in the NMP solution as in the previous examples, and the number of reinforcing fibers exceeding 10 cm was counted. As a result, the number of reinforcing fibers longer than 10 cm contained in the strip-shaped base material was 1000 (about 3%) in Example 8, 900 (about 2%) in Example 9, and in Example 10 There were 800 (about 2%). Therefore, it was confirmed that substantially all the carbon fibers were divided to 100 mm or less. In addition, the amount of uncut fibers decreased as the angle θ decreased. It is considered that such a difference was born by reducing θ, making it difficult for fibers to escape from the blade.

  Moreover, the produced cut prepreg base material was shape | molded according to the said procedure, and the flat fiber reinforced plastic was obtained similarly to Examples 1-4. When the surface of the fiber reinforced plastic is observed, in the model of Example 4, as shown in FIG. 6B, the reinforcing fiber 1 hardly flows into the cut opening 16 from the fiber orthogonal direction 4, and the shape of the opening Was also roughly rectangular. However, as Examples 8, 9, 10 and θ become smaller, the reinforcing fiber 1 flows into the cut opening 16 from the fiber orthogonal direction 4 as shown in FIG. It also decreased. When θ in Example 10 was 10 °, the opening was approximately curved, and the fibers in the inner layer could not be confirmed, and high surface quality was obtained. As for the tensile strength, as shown in Table 3, it was confirmed that as the θ became smaller, the projected length Ws also became smaller, and further the tensile strength improved. It is considered that the resin-rich portion can be made small by arranging the notches obliquely with respect to the direction perpendicular to the fiber and reducing the projection length Ws, which contributes to the strength improvement. The elastic modulus was 43 GPa as shown in Table 3, which was the same as the previous examples.

<Examination of Blade Interval (Example 11)>
(Example 11)
Production of a cut prepreg base material by the same procedure as in Example 3, except that the interval between the two sewing blades arranged in the punching die is 45 mm, and the feed amount of the base material per press is 30 mm, Evaluation was performed. In the punching die used in Example 11, as shown in FIG. 19, the two sewing blades are arranged in a direction perpendicular to the fiber and separated from each other by 45 mm, and the phase of each sewing blade (the length W of the cut portion and the length of the cutting portion). The distance b) between the cut parts is arranged so as to be shifted by a half phase (the length W of the cut part or half the distance b between the cut parts) in the fiber orthogonal direction.

  In Examples 1 to 10, since the distance between adjacent blades was short (15 mm or less), a large tool could not be used and it was difficult to attach the blades. In this example, the distance between the blades was 45 mm. Widely, it was possible to install the blade without any tool restrictions.

  The produced cut prepreg base material was immersed in the NMP solution in the same manner as in the previous examples, and the number of reinforcing fibers exceeding 10 cm was counted. As a result, the number of reinforcing fibers longer than 10 cm contained in the strip-shaped base material was 1500 (about 4%). Therefore, it was confirmed that substantially all the carbon fibers were divided to 100 mm or less.

  Further, the produced cut prepreg base material was molded according to the above procedure, and a flat fiber-reinforced plastic was obtained in the same manner as in Example 3. The appearance quality and the size of the resin rich portion were almost the same as in Example 3. The tensile strength and elastic modulus were 420 MPa and 43 GPa, respectively, which were almost the same as those in Example 3.

<Examination of substrate used (Example 12)>
Example 12
Cuts were inserted in the same manner as in Example 10 except that the base material to be used was a sheet base material (not including a resin) in which carbon fibers were arranged in one direction to obtain a cut sheet base material. The base material used in this example is a UD fabric UT70-30 (manufactured by Toray Industries, Inc.) in which carbon fibers are arranged in one direction and woven with glass fibers. The RTM resin is 70 parts by weight of “Epicoat 807” (manufactured by Yuka Shell Epoxy), 30 parts by weight of “Epicoat 630” (manufactured by Yuka Shell Epoxy), and an amine curing agent. A liquid epoxy resin obtained by mixing 43 parts by weight of “Ancamine 2049” (Pacific Anchor Chemical Co., Ltd.) was used. When the base material after cutting was observed, there was no portion where continuous fibers were present, and cutting was able to be performed smoothly.

  In the same manner as in Example 1, a strip-shaped base material was cut out from the produced cut sheet base material, and the number of reinforcing fibers exceeding 10 cm was counted (However, in this example, it is not necessary to dissolve the resin, so NMP Only the work of immersing in the solution was omitted). As a result, the number of reinforcing fibers longer than 10 cm contained in the strip-shaped base material is 1800 (about 5%), and it can be confirmed that substantially all the carbon fibers are divided to 100 mm or less. It was.

Further, Va-RTM molding was performed to obtain a fiber-reinforced plastic by injecting a resin into the laminate of the base materials. As shown in FIG. 20, the mold used was a mold 40 having convex portions having a height of 5 cm, a width of 30 cm, and a length of 20 cm. The radius of curvature of the R portion 44 of this mold was 10 mm. An injection port 41 made of a nylon tube and a decompression port 42 were provided at the end of the mold, and the whole including the molding material was sealed with a bagging film covering the upper surface. At this time, the base material arranged in the mold is a 16-layer pseudo-isotropic ([45/0 / −45 / 90], with the cut sheet base material cut into 400 mm × 100 mm and the longitudinal direction of the base material as 0 °. _2S ). Furthermore, the base material was arrange | positioned at the metal mold | die so that the longitudinal direction of this base material might correspond with the longitudinal direction of a metal mold | die. The injection port 41 and a disposable cup containing an epoxy resin were connected, and suction was performed with a vacuum pump from the decompression port 42 to perform Va-RTM molding. After completion of the injection, the mold was placed in an oven and heated to 100 ° C., and the state was maintained for 2 hours to cure the resin. After the mold was cooled, demolding was performed to obtain a fiber reinforced plastic having no unimpregnated portion.

  The obtained fiber reinforced plastic had no fiber undulations, a small opening at the notch, and good appearance quality. Further, a portion corresponding to the R portion 44 was cut out and the cut surface was polished, and then observed with an optical microscope. As a result, it was confirmed that the fiber reinforced plastic maintained the layer structure evenly in the thickness direction even in the R portion 44.

  Hereinafter, a comparative example is shown.

<Comparison with other manufacturing methods>
(Comparative Example 1)
The incision prepreg base material produced in Example 1 was produced by a cutter method (incision was inserted by an automatic cutting machine). An example of the cutting device is shown in FIG. The blade was a single blade made of stainless steel, which was attached to the head 45 of the machine, and the movement amount of the head in the XY directions was controlled by a servo motor. The target cutting pattern is shown in FIG. 13 and is obtained by dividing the fiber so that the fiber length is 30.0 mm and the cutting length is 5.0 mm. The base material used for the cutting was the same as in Example 1.

However, since all the cuts were cut with a single blade, the production rate of the base material was extremely slow at 0.6 m / min. Compared with the press-cutting method of Example 1, it took 15 times as much time, and it was confirmed that this is not a technique that can be industrially mass-produced.
(Comparative Example 2)
The same cut prepreg base material produced in Example 1 was produced by the rotary blade method. A schematic diagram of the cutting scenery is shown in FIG. The blade used for cutting the substrate was a rectangular blade having a width of 10 mm shown in FIG. 22A, and a plurality of these blades were embedded in a metal roller 56 having a diameter of 95 mm, and this was used as a punching die. The position in which the blade was embedded was determined so that the developed view in the circumferential direction of the punching die coincided with the cutting pattern of the cutting prepreg base material produced in Example 1. Further, the height at which the blade protrudes from the roller surface was about 0.5 mm. As a result, the length of the substrate conveyed while the punching die was rotated once was 300 mm. However, it was not easy to embed the blade on the surface of the roller, and it took a considerable amount of time to produce the punching die.

The prepreg base material was cut using the punching die. The rotation speed of the roller at the time of cutting was 10 rotations / minute. Therefore, the production speed of the cut prepreg base material was about 3.0 m / min. However, at the time when the base material was cut by about 300 m, it was observed that the tip of the blade was deteriorated, or a part where the length of the cut was shorter than the other cuts, and a lot of continuous fibers remained on the sheet base material. . As in Example 1, in a punching type in which a blade is embedded in a plywood plate, for example, a metal tape called unevenness removal tape is attached to the back surface (the surface on which the blade does not protrude) of the punching die, so that the protruding amount of the blade However, unevenness removal by the above method cannot be performed with the rotary blade implemented in this comparative example. Therefore, it is necessary to replace the corresponding blade itself, and the productivity of the sheet base material is greatly reduced.
(Comparative Example 3)
A punching die was prepared in the same manner as in Comparative Example 2 except that the angle at which the blade was attached was inclined by 30 ° in the circumferential direction of the roller, and an attempt was made to prepare a cut prepreg base material. However, the operation of attaching the rectangular blade to the roller at an angle is more difficult than Comparative Example 2, and it took a considerable amount of time to produce the punching die. Moreover, even if it tried using the punching die after preparation, since the excessive load was applied to each blade, the attachment position of the blade shifted | deviated immediately and the cutting could not be inserted appropriately. It may be possible to produce a die that can be inserted properly by devising the method of making the die and the shape of the blade, but the cost was increased and it was not practical, so we abandoned the study. .

(Comparative Example 4)
A fiber reinforced plastic was molded in the same manner as in Example 11 except that the cut was not inserted into the sheet base material. Overall, there was no fiber undulation as in Example 11 and the appearance quality was good, but at the portion corresponding to the R portion 44, it was observed that the color of the plastic was partly yellowish. Further, when the cross section at the R portion was observed in the same manner as in Example 11, the portions where the reinforcing fibers were biased toward the mold side and the layers arranged in the 90 ° direction were dropped off were observed. Therefore, a resin rich portion is formed on the opposite side of the R portion from the mold, and it is presumed that the surface appears slightly yellowish. In addition, when a resin rich part exists in the surface of a fiber reinforced plastic, it will cause a chip etc. In this case, since the continuous fiber was shaped across the R portion, the reinforcing fiber was considered to have been subjected to tension and biased toward the mold side.

(Comparative Example 5)
A prepreg base material similar to that in Example 1 was cut into strips by an automatic cutting machine, and dispersed in a sheet shape and randomly to produce a sheet of an SMC base material. Here, the size of the strip-shaped substrate was 5 mm in width and 30 mm in length, and the basis weight of the sheet substrate was 2.4 kg / m ² corresponding to 16 layers of the prepreg substrate.

  The obtained SMC substrate was molded according to the same procedure as in Example 1 to obtain a flat fiber reinforced plastic. Some warpage was observed in the flat plastic because the reinforcing fibers were randomly oriented. Moreover, the unfilled part of the base material was observed at the end of the mold, and it was confirmed that the fluidity was inferior to that of the cut prepreg base material produced in Example 1. Furthermore, as a result of carrying out the tensile strength by the same procedure as in Example 1, the tensile strength was 180 MPa, and the elastic modulus was 35 GPa, which is much lower than that in Example 1.

It is a perspective view which shows an example of the manufacturing method of this invention. It is the top view (A) which shows an example of the cutting die of this invention, and sectional drawing (B). It is the top view (B) which shows an example of the cutting die used for this invention, and the top view (A) which shows an example of the cutting sheet base material manufactured by this invention. It is a top view which shows an example of the cutting sheet base material manufactured by this invention. It is a top view which shows an example of the cutting die of this invention. It is a top view (A) which shows an example of the cutting sheet base material manufactured by this invention, and a figure (B) which shows an example of the fiber reinforced plastic shape | molded from this cutting sheet base material. It is a top view (A) which shows an example of the cutting sheet base material manufactured by this invention, and a figure (B) which shows an example of the fiber reinforced plastic shape | molded from this cutting sheet base material. It is a top view which shows the example of the sewing machine blade used for this invention. It is a top view which shows an example of the sewing machine blade used for this invention. It is a top view (A) which shows an example of the cutting die used for this invention, and a top view (B) which shows an example of the cutting sheet base material manufactured using the said cutting die. It is a top view which shows an example of the cutting die used for this invention. It is sectional drawing which shows an example of the manufacturing method of the cutting prepreg base material in this invention. It is a top view which shows an example of the cutting of the cutting sheet base material used for this invention. It is the perspective view (A) which showed an example of the blade used for this invention, and the perspective view (B) which showed an example of the punching die which has arranged this blade a plurality. It is a top view which shows an example of the cutting of the cutting sheet base material used for this invention. It is the perspective view which showed an example of the cutting die used for this invention. They are a perspective view (A) showing an example of a sewing machine blade used in the present invention and a perspective view (B) showing an example of a punching die in which two sewing machine blades are arranged. It is a top view which shows an example of the cutting die used for this invention. It is the top view which showed an example of the cutting die used for this invention. It is a perspective view which shows an example of the shaping | molding method using the cutting sheet base material manufactured by this invention. It is a perspective view which shows an example of the manufacturing method of the conventional cutting sheet base material. It is the perspective view which shows an example of the blade used for the manufacturing method of the conventional cutting sheet base material, and a perspective view which shows an example of a manufacturing method (B). The perspective view (A) which shows an example of the manufacturing method of the cutting sheet base material of this invention, (B), The top view (C) which shows an example of the cutting sheet base material manufactured by this invention, (D) It is.

Explanation of symbols

1: Reinforcing fiber 2: Fiber arrangement direction 3: Sheet substrate 4: Fiber orthogonal direction 5: Fiber orthogonal direction component Ws ′ of projection line A obtained by projecting the ridge line of the cut portion onto the sheet substrate
6: Blade 7: Die 8: Cut 9: Ridge line 10 of the cut part: Cut inserted by the first press 11: Cut inserted by the second press 12: Feed amount 13 of the base material: Projection line B
14: Unconnected portion of projection line B 15: Width of unconnected portion of projection line B 16: Resin rich portion 17: Length of opening in fiber array direction 18: Sewing blade 19: Length W of cut portion
20: Length b between the cut portions
21: A set 1 of sewing blades having the same phase in the fiber arrangement direction.
22: A set of sewing blades 2 in phase with each other in the fiber arrangement direction
28: Pre-preg base material 29: Tape-like support 30: Cutting edge 31: Release film 32: Base 33: Cutting length W
34: Fiber length L
35: Intermittent cut row 35a: First intermittent cut row 35b: Second intermittent cut row 35c: Third intermittent cut row 35d: Fourth Intermittent notch row 36: plywood plate 37: central region 38 of the plywood plate: rectangular blade 39: angle θ between the projection line A and the fiber arrangement direction
40: Mold 41: Injection port 42: Decompression port 43: Cutting sheet base material 44: R part
45: Head 46: Cut section 47: Projected line segment A
48: Fiber orthogonal plane 49: Region A when n = 1
50: Region B when n = 3
51: Length of L / 2 52: Sewing blade A
53: Sewing machine blade B
54: Fiber orthogonal component Ws of cut
55: Length 56 along the cutting curve 56: Rotating roller 57: Observation target region 58: Pushing direction 59: Projection line O

Claims (12)

A sheet base material including reinforcing fibers arranged in one direction, the sheet base material having a sheet thickness H in the range of 30 to 300 μm is sent in the fiber array direction, and a cutting die in which a blade is arranged on the sheet base material Are intermittently pressed, the blade is allowed to enter the sheet base material intermittently, intermittent cuts are inserted, and the fiber orthogonal component Ws of the cuts is within a range of 30 μm to 100 mm, A method for producing a cut sheet substrate, wherein the fiber length L of substantially all the reinforcing fibers is in the range of 10 to 100 mm. The means for setting the fiber perpendicular direction component Ws of the incision within a range of 30 μm to 100 mm is a part of the blade, and a portion that penetrates the base material or enters the base material when inserting the incision is cut. And when the direction in which the punching die is pressed against the sheet base material is the pressing direction, the fiber orthogonal direction component of the projection line A in which the ridge line of the cut portion is projected onto the sheet base material in the pressing direction. The manufacturing method of the cutting sheet base material of Claim 1 which is pressing the said cutting die | mold against the said sheet base material so that Ws' may exist in the range of 30 micrometers-100 mm. The part which makes the fiber length L of substantially all the reinforcing fibers within the range of 10 to 100 mm is a part of the blade, and penetrates the base material or enters the base material when inserting the cut. , And the ridge line of all the cut portions included in the punching die in the pressing direction, when the direction in which the punching die is pressed against the sheet base material is the pressing direction. By pressing the sheet base material against the punching die so that projection lines A projected onto the material are projected in the fiber arrangement direction onto the same fiber orthogonal plane, and all the projection lines B are connected to each other. The manufacturing method of the cutting sheet base material of Claim 1 or 2. When part of the blade is a part that penetrates the base material or enters the base material when inserting a cut, and the pressing direction is the direction in which the punching die is pressed against the sheet base material Further, in the pressing direction, the sheet is placed in the punching die so that an angle θ formed by the projection line A obtained by projecting the ridge line of the cut portion on the sheet base material and the fiber arrangement direction is within a range of 2 to 60 °. The manufacturing method of the cutting sheet base material in any one of Claims 1-3 which presses a base material. The manufacturing method of the cutting sheet base material in any one of Claims 1-4 which uses a plate-shaped sewing blade as the said blade. The manufacturing method of the cutting sheet base material of Claim 5 which uses what was arrange | positioned at the said punching die so that it may be flat and used as the said punching die so that it may become mutually parallel. A part that is a part of the sewing machine blade and penetrates the base material or enters the base material when inserting a cut is defined as a cut part, and the distance between adjacent cut parts in the same sewing machine blade is the distance b between the cut parts. The cutting die base material according to claim 5 or 6, wherein the cutting die is pressed against the sheet base material so that the length W of the cut part and the distance b between the cut parts are constant. Production method. The projection lines B are connected to each other only at the ends, and each time the sheet base material is moved 10 to 100 mm in the fiber array direction, the punching die is pressed against the sheet base material. The manufacturing method of the cut sheet base material in any one of. The ratio (W / b) of the length W of the cut part to the distance b between the cut parts is in the range of 1 to 1.5, and the projection lines B are connected to each other only at the end part. The manufacturing method of the cutting sheet base material of Claim 8 which presses the said cutting die against the said sheet base material whenever the said sheet base material is moved 10-100 mm in the fiber arrangement | sequence direction. The manufacturing method of the cutting sheet base material of Claim 9 which arrange | positions the said sewing-machine blades 1.5 times or more of the fiber length L of a reinforced fiber in a fiber arrangement direction, and arrange | positions them in a punching die. The manufacturing method of the cutting sheet base material in any one of Claims 1-10 whose said sheet base material is a prepreg base material which consists of a reinforced fiber and matrix resin. Using the prepreg base material gripped by the tape-shaped support, the punching die is pressed against the prepreg base on the side opposite to the tape-shaped support, penetrates the prepreg base, and the tape-shaped support The manufacturing method of the cutting sheet base material of Claim 11 which inserts the said cutting which penetrates only a part of body.

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