Prepreg manufacturing equipment

Abstract

To provide a prepreg manufacturing apparatus capable of manufacturing a prepreg with a stable film thickness (target film thickness or approximately target film thickness).SOLUTION: A prepreg manufacturing apparatus that manufactures a prepreg m2 by heating and welding a resin powder of a sheet-like fiber base material m1 being conveyed to which the resin powder sprayed from a resin powder discharge port 33 is attached, using a resin welding heater 60 includes: thickness calculation means 110a that calculates a thickness of each of a plurality of locations within a measurement width corresponding to a width direction of the sheet-like fiber base material; thickness average value calculation means 110b that outputs an average value of the thickness calculated by the thickness calculation means as a measurement value; and resin powder supply amount control means 110c that controls a supply amount of the resin powder so that the measurement value output by the thickness average value calculation means becomes a predetermined target thickness.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to a prepreg manufacturing apparatus capable of manufacturing a prepreg having a stable film thickness (target film thickness or approximately target film thickness).

Background Art

[0002] There is known a prepreg manufacturing apparatus configured to attach charged resin powder to a sheet-like fiber base material by Coulomb force due to an electric field formed between an electrode (high-voltage plate) to which a high voltage is applied and the sheet-like fiber base material being conveyed and the conveying force of air jetted from an air nozzle (see, for example, Patent Document 1). When the sheet-like fiber base material to which this resin powder adheres passes through a resin welding heater, it is heated by the resin welding heater. Thereby, the resin powder adhering to the sheet-like fiber base material is welded to the sheet-like fiber base material, and a prepreg is manufactured. Then, the film thickness of the prepreg manufactured in this way is measured by a film thickness meter (fixed-point film thickness meter) arranged downstream of the resin welding heater, and the supply amount of the resin powder is controlled (feedback control) so that the measured film thickness becomes the target film thickness.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in Patent Document 1, in the case of a sheet-like fiber base material with large quality unevenness and unstable quality (for example, when the sheet-like fiber base material is a UD base material), the measured value of the prepreg measured by the film thickness meter is also unstable. Therefore, even if the supply amount of the resin powder is controlled so that the film thickness of the prepreg measured by the film thickness meter becomes the target film thickness, it is difficult to manufacture a prepreg having a stable film thickness (target film thickness or approximately target film thickness).

[0005] Other challenges and novel features will become apparent from the description and accompanying drawings in this specification. [Means for solving the problem]

[0006] A prepreg manufacturing apparatus according to one embodiment is a prepreg manufacturing apparatus that manufactures a prepreg by heating and welding the resin powder, which is attached to a sheet-like fibrous substrate being transported and sprayed from a resin powder discharge port, using a resin welding heater, and comprises: a thickness calculation means for calculating the thickness of each of multiple locations within a measurement width corresponding to the width direction of the sheet-like fibrous substrate; a thickness average value calculation means for outputting the average value of the thickness calculated by the thickness calculation means as a measured value; and a resin powder supply amount control means for controlling the amount of resin powder supplied so that the measured value output by the thickness average value calculation means becomes a predetermined target thickness. [Effects of the Invention]

[0007] According to the above embodiment, a prepreg manufacturing apparatus can be provided that can manufacture prepregs with a stable film thickness (target film thickness or approximately target film thickness). [Brief explanation of the drawing]

[0008] [Figure 1] This is a plan view showing an overview of the configuration of a prepreg manufacturing apparatus according to the present disclosure. [Figure 2] This is a side view showing an overview of the configuration of a prepreg manufacturing apparatus according to the present disclosure. [Figure 3] This is a view along arrow AA in Figure 2. [Figure 4] This diagram illustrates a manufacturing method for producing prepregs using a prepreg manufacturing apparatus as an example. [Figure 5] (a) A diagram showing the measurement of the film thickness of prepreg m2 using a film thickness gauge 80 positioned in the center in the width direction, and (b) Graph G1 of the film thickness of prepreg m2 measured using a film thickness gauge 80 positioned as shown in Figure 5(a), and graph G2 of the film thickness of the prepreg of Comparative Example 1. [Figure 6] This diagram illustrates a manufacturing method for producing prepregs using a prepreg manufacturing apparatus that uses a scanning X-ray film thickness gauge 100 instead of a film thickness gauge 80. [Figure 7] This is a magnified view of the vicinity of the scanning X-ray film thickness gauge 100. [Figure 8] This diagram illustrates the measurement width L5, spots (for example, spots SP1 to SP20), etc. [Figure 9] This figure shows the measurement of the thickness of a UD substrate m1 to which resin powder is attached using a scanning X-ray film thickness gauge 100. [Figure 10] This is a flowchart illustrating an example of the operation (prepreg thickness control process) of a prepreg manufacturing apparatus using a scanning X-ray film thickness gauge 100. [Figure 11] Graph G3 shows the average thickness measured by the scanning X-ray film thickness gauge 100 of this embodiment, and graph G4 shows the average thickness of Comparative Example 2. [Modes for carrying out the invention]

[0009] <Reference example> A reference example of a prepreg manufacturing apparatus will be described with reference to Figures 1 to 3.

[0010] The reference example prepreg manufacturing apparatus is an apparatus for manufacturing a prepreg by attaching resin powder 30 to a sheet-like fibrous base material 50 such as carbon fiber fabric or UD tape, and as shown in Figures 1 and 2, it mainly comprises two chambers 31 and 32 provided on the left and right sides with the sheet-like fibrous base material 50 in between, supply pipes 37 and 38 provided in the chambers 31 and 32 respectively, flat-type air nozzles 41 and 42 connected to the ends of the supply pipes 37 and 38 respectively, and powder resin charging units 43 and 44 provided on the supply pipes 37 and 38 respectively.

[0011] Chambers 31 and 32 have rectangular outer shells 31a and 32a, and roughly rectangular inner shells 31b and 32b with rounded corners, which are provided inside the outer shells 31a and 32a.

[0012] On the side of the sheet-like fiber base material 50 of the outer shells 31a and 32a, that is, the positions at the right end (front surface) of the left chamber 31 and the left end (front surface) of the right chamber 32 are open, and a sheet-like fiber base material 50 to which the resin powder 30 adheres is installed therebetween. Also, on the side opposite to the sheet-like fiber base material 50 side of the outer shells 31a and 32a, that is, the positions at the left end (rear surface) of the left chamber 31 and the right end (rear surface) of the right chamber 32, discharge ports 35 and 36 are formed. Dust collectors 53 and 54 for collecting the resin powder 30 discharged from the discharge ports 35 and 36 are attached to the discharge ports 35 and 36.

[0013] Also, at the front positions facing the sheet-like fiber base material 50 of the inner shells 31b and 32b, that is, the positions at the right end (front surface) of the inner shell 31b of the left chamber 31 and the left end (front surface) of the inner shell 32b of the right chamber 32, openings 33 and 34 are formed. High voltage plates 51 and 52 are installed around the openings 33 and 34 so as to surround the whole.

[0014] Also, the inner shells 31b and 32b of the chambers 31 and 32 are provided in a partitioned state without intersecting the outer shells 31a and 32a, and between the outer shells 31a and 32a and the inner shells 31b and 32b, flow paths (gaps) 45 and 46 are formed such that the resin powder 30 that is discharged together with air from the openings 33 and 34 and does not adhere is discharged from the discharge ports 35 and 36 to the outside of the chambers 31 and 32.

[0015] The supply pipes 37 and 38 are respectively provided at positions at approximately the central height inside the inner shells 31b and 32b of the two chambers 31 and 32, and one end thereof extends substantially horizontally to the openings 33 and 34. Also, flat air nozzles 41 and 42 are connected to the other ends of the supply pipes 37 and 38.

[0016] The flat-type air nozzles 41 and 42 have main bodies 41a and 42a that extend in the width direction of the two chambers 31 and 32 (in Figure 2, the front and back directions of the paper). Elongated injection slits (not shown) are formed at the sheet-like fibrous substrate 50 side ends of the main bodies 41a and 42a, extending in the width direction of the chambers 31 and 32, similar to the main bodies 41a and 42a, and air is ejected from the injection slits in a curtain-like manner.

[0017] The base ends of the main bodies 41a and 42a of the flat-type air nozzles 41 and 42 are connected to the other ends of input pipes 47 and 48, each having an input port 47a and 48a at one end into which resin powder 30 is introduced. The other ends of the input pipes 47 and 48 are inserted into the inner shells 31b and 32b of the chambers 31 and 32, but one end of the input pipes 47 and 48 is located outside the chambers 31 and 32, and a fixed amount of resin powder 30 is continuously introduced through the input port 47a and 48a at that end by a quantitative feeder or the like.

[0018] Furthermore, compressors 39 and 40 are connected to the approximate center of the inlet pipes 47 and 48 via an air amplification device T. As a result, the compressed air sent from the compressors 39 and 40 has its flow velocity further increased by the air amplification device T and is mixed with the resin powder 30 supplied from the inlet ports 47a and 48a by a metering feeder or the like, and is then pushed into the flat-type air nozzles 41 and 42 as a high-pressure solid-gas two-phase flow.

[0019] The powder resin charging units 43 and 44 are located approximately in the center of the supply pipes 37 and 38, and charge the resin powder 30 negatively (or positively) along with the air, thereby providing the resin powder 30 with a high amount of charge.

[0020] Generally, thermosetting resins are used as the resin powder 30, but thermoplastic resins or natural resins may also be used. Furthermore, the sheet-like fibrous base material 50 may consist of metal fibers other than carbon fibers, mineral fibers, glass fibers, or synthetic fibers.

[0021] Furthermore, the sheet-like fiber substrate 50 is connected to ground, and a high-voltage electric field is applied between it and the high-voltage plates 51 and 52 installed around the openings 33 and 34 formed in the inner shells 31b and 32b of the chambers 31 and 32.

[0022] A method for manufacturing prepregs using a prepreg manufacturing apparatus configured in this way will be described.

[0023] When a fixed amount of resin powder 30 is continuously fed in through the inlet ports 47a and 48a of the input pipes 47 and 48 by a quantitative feeder or the like, the resin powder 30 is mixed inside the input pipes 47 and 48 with high-pressure air whose flow velocity has been further increased by the air amplification device T, which is compressed air sent from the compressors 39 and 40, and then pushed into the flat-type air nozzles 41 and 42.

[0024] As a result, the air velocity is made uniform from the injection slits of the flat-type air nozzles 41 and 42 into the supply pipes 37 and 38, and a fixed two-phase flow of resin powder 30 mixed with air is sent in an air curtain shape, and both the resin powder 30 and the air are negatively charged by the powder resin charging sections 43 and 44 provided in the supply pipes 37 and 38.

[0025] Then, the stationary two-phase flow, which is a mixture of charged resin powder 30 and air, is discharged from the openings 33 and 34 of the chambers 31 and 32 and blown onto the sheet-like fibrous substrate 50. At this time, a high-voltage electric field is applied between the openings 33 and 34 and the sheet-like fibrous substrate 50, which is connected to ground, by high-voltage plates 51 and 52 installed around the openings 33 and 34. Additionally, a negative high voltage is applied to the openings 33 and 34. As a result, the negatively charged resin powder 30 is forcefully discharged from the openings 33 and 34 towards the sheet-like fibrous substrate 50 and adheres to the sheet-like fibrous substrate 50 with strong adhesive force, thereby manufacturing a prepreg.

[0026] Furthermore, when the resin powder 30 is positively charged by the powder resin charging sections 43 and 44, a positive high voltage is applied to the openings 33 and 34 by the high-voltage plates 51 and 52. In this specification, prepreg includes semipreg.

[0027] Furthermore, any resin powder 30 that does not adhere to the sheet-like fibrous substrate 50 flows through the channels 45 and 46 formed between the outer shells 31a and 32a and the inner shells 31b and 32b of the two chambers 31 and 32 to the rear side of the outer shells 31a and 32a, and is discharged to the outside of the two chambers 31 and 32 from the outlets 35 and 36.

[0028] The discharged resin powder 30 is collected by dust collectors 53 and 54 connected to the discharge ports 35 and 36 and reused. In this embodiment, as shown in Figure 1, the resin powder 30 collected by the dust collectors 53 and 54 is again fed into the inlet ports 47a and 48a of the input pipes 47 and 48 via a quantitative feeder, and pushed into flat-type air nozzles 41 and 42 along with air via compressors 39 and 40.

[0029] According to this configuration, chambers 31 and 32, each consisting of outer shells 31a and 32a and inner shells 31b and 32b, are provided on either side of a sheet-like fibrous substrate 50, and flat-type air nozzles 41 and 42 are provided in the inner shells 31b and 32b of the chambers 31 and 32, respectively. As a result, the entire apparatus is made smaller and space-saving, and the resin powder 30 can be simultaneously attached to both sides of the sheet-like fibrous substrate 50.

[0030] Furthermore, by employing flat-type air nozzles 41 and 42, the resin powder 30 is mixed with air and pushed in from the rear of the supply pipes 37 and 38 at high pressure and a uniform flow rate. As a result, the solid-gas two-phase flow consisting of the charged resin powder 30 and air within the supply pipes 37 and 38 is fast and uniform, eliminating the need for conventional flow straighteners and blowers. This also allows for miniaturization of the entire device.

[0031] In this reference example, the sheet-like fibrous substrate 50 is fixed between two chambers 31 and 32 to simultaneously adhere the resin powder 30 to both sides. However, by further providing a conveying device capable of continuously transporting the sheet-like fibrous substrate 50 itself in an upward or downward direction, the resin powder 30 can be adhered to both sides of the sheet-like fibrous substrate 50 over a wide area and continuously in a short time.

[0032] Furthermore, in this reference example, high-voltage plates 51 and 52 are installed around the openings 33 and 34 of the chambers 31 and 32 to ensure that the resin powder 30 adheres more firmly to the sheet-like fibrous substrate 50. However, the resin powder 30 can also be adhered to the sheet-like fibrous substrate 50 even without the high-voltage plates 51 and 52 and the powder resin charging sections 43 and 44.

[0033] Next, we will explain a manufacturing method for producing prepregs using the prepreg manufacturing apparatus described in the above reference example.

[0034] Figure 4 is a diagram illustrating a manufacturing method for producing prepregs using a reference example prepreg manufacturing apparatus.

[0035] Hereafter, a UD substrate will be used as the sheet-like fiber substrate 50. A UD substrate is a sheet-like fiber substrate that lacks fibers corresponding to weft threads and is composed of fibers corresponding to warp threads. Hereafter, it will be referred to as UD substrate m1. For the sake of simplicity, only the opening 33 (supply pipe 37) is shown in Figure 4, and the opening 34 (supply pipe 38) has been omitted. The following explanation will also focus on the operation of the opening 33 (supply pipe 37), and the operation of the opening 34 (supply pipe 38) will be omitted.

[0036] As shown in Figure 4, the UD substrate m1 is continuously drawn from a roll body M1 in which the UD substrate m1 is wound into a roll, passed over driven rollers R1 and R2, and connected to a winding shaft A. The UD substrate m1 is transported (in the direction indicated by arrows AR1 to AR3 in Figure 4) by the rotation of the winding shaft A by a motor (not shown), and passes through the opening 33 (supply pipe 37) located between the driven rollers R1 and R2, the resin welding heater 60, and the film thickness gauge 80 (fixed point film thickness gauge) located downstream of the resin welding heater 60 in that order.

[0037] A high-voltage power supply 70 is electrically connected to the high-voltage plate 51 (electrode plate), and a high voltage V (for example, several tens of kV) is applied. As a result, corona discharge occurs from the high-voltage plate 51 toward the UD substrate m1 which is grounded. Therefore, the resin powder ejected from the opening 33 together with air is charged by ions generated by the corona discharge as it passes through the high-voltage plate 51. This charged resin powder adheres to the UD substrate m1 (front or back surface) passing through the opening 33 due to the Coulomb force created by the electric field formed between the high-voltage plate 51 and the UD substrate m1 and the transport force of the air ejected from the opening 33 (principle of electrostatic powder coating). As shown in Figure 3, the opening 33 is a slit-shaped opening (an example of a resin powder discharge port in this disclosure) that extends in the width direction (left-right direction in Figure 3) of the UD substrate m1. The length L1 of this opening 33 (see Figure 3) corresponds to the width of the UD substrate m1 and is, for example, 400 mm. On the other hand, the width W (slit width; see Figure 3) of this opening 33 is, for example, 20 mm. The air and resin powder that are sprayed from this opening 33 toward the UD substrate m1 are supplied to the opening 33 by the supply pipe 37 (see Figures 1 and 2) and sprayed from the opening 33.

[0038] As described above, the UD substrate m1 to which the resin powder is attached is heated by the resin welding heater 60 as it passes through the heater. This causes the resin powder attached to the UD substrate m1 to weld to the UD substrate m1, and the prepreg m2 (see Figure 4) is manufactured.

[0039] As the manufactured prepreg m2 passes through the film thickness gauge 80, the film thickness is measured by the film thickness gauge 80. The thickness measured here is, for example, the thickness of the prepreg m2 (thickness of the resin powder welded to the UD substrate m1 + thickness of the UD substrate m1 itself). Then, the quantitative feeder 90 (amount of resin powder supplied) is controlled (feedback control) so that this measured film thickness becomes the target film thickness.

[0040] The prepreg m2 manufactured in the manner described above is wound onto a winding shaft A, which is rotated by a motor (not shown), via a driven roller R2.

[0041] <Embodiment> First, we will explain the problems that the inventors have found in the manufacturing method for producing prepregs using the prepreg manufacturing apparatus described in the above reference example.

[0042] Figure 5(a) shows the measurement of the film thickness of the prepreg m2 using a film thickness gauge 80 positioned in the center in the width direction. The downward arrows in Figure 5(a) indicate the measurement points (measurement lines) by the film thickness gauge 80. Figure 5(b) shows graph G1 of the film thickness of the prepreg m2 and graph G2 of the film thickness of the prepreg of Comparative Example 1, both measured using the film thickness gauge 80 positioned as shown in Figure 5(a). The prepreg of Comparative Example 1 is a prepreg manufactured using a woven fabric base material (a sheet-like fibrous base material composed of fibers corresponding to weft and warp threads) as the sheet-like fibrous base material 50, and produced by the manufacturing method shown in Figure 4 above.

[0043] The inventors found that while the prepreg of Comparative Example 1 exhibits stable quality, resulting in stable measurements from the film thickness gauge 80 (see graph G2 in Figure 5(b)), the prepreg m2 of the Reference Example exhibits significant quality variations and is not stable, leading to unstable measurements from the film thickness gauge 80 (see graph G1 in Figure 5(b)). As a result, even when controlling the quantitative feeder 90 (amount of resin powder supplied) to achieve a film thickness of the prepreg m2 measured by the film thickness gauge 80 (feedback control), it is difficult to produce a prepreg m2 with a stable film thickness (target film thickness or approximately target film thickness).

[0044] Furthermore, in the above reference example, since the film thickness gauge 80 is located downstream of the resin welding heater 60 (see Figure 4), that is, the opening 33 for spraying the resin powder and the film thickness gauge 80 are far apart, we found that a considerable amount of time is required after the resin is applied until the film thickness is measured and the above-mentioned feedback control is performed.

[0045] Next, as an embodiment, an example in which a configuration example for solving the above problems is applied to the above reference example will be described.Hereafter, an example using a scanning X-ray film thickness gauge 100 will be described as a configuration example for solving the above problems.Note that components similar to those in the above reference example will be denoted by the same reference numerals and their descriptions will be omitted as appropriate.The scanning X-ray film thickness gauge 100 is used in place of the film thickness gauge 80 (fixed-point film thickness gauge) in the above reference example.For the sake of simplicity, the following description will be representative of an example using the opening 33 (supply pipe 37), and the example using the opening 34 (supply pipe 38) will be omitted.

[0046] Figure 6 illustrates a manufacturing method for producing prepregs using a prepreg manufacturing apparatus that uses a scanning X-ray film thickness gauge 100 instead of a film thickness gauge 80.

[0047] As shown in Figure 6, the scanning X-ray film thickness gauge 100 is positioned between the opening 33 (an example of a resin powder discharge port in this disclosure) and the resin welding heater 60.

[0048] Figure 7 is a magnified view of the vicinity of the scanning X-ray film thickness gauge 100.

[0049] As shown in Figure 7, the scanning X-ray film thickness gauge 100 includes an X-ray source, an X-ray detector, and a moving means for moving the X-ray source and X-ray detector in the width direction of the UD substrate m1, which are provided on a movable part 103 that is slidably mounted on frames 101 and 102 that extend in the width direction of the UD substrate m1. As the scanning X-ray film thickness gauge 100, for example, the one described in Japanese Patent Application Publication No. 2007-298387 can be used.

[0050] The X-ray source irradiates the UD substrate m1 with X-rays, creating spots with a spot diameter D1 (see Figure 8) (for example, spots SP1 to SP in Figure 8). 20 (See reference) is formed. The X-ray detector detects the intensity of X-rays irradiated from the X-ray source and transmitted through the UD substrate m1. Figure 8 shows the measurement width L5, spot (e.g., spot SP1~SP 20 This is a diagram explaining things like ).

[0051] Next, the control device 110 of this embodiment will be described.

[0052] As shown in Figure 6, the control device 110 is electrically connected to the quantitative feeder 90, the scanning X-ray film thickness gauge 100, and the storage unit 120. The control device 110 is equipped with a processor, RAM, etc., although not shown. The storage unit 120 is a non-volatile storage unit such as a hard disk drive or ROM. The storage unit 120 stores the program 121 and the target thickness 122. The program 121 is a program executed by the control device 110 (processor). The target thickness 122 is the target thickness of the UD substrate m1 (thickness of resin powder attached to the UD substrate m1 + thickness of the UD substrate m1 itself).

[0053] The processor is, for example, a CPU. There may be one processor or multiple processors. For example, the processor functions as a thickness calculation means 110a, a thickness average value calculation means 110b, and a resin powder supply amount control means 110c by executing a program 121 loaded from the memory unit 120 (for example, ROM) into RAM. Some or all of these may be implemented by hardware.

[0054] The thickness calculation means 110a calculates the thickness at multiple locations within the measurement width L5 (see Figures 7 to 9) corresponding to the width direction of the UD substrate m1, while the X-ray source (movable part 103) moves along the frames 101 and 102, that is, from the left end PL to the right end PR (or from the right end PR to the left end PL) in Figure 7 (i.e., during one scan), for example, spots SP1 to SP in Figure 8. 20The thickness of each layer is calculated (measured). The thickness calculated here is, for example, the thickness of the UD substrate m1 (thickness of the resin powder attached to the UD substrate m1 + thickness of the UD substrate m1 itself). Figure 9 shows the measurement of the thickness of the UD substrate m1 with the resin powder attached using a scanning X-ray film thickness gauge 100. The dotted arrows in Figure 9 represent the locations (measurement lines) measured by the scanning X-ray film thickness gauge 100 when 7 scans are performed. SP in Figure 9 represents the X-ray spots formed on the UD substrate m1 after irradiation from the X-ray source.

[0055] For example, the thickness calculation means 110a measures multiple locations within the measurement width L5 (for example, spots SP1 to SP in Figure 8). 20 In each of these locations, the amount of X-ray attenuation is calculated based on the X-ray intensity detected by the X-ray detector and the reference X-ray intensity, and the thickness of each of these locations is calculated based on this amount of attenuation. The reference X-ray intensity is stored, for example, in the memory unit 120.

[0056] As shown in Figure 8, the measurement width L5 of the scanning X-ray film thickness gauge 100 is set to the length obtained by adding the width L2 of the UD substrate m1 to the additional widths L3 and L4 on both sides of the UD substrate m1 in the width direction (L2 + L3 + L4). For example, L5 is 400 mm, L2 is 360 mm, and L3 and L4 are 20 mm each. Also, the spot diameter D1 on the UD substrate m1 irradiated by the X-ray source is 20 mm.

[0057] The average thickness calculation means 110b outputs the average thickness calculated by the thickness calculation means 110a as the measured value. For example, once one scan is completed, the average thickness calculation means 110b outputs the average of the thickness(s) calculated (measured) during that scan as the measured value.

[0058] In this case, the measurement width L5 of the scanning X-ray film thickness gauge 100 is set to the length obtained by adding the width L2 of the UD substrate m1 to the additional widths L3 and L4 on both sides of the UD substrate m1 in the width direction (L2 + L3 + L4). Therefore, the average thickness calculation means 110b outputs the average of the thickness measured (calculated) within the width L2 of the UD substrate m1 and the thickness measured (calculated) within the additional widths L3 and L4 on both sides of the UD substrate m1 in the width direction as the measured value. This makes it possible to output a measured value that is not affected by fluctuations in the width of the UD substrate m1 due to quality inconsistencies, etc.

[0059] The resin powder supply amount control means 110c controls the quantitative feeder 90 (resin powder supply amount) (feedback control) so that the measured value (average value) output by the average thickness calculation means 11b, i.e., the thickness of the UD substrate m1 (thickness of resin powder attached to the UD substrate m1 + thickness of the UD substrate m1 itself), becomes a predetermined target thickness 122.

[0060] Next, a brief explanation will be given of a manufacturing method for producing prepregs using a prepreg manufacturing apparatus that utilizes the scanning X-ray film thickness gauge 100 configured as described above.

[0061] Figure 10 is a flowchart showing an example of the operation of a prepreg manufacturing apparatus using a scanning X-ray film thickness gauge 100 (prepreg thickness control process).

[0062] As a premise, it is assumed that the UD substrate m1, to which the resin powder is attached, is being transported in the transport direction shown in Figures 7 to 9, and that scanning is being performed as shown in Figure 9.

[0063] First, the thickness of each of the multiple locations within the measurement width L5 is calculated (step S10). This is achieved by the thickness calculation means 110a. For example, the thickness calculation means 110a calculates the thickness of multiple locations within the measurement width L5 during one scan (for example, spots SP1 to SP in Figure 8). 20 In each of these locations, the amount of X-ray attenuation is calculated based on the intensity of the X-rays detected by the X-ray detector and the reference X-ray intensity, and the thickness of each of these locations is calculated based on this amount of attenuation.

[0064] The process in step S10 is repeated until one scan is completed (step S11: NO).

[0065] On the other hand, when one scan is completed (step S11: YES), the average value of the thickness calculated in step S10, that is, the average value of the thickness(s) calculated during one scan, is output as the measured value (step S12). This is achieved by the average thickness calculation means 110b.

[0066] Next, the quantitative feeder 90 (amount of resin powder supplied) is controlled so that the measured value (average value) output in step S12 becomes the target thickness 122 (step S13). This is achieved by the resin powder supply amount control means 110c. For example, if the measured value (average value of thickness) output in step S12 is less than the target thickness 122, the resin powder supply amount control means 110c controls the quantitative feeder 90 to increase the amount of resin powder supplied. This brings the thickness of the UD substrate m1 (thickness of resin powder attached to the UD substrate m1 + thickness of the UD substrate m1 itself) closer to the target thickness 122. On the other hand, if the measured value (average value of thickness) output in step S12 is greater than the target thickness 122, the resin powder supply amount control means 110c controls the quantitative feeder 90 to decrease the amount of resin powder supplied. This brings the thickness of the UD substrate m1 (thickness of resin powder attached to the UD substrate m1 + thickness of the UD substrate m1 itself) closer to the target thickness 122.

[0067] Thereafter, the processes described in steps S10 to S13 above are repeatedly executed.

[0068] As described above, the UD substrate m1 to which the resin powder is attached is heated by the resin welding heater 60 as it passes through the resin welding heater 60, similar to the reference example above. This causes the resin powder attached to the UD substrate m1 to weld to the UD substrate m1, and a prepreg m2 (see Figure 4) is manufactured. This manufactured prepreg m2 is wound onto a winding shaft A, which is rotated by a motor (not shown), via a driven roller R2.

[0069] Figure 11 is a graph G3 showing the average thickness measured by the scanning X-ray film thickness gauge 100 of this embodiment. For reference, Figure 11 also includes a graph G4 showing the average thickness of Comparative Example 2. Comparative Example 2 is a prepreg manufactured by the prepreg thickness control process shown in Figure 10, using a woven fabric substrate (a sheet-like fiber substrate composed of fibers corresponding to weft threads and fibers corresponding to warp threads) as the sheet-like fiber substrate 50.

[0070] Referring to Figure 11, it can be seen that the measured value (average thickness) of the scanning X-ray film thickness gauge 100 in this embodiment is stable (see graph G3 in Figure 11), and as a result, by controlling the quantitative feeder 90 (amount of resin powder supplied) so that this measured value (average thickness) becomes the target thickness 122, it is possible to manufacture prepreg m2 with a stable film thickness (target thickness or approximately target thickness).

[0071] As described above, according to this embodiment, it is possible to manufacture a prepreg m2 with a stable thickness (target thickness or approximately target thickness).

[0072] Furthermore, according to this embodiment, since the scanning X-ray film thickness gauge 100 is positioned between the opening 33 for spraying resin powder (an example of a resin powder discharge port in this disclosure) and the resin welding heater 60, that is, because the opening 33 for spraying resin powder and the scanning X-ray film thickness gauge 100 are close together, the time from resin adhesion to measuring the thickness and performing the above-mentioned feedback control can be shortened.

[0073] The present inventors have described the invention in detail based on embodiments, but it goes without saying that this disclosure is not limited to the embodiments already described, and various modifications are possible without departing from the spirit of the invention. [Explanation of Symbols]

[0074] 11 Inlet 12 Accelerator 13 brushes 14 Compression section 15 Storage Box 16 tubes 17 Powder 18 holes 19 Chambers 20 Carbon fiber fabric 30 Resin powder 31, 32 chambers 31a,32a Outer shell 31b,32b inner shell 33,34 Opening (resin powder discharge port) 35,36 Outlet 37,38 Supply pipe 39,40 Compressor 41,42 Flat-type air nozzle 41a, 42a Main body 43,44 Powder resin charging part 45,46 channel 47,48 Inlet pipe 47a,48a Inlet 50 Sheet-like fiber base material 51, 52 High Voltage Plate 53, 54 Dust collector T Air Multiplier 60 Resin welding heater 70 High-voltage power supply 80 Film Thickness Gauge 90 Quantitative Feeder 100 Scanning X-ray film thickness gauge 110 Control device 110a Thickness calculation means 110b Means for calculating average thickness 110c Resin powder supply amount control means

Claims

1. A prepreg manufacturing apparatus for manufacturing a prepreg by heating and welding the resin powder, which is supplied from a quantitative feeder and sprayed from a resin powder discharge port, onto a sheet-like fibrous substrate being transported, using a resin welding heater, A thickness calculation means for calculating the thickness of each of multiple locations within a measurement width corresponding to the width direction of the sheet-like fibrous substrate, A thickness average value calculation means that outputs the average value of the thickness calculated by the thickness calculation means as a measured value, A prepreg manufacturing apparatus comprising: a resin powder supply amount control means for controlling the amount of resin powder supplied from the quantitative feeder so that the measured value output by the thickness average value calculation means becomes a predetermined target thickness.

2. The prepreg manufacturing apparatus according to claim 1, wherein the thickness calculation means calculates the thickness of each of the multiple locations within the measurement width based on the amount of attenuation of X-rays that pass through each of the multiple locations.

3. An X-ray source that irradiates with the aforementioned X-rays, An X-ray detector that detects the aforementioned X-rays, The prepreg manufacturing apparatus according to claim 2, further comprising a moving means for moving the X-ray source and the X-ray detector in the width direction of the sheet-like fibrous substrate.

4. The prepreg manufacturing apparatus according to claim 3, wherein the X-ray source and the X-ray detector are arranged between the resin powder discharge port and the resin welding heater.

5. The prepreg manufacturing apparatus according to any one of claims 1 to 3, wherein the measurement width is set to a length equal to the width of the sheet-like fiber base material plus an additional width on both sides in the width direction of the sheet-like fiber base material.

6. The prepreg manufacturing apparatus according to any one of claims 1 to 3, wherein the sheet-like fibrous base material is a UD base material.

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