JP6165207B2 - Fiber reinforced resin base sheet and method for confirming internal flow of fiber reinforced resin base sheet - Google Patents

Description

  The present invention is a fiber reinforced resin base sheet that is formed into a sheet with a resin containing long fibers and is pressed into a predetermined shape in a state of being laminated in a plurality of layers, and internal flow confirmation of the fiber reinforced resin base sheet With respect to methods.

  When heat-pressing the long fiber reinforced resin with a mold, the temperature of the long fiber reinforced resin is calculated according to the molding conditions, and the calculated temperature is calculated from a plurality of viscosity fitting models provided for each predetermined temperature range. Patent Document 1 below discloses that a viscosity fitting model corresponding to the above is selected, and the viscosity of the long fiber reinforced resin is calculated using the selected viscosity fitting model, thereby improving the analysis accuracy of the flow state of the resin. It is.

  Also known is a method of drawing a line in advance with a heat-resistant white marker on the surface of a fiber reinforced resin base sheet and inferring the flow state of the resin from the distortion of the line remaining on the surface of the product after hot press processing. ing.

Japanese Patent Laying-Open No. 2015-66873

  However, the former technique has a high viscosity because the resin in contact with the cavity surface of the mold is easily cooled, and the viscosity is low because the resin not in contact with the cavity surface of the mold is difficult to cool. It is difficult to analyze with high accuracy the flow state of different resins in each part in the thickness direction.

  The latter technique can confirm the flow state of the resin on the surface of the product, but cannot confirm the flow behavior of the resin inside the product.

  The present invention has been made in view of the above circumstances, and the flow state of resin and the movement state of long fibers in a product obtained by laminating a plurality of fiber reinforced resin base sheets into a predetermined shape and pressing into a predetermined shape are accurately obtained. The purpose is to confirm.

  In order to achieve the above object, according to the invention described in claim 1, the fiber reinforcement is formed into a sheet shape with a resin containing long fibers, and is hot pressed into a predetermined shape in a state of being laminated in a plurality of layers. A fiber reinforced resin base sheet, wherein a resin base sheet is printed with markings on at least one surface of the resin containing a radiopaque material so that the flow state of the resin and the movement state of the long fibers can be read. Is proposed.

  According to the invention described in claim 2, in addition to the structure of claim 1, a fiber-reinforced resin base sheet is proposed in which the marking has a grid shape.

  According to the invention described in claim 3, in addition to the configuration of claim 2, the length of one side of the grid shape ranges from the plate thickness of the fiber reinforced resin base sheet to half the maximum fiber length. A fiber-reinforced resin base sheet is proposed which is characterized in that it is inside.

  According to the invention described in claim 4, in addition to the configuration of claim 2 or claim 3, a fiber reinforced resin base sheet is proposed in which the grid shape has a blank intersection. .

  According to the invention described in claim 5, in addition to the configuration of any one of claims 1 to 4, the number of laminated fiber reinforced resin base sheets depends on the thickness of the product. A fiber-reinforced resin base sheet characterized by being adjusted is proposed.

  According to the invention described in claim 6, the method for confirming the internal flow of the fiber-reinforced resin base sheet according to any one of claims 1 to 5, wherein the product is subjected to hot press processing. A method for confirming the internal flow of a fiber-reinforced resin base sheet is proposed, wherein the flow state of the resin and the movement state of the long fibers are confirmed from the deformation state of the grid shape in the X-ray image.

  The grid shape 13 of the embodiment corresponds to the marking of the present invention.

  According to the structure of Claim 1, a fiber reinforced resin base material sheet is formed in the sheet form with resin containing a long fiber, and is press-processed by the predetermined shape in the state laminated | stacked on multiple layers. Since the marking that can read the flow state of the resin and the movement state of the long fibers is printed on at least one surface of the fiber reinforced resin base sheet with the ink containing the X-ray opaque material, the marking of the pressed product is performed with the X-ray. By imaging, the flow state of the resin of the fiber reinforced resin base sheet on which the marking is printed, that is, the moving state of the long fibers at an arbitrary position inside the product can be confirmed with high accuracy.

  According to the second aspect of the present invention, since the marking has a grid shape, the longitudinal and lateral movement states of the long fibers can be confirmed with higher accuracy.

  According to the configuration of claim 3, since the length of one side of the grid shape is within the range of half of the maximum fiber length from the plate thickness of the fiber reinforced resin base sheet, the fiber length of the long fibers and the grid shape The ratio with the length of one side becomes appropriate, and the waviness state of the long fibers can be accurately confirmed based on the deformation of the grid shape.

  According to the configuration of claim 4, since the intersection of the marking is blank, it is possible to avoid the fact that the density of tungsten is locally increased in the vicinity of the intersection and the strength of the fiber-reinforced resin base sheet is affected. it can.

  Further, according to the configuration of the fifth aspect, since the number of laminated fiber reinforced resin base sheets is adjusted according to the thickness of the product, the flow of the resin can be minimized and the strength of the product can be increased. .

  Moreover, according to the structure of Claim 6, since the flow state of the resin of a fiber reinforced resin base material sheet is confirmed from the deformation state of the marking in the X-ray image of the hot-pressed product, the product is cut and damaged. And the moving state of the long fibers in the interior can be confirmed.

The figure which shows the fiber reinforced resin base material sheet used as the raw material of a product. The figure which shows the metal mold | die which heat-press-molds the product made from a fiber reinforced resin. The figure which shows the cross-sectional shape of a product, and the lamination | stacking state of the several fiber reinforced resin base material laminated | stacked. The figure which shows an X-ray imaging device. The figure which shows the imaging result of the grid corresponding to the af surface of FIG. 3 (B). The figure which shows the imaging result of the grid corresponding to the gk plane of FIG.3 (C). The figure which shows the lamination | stacking state of the fiber reinforced resin base material sheet according to the flow state of resin. The figure which shows the suitable application components of the product by this invention.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  FIG. 1 shows a fiber reinforced resin base sheet 11 which is a material for hot press molding a product made of fiber reinforced resin. The fiber reinforced resin base sheet 11 is made of a thermoplastic material such as nylon 6. A polyamide resin is used as a matrix to form a constant thickness of, for example, 0.5 mm to 2 mm, and a reinforcing material made of long fibers 12 of carbon fibers or glass fibers is arranged so as to be intertwined randomly. The fiber length of the long fibers 12 is 10 mm to 50 mm, which is significantly larger than the plate thickness of the fiber reinforced resin base sheet 11, and therefore the long fibers 12 are arranged substantially parallel to the surface of the fiber reinforced resin base sheet 11. The fiber reinforced resin base sheet 11 is not disposed in the thickness direction.

  In FIG. 1, the long fibers 12 are conceptually drawn so that they can be easily understood. However, in actuality, the long fibers 12 are longer and linear, and the fiber density Vf is about 45%, which is more dense. . Further, an uncured thermosetting resin may be used in place of the thermoplastic resin.

  In order to make a marking that allows the movement of the long fibers 12 to be read, a grid-like grid shape 13 is printed on one surface of the fiber-reinforced resin base sheet 11. When the fiber length of the long fiber 12 is within the range of the minimum value 10 mm to the maximum value 50 mm and the plate thickness of the fiber reinforced resin base sheet 11 is 2 mm, the length of one side of the grid shape 13 is 2 mm to 25 mm.

  In general, the fiber length of the long fibers 12 may vary within a range of 10 mm to 50 mm, or may be all 50 mm. If the length of one side of the grid shape 13 is 25 mm in order to confirm the movement state of the long fibers 12, it is too large to confirm the movement state of the long fibers 12. In general, when the plate thickness is thin, the undulation of the long fibers 12 due to the resin flow of the fiber reinforced resin base sheet 11 is small, and when the plate thickness is large, the undulation of the long fibers 12 due to the resin flow of the fiber reinforced resin base sheet 11 is small. Because it is big. By setting the length of one side of the grid shape 13 to be equal to or greater than the plate thickness of the fiber reinforced resin base sheet 11, the waviness state of the long fibers 12 can be accurately confirmed. On the other hand, if the length of one side of the grid shape 13 is equal to or less than the plate thickness of the fiber reinforced resin base sheet 11, it becomes difficult to analyze the grid when photographing with X-rays, and the moving state of the long fibers 12 can be accurately confirmed. Can not.

  Therefore, in practice, if the length is about 5 mm to 10 mm, the moving state of the long fibers 12 can be accurately confirmed. In the present invention, not only a resin containing long fibers 12 but also a resin containing continuous fibers can be applied.

  The ink for printing the grid shape 13 includes a radiopaque material. The X-ray opaque material contains tungsten, which is a substance that does not transmit X-rays, and is manufactured by mixing 15 wt% of tungsten powder having a purity of 99.9% or more and a particle size of 8 μm or less with thermosetting ink. Then, it is printed on the surface of the fiber reinforced resin base sheet 11 that has been dried to remove moisture. In order to sufficiently block X-rays, it is advantageous to have a thick ink coating film. However, if the coating film is too thick, it tends to crack and hinders molding of the fiber-reinforced resin base sheet 11. , Printing is carried out several times so that a coating film of about 50 μm is obtained. After the printing is completed, the grid shape 13 is fixed by heat curing the thermosetting ink. The X-ray opaque material is not limited to tungsten, and may be any material that has a lower X-ray transmission level than fibers and resins and provides contrast.

  The ink coating is interrupted at the intersections of the grid shape 13. Thereby, it can prevent that the density of tungsten increases locally in the vicinity of the intersection of the grid shape 13, and it can avoid affecting the intensity | strength of the fiber reinforced resin base material sheet 11. FIG.

  FIG. 3A shows a cross-sectional shape of a product 14 made of fiber reinforced resin. This product 14 is a member having a constant cross section in which a thick portion 14a and a thin portion 14b are continuous through a step portion 14c.

  FIG. 2 shows a mold 15 for heat-pressing the product 14, and the mold 15 includes an upper mold 16 and a lower mold 17, and a plurality of fibers heated in advance between the upper mold 16 and the lower mold 17. In a state where the reinforced resin base sheets 11 are arranged in a laminated state, the product 14 is heated and press-molded by lowering the upper mold 16 toward the lower mold 17. The laminated state of the plurality of fiber reinforced resin base sheets 11 in the mold 15 is arbitrary, and in the example of FIG. 3B, four fibers corresponding to both the thick part 14a and the thin part 14b. The reinforced resin base sheet 11 and two fiber reinforced resin base sheets 11 and 11 corresponding only to the thick part 14a are laminated. In the example of FIG. 3C, the thick part 14a and the thin part Five fiber reinforced resin base sheets 11 corresponding to both of 14b are laminated.

  At this time, the grid shape 13 is printed on one surface of any one of the plurality of fiber reinforced resin base sheets 11. Among the plurality of fiber reinforced resin base sheets 11..., The position of the fiber reinforced resin base sheet 11 on which the grid shape 13 is printed (position in the thickness direction of the product 14) is the fiber reinforced resin at the time of hot press processing. It is set at a position where it is desired to check the resin flow state of the base sheet 11. In particular, when it is disposed between adjacent fiber reinforced resin base sheets 11..., It becomes easy to confirm the flow state of the resin.

  The grid shape 13 can be printed on two or more of the fiber reinforced resin base sheets 11... Of the plurality of fiber reinforced resin base sheets 11. Care must be taken because the grid shapes 13 at the above thickness positions are overlapped and imaged.

  FIG. 4 shows an X-ray imaging apparatus. The product 14 placed on the imaging plate 18 is irradiated with X-rays from the X-ray irradiation apparatus 19, and an image of the grid shape 13 captured on the imaging plate 18 is obtained. It can be read by a reading device, displayed on a monitor, and digital image data can be analyzed.

  FIG. 6 shows grids respectively corresponding to the gj plane inside the product 14 and the k plane on the bottom surface of the product 14 when the laminated state of the fiber reinforced resin base sheets 11... Shown in FIG. An image of the shape 13 is shown. For example, in the image of FIG. 6G, the grid shape 13 is printed on the lower surface of the first layer of the fiber reinforced resin base sheet 11 from the top, or the second layer of fiber reinforced resin base sheet 11 from the top. 6 (k) corresponds to the case where the grid shape 13 is printed on the lower surface of the fiber reinforced resin base sheet 11 in the fifth layer from the top. .

  As described above, when all of the five layers of the fiber reinforced resin base sheets 11, which are laminated, have the same shape, as shown in (g), (h), (i), and (j) of FIG. In the g, h, i, and j planes inside, the grid shape 13 that is originally a square in the portion corresponding to the thick portion 14a is crushed in the left-right direction in the figure and deformed into a vertically long shape. It can be seen that the resin of the base sheet 11 is flowing in the left-right direction in the figure. Further, on the g, h, i, j surface inside the product 14, the grid shape 13 corresponding to the thin portion 14b is stretched in the left-right direction in the drawing and deformed horizontally, and the fiber reinforced resin base sheet 11 It can be seen that the resin of ... flows in the left-right direction in the figure. Since the fiber reinforced resin base material sheet 11 hardly deforms on the k surface corresponding to the flat lower surface of the product 14 (see (k) in FIG. 6), the shape of the grid shape 13 is not naturally collapsed.

  When the resin flows during the hot pressing of the fiber reinforced resin base sheet 11..., The randomly oriented long fibers 12 contained therein move together with the resin, causing the long fibers 12 to bend and swell, and the strength of the portion is remarkably increased. May decrease. Further, when the resin further flows, the long fibers 12 are aligned along the resin flow direction, and the product 14 may be easily broken along the alignment direction of the long fibers 12.

  On the other hand, FIG. 5 corresponds to the a to e surfaces inside the product 14 and the f surface on the bottom surface of the product 14 when the laminated state of the fiber reinforced resin base sheets 11 shown in FIG. The image of the grid shape 13 to be shown is shown.

  In this way, when the number of laminated fiber reinforced resin base sheets 11... Is varied according to the cross-sectional shape of the product 14, the thickness of the product 14 is as shown in FIGS. 5 (a) and 5 (b). As shown in FIGS. 5C to 5E, both the thick part 14a and the thin part 14b of the product 14 are not collapsed on the inner a and b surfaces corresponding to the meat part 14a. It can be seen that the grid shape 13 is not collapsed in the internal c, d, e planes corresponding to. Since the fiber reinforced resin base material sheet 11 hardly deforms on the f surface (see FIG. 5F) corresponding to the flat lower surface of the product 14, the grid shape 13 is naturally not collapsed.

  Therefore, by changing the number of laminated fiber reinforced resin base sheets 11 at the thick wall portion 14a and the thin wall portion 14b of the product 14, the deformation of the grid shape 13 is suppressed to the minimum on all the surfaces inside the product 14. In addition, the strength of the product 14 can be ensured by preventing the long fibers 12 from being bent or undulated by the flow of the resin.

  FIG. 7 shows an example in which a product 14 having a reverse hat-shaped cross section is subjected to hot press molding from a fiber reinforced resin base sheet 11 laminated in five layers. As shown in FIG. 7A, when all the fiber reinforced resin base sheets 11 are set to the same shape, the resin is pulled at the corners 14d and 14d of the product 14 so that the grid shape 13 is horizontally long (reverse) The long fibers 12 are aligned along the flow direction of the resin, and the product 14 may be easily broken along the alignment direction of the long fibers 12. There is sex. Moreover, since resin is compressed in the bottom wall 14e and the grid shape 13 swells and deforms, the arrangement of the long fibers 12 is disturbed at those portions, and the strength is reduced.

  However, as shown in FIG. 7 (B), if the central portion of the three-layer fiber reinforced resin base sheet 11 ... is cut out in advance from among the five layers of fiber reinforced resin base sheet 11 ... Since the deformation of the grid shape 13 of each part of the product 14 is minimized, in other words, the resin flow is minimized, so that the strength of the product 14 can be ensured.

  As described above, according to the present embodiment, the marking (grid shape 13) is printed on at least one surface of any one of the fiber-reinforced resin base sheets 11 to be laminated with ink containing an X-ray opaque material. Therefore, by imaging the marking (grid shape 13) of the hot-pressed product 14 with X-rays, the flow state of the resin of the fiber reinforced resin base sheet 11 on which the marking (grid shape 13) is printed, That is, the flow state of the resin at an arbitrary position inside the product 14 can be confirmed without cutting and damaging the product 14. Therefore, the number of laminated fiber reinforced resin base sheets 11 is set according to the plate thickness of each part of the product 14 so that the flow amount of the resin is small, that is, the deformation amount of the marking (grid shape 13) is small. By adjusting, the strength of the product 14 can be increased.

  Moreover, since the length of one side of the grid shape 13 is within a range of half the maximum fiber length from the plate thickness of the fiber reinforced resin base sheet 11, the fiber length of the long fiber 12 and the length of one side of the grid shape 13 The ratio becomes appropriate, and the waviness state of the long fibers 12 can be accurately confirmed based on the deformation of the grid shape 13.

  FIG. 8A shows a door inner 20 of an automobile made of fiber reinforced resin. In the door inner 20, the periphery of the recess 20a that houses the door regulator is abruptly bent, and resin flow easily occurs around the recess 20a when the door inner 20 is heated and pressed. By applying, the strength of the door inner 20 can be increased.

  FIG. 8B shows a vehicle floor panel 21 made of fiber reinforced resin. In the floor panel 21, the periphery of the floor tunnel 21a extending in the longitudinal direction of the vehicle body is abruptly bent, and resin flow tends to occur around the floor tunnel 21a when the floor panel 21 is heated and pressed. By applying the invention, the strength of the floor panel 21 can be increased.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the resin of the fiber reinforced resin base sheet 11 is not limited to a thermoplastic resin such as nylon 6, and may be a thermosetting resin such as epoxy.

  Further, the long fibers 12 of the fiber reinforced resin base sheet 11 are not limited to those that are randomly oriented, but may be those that are aligned in substantially one direction. In this case, it is the same as the fiber reinforced resin base sheet 11 in which the long fibers 12 are randomly oriented by laminating a plurality of fiber reinforced resin base sheets 11 so that the orientation directions of the long fibers 12 are different from each other. Pseudoisotropy can be given.

  The marking of the present invention is not limited to the grid shape 13 of the embodiment, and an appropriate shape can be selected.

11 Fiber reinforced resin base sheet 12 Long fiber 13 Grid shape (marking)
14 products

Claims (6)

A fiber-reinforced resin base sheet that is formed into a sheet with a resin containing long fibers (12) and is pressed into a predetermined shape in a state of being laminated in a plurality of layers,
A fiber reinforced resin base sheet, on which at least one surface is printed with a marking (13) that allows the flow state of the resin and the movement state of the long fibers (12) to be read with ink containing an X-ray opaque material.   The fiber-reinforced resin base sheet according to claim 1, wherein the marking (13) has a grid shape.   3. The fiber according to claim 2, wherein the length of one side of the grid shape (13) is within a range of half the maximum fiber length from the plate thickness of the fiber reinforced resin base sheet (11). Reinforced resin base sheet.   The fiber-reinforced resin base sheet according to claim 2 or 3, wherein the grid shape (13) has a blank intersection.   The fiber according to any one of claims 1 to 4, wherein the number of layers of the fiber-reinforced resin base sheet (11) is adjusted according to the thickness of the product (14). Reinforced resin base sheet. It is an internal flow confirmation method of the fiber reinforced resin base sheet (11) according to any one of claims 1 to 5,
Fiber reinforcement characterized by confirming the flow state of the resin and the movement state of the long fibers (12) from the deformation state of the grid shape (13) in the X-ray image of the hot-pressed product (14) Method for confirming internal flow of resin base sheet.

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