JP5626580B2 - Method for producing vegetable fiber-containing board member - Google Patents

Description

  The present invention relates to a method for producing a vegetable fiber-containing board member comprising a substrate containing vegetable fibers and a thermoplastic resin, and a hinge configured by thinning at least a part of the substrate.

  There is known a board member including a base material including a thermoplastic resin such as polypropylene and a hinge formed by thinning a part of the base material. Such a board member is used as a luggage mat that is placed in a trunk of a vehicle, for example, with a base material bent along a hinge. As a conventional example of such a board member, for example, the one described in Patent Document 1 is known.

  In recent years, a vegetable fiber-containing board member including a base material containing vegetable fibers in addition to a thermoplastic resin is known. Plant fiber is a plant-derived fiber material, and kenaf fiber, jute fiber, etc. are used as plant fiber. Such a plant fiber-containing board member is effective for the global environment by using natural fibers.

JP 2009-12505 A

  Since the hinge is configured by thinning a part of the base material, a large stress is applied to the hinge when it is bent. In the above-mentioned vegetable fiber-containing board member, when a hinge is provided on the base material by thinning, a large stress is applied to the hinge at the time of bending, and whitening occurs along the hinge. There is a risk of falling. Thereby, there exists a possibility that the designability of the surface of the board member made into a design surface may fall.

  The present invention has been created in view of the above problems. An object of this invention is to provide the manufacturing method of the vegetable fiber containing board member in which the designability in the design surface was improved.

  The technology disclosed in the present specification includes a base material including a vegetable fiber and a thermoplastic resin, and a hinge configured by thinning at least a part of the base material, along the hinge. A method for producing a vegetable fiber-containing board member that can be bent with one surface side of the substrate as a valley, and heating the both plate surfaces of the substrate; and the one surface of the substrate And the other surface of the base material as the back surface, pressing the portion to be the hinge of the surface of the base material after the heating step to form a groove-shaped surface side recess, A thinning step of thinning the portion to be the hinge by pressing the portion to be the hinge of the back surface of the base material after the heating step to form a groove-like back side recess. In the thinning step, the width of the bottom end portion of the back side concave portion is The width of the bottom end of the front side recess forms a and the surface-side recess so as to be smaller and the back-side recess.

  According to said manufacturing method, the vegetable fiber containing board member by which the stress added to a hinge at the time of bending was reduced can be manufactured by forming a recessed part in both surfaces of the surface of a base material, and a back surface in a thinning process. Furthermore, by making the width of the bottom end portion of the front surface side concave portion of the base material smaller than the width of the bottom end portion of the back surface side concave portion, it is possible to bend along the hinge with the front surface side of the base material as a valley, The vegetable fiber-containing board in which the portion where the stress is applied in the surface-side recess can be made smaller than the portion where the stress is applied in the back-side recess during bending, and the whitening of the surface-side recess is reduced on the surface of the base material used as the design surface A member can be manufactured. Thereby, the vegetable fiber containing board member by which the design property in the design surface was improved can be manufactured.

  In the thinning step, when the base material is viewed in a cross section in a cross section orthogonal to the direction in which the front surface side concave portion and the rear surface side concave portion extend in a groove shape, the front surface side concave portion becomes V-shaped or U-shaped. The surface side recess may be formed on the surface.

  Since stress is applied to the bottom end of the front-side recess when it is bent, whitening is likely to occur at the bottom end. According to this manufacturing method, the portion that causes whitening in the surface-side recess can be reduced as compared with the case where the bottom end of the surface-side recess is formed in a planar shape. Thereby, the vegetable fiber containing board member in which the design property in the design surface was further improved can be manufactured.

  Before the thinning step, the method further comprises a skin material laminating step of laminating a skin material on the surface of the base material after the heating step, and in the thinning step, the hinge of the skin material is used as the hinge. A section is formed by pressing a portion to form a skin material recess, forming the surface side recess through the skin material, and crossing the base material perpendicularly to the direction in which the surface side recess and the back surface recess extend in a groove shape. The skin material concave portion may be formed so that the bottom end portion of the skin material concave portion is located on the surface side of the surface of the substrate when viewed in cross section.

  If the surface side recesses and the skin material recesses are formed deeply, it becomes difficult to bend with the surface side of the substrate as a valley. According to said manufacturing method, a surface side recessed part can be formed shallowly and the vegetable fiber containing board member which can be bent easily by making the surface side of a base material into a trough can be manufactured.

  In the thinning step, when the substrate is viewed in cross section in a cross-section orthogonal to the direction in which the front-side recess and the back-side recess extend in a groove shape, the opening edge of the front-side recess is a side wall of the back-side recess. You may form the said surface side recessed part and the said back surface side recessed part so that it may become in the range which overlaps with a part.

  According to this manufacturing method, the horizontal position of the front surface side recessed part and the back surface side recessed part in a base material can be made into the substantially same position. Thereby, the vegetable fiber containing board member which is easy to bend along a hinge can be manufactured.

  According to the technique disclosed in this specification, a vegetable fiber-containing board member having improved design properties on the design surface can be manufactured.

A schematic diagram of the rear of the vehicle 2 is shown. 1 is a schematic diagram illustrating an entire luggage mat 4 according to Embodiment 1. FIG. Sectional drawing of the hinge 6 of the luggage mat 4 in the state before bending is shown. Sectional drawing of the hinge 6 of the luggage mat 4 in the state after bending is shown. Sectional drawing of the heating process in the manufacturing method of the luggage mat 4 is shown. Sectional drawing of the thinning process in the manufacturing method of the luggage mat 4 is shown. Sectional drawing of the hinge 106 of the luggage mat 104 which concerns on Embodiment 2 in the state before bending is shown.

<Embodiment 1>
Embodiment 1 will be described with reference to the drawings. FIG. 1 shows a schematic diagram of the rear of the vehicle 2. As shown in FIG. 1, a trunk 2 a is provided on the side of the vehicle 2. A luggage mat 4 (an example of a vegetable fiber-containing board member) is placed in the trunk 2a. The luggage mat 4 plays a role as a flooring material when placing a luggage or the like on the luggage mat 4, and also plays a role in adjusting the aesthetics in the trunk 2a. The trunk 2a is configured such that the area of the opening 2b (opening area) is smaller than the area of the trunk floor 2b inside the housing.

  FIG. 2 is a schematic view showing the entirety of the luggage mat 4. As shown in FIG. 2, the luggage mat 4 is provided with a main floor portion 8a, a pair of side floor portions 8b, a hinge 6, a front buried portion 8a1, and a side buried portion 8b1. The main floor 8a is provided adjacent to the pair of side floors 8b. The hinge 6 is a portion that is thinned by being compressed by pressing a portion of the luggage mat 4 in the thickness direction, and is substantially linear in a plan view between the main floor portion 8a and the side floor portion 8b. Is provided. The front buried portion 8a1 is formed by burying a part of the front of the main floor portion 8a. The side buried portion 8b1 is formed by partially burying the side floor portion 8b.

  When the luggage mat 4 is inserted into and removed from the trunk 2a, the area of the opening 2b of the trunk 2a is smaller than the area of the floor 2c. It is put in and out in a folded state (front side of the paper). Specifically, the side floor 8b is bent toward the main floor 8a (for example, substantially perpendicular to the vehicle width direction) with respect to the main floor 8a. When the luggage mat 4 is accommodated in the trunk 2a, the folded portion is returned to the original position, and the luggage mat 4 is spread and placed on the surface of the trunk floor portion 2c. Therefore, the surface of the luggage mat 4 is a design surface.

  Next, the structure of the luggage mat and the structure of the hinge will be described. 3 is a cross-sectional view taken along the line AA in FIG. 2 (a cross-sectional view of the hinge 6 of the luggage mat 4 in a state before bending), and the luggage mat 4 is orthogonal to the direction in which the hinge 6 extends substantially linearly. The cross-sectional structure when cut in a cross section is shown. FIG. 4 shows a cross-sectional view of the hinge 6 of the luggage mat 4 in a state after bending, and shows a cross-sectional configuration of a cross-section corresponding to FIG.

  As shown in FIG. 3, the luggage mat 4 includes a base material 12 and a skin material 14. The skin material 14 is bonded to the surface of the base material 12, and is formed of, for example, a nonwoven fabric. The base material 12 is formed by mixing a thermoplastic resin and vegetable fibers. Specifically, polypropylene (PP) and kenaf fiber are included in a ratio of about 1: 1. For example, polyethylene (PE), polyethylene terephthalate (PET), or polylactic acid (PLA) can be used as the thermoplastic resin other than polypropylene. As plant fibers other than kenaf fibers, for example, plant fibers collected from cotton, hemp, sisal, jute and the like can be used.

  As shown in FIGS. 3 and 4, the base material 12 is provided with a front surface side concave portion 26 and a back surface side concave portion 22 at a portion constituting the hinge 6 of the luggage mat 4. The front surface side concave portion 26 is a portion where a part of the surface of the base material is recessed from the front side toward the back side, and the back surface side concave portion 22 is a portion where a part of the back surface of the base material 12 is recessed from the back side toward the front side. is there. The depth of the surface side recess 26 is about 0.5 mm. The depth of the back side recess 22 is about 1.8 mm. Further, on the surface of the skin material 14, a skin material concave portion 24 is provided in a portion constituting the hinge 6 of the luggage mat 4. The skin material recess 24 is a part where a part of the surface of the skin material 14 is recessed from the front side to the back side. The depth of the skin material recess is about 0.5 mm. The front surface side concave portion 26, the back surface side concave portion 22 and the skin material concave portion 24 are formed in a groove shape along the hinge 6 so as to overlap each other in the AA sectional view. The base 12 is thinned by these concave portions, and the hinge 6 is configured. In addition, the thickness of the base material 12 is about 2.8 mm, and the hinge 6 is compressed until the thickness becomes about 0.5 mm.

  As shown in the cross-sectional view of FIG. 3, both the front surface side concave portion 26 and the skin material concave portion 24 are V-shaped in cross section. Accordingly, the bottom end portions 26 a and 24 a which are the deepest portions of the front surface side concave portion 26 and the skin material concave portion 24 have a line-like shape in a plan view (a point in a cross-sectional view) along the hinge 6. On the other hand, the back surface side recessed part 22 has comprised the cross-sectional view trapezoid shape. Accordingly, the bottom end portion 22a, which is the deepest portion of the back-side concave portion 22, has a planar view surface shape (linear shape in a cross-sectional view) along the hinge 6. For this reason, in the cross-sectional view shown in FIG. 3, the width of the bottom end portion 26 a of the front surface side concave portion 26 is smaller than the width of the bottom end portion 22 a of the back surface side concave portion 22. When the width of the bottom end portion has such a relationship, the substrate 12 can be easily bent with the side (surface side) where the width of the bottom end portion is small as a valley. Furthermore, as the width of the bottom end portion is smaller, the portion to which stress is applied when the luggage mat 4 is bent can be reduced, so that the portion where whitening occurs can be reduced, and the design can be improved.

  As shown in FIG. 3, the bottom end portion 24 a of the skin material recess 24 is located on the surface side from the surface 12 a of the base material 12 (surface side from the back surface of the skin material 14). When the bottom end 24a of the skin material recess 24 and the base material 12 have such a positional relationship, the depth of the skin material recess 24 can be made shallow. By reducing the depth of the skin material recess 24, the angle formed by the surfaces along the both side walls of the skin material recess 24 can be increased. Here, when the luggage mat 4 is bent along the hinge 6, the luggage mat 4 can be bent until both side surfaces of the recess along the hinge 6 come into contact with each other. In the luggage mat 4 according to the present embodiment, the side wall portions 22c of the back surface side concave portion 22 are inclined so that the angle formed by the surfaces along the both side wall portions 22c is about 60 °. On the other hand, the skin material recess 24 is formed with a shallow depth, so that the angle formed by the surfaces along the side wall portions is an angle larger than 60 °, specifically, an angle of 90 ° or more. ing. For this reason, the luggage mat 4 can be bent along the hinge 6 at a bending angle larger than 90 ° with the surface side as a valley.

  The front surface side concave portion 26 and the back surface side concave portion 22 are formed starting from the opening edge portions 26b and 22b, respectively. And in the back surface side recessed part 22, it is the side wall part 22c between the opening edge part 22b and the bottom end part 22a. Here, as shown in FIG. 3, the horizontal position of the opening edge portion 26 b of the front surface side concave portion 26 is located on the inner side (bottom end portion 22 a side) than the opening edge portion 22 b of the back surface side concave portion 22. That is, the opening edge portion 26a of the front surface side concave portion 26 is located within a range overlapping with the side wall portion 22c of the rear surface side concave portion 22 in a cross-sectional view. When the opening edge portion 26a of the front surface side concave portion 26 and the side wall portion 22c of the back surface side concave portion 22 have such a positional relationship, the horizontal positions of the front surface side concave portion 26 and the back surface side concave portion 22 in the substrate 12 are substantially the same. The luggage mat 4 can be easily bent along the hinge 6.

  When the luggage mat 4 is folded, it can be folded along the hinge 6 as shown in FIG. As described above, since the surface side recess 26 and the skin material recess 24 are shallow in depth, the luggage mat 4 may be bent to an angle exceeding 90 ° with the surface side of the substrate as a valley. it can. For this reason, the luggage mat 4 is easily accommodated when accommodated in the trunk 2a.

  Next, a method for manufacturing the luggage mat 4 will be described. FIG. 5 shows a cross-sectional view of the heating process in the method of manufacturing the luggage mat 4. FIG. 6 shows a cross-sectional view of the thinning step in the method of manufacturing the luggage mat 4. In this method, first, a heating step is performed. In the heating step, as shown in FIG. 5, the substrate 12 is set between the upper heater 34 and the lower heater 32, and both plate surfaces of the substrate 12 are heated. The heating temperature in the heating step is 170 ° C to 230 ° C.

  Next, a skin material bonding process is performed. In the skin material laminating step, as shown in FIG. 6, the skin material 14 is superposed on the surface of the base material 12 and the skin material 14 is laminated. Next, a thinning process is performed. In the thinning process, as shown in FIG. 6, the substrate 12 heated by the heating process is placed between the lower mold 52 and the upper mold 54 and cold-pressed. The lower mold 52 is provided on the surface of the lower mold stage 42, and a lower pressing portion 62 protruding to the front side is formed on a part of the surface. The lower pressing portion 62 serves as a mold for forming the back surface side recess 22, and the contour thereof matches the contour of the back surface side recess 22 formed on the back surface of the substrate 12. Further, an embedded portion forming recess 52 a is formed on a part of the surface of the lower mold 52 and outside the lower pressing portion 62. On the other hand, the upper side 54 is provided on the back surface of the upper mold stage 44, and an upper pressing portion 64 protruding to the back side is formed on a part of the back surface. The upper pressing portion 64 serves as a mold for forming the surface side concave portion 26 and the skin material concave portion 24, and the contour thereof is the surface side concave portion 26 formed on the surface of the base material 12 and the surface of the skin material 14 and It coincides with the contour of the skin material recess 24 and has a tip sharpened in a V shape. An embedded portion forming convex portion 54 a is formed on a part of the surface of the upper mold 54 and outside the upper pressing portion 62.

  Specifically, in the thinning step, first, the base material 12 after the heating step is moved to the lower pressing portion 62 so that the portion of the base material 12 that is the hinge 6 matches the position of the lower pressing portion 62. Place on the surface. Next, the position of the upper mold is set so that the portion of the base material 12 that is the hinge 6 matches the position of the upper pressing portion 62, and the upper mold 54 is lowered downward. Then, first, the buried portion forming convex portion 54a comes into contact with a part of the surface of the skin material 14, and the upper skin 54 is lowered, so that the skin material 14 and the base material 12 are pressed by the buried portion forming convex portion 54a. To go. The skin material 14 and the base material 12 pressed to the back surface side of the base material 12 are extruded into the embedded portion forming convex portion 52a. Thereby, a part of skin material 14 and a part of base material 12 are shaped, and the side buried part 8b1 is formed. The upper die 54 is formed with another buried portion forming convex portion (not shown) on the front side (the back side of the paper in FIG. 6). A part of the front side of the skin material 14 and a part of the front side of the base material 12 are shaped to form a front buried part 8a1.

  When the upper mold 54 is lowered, the tip of the upper pressing portion 64 reaches the surface of the skin material 14. When the upper die 54 is further lowered, a part of the surface of the skin material 14 is pressed by the upper pressing part 64, and accordingly, a part of the back surface of the substrate 12 starts to be pressed by the lower pressing part 62. A part of the surface of the skin material 14 pressed by the upper pressing part 64 and a part of the surface of the base material 12 are compressed, whereby the skin material having a V-shaped cross-sectional view along the contour of the upper pressing part 64 is compressed. A recess 24 and a front-side recess 26 are formed. On the other hand, a part of the back surface of the base material 12 pressed by the lower pressing portion 62 is compressed, thereby forming a trapezoidal back surface-side concave portion 22 along the outline of the lower pressing portion 62. .

  The luggage mat 4 can be manufactured by the above steps. The luggage mat 4 manufactured by the above manufacturing method can be bent along the hinge 6 with the surface side as a valley. Furthermore, since the portion where the stress is applied to the surface side concave portion 26 and the skin material concave portion 24 when the luggage mat 4 is bent is small, whitening of the surface side concave portion 26 and the skin material concave portion 24 can be suppressed, and the design property on the design surface can be reduced. Can be improved.

  As described above, in the method of manufacturing the luggage mat 4 according to the present embodiment, the concave portion is formed on both the front surface and the back surface of the base material 12 in the thinning process, thereby reducing the stress applied to the hinge 6 during bending. The mat 4 can be manufactured. Furthermore, by making the width of the bottom end portion 26 a of the front surface side concave portion 26 of the base material 12 smaller than the width of the bottom end portion 22 a of the back surface side concave portion 22, the front surface side of the base material 12 is along the hinge 6. Can be folded, and the portion to which the stress is applied in the surface side recess 26 can be made smaller than the portion to which the stress is applied in the back surface side recess 22 during bending, and the surface side recess 26 can be formed on the surface of the base material 12 to be a design surface. The luggage mat 4 with reduced whitening can be produced. Thereby, the luggage mat 4 with improved designability on the design surface can be manufactured.

  Further, in the manufacturing method of the luggage mat 4 according to the present embodiment, the surface of the base material 12 is viewed in a cross section perpendicular to the direction in which the front surface side concave portion 26 and the rear surface side concave portion 22 extend in a groove shape in the thinning step. The front side concave portion 26 is formed so that the side concave portion 26 has a V shape. Here, since stress is applied to the bottom end portions 26a and 24a of the surface side recess portion 26 and the skin material recess portion 24 at the time of bending, the fiber material tends to fall down or whiten at the bottom end portions 26a and 24a. According to said manufacturing method, compared with the case where the bottom end part of the surface side recessed part 26 is formed in planar shape, the part which produces the hair fall and whitening in the surface side recessed part 26 and the skin material recessed part 24 can be made small. it can. Thereby, the luggage mat 4 in which the design property on the design surface is further improved can be manufactured.

  Moreover, in the manufacturing method of the luggage mat 4 which concerns on this embodiment, before the thinning process, the skin material bonding process which bonds the skin material 14 to the surface of the base material after a heating process is further provided, In a thinning process, Then, a portion of the skin material 14 that is a hinge is pressed to form the skin material recess 24, and the surface side recess 26 is formed via the skin material 14. Furthermore, the bottom end portion of the skin material concave portion 24 is located on the front side of the surface of the base material 12 when the base material is viewed in a cross section in a cross section orthogonal to the direction in which the front surface side concave portion 26 and the back surface side concave portion 22 extend in the groove shape. Thus, the skin material recess 24 is formed. For this reason, the surface side recessed part 26 can be formed shallowly, and the luggage mat 4 which can be bent easily by making the surface side of the base material 12 into a trough can be manufactured.

  Further, in the manufacturing method of the luggage mat 4 according to the present embodiment, in the thinning step, the surface of the base material 12 is viewed in a cross section perpendicular to the direction in which the front surface side concave portion 26 and the rear surface side concave portion 22 extend in a groove shape. The front surface side concave portion 26 and the rear surface side concave portion 22 are formed so that the opening edge portion of the side concave portion 26 is within a range overlapping with the side wall portion of the rear surface side concave portion 22. For this reason, the horizontal position of the surface side recessed part 26 and the back surface side recessed part 22 in the base material 12 can be made into the substantially same position. Thereby, the luggage mat 4 which can be easily bent along the hinge 6 can be manufactured.

<Embodiment 2>
A second embodiment will be described with reference to the drawings. FIG. 7 is a cross-sectional view of the hinge 106 of the luggage mat 104 according to the second embodiment in a state before bending, and is a cross-sectional view corresponding to FIG. 3 of the first embodiment. In the second embodiment, the cross-sectional shapes of the front surface side concave portion 126 and the skin material concave portion 124 are different from those of the first embodiment. Since other configurations are the same as those of the first embodiment, description of the structure, operation, and effect is omitted. In FIG. 7, the part obtained by adding the numeral 100 to the reference numeral in FIG. 3 is the same as the part described in the first embodiment.

  In the luggage mat 104 according to the second embodiment, as shown in FIG. 7, in the cross-sectional configuration when the luggage mat 104 is cut in a cross section orthogonal to the direction in which the hinge 106 extends in a substantially linear shape, All of the recesses 124 are U-shaped in cross section. In this case, the bottom end portions 126a and 124a of the surface-side concave portion 126 and the skin material concave portion 124 are the deepest portions of the surface-side concave portion 126 and the skin material concave portion 124 that form a U-shape in cross-sectional view. As in the case of the letter shape, it is formed in a planar view along the hinge 106. For this reason, the width of the bottom end portion 126 a of the front surface side recessed portion 126 is made smaller than the width of the bottom end portion 122 a of the back surface side recessed portion 122. Thus, even when the front surface side concave portion 126 has a U-shape in cross section, the width of the bottom end portion 126a of the front surface side concave portion 126 of the base material 112 is set to the bottom end portion 122a of the rear surface side concave portion 122. Thus, the luggage mat 104 with improved design on the design surface can be realized.

The modifications of the above embodiments are listed below.
(1) In each of the above embodiments, the bottom end portion of the front surface side recess is formed in a planar view along the hinge, but the bottom end portion of the front surface side recess is the bottom end of the back surface side recess. You may employ | adopt the structure made into planar shape like a part. Even in this case, if the width of the bottom end of the front-side recess is smaller than the width of the bottom end of the back-side recess, the stress applied to the back-side recess when bending along the hinge In addition, it is possible to realize a luggage mat with a small stress applied to the surface-side concave portion.

(2) In addition to the above embodiments, the method for forming the front surface side concave portion and the back surface side concave portion, the method for forming the skin material concave portion, and the like can be appropriately changed.

(3) In addition to the above embodiments, the arrangement and shape of the hinges in the entire luggage mat can be changed as appropriate.

  As mentioned above, although embodiment of this invention was described in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

  2: vehicle, 2a: trunk, 2b: opening, 2c: trunk floor, 4: luggage mat, 6: hinge, 8a: main floor, 8b: side floor, 12: base material, 12a: (base Material) front surface, 12b: back surface (base material), 14: skin material, 22: back surface side recess, 22a: bottom end (back surface side recess), 22b: opening edge (back surface side recess), 22c : Side wall part (of the back surface side recess), 24: skin material recess, 24a: bottom end part (of skin material recess), 24b: opening edge part (of skin material recess), 26: surface side recess, 26a: (surface Bottom end of the side recess, 32: lower heater, 34: upper heater, 42: lower mold stage, 44: upper mold stage, 52: lower mold, 54: upper mold, 62: lower pressing section, 64: Upper pressing part

Claims (4)

A base material including vegetable fibers and a thermoplastic resin, and a hinge formed by thinning at least a part of the base material, and one surface side of the base material is valleyd along the hinge. A method for producing a foldable vegetable fiber-containing board member as
A heating step of heating both plate surfaces of the substrate;
With the one surface of the base material as the front surface and the other surface of the base material as the back surface, the front side pressing portion presses a portion of the surface of the base material after the heating step that is the hinge. The groove-shaped front side recess is formed , and the groove-shaped back side recess is formed by pressing the hinge portion of the back surface of the base material after the heating step with a back-side pressing portion. A thinning process for thinning a portion to be a hinge,
In the thinning process,
With the bottom end of the back-side recessed portions forms a flat surface shape, Ri the width of the bottom end of the front side recess than the width of the bottom end of the back-side recessed portions is small, furthermore, the back side forming a than the width of the bottom end width the surface side recess so that the Do greater of the surface recess of the concave portion and said back-side recessed portions,
In the pressing direction of the back side pressing portion, the bottom end portion of the front surface side concave portion of the front side pressing portion is formed in a range overlapping with a flat surface forming the bottom end portion of the back side concave portion of the back side pressing portion. A surface is arranged, and the side wall portion of the front surface side concave portion of the front side pressing portion is formed at a position overlapping the boundary portion forming the boundary between the bottom end portion of the back surface side concave portion and the side wall portion of the back side pressing portion. The manufacturing method of the vegetable fiber containing board member characterized by pressing the site | part made into the said hinge with the said front side press part and the said back side press part in the aspect which arrange | positions a surface .   In the thinning step, when the base material is viewed in a cross section in a cross section orthogonal to the direction in which the front surface side concave portion and the rear surface side concave portion extend in a groove shape, the front surface side concave portion becomes V-shaped or U-shaped. The method for producing a vegetable fiber-containing board member according to claim 1, wherein the concave portion on the surface side is formed on the surface. Before the thinning step, further comprising a skin material laminating step of laminating a skin material on the surface of the base material after the heating step,
In the thinning step, a portion that is the hinge of the skin material is pressed to form a skin material concave portion, the surface side concave portion is formed through the skin material, and the base material is The skin material recess is arranged so that the bottom end portion of the skin material recess is located on the surface side of the surface of the substrate when the recess and the back surface side recess are viewed in a cross section perpendicular to the direction extending in the groove shape. It forms, The manufacturing method of the vegetable fiber containing board member of Claim 1 or Claim 2 characterized by the above-mentioned.   In the thinning step, when the substrate is viewed in cross section in a cross-section orthogonal to the direction in which the front-side recess and the back-side recess extend in a groove shape, the opening edge of the front-side recess is a side wall of the back-side recess. 4. The vegetable fiber-containing board member according to claim 1, wherein the front surface side concave portion and the rear surface side concave portion are formed so as to be within a range overlapping with the portion. 5. Production method.

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