JP4901345B2 - Board body - Google Patents

Description

  The present invention relates to a board body used as an automobile interior material.

  Recently, a board body made of a synthetic resin having a hollow plate shape has attracted attention as an interior material applied to an automobile from the viewpoints of weight reduction, removal of wood, recycling, and the like. As a method for manufacturing the board body, for example, the following is known.

A large number of protruding caps are formed on a cap sheet that is sequentially supplied in a thermoplastic state from a first die by a vacuum forming roll connected to a vacuum source, and is sequentially supplied in a thermoplastic state from a second die. The back sheet is pressed against the cap sheet by a pressure roll. Through this process, the back sheet is sequentially bonded to the bottom side of the cap, that is, the back surface of the cap sheet, and a two-layer hollow structure is continuously generated. Then, the board body, which is a three-layered hollow structure, is obtained by pasting the liner sheet on the top side of the cap while the board body is transported in a certain direction while maintaining an elastic body state with a uniform temperature distribution. (For example, Patent Document 1).
JP 2002-326297 A (FIG. 3 etc.)

  By the way, as for such a board body, the part which contributes most to rigidity as a physical characteristic is a flat back sheet and liner sheet which form the surface layer of a board body. That is, the cap sheet only needs to have a function of securely holding the bark sheet and the liner sheet, in other words, a strength capable of maintaining the relative positional relationship between the bark sheet and the liner sheet, and no further strength should be required. is there.

  However, since a large number of caps are vacuum formed using a vacuum forming roll, the portion in the vicinity of the boundary between the top portion and the side wall portion of each cap becomes the thinnest portion, and there is a difference in thickness between this thinnest portion and other portions. If it is large, the strength of each cap is reduced, and there is a risk that the inherent function of maintaining the relative positional relationship between the bark sheet and the liner sheet cannot be exhibited. In other words, when the force in the direction of peeling the liner sheet from the cap sheet is applied, the thinnest part may be broken, while when the large load is applied to the entire board body in the stacking direction, the thinnest part may be broken. The thin part may be crushed and the entire cap may be damaged. Such a defect becomes more prominent as the difference in thickness between the thinnest part and the other part becomes larger, resulting in lack of practicality and loss of commercial value.

  The side walls of each cap function as ribs. However, when the diameter of each cap is set to be large, the density of ribs per unit area is reduced, which may lead to a decrease in strength. On the other hand, when the diameter of each cap is set small, the density of ribs per unit area can be increased and sufficient strength can be ensured, but the thickness difference becomes more prominent because the degree of deep drawing increases. Thus, the above-described problem occurs.

  In addition, it is mentioned that a plurality of caps are formed in a staggered pattern on the cap sheet, and the distance between the adjacent caps is determined by the arrangement pattern of the suction cavities recessed in the outer peripheral surface of the vacuum forming roll. Needless to say, since the density of ribs per unit area varies depending on the distance between adjacent caps, the distance between the caps is also an important factor that determines the strength of the cap sheet, and hence the strength of the board body. Become. Further, when the distance between the caps is extremely small, sufficient resin is not supplied to the adjacent caps, resulting in variations in the wall thickness distribution of each cap, resulting in no board body original function. It will be a thing.

  The present invention has been made paying attention to such problems, and the main purpose is to improve the strength of each cap and the strength of the entire cap sheet, and to improve the uniformity of the thickness distribution of each cap. An object of the present invention is to provide a board body that can enhance and effectively perform the function as an automobile interior material.

That is, the board body of the present invention includes a cap sheet in which a plurality of projecting caps are formed using a vacuum forming roll in which a plurality of suction cavities for cap formation are provided on the outer peripheral surface of the roll body, and the cap sheet. A board body used as an automotive interior material, comprising a back sheet bonded to the bottom side of the cap, and a liner sheet bonded to the top side of the cap of the cap sheet, The cap sheet has a height dimension H of each cap with respect to the outer diameter D of each cap, a radius of curvature R of a round portion provided at a boundary portion between the top and side wall of each cap, and a circle of the roll body. A spacing dimension P1 between adjacent caps along the circumferential direction and a spacing dimension P2 between adjacent caps along the width direction of the roll body are respectively represented by formulas. 1] all SANYO set to a value that satisfies ~ a [4], the original thickness of the cap sheet, characterized by being set smaller than the thickness of the backsheet and the liner sheet.
0.35D ≦ H ≦ 0.45D Formula [1]
0.075D ≦ R ≦ 0.125D Formula [2]
0.9D ≦ P1 ≦ D (3)
1.1D ≦ P2 ≦ 1.25D Formula [4]
If the height dimension H of the cap and the radius of curvature R of the rounded portion are set to values larger than 0.45D and 0.125D, respectively, the degree of deep drawing at the time of vacuum suction becomes large. The thickness difference between the portion to be fused with the sheet and the rounded portion which is the thinnest portion increases, resulting in a problem that the strength of each cap is reduced.

  On the other hand, when the height dimension H of the cap and the radius of curvature R of the rounded portion are set to values smaller than 0.35D and 0.075D, respectively, the height dimension H of each cap becomes extremely small, On the other hand, when the height dimension H of each cap is set to such an extent that it can function as an automobile interior material, the outer diameter D of the cap increases accordingly, and as a result, the unit area The number of surrounding ribs is reduced too much, and the strength of the entire cap sheet is lowered.

  Further, the separation dimension P1 between the caps adjacent to each other along the circumferential direction of the roll body and the separation dimension P2 between the caps adjacent to each other along the width direction of the roll body are larger than “D” and “1.25D”, respectively. When set to, the number of ribs per unit area decreases too much, and the strength of the entire cap sheet also decreases.

  On the other hand, when each of the separation dimensions P1 and P2 is set to a value smaller than “0.9D” and “1.1D”, the number of ribs per unit area increases, but the resin is evenly distributed on the adjacent cap. This causes a problem that the thickness distribution of each cap becomes non-uniform.

  Thus, by setting the height dimension H of each cap BC1 and the radius of curvature R of the round portion BC1r and the pitch dimensions P1 and P2 between the caps BC1 to values satisfying the above equations [1] to [4], respectively. In addition to improving the strength of each cap BC1 and the strength of the entire cap sheet BC, the uniformity of the thickness distribution of each cap is also increased, and the board body can effectively exhibit the function as an automobile interior material.

Further, the side wall portion of each cap includes a side wall portion main body that is substantially perpendicular to the bottom portion, and an inclined portion that is continuous with the side wall portion main body and has a gradually increasing opening diameter toward the opening side. The inclined portion S has a gradually larger opening diameter within a range satisfying the equation [5] with respect to the outer diameter D ′ of the side wall portion main body of each cap.
0.04D ′ ≦ S ≦ 0.06D ′ Formula [5]
As described above, by providing the cap BC1 with the inclined portion, it is possible to effectively increase the rigidity against the force perpendicular to the surface direction of the cap sheet. On the other hand, in the case where the inclined portion gradually increases the opening diameter beyond the range of 0.04D ′ to 0.06D ′, the strength of each cap and the strength of the entire cap sheet are reduced, so The function as a material cannot be fully exhibited.

  As a preferred embodiment for improving dimensional stability, rigidity, and heat resistance during molding, the cap sheet is a material in which an inorganic filler such as talc is added to a thermoplastic resin such as polypropylene. Can be mentioned.

  As described above, according to the present invention, the height dimension H of each cap, the radius of curvature R of the round portion BC1r, and the pitch dimensions P1 and P2 between the caps BC1 satisfy the above equations [1] to [4], respectively. By setting to, each cap and the entire cap sheet can be given strength that can maintain the relative positional relationship between the bark sheet and the liner sheet, and can effectively exhibit the function as an automobile interior material. Become.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
<First Embodiment>
The board body B according to the first embodiment is used as an automobile interior material, and FIG. 1 (FIGS. 1A and 1B are side views of the board body B, respectively, z in FIG. As shown in the enlarged region), a cap sheet BC provided with a plurality of protruding caps BC1, a back sheet BB bonded to the bottom side of the cap BC1 of the cap sheet BC, and a cap of the cap sheet BC It is a three-layered hollow structure comprising a liner sheet BL bonded to the top BC1t side of BC1.

  The board body B is manufactured by a board body manufacturing machine X shown in FIG.

  The board manufacturing machine X includes a cap sheet supply device X1 that supplies a cap sheet BC, and a vacuum forming roll that is connected to the vacuum source X2v and forms a large number of caps BC1 on the cap sheet BC supplied from the cap sheet supply device X1. The back sheet BB supplied from the back sheet supply device X3 is pressed against the back surface side of the cap sheet BC formed by the vacuum forming roll X2 and the back sheet supply device X3 for supplying the back sheet BB. A pressure roll X4 for fusing, a peeling roll X5 for peeling the board body B formed by mutually fusing the cap sheet BC and the back sheet BB from the vacuum forming roll X2, and a pair of pinch rolls for pinching the board body B X6 and liner sheet supply device X7 for supplying liner sheet BL A pair of cooling rolls X8 for cooling the supplied liner sheet BL from the liner sheet supply apparatus X7, those having at least a pair of nip rolls X9 bonding the liner sheet BL on the surface side of the cap sheet BC.

  The cap sheet supply device X1, the back sheet supply device X3, and the liner sheet supply device X7 are well-known devices configured by extruders X11, X31, and X71 and flat dies X12, X32, and X72, respectively. In this embodiment, the material which added inorganic fillers, such as a talc, to thermoplastic resins, such as a polypropylene, is applied as a cap sheet supplied from the cap sheet supply apparatus X1. In addition, the pressure roll X4, the peeling roll X5, the pinch roll X6, the cooling roll X8, and the nip roll X9 are each well-known, and detailed description is abbreviate | omitted.

  The vacuum forming roll X2 is mainly cylindrical as shown in FIG. 3 (the same figure (a), (b) is an overall schematic view of the vacuum forming roll X2 and an enlarged view of the Z region in (a)). Roll body X21, a rotation shaft X22 provided so as to penetrate the roll body X21, and a pair of side plates X23 biased toward the roll body X21 by biasing means X2S such as a spring. is there. The rotary shaft X22 is a hollow body supported by a bearing (not shown), and a medium for cooling the roll body X21 from the inside can be circulated using this hollow.

  The roll main body X21 includes a plurality of suction cavities X211 that are recessed in the outer peripheral surface, a plurality of suction horizontal holes X212 that are formed from one end to the other end of the roll main body X21 and open at both ends, and each suction cavity X211. And suction holes X213 that communicate with the corresponding suction side holes X212.

  Each suction cavity X211 has a substantially stepped trapezoidal cavity main body X211a in section and formed with a vacuum passage extending toward the axis of the roll main body X21 and communicating with the suction horizontal hole X212, and a step portion of the cavity main body X211a. In this embodiment, such a suction cavity X211 is shown in FIG. 4 (the figure schematically shows a state in which the roll main body X21 is expanded). As shown in FIG. 5A, the outer circumferential surface of the roll body X21 is provided in a staggered pattern. In FIG. 4, only the opening edge of the suction cavity X211 is shown in order to clearly show the arrangement state of the suction cavities X211. In FIG. 3A, only a portion of the suction cavity X211 that is recessed in the outer peripheral surface of the roll body X21 and that is provided in a partially broken region is illustrated and provided in other regions. Things are omitted.

  Each suction side hole X212 is substantially linear and extends along the axial direction of the roll body X21. The plurality of suction side holes X212 are separated by a predetermined pitch along the circumferential direction of the roll body X21. It is provided. In the present embodiment, both ends of each suction horizontal hole X212 are configured to be connected to the vacuum source X2v. When the roll body X21 is rotated, a plurality of suction lateral holes X212 that come to a position communicating with a vacuum port X23a (so-called “vacuum zone”) provided on the side plate X23 are evacuated via the vacuum port X23a. It is connected to the source X2v so as to be vacuumed.

  The suction hole X213 is configured by a cut portion provided in the plug X211b such as a slit or a notch and a vacuum passage of the suction cavity X211.

Thus, in this embodiment, when the opening diameter of each suction cavity X211 is d, the height dimension of the suction cavity X211 (specifically, the dimension from the upper surface portion of the plug X211b to the opening portion of the suction cavity X211) h The radius of curvature r of the rounded portion X211r provided in the vicinity of the step portion of the suction cavity body X211a is set to a value satisfying the equations [1 ′] and [2 ′], respectively.
0.35d ≦ h ≦ 0.45d Formula [1 ′]
0.075d ≦ r ≦ 0.125d Formula [2 ′]
Further, as shown in FIG. 4, the separation dimension p1 between the suction cavities X211 adjacent along the circumferential direction of the roll body X21, more specifically, the suction cavities adjacent along the circumferential direction of the roll body X21. The distance p1 between the centers of the X211 is set to a value satisfying the expression [3 ′], and the distance p2 between the suction cavities X211 adjacent along the width direction of the roll body X21, more specifically, the roll The distance p2 between the centers of the suction cavities X211 adjacent to each other along the width direction of the main body X21 is set to a value satisfying the equation [4 ′].
0.9d ≦ p1 ≦ d Formula [3 ′]
1.1d ≦ p2 ≦ 1.25d Formula [4 ′]
Next, a method and an operation of manufacturing the board body B using the board body forming machine X provided with such a vacuum forming roll X2 will be described with reference to FIG.

  First, a film-like cap sheet BC in a thermoplastic state is sequentially supplied from the cap sheet supply device X1 to the rotating vacuum forming roll X2, and a suction cavity is generated by the vacuum suction action of the vacuum forming roll X2 connected to the vacuum source X2v. A cap sheet BC having a large number of caps BC1 corresponding to the shape of X211 is continuously formed.

  On the other hand, a film-like backsheet BB in a thermoplastic state is sequentially supplied from the backsheet supply device X3 to the vacuum forming roll X2, and the backsheet BB is moved to the back side of the cap sheet BC by the pressure roll X4 (the bottom of the cap BC1). Side) and paste them together. As a result, a two-layer hollow structure composed of the cap sheet BC and the back sheet BB is formed, and then the two-layer hollow structure peeled from the vacuum forming roll X2 by the peeling roll X5 has an elastic property with uniform temperature distribution. The liner sheet BL is conveyed in a certain direction while being maintained in the body state, and the liner sheet BL supplied from the liner sheet supply device X7 is pressed against the surface side of the cap sheet BC (the top BC1t side of the cap BC1) by the pair of nip rolls X8. Bonded. Through the above steps, a board body B (plastic hollow plate) that is a three-layer hollow structure is formed.

Therefore, the cap BC1 having a shape and an arrangement pattern corresponding to the shape and arrangement pattern of the suction cavity X211 provided in the roll body X21 is formed on the cap sheet BC formed using the vacuum forming roll X2. That is, when the outer diameter of each cap BC1 is D, the height H of each cap BC1 and the radius of curvature R of the rounded portion BC1r formed at the boundary portion between the top portion BC1t and the side wall portion BC1s of each cap BC1 are: The values satisfy the following equations [1] and [2], respectively (see FIG. 1).
0.35D ≦ H ≦ 0.45D Formula [1]
0.075D ≦ R ≦ 0.125D Formula [2]
Further, as shown in FIG. 5 (the figure schematically shows a plan view of the board body B), a separation dimension P1 between caps BC1 adjacent to each other along the circumferential direction of the roll body X21, Specifically, the separation dimension P1 between the centers of the caps BC1 adjacent along the circumferential direction of the roll body X21, and the separation dimension P2 between the caps BC1 adjacent along the width direction of the roll body X21, more specifically. The distance P2 between the centers of the caps BC1 adjacent along the width direction of the roll body X21 is a value that satisfies the following equations [3] and [4], respectively.
0.9D ≦ P1 ≦ D (3)
1.1D ≦ P2 ≦ 1.25D Formula [4]
In the present embodiment, as an example, the outer diameter D of the cap BC1 (the opening diameter d of the suction cavity X211) is set to 10 mm, the height dimension H of the cap BC1 (height dimension h of the suction cavity X211) is 4 mm, and the cap The radius of curvature R of the radius portion BC1r of BC1 (the radius of curvature r of the radius portion X211r of the suction cavity X211) is 1 mm, and the separation dimension P1 between the caps BC1 adjacent along the circumferential direction of the roll body X21 (the circle of the roll body X21) The separation dimension p1 between the suction cavities X211 adjacent along the circumferential direction is 9.5 mm, and the separation dimension P2 between the caps BC1 adjacent along the width direction of the roll body X21 (adjacent along the width direction of the roll body X21) The separation dimension p2) between the suction cavities X211 is set to 11.5 mm.

  By setting such a dimension, the initial thickness dimension formed by the cap sheet flat die X12 that is not directly sucked into the portion BC2 of the cap sheet BC to be fused with the back sheet BB, that is, the suction cavity X211. The thickness dimension C1 of the rounded portion BC1r of each cap BC1 is approximately 0.25C with respect to the thickness dimension (original thickness) C of the portion to be maintained, and each cap BC1 can exhibit effective strength. Note that FIG. 1 is not an accurate representation of the thickness distribution, but a deformed one.

  If the height dimension H of the cap BC1 and the radius of curvature R of the rounded portion BC1r are set to values larger than 0.45D and 0.125D, respectively, the deep drawing will be deeper during vacuum suction. The thickness difference between the part BC2 to be fused with the backsheet BB and the rounded part BC1r which is the thinnest part causes a decrease in strength of each cap BC1 and cannot exhibit the function that should originally be present. Occurs. That is, when a force in the direction of peeling the liner sheet BL from the cap sheet BC is applied, there is a risk that the rounded portion BC1r is torn off, while when a large load is applied to the entire board body B in the stacking direction. May begin to collapse from the rounded portion BC1r and the entire cap BC1 may be damaged.

  On the other hand, when the height dimension H of the cap BC1 and the radius of curvature R of the round portion BC1r are set to values smaller than 0.35D and 0.075D, respectively, the height dimension H of each cap BC1 becomes extremely small, and the hollow board On the other hand, when the height dimension H of each cap BC1 is set to such an extent that the function as a hollow board body can be exhibited, the outer diameter D of the cap BC1 increases accordingly, As a result, the number of side wall parts BC1s of the cap BC1 functioning as a rib is too small in the unit area, and the strength of the entire cap sheet BC is lowered.

  Further, a separation dimension P1 between the caps BC1 adjacent along the circumferential direction of the roll body X21 and a separation dimension P2 between the caps BC1 adjacent along the width direction of the roll body X21 are respectively “D” and “1.25D. If the value is set to a value larger than “,” the number of ribs per unit area is excessively reduced, leading to a decrease in strength.

  On the other hand, when each of the separation dimensions P1 and P2 is set to a value smaller than “0.9D” and “1.1D”, the number of ribs per unit area increases, but the resin is applied to the adjacent cap BC1. There is a problem in that the cap BC1 is not evenly distributed and the thickness distribution of each cap BC1 becomes non-uniform. Furthermore, in order to form the cap BC1 at such a very high density, naturally, the roll body X21 Although it is necessary to provide the suction cavities X211 on the outer peripheral surface with a very high density, in this case, an advanced cutting technique is required, and there is a possibility that the distribution of the suction holes X213 may vary.

  Thus, in the board body according to the present embodiment, the height dimension H of each cap BC1, the radius of curvature R of the rounded portion BC1r, and the pitch dimensions P1 and P2 between the caps BC1 are expressed by the equations [1] to [4], respectively. ] To increase the strength of each cap BC1 and the overall strength of the cap sheet BC, increase the uniformity of the thickness distribution of each cap BC1, and effectively function as an automobile interior material. It can be demonstrated.

  Moreover, as long as the strength of each cap BC1 and the entire cap sheet BC is secured, the original thickness of the cap sheet BC is set smaller than the thickness dimension of the back sheet BB and the liner sheet BL that greatly contributes to the strength of the board body B. Is also possible. In the present embodiment, the thickness dimension of the back sheet BB and the liner sheet BL is set to 0.5 mm, whereas the original thickness C of the cap sheet BC is 0.25 mm, that is, the back sheet BB and the liner sheet BL. The thickness dimension is set to about half. Even if it is a case where it sets to such a value, the intensity | strength required as the board body B can be ensured, and also the weight reduction of the board body B can be achieved, suppressing generation | occurrence | production of useless meat. Furthermore, by using the back sheet BB and the liner sheet BL for the portion saved by the cap sheet BC, the raw material of the entire board body B can be minimized, which is desirable from the viewpoint of reducing the environmental load.

In particular, since the cap sheet BC is a material in which an inorganic filler such as talc is added to a thermoplastic resin such as polypropylene, it is excellent in dimensional stability at the time of vacuum forming, and effectively improves rigidity and heat resistance. it can.
Second Embodiment
As shown in FIG. 6 (the figure is a diagram corresponding to FIG. 1B), the board body B according to the second embodiment has caps BC1 as compared with the first embodiment. The side wall portion BC1s includes a side wall portion body BC1sa and an inclined portion BC1sb that is continuous with the side wall portion body BC1sa and has an opening diameter gradually increased toward the opening side. That is, a skirt is provided on the bottom side of each cap BC1.

  The vacuum forming roll X2 applied when manufacturing the board body B according to the present embodiment has each suction as shown in FIG. 7 (the figure is a diagram corresponding to FIG. 3B). Of the cavities X211, the side wall forming part X211s that contributes to the formation of the side wall part BC1s of each cap BC1 is substantially perpendicular to the bottom part of the suction cavity X211 (the upper surface part of the plug X211b) and contributes to the molding of the side wall part body BC1sa. The second embodiment is different from the first embodiment in that it includes a main body forming portion X211sa and an inclined forming portion X211sb that is continuous with the main body forming portion X211sa and contributes to forming the inclined portion BC1sb. That is, in the present embodiment, the vacuum forming roll X2 that is chamfered at the connection portion between the suction cavity X211 and the outer peripheral surface of the roll body X21 is applied. Note that the other parts of the board body B and the vacuum forming roll X2 and the dimensions of each part conform to those shown in the first embodiment, and thus detailed description thereof is omitted. In FIGS. 6 and 7, parts corresponding to those in the first embodiment are denoted by the same reference numerals.

And when it is set as opening diameter d 'in main body shaping | molding part X211sa among each suction cavity X211, the inclination shaping | molding part X211sb (it is set to "s" for convenience of a formula) is in the range of the value which satisfy | fills the following formula [5']. The gradual opening diameter is set larger.
0.04d ′ ≦ s ≦ 0.06d ′ Formula [5 ′]
The cap sheet BC formed by using the vacuum forming roll X2 provided with many suction cavities X211 on the outer peripheral surface of the roll body X21 corresponds to the shape and arrangement pattern of the suction cavities X211 provided in the roll body X21. The cap BC1 having the shape and arrangement pattern thus formed is formed. That is, when the outer diameter of the side wall portion BC1sa of each cap BC1 is D ′, the inclined portion BC1sb (referred to as “S” for convenience of the equation) of each cap BC1 has a value satisfying the following equation [5]. The opening diameter is gradually increased within the range.
0.04D ′ ≦ S ≦ 0.06D ′ Formula [5]
By providing a skirt such as the inclined portion BC1sb (S) in each cap BC1, it is possible to effectively increase the rigidity against a force perpendicular to the surface direction of the cap sheet BC. On the other hand, when the inclined part BC1sb (S) gradually increases the opening diameter beyond the range of 0.04D 'to 0.06D', as shown in Table 1 and Table 2 below, Compared with the case where the part BC1sb gradually increases the opening diameter in the range of 0.04D ′ to 0.06D ′, the bending strength of the board body B is reduced, and the function as the board body B is fully exhibited. It can't be done.

  As described above, the board body B according to the second embodiment effectively increases the strength of each cap BC1, and consequently the strength of the entire cap sheet BC1, and improves the molding ratio by providing the inclined portion BC1sb (S). This contributes to improving the uniformity of the wall thickness distribution of each cap BC1 and effectively exhibiting the function as an automobile interior material.

  The present invention is not limited to the embodiment described in detail above.

  For example, in the above-described embodiment, the aspect in which the plug is fitted to the stepped cavity body is illustrated as the suction cavity. However, the suction cavity is not limited to this, and a bottomed one having a substantially trapezoidal shape in cross section is applied. May be. In this case, the suction hole is configured by a small through hole extending from the bottom wall of each cavity toward the axis of the roll body and communicating with the suction side hole.

  Further, the cap sheet, the back sheet and the liner sheet may all be made of the same material, or may be made of different materials. Examples of the material to be applied include polyolefin polymers such as polyethylene and polypropylene.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

The figure which shows the board body which concerns on 1st Embodiment of this invention. The schematic diagram of the board body manufacturing machine concerning the embodiment. Schematic of the vacuum forming roll which concerns on the same embodiment. The figure which shows typically the expansion | deployment state of the roll main body which concerns on the same embodiment. The figure which shows typically the top view of the board body which concerns on the same embodiment. The elements on larger scale of the board body which concerns on 2nd Embodiment of this invention. The elements on larger scale of the vacuum forming roll which concerns on the same embodiment.

Explanation of symbols

B ... Board body BB ... Back sheet BC ... Cap sheet BC1 ... Cap BC1r ... Earl part BC1s ... Side wall part BC1sa ... Side wall part body BC1sb (S) ... Inclined part BC1t ... Top part BL ... Liner sheet X2 ... Vacuum forming roll X21 ... Roll Body X211 ... Suction cavity

Claims (3)

A cap sheet in which a plurality of protruding caps are formed using a vacuum forming roll having a plurality of cap forming suction cavities formed on the outer peripheral surface of the roll body, and the cap sheet is bonded to the bottom side of the cap. A board body used as an automobile interior material, comprising a back sheet and a liner sheet bonded to the top side of the cap of the cap sheet,
The cap sheet has a height dimension H of each cap with respect to the outer diameter D of each cap, a radius of curvature R of a round portion provided at a boundary portion between the top and side wall of each cap, and a circle of the roll body. The spacing dimension P1 between adjacent caps along the circumferential direction and the spacing dimension P2 between adjacent caps along the width direction of the roll body are set to values satisfying the equations [1] to [4], respectively. Oh it is,
A board body , wherein an original thickness of a cap sheet is set smaller than a thickness dimension of a back sheet and a liner sheet .
0.35D ≦ H ≦ 0.45D Formula [1]
0.075D ≦ R ≦ 0.125D Formula [2]
0.9D ≦ P1 ≦ D (3)
1.1D ≦ P2 ≦ 1.25D Formula [4] The side wall portion of each cap is composed of a side wall portion main body that is substantially perpendicular to the bottom portion, and an inclined portion that is continuous with the side wall portion main body and has a gradually larger opening diameter toward the opening side. The board body according to claim 1, wherein the inclined portion S has a gradually larger opening diameter within a range satisfying the equation [5] with respect to the outer diameter D ′ of the side wall portion main body of each cap.
0.04D ′ ≦ S ≦ 0.06D ′ Formula [5] The board body according to claim 1, wherein the cap sheet is made of a material obtained by adding an inorganic filler to a thermoplastic resin.

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