JP2009160253A - Back pad member, its manufacturing method, and backpack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a back pad member improving the stability in walking and traveling of a user carrying a backpack by forming an upholstery material into a three-dimensional shape corresponding to the recessed/projecting shape of the back of the user, and to provide its manufacturing method. <P>SOLUTION: This back pad member 4 for use in the backpack has a sheet-like upholstery coming into contact with the back of the user when carrying the backpack, and elastic core materials 21-24 disposed on the back side of the upholstery 1. The upholstery 1 used is formed into the three-dimensional shape corresponding to the recessed/projecting shape of the back of the user. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a back support member, a manufacturing method thereof, and a backpack, and more specifically, a back support member used for a backpack, a manufacturing method thereof, and a backpack configured using the back support member. It is about.

In backpacks such as school bags and rucksacks, a back support member is provided at a portion that hits the back of the back user. As this type of backing member, conventionally, an elastic core material formed by cutting a foamed material such as a flat polyurethane foam having a thickness of about 10 to 30 mm into a predetermined shape to a predetermined thickness, a synthetic resin material, It is placed on a hard board, which is a board for core materials such as cardboard, and a sheet-like skin material made of artificial, synthetic, natural leather, etc. is covered on this elastic core material, and the periphery of the skin material is the above What is configured by sewing and bonding to a hard board is used (see Patent Documents 1 and 2). At that time, there is a method of forming an uneven portion corresponding to the uneven shape of the back user's back on the back member by sewing or bonding a predetermined portion other than the peripheral portion of the skin material to a hard board (hard core material). The convex portion provided on the skin material accommodates a cushion material on the back side (inside) to provide cushioning properties, and the concave portion provided between the convex portions provides a ventilation groove on the surface. ing.
Utility Kaihei 7-18623 JP-A-5-337005

  Known techniques for molding artificial leather, synthetic leather, natural leather, etc. include compression molding, thermal compression molding, ultrasonic molding, high frequency molding, etc. When a sheet having a low melting point thermoplastic fiber or non-woven fabric or a similar resin coated or impregnated is laminated on the back surface of the skin material and the uneven shape is maintained by thermoforming, forming the surface material with a low melting point No melting or damage to the surface design occurs.

  That is, the melting point of the skin material compared to the melting point of polyester (softening point around 240 ° C.), nylon (softening point around 180 ° C.) or polyurethane resin (softening point around 150 ° C.), which are skin materials used for artificial and synthetic leather. However, since the low melting point fiber or resin has a softening point of around 100 ° C., it could be molded in a low temperature region. Furthermore, although there are some which are formed by pasting ordinary woven fabric or non-woven fabric as a reinforcing material on the back side of the skin material, the reinforcing material does not have moldability, so it is molded at a higher temperature than the artificial / synthetic leather described above. There was a need to do.

  For example, the temperature of the upper and lower molds when pressing the polyurethane resin used for the finished surface of artificial leather is substantially constant in the high temperature region above the melting point of the thermoplastic resin. The skin material could be melted. That is, there is a possibility that the upper mold is brought into close contact with the surface of the skin material accommodated in the upper and lower molds and the surface design provided on the skin material is damaged by high heat. In order to prevent this, for example, when molding is performed in a low temperature region having a melting point temperature of 150 ° C. or lower, there is a problem that the thermoplastic resin contained in the reinforcing material and the like is not cured and the molding retainability is remarkably lowered. In addition, there is a problem that it is not suitable for molding a complicated three-dimensional structure because it hinders the elongation of artificial leather and the like.

  Laminating a film, sheet, foam of thermoplastic resin, or woven fabric, knitted fabric, nonwoven fabric, etc. using thermoplastic fiber when providing uneven parts by thermoforming the skin material by press processing However, although thermoforming is performed, the texture after molding becomes hard, and it is difficult to obtain a soft cushioning property.

  In the above conventional method, an elastic core material cut into a certain thickness is positioned on the back side of the skin material, and the peripheral edge of the skin material is sewn or bonded to a hard board to attach the internal elastic core material. By deforming, an uneven portion is formed on the surface of the backing member. And since the back support member can not correspond to various designs and shapes, it is difficult to make a back support member with a shape that sufficiently corresponds to the uneven shape of the back of the backpack user. The back weight to the user cannot be well distributed over the entire back, and the frictional resistance generated on the contact surface between the back user's back and the backing member increases, resulting in large pain due to rubbing on the back user's back In addition, schoolchildren who do not have physical strength have poor stability during walking and running.

  In the above-described conventional method, the skin material is not molded, but the thermoplastic material is molded on the back surface side of the laminated skin material to the last. Therefore, there is a problem that distortion occurs due to changes over time. In addition, the low melting point thermoplastic skin material becomes resinous at the time of molding, so that the texture becomes hard and it is difficult to obtain an appropriate cushion feeling.

  Compared to the conventional molding method described above, when a schoolchild walks or runs with a backpack on the back, the backpack surface part of the backpack is made into a three-dimensional solid shape so that the backpack is in close contact with the back. The goal is to reproduce it on the surface of the material. In other words, sufficient heat must be applied in order to impregnate the reinforcing material attached to the front surface or the back surface of the skin material with the resin so as to have shape retention after molding.

  The present invention makes the temperature of the upper and lower press dies used for the press working different, that is, the temperature region of the lower die is made higher and the temperature region of the upper die is made lower to make the surface of the skin material during the press work. In order to prevent damage to the design provided on the upper mold, the temperature of the upper mold is set lower than that of the lower mold so that the surface of the skin material is not damaged during processing.

  The backrest member according to the present invention is a backrest member used for a backpack-type back, and when the back is carried on the back, a sheet-like skin material that hits a user's back and a back surface side of the skin material It has an elastic core material arranged and is characterized in that a material molded into a three-dimensional solid shape corresponding to the uneven shape (curved shape) of the back of the user is used as the skin material. is there.

  As the elastic core material, a molded product having a convex portion corresponding to the concave portion formed on the back surface side of the skin material is used. In one embodiment, a plurality of recesses are formed on the back surface side of the skin material, and the elastic core member is made of a plurality of members having protrusions corresponding to the plurality of recesses. In another embodiment, a plurality of recesses are formed on the back surface side of the skin material, and the elastic core member is formed of a single member having projections corresponding to the plurality of recesses.

  In one preferred form, when a part of the three-dimensional solid shape of the skin material forms a ventilation groove and carries a backpack-type back provided with the backrest member, the user's back and the skin material The air flow through the ventilation groove is formed between the two.

  According to the present invention, there is provided a backpack-type bag in which the backrest member having the above-described configuration is fixed to the base board. This type of backpack may be a school bag or a rucksack, for example.

  According to this invention, the manufacturing method of the backrest member used for a backpack type | formula back | bag is provided further. This method comprises a step of forming the surface side of a sheet-like skin material that comes into contact with a user's back when carrying the back into a three-dimensional solid shape corresponding to the uneven shape of the user's back, the skin The elastic core material disposed on the back surface side (inside) of the material is formed into a shape having a convex portion corresponding to the concave portion formed on the back surface side of the skin material, and the elasticity is applied to the concave portion of the skin material. It has the process of fitting the convex part of a core material.

  The skin material is manufactured by hot press molding using an upper mold and a lower mold, and a temperature difference is provided between the upper mold and the lower mold during the hot press molding. Specifically, the upper mold at the time of the hot press molding is a low temperature region where the surface design applied on the surface side of the skin material is not melted or damaged, specifically, a low temperature of 0 to 40 ° C. The lower mold is set to a temperature range in which the skin material can be molded, specifically, a high temperature range of 130 to 180 ° C. to provide a temperature difference.

  The gap provided between the upper mold and the lower mold at the time of the hot press molding is provided wider than the thickness of the skin material accommodated in the upper and lower molds. Specifically, the distance between the upper mold and the lower mold is about 0.2 to 2.0 mm wider than the thickness of the skin material, and the skin pressed against the surface of the lower mold The press work is performed with a slight play space between the surface of the material and the inner surface of the upper mold. Therefore, the surface of the skin material is not scratched, and the upper mold is at a lower temperature than the heat molding temperature, so that it faces the surface design provided in the finishing layer of the skin material by heat in the final press process. It can be finished beautifully without melting with heat from the upper mold.

  In the present invention, as the skin material, the one formed into a three-dimensional solid shape corresponding to the uneven shape of the user's back is used, and the elastic core material positioned on the back surface side of the skin material is on the back surface side of the skin material. Because it is a molded product that has a convex part corresponding to the provided concave part, the shape and height of the uneven part of the backing member can be freely set without damaging the various designs provided on the surface of the skin material In addition, it is possible to provide a back support member for a backpack with excellent cushioning properties and improved adhesion.

  The embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a skin material made by the manufacturing method according to the embodiment of the present invention, and FIG. 2 is an end view taken along line AA in FIG. 3 is a plan view of a state in which a plurality of elastic core members made by the manufacturing method of the embodiment of the present invention are arranged with a space between each other, FIG. 4 is a cross-sectional view taken along line BB in FIG. 3, and FIG. The perspective view of the back support member which concerns on invention, FIG. 6 is sectional drawing of the CC arrow direction of FIG. 5, FIG. 7 is the back surface side of the state which the elastic core material in other embodiment combined in the space | interval FIG. 8 is a plan view of a state in which a plurality of elastic core members are integrally formed, FIG. 9 is a cross-sectional view taken along the line DD of FIG. 8, and FIG. 10 is a school bag using the backing member according to the present invention. FIG. 11 is a front view of a back support member according to the present invention, and FIG. 12 is a backpack carrying a backpack using the back support member. FIG. 13 is a cross-sectional view taken along line EE in FIG. 11, FIG. 14 is a cross-sectional view taken along line FF in FIG. 11, and FIG. 15 is a cross-sectional view taken along the line GG of FIG.

  The following embodiment is for manufacturing a back support member for a school bag according to the present invention, and the manufacturing method of this embodiment is as follows. As shown in FIG. 1, a skin material 1 molded into a required three-dimensional solid shape is formed. In other words, non-woven fabric base using ultrafine fibers such as 7/100 denier. In other words, it is made of non-woven fabric material, impregnated with polyurethane resin, and heat-press molded (thermo-compression molded) artificial leather made of polyurethane resin. By doing so, the sheet-like skin material 1 which is a three-dimensional solid molded product having a plurality of convex portions 11 to 14 having an arbitrary shape can be obtained. Of course, it is possible to use synthetic leather or natural leather that does not use a material having molding retention properties, for example, a film made of a thermoplastic resin, a sheet, or the like, instead of the artificial leather.

  Reference numerals 11a to 14a denote concave portions formed on the back surfaces, that is, the back sides of the convex portions 11 to 14, respectively, which are formed by projecting to the front surface side which is the finishing layer of the top cloth material 1. Since this convex portion is processed by hot pressing, the tops of the concave portions 11a to 14a can be formed into a flat shape, an arc shape, a concave arc shape, or a complicated uneven shape as necessary. .

  Here, when molding a skin material that is a molded product having a three-dimensional shape by hot press molding, if the temperature applied at the time of molding is too high, the skin material will be cured, or the surface design of the molded product will melt at a high temperature. Alternatively, damage may be caused by pressing the surface portion of the skin material. On the other hand, when the temperature at the time of hot pressing is suppressed, the molding becomes insufficient, the molding retention property is deteriorated, and the required shape cannot be maintained.

  When molding a complicated three-dimensional uneven shape with a height difference in a narrow area on the surface side that is the finishing layer by general hot press molding, the skin material is accommodated in the upper and lower molds In order to perform hot pressing, the elongation of the material and shape retention must be maintained. Also, during pressing, the skin material is pressed by the upper and lower molds from the front and back sides, which are the finished layers. The surface design of an arbitrary shape processed on the surface of the skin material due to high heat at times may be damaged by melting or pressing.

For this reason, the following method is used in the present invention.
First, at the time of hot press molding, an upper mold located on the upper side corresponding to the surface side (surface side on which the surface design is applied), which is the finishing layer side of the skin material, and a lower mold corresponding to the back surface side of the skin material A temperature difference is provided between the lower mold located on the side. Specifically, the lower mold is set to a temperature range in which a skin material made mainly of a polyurethane resin or the like that is mainly used can be molded, for example, a high temperature range of 130 to 180 ° C., preferably 140 to 160 ° C. The mold is set in a low temperature region where the surface design applied to the surface side which is the finish layer side of the skin material is not damaged by melting or hot pressing, for example, a temperature range of 0 to 40 ° C., preferably about 25 to 30 ° C. Thus, a feature is that a temperature difference is provided between the upper mold and the lower mold. In this case, depending on the material and thickness of the skin material, the upper and lower molds preferably have a temperature adjusting function so that the heating or cooling temperature can be adjusted as necessary.

  Further, an appropriate gap between the upper and lower molds, for example, a gap of 0.2 to 2.0 mm (between both molds depending on the thickness of the skin material before molding) The width (distance) of the gap is added to the material and thickness of the skin material, and is increased or decreased within the range of the gap) to perform hot press molding. In other words, the space provided between the upper and lower molds is provided with a wide space between the thickness of the skin material and 0.2 to 2.0 mm. The gap of 0.2 to 2.0 mm is a numerical value obtained from an experimental result that the inventor conducted a number of experiments by hot pressing using a cover material.

  As described above, the upper mold that heat-presses the skin material arranged on the upper surface of the lower mold from above is flexible when performing press working if the above-described slight gap is provided between the upper mold and the skin material. Even in the intermediate state and the final state of pressing on the surface portion of a certain skin material, some gaps remain and do not come into close contact for a certain period of time. That is, even if both molds are in close contact with each other, there is a gap of 0.2 to 2.0 mm in addition to the thickness of the skin material, so that the surface design applied to the surface side of the skin material is melted by heat. Or has a function that can be beautifully finished without being damaged by pressing.

  In the present invention, hot press molding is performed by providing a temperature difference between the upper and lower molds, and an extra space (play) between the upper and lower molds than the thickness of the skin material accommodated in both molds. The three-dimensional solid shape having a predetermined shape is eliminated by eliminating the above-mentioned disadvantages of the prior art by preventing the entire lower surface of the upper mold from being in close contact with the skin material during pressing. The convex portion is formed.

  In the press working of this manufacturing method, the upper and lower molds have a skin material and a gap (play gap) that is about 0.2 to 2.0 mm wider than the skin material. In this state, the skin material does not adhere between the upper and lower molds, and the skin material placed on the lower mold has a surface design provided on the surface side of the skin material due to the high heat of the lower mold. It can prevent melting and breakage. That is, since the surface side of the skin material faces the upper mold set at a temperature in a low temperature range of 0 to 40 ° C., the surface design is not melted by the heat of the upper mold.

  An elastic core material made of a foam or the like molded as shown in FIG. 3 is manufactured by the method for manufacturing a backing member in the embodiment of the present invention. 3 and 4 are formed on the back surface side of a plurality of convex portions 11 to 14 having an arbitrary shape provided on the front surface side of the skin material 1 (on the back surface side in a state where the back support member of the finished product is mounted on the backpack). An example in which elastic core materials 21 to 24 each formed of a plurality of parts having convex portions 21 b to 24 b corresponding to the plurality of concave portions 11 a to 14 a (recesses formed on the back side of the above-described convex portions 11 to 14) are formed. Is shown.

  Specifically, each of the elastic core materials 21 to 24 is made of a foamed material such as polyurethane, EVA or polyethylene as a raw material, and these raw materials are formed into a predetermined shape by profile processing, punching processing, thermal compression processing, foam molding processing, or the like. To be heat-molded.

  The elastic core materials 21 to 24 molded as described above are recessed portions 11a to 14a formed on the back side of the protruding portions 11 to 14 provided on the surface side which is the finishing layer of the skin material 1 shown in FIG. Each is fitted inside. At that time, the surfaces of the elastic core materials 21 to 24 are fixed to the inner surfaces of the corresponding concave portions 11a, 12a, 13a, and 14a of the skin material 1 by adhesion or welding.

  If artificial leather is used as the skin material, the back surface of the finish layer is impregnated with a reinforcing material made of a material with mold retention, for example, a thermoplastic resin, or stuck, and the convex part molded by hot pressing is molded. Holds. On the other hand, when synthetic leather or natural leather is used as the skin material, the molding convexity of the molded convex part itself is short-term. In order to fit the elastic core material formed on the convex part of the shape corresponding to the concave part provided on the back surface of the inner part into the concave part and to adhere and fix to the inner surface of the concave part by adhesion or the like, the convex part of the skin material The mold holding property is improved, and has an effect of sufficiently functioning as the backing member 4.

  Here, the elastic core members 21 and 22 are portions in contact with the vicinity of the shoulder blade of the school bag wearer when the backrest member 4 is attached to the school bag (FIGS. 11, 12, and 15). As shown in FIGS. 13 and 15, similarly, in the vicinity of the spine, the elastic core member 24 is a portion in contact with the vicinity of the hip bone from the spine as shown in FIGS. 12, 13, and 14. Each of the elastic core members 21 to 24 has an appropriate hardness according to the place where the elastic core members 21 to 24 are mounted, and has appropriate shock absorption and cushioning properties.

  Specifically, the elastic core members 21 and 22 to be fitted inside the convex portions 11 and 12 of the back support member that contact the vicinity of the left and right shoulder blades of the school bag wearer are 20 to 30 close to the body hardness of the school bag wearer. It is set to be a foam of (JIS-C) (FIGS. 11 and 15). Also, when the school bag wearer walks, the elastic core is fitted into a recess 14a provided on the inner side of the projecting portion 14 of the skin material 1 that constitutes the back member 4 that is in contact with the back of the waist where the load or impact of the school bag is applied. The material 24 is set so as to be a foam having excellent shock absorption (FIGS. 13 and 14).

  The elastic core materials 21 to 24 are uniform cushions because foams such as urethane foam are formed to be convex portions 21 b to 24 b corresponding to the concave portions 11 a to 14 a formed on the back surface side of the skin material 1. It has sex. However, when it is necessary to partially adjust the cushioning property of the elastic core material, for example, as shown in FIG. 7, any elastic core material among the elastic core materials 21 to 24, for example, a molded elastic material It is also possible to finely adjust the cushioning properties by forming blind holes 26, 26 on the back surfaces of the core materials 21, 22 by post-processing. Even if the hole 26 is provided on the back side of the elastic core member, the outer shape of the elastic core member is not changed, so that the outer shape is not deformed.

  The intermediate product which combined the skin material 1 which manufactured the some convex parts 11-14 with said procedure, and the elastic core materials 21-24 is shown in FIG. Then, the base board 3 which is a hard board is positioned on the back surface and bonded or fused to form the back support member 4 of the finished product. In that case, the peripheral part of the skin material 1 and the base board 3 is sewn as needed. Moreover, the surrounding part of the skin material may be formed long and the base board 3 may be wrapped. The finished product backing member 4 is assembled to the school bag 5 by sewing, as shown in FIG.

  In the above, as the elastic core material, a material composed of a plurality of parts having convex portions 21 b to 24 b corresponding to the concave portions 11 a to 14 a formed on the back side of the convex portions 11 to 14 of the skin material 1 was used. What formed these several convex parts integrally can also be used. FIGS. 8 and 9 show such an example, and a plurality of elastic core members are formed by connecting the gaps 27 having the same shape as the elastic core members 21 to 24 with thin connecting portions 36 and 36, respectively. The elastic core member 30 may be formed by integrally forming 31 to 34. Since the elastic core members 31 to 34 are integrally formed by the connecting portions 36 and 36, respectively, when they are fitted into the recesses 11a to 14a provided on the back surface of the skin material 1, they are assembled once. Since it can be accommodated, there is an advantage that workability is improved.

  In order to improve the stability when the school bag user walks and runs with the school bag 5 on the back 7, the shape of the back support member 4 of the school bag is fitted to wrap the user's back (FIG. 12). Therefore, it is necessary to suppress the vibration and amplitude of the school bag when walking and running. In order to improve such fit, it is necessary to match the shape of the back support member 4 to the curved shape of the back of the school bag user while the back support member 4 of the school bag is in contact with the back of the school bag user. Yes (Figs. 13-15). For this purpose, it is necessary to mold the skin material 1 and the elastic core materials 21 to 24 into an uneven shape having a height of 0 mm to 50 mm. Specifically, the skin material 1 and the elastic core materials 21 to 24 are molded so as to have a complicated three-dimensional uneven shape with a height difference along the curved shape of the wearer's back in this height range. It will be.

  Further, in the case of a back support member having a conventional structure, when the school bag user wears the school bag on the back 7, the school bag user's back and the back support member are in contact with each other over a large area, so that the school bag user's back There were many cases in which discomfort was caused by the stickiness caused by sweating. Therefore, in the back support member 4 of the present invention, as shown in FIGS. 11 to 15, there is a ventilation portion between the back 7 of the school bag user and the back support member 4 with the school bag user wearing the school bag. Between the plurality of convex portions 11 to 14 provided on the front surface side of the skin material 1, there is provided a ventilation groove 6 having a flat back surface as a partitioning portion of each convex portion, A gap is provided between each of the convex portions 11 to 14 in which the elastic core materials 21 to 24 are fitted. Specifically, the recessed ventilation groove 6 has a height from the surface side of the skin material 1 to the top of the convex portions 11 to 14 provided to protrude to the surface side in a range of 0 to 50 mm. The depth is provided on the surface of the skin material 1.

  In addition, it is preferable to form the ventilation groove 6 deeply in a portion where pressure bonding when wearing the school bag is large and it is desired to improve comfort. As described above, it is possible to increase or decrease the height of the bottom surface portion (back surface portion) of the ventilation groove 6 in which the surface side of the skin material is recessed. In addition, when this ventilation groove is located at a higher position, that is, above the surface of the base board, a filling material may be attached to the back surface side of the ventilation groove of the skin material, if necessary. In this case, since the elastic core material adjacent to the ventilation groove is bonded and fixed to the base board, the filling material is not necessarily required.

It is a top view of the skin material produced by the manufacturing method of the embodiment concerning the present invention. It is an AA line end view of FIG. It is a top view in the state where a plurality of elastic core materials made by the manufacturing method according to the embodiment of the present invention are arranged with intervals. FIG. 4 is a sectional view taken along line BB in FIG. 3. It is a perspective view of the backrest member concerning the present invention. It is sectional drawing of the CC arrow direction of FIG. It is a perspective view from the back surface side of the state which combined the elastic core material in the other embodiment at intervals. It is a top view in the state where a plurality of elastic core materials were fabricated in one. It is the DD sectional view taken on the line of FIG. It is explanatory drawing which showed the school bag using the back support member which concerns on this invention. It is a front view of the backrest member concerning the present invention. It is explanatory drawing which represented the altitude difference of the front surface (back side of a user) of the school bag of the state which carried the school bag which used the back support member on the back by the shading. It is the EE sectional view taken on the line of FIG. It is the FF sectional view taken on the line of FIG. It is the GG sectional view taken on the line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Skin material 3 Base board 4 Backing member 5 School bag 6 Venting groove 11 Convex part 12 Convex part 13 Convex part 11a Concave part 12a Concave part 13a Concave part 14a Concavity 21 Elastic core material 22 Elastic core material 23 Elastic core material 24 Elastic core Material 21b Convex part 22b Convex part 23b Convex part 24b Convex part

Claims (10)

A backrest member used for a backpack, comprising a sheet-like skin material that hits a user's back when the back is carried, and an elastic core material disposed on the back side of the skin material And
A back support member that is formed into a three-dimensional solid shape corresponding to the uneven shape of the user's back as the skin material.   The back support member according to claim 1, wherein the elastic core member is a molded product having a convex portion corresponding to a concave portion formed on a back surface side of the skin material.   3. The backrest according to claim 2, wherein a plurality of recesses are formed on the back surface side of the skin material, and the elastic core member is made of a member having projections corresponding to the plurality of recesses. Element. A part of the three-dimensional solid shape of the skin material forms a ventilation groove,
4. An air flow passing through the ventilation groove is formed between a user's back and the skin material when carrying a backpack with the backrest member. The backrest member according to any one of the above.   A backpack according to any one of claims 1 to 4, wherein the backrest member is fixed to a base board. A method for manufacturing a backing member used for a backpack-type back,
The surface side of the sheet-like skin material that hits the user's back when carrying the back is molded into a three-dimensional solid shape corresponding to the uneven shape of the user's back,
As an elastic core material arranged on the back surface side of the skin material, it is molded into a shape having a convex portion corresponding to a concave portion formed on the back surface side of the skin material,
A method for manufacturing a backing member, wherein the convex portion of the elastic core member is fitted into the concave portion of the skin material.   The back support member according to claim 6, wherein a plurality of recesses are formed on a back surface side of the skin material, and the elastic core member is formed of a member having projections corresponding to the plurality of recesses. Manufacturing method.   The skin material is manufactured by hot press molding using an upper mold and a lower mold, and a temperature difference is provided between the upper mold and the lower mold at the time of the hot press molding. The manufacturing method of the back member of Claim 6 or 7.   The upper mold at the time of the heat press molding is set to a low temperature region where the surface design applied to the surface side of the skin material is not damaged by melting, and the lower mold is set to a temperature of a high temperature region where the skin material can be molded. The method for manufacturing a backrest member according to claim 8, wherein a temperature difference is provided.   The gap provided between the upper mold and the lower mold at the time of the hot press molding is provided wider than the thickness of the skin material accommodated in the upper and lower molds. The manufacturing method of the backrest member of Claim 8.

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