JP2008087337A - Manufacturing method of cushion member for seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a cushion member for a seat where a skin material and a back base material are integrated by simultaneously foam molding with a foaming resin and which has good touchness and sitting feeling. <P>SOLUTION: When a foam molding is performed by injecting the foaming resin between a skin material 12 disposed on a seat surface side and a back base material 14 disposed on a seat frame side, an activation treatment for improving adhesiveness for the foaming resin 16 is applied to the surface of the back base material 14 composed of thermoplastic resin seat 21 to form an activated surface 22. The cushion member for the seat is manufactured by contacting the foam resin on the activated surface 22 of the back base material 14 and performing the foam molding. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a cushion member for a seat, and in particular, foams by injecting a foamed resin between a skin material disposed on the seat surface side and a back substrate disposed on the seat frame side. It is related with the method of manufacturing the cushion member for sheets by this.

  A cushion member for a seat is usually configured by interposing a pad portion made of foamed resin between a skin material arranged on the seat surface side and a back base material arranged on the seat frame side. The skin material is a surface material made of resin sheet, fabric material, cloth, leather, etc. arranged on the surface of the sheet, and a padding that is arranged on the pad side by foamed resin to suppress displacement between the surface material and the pad part And is formed. As the backing substrate, a nonwoven fabric is usually used in order to prevent rubbing between the seat frame and the pad portion due to the foamed resin.

  In order to manufacture such a sheet, the skin material is set in a mold, and the foamed resin is filled and foamed inside the skin material. Therefore, the foamed pad portion and the skin material are integrally foam-molded. (Patent Document 1).

In addition, since the nonwoven fabric molded into a three-dimensional shape by hot pressing is used as a backing substrate, the backing substrate is assembled to the mold surface of the mold and foamed resin is foamed. Is also integrally molded (Patent Document 2).
JP 2005-192634 A JP 11-192629 A

  In such a cushion member for a seat, the skin material and the pad portion are integrated, and the back base material and the pad portion are integrated. It was difficult to integrate with the pad portion made of foamed resin.

  It improves the cushioning of the pad part as much as possible on the skin material side, and the bonding strength between the back base material and the pad part is sufficient on the back base material side so that no peeling or breakage occurs due to rubbing with the seat frame. However, it is not easy to satisfy both at the same time.

  The present invention provides a method capable of producing a cushion member for a seat that can simultaneously integrate a skin material and a back base material by foam molding of a foamed resin and that has a good surface feel and seating feeling. Is an issue.

  When a nonwoven fabric is used as the backing substrate and integrated by foam molding of the foamed resin, the nonwoven fabric must be sufficiently impregnated with the foamed resin. Therefore, the amount of resin material injected during molding is increased to increase the foaming pressure. There must be. As a result, the foamed resin also comes into contact with the skin material at a high pressure, so that the wadding material is impregnated and solidified. On the skin material side, a hard layered portion is formed by the foamed resin, and the cushion member surface feel and seating The feeling is getting worse. The present inventors have found that a cushion member having desired properties can be manufactured from solving the above-described points.

  In the invention according to claim 1 of the present application, the skin material is formed by injecting a foamed resin between the skin material arranged on the seat surface side and the back base material arranged on the seat frame side to perform foam molding. And a process for producing a cushion member for a sheet by integrating the back base material with a foam resin, and an activation treatment for increasing the adhesion to the foam resin on the surface of the back base material made of a thermoplastic resin sheet To form an activated surface, and the foamed resin is brought into contact with the activated surface of the back substrate to perform foam molding.

  The invention according to claim 2 of the present application is characterized in that after the activation surface is formed, a thermoplastic resin sheet is thermoformed to form a back substrate.

  The invention according to claim 3 of the present application is characterized in that molding is performed by heating from the side opposite to the activated surface that contacts the foamed resin.

  In the invention according to claim 4 of the present application, the thermoplastic resin sheet is composed of a laminated film of a high-density polyethylene layer and a low-density polyethylene layer, and an activated surface that contacts the foamed resin is formed in the high-density polyethylene layer. It is characterized by that.

  According to the method for manufacturing a cushion member for a seat according to claim 1 of the present application, a back substrate in which an activation surface is formed on a surface of a thermoplastic resin sheet by performing an activation treatment for improving adhesion to a foamed resin. Since the foamed resin is brought into contact with the activated surface of the back base material and foam molding is performed, the back base material and the foamed resin can be easily joined with sufficient joining strength.

  This eliminates the need to impregnate the back substrate with foam resin during foam molding, making it possible to keep the amount of foam resin injected and the pressure during foaming low, and the foam resin contacts the skin material with excessive pressure. Thus, impregnation and solidification can be suppressed. As a result, it is difficult to form a hard surface layer of foamed resin on the skin material side, and even if the skin material and the back substrate are integrated by foam molding at the same time, a cushion member for a seat having a good surface feel and seating feeling can be obtained. Can be manufactured.

  According to the method for producing a cushion member for a seat according to claim 2 of the present application, the thermoplastic resin sheet is thermoformed after the activation surface is formed to form the backing substrate, so that the backing substrate having a three-dimensional shape is formed. Even so, the activated surface can be uniformly formed on the entire surface in contact with the foamed resin.

  According to the method for manufacturing a cushion member for a seat according to claim 3 of the present application, since molding is performed by heating from the side opposite to the activation surface in contact with the foamed resin, fine irregularities are formed on the surface by the activation treatment. The heat applied to the activated surface can be reduced to a minimum, and the effect of modifying the activated surface is difficult to decrease during thermoforming, ensuring sufficient bonding strength between the backing substrate and the foamed resin. Easy to do.

  According to the method for manufacturing a cushion member for a seat according to claim 4 of the present application, the thermoplastic resin sheet is a laminated film of a high-density polyethylene layer and a low-density polyethylene layer having a softening temperature or a glass transition point lower than that of the high-density polyethylene layer. Therefore, the thermoplastic resin sheet can be molded without completely softening the high-density polyethylene. In addition, since the activated surface that contacts the foamed resin is formed on the high-density polyethylene layer, the effect of heating on the activated surface formed on the high-density polyethylene layer can be reduced, and the modification effect of the activated surface can be reduced. It can be more easily prevented.

  Hereinafter, a description will be given based on the illustrated embodiment. FIG. 1 shows a cushion member of a vehicle seat. The cushion member 10 is formed as an elastically deformable member that is mounted on a seat frame (not shown) such as a seat cushion or a seat back and supports an occupant.

  In the cushion member, the skin material 12 is exposed on the outer surface of the vehicle seat and is disposed on the seat surface S side in direct contact with the occupant, and the back substrate 14 is disposed on the back surface R side in contact with the seat frame. The pad portion 16 made of foamed resin is disposed between the skin material 12 and the back substrate 14.

  As shown in FIG. 2, the skin material 12 includes a surface material 13 made of a resin sheet, fabric, cloth, leather, and the like, and a wadding material 17 that suppresses a displacement between the surface material 13 and the pad portion 16. ing. Although it can select suitably as the wadding material 17, the polyester-type foamed resin slab is used here. Further, the wadding material 17 and the surface material 13 are joined in a laminated state over the entire surface.

  In the central portion of the skin material 12, the wadding material 17 and the pad portion 16 are joined over the entire surface to such an extent that no deviation occurs during use. On the other hand, a part or all of the peripheral portion of the skin material 12 is a free end 12e separated from the pad portion 16 made of foamed resin, and the cushion member 10 is locked to the terminal in a state of being attached to the seat frame. For this purpose, hooks 12f (see FIG. 1) are attached at predetermined intervals.

  The pad portion 16 made of foamed resin preferably has a sufficient cushioning property and is made of a foamed resin that hardly undergoes deterioration when repeatedly elastically deformed. Here, foamed polyurethane is used.

  The back substrate 14 is provided to prevent the pad portion 16 from being contacted and rubbed in a state of being locally pressed against the seat frame when the cushion member 10 is deformed. Further, when the pad portion 16 is rubbed against the seat frame, a rubbing sound is generated, and the contact portion of the pad portion 16 is easily broken due to mechanical stress.

  The back substrate 14 is formed by bending a thermoplastic resin sheet into a three-dimensional shape, and has a higher durability than the pad portion 16 when it repeatedly receives contact with the seat frame and receives vibrations. A material that can secure sufficient bonding strength is preferable. In the illustrated embodiment, as shown in FIG. 3, a laminated structure in which a base material outer layer 18 disposed on the back surface side R and a base material inner layer 19 disposed on the pad portion 16 side are integrally joined. Is formed.

  In the back base material 14, since the base material outer layer 18 is in direct contact with the seat frame when the cushion member 10 is used, the base material inner layer 18 is in contact with the seat frame in a pressurized state and rubbed. In this case, it is preferable to use a thermoplastic resin that does not easily generate a rubbing sound and is not easily destroyed by a local stress and that is easy to mold.

  Examples of the thermoplastic resin include polyolefin resins such as polyethylene and polypropylene, and low density polyethylene is preferable because it is inexpensive and easy to mold. In this embodiment, the foamed low-density polyethylene is easy to be molded when the back substrate 14 described later is heat-molded, and because it is easy to ensure flexibility and prevent separation from the resin pad portion 16. Is used.

  The base material inner layer 19 is preferably made of a thermoplastic resin that can be laminated and integrated with the base material outer layer 18 with sufficient strength, and at the same time, can improve the bonding strength with the pad portion 16 by an activation process described later. The resin similar to the outer layer 18 can be illustrated. In particular, it is preferably made of a resin having a softening point or a glass transition point higher than that of the substrate outer layer 18. In this embodiment, the base material outer layer 18 is made of low density polyethylene, whereas the base material inner layer 19 is made of high density polyethylene.

  In addition, the base material inner layer 19 is preferably formed thinner than the base material outer layer 18 for reasons such as ensuring the moldability as the back base material 14. For example, it is preferable to set it to 1/30 or less of the thickness of the base material outer layer 18, particularly 1/300 or less of the thickness of the base material outer layer 18.

  The process of manufacturing the cushion member 10 for a vehicle seat from the above-described configuration and materials is exemplified. First, the skin material 12 formed by laminating and integrating the surface material 13 and the wadding material 17 into a predetermined shape is appropriately applied. The thermoplastic resin sheet 21 in which the base material outer layer 18 and the inner base layer 19 are laminated and integrated is prepared in advance by an appropriate method.

  Next, the back substrate 14 is produced using the thermoplastic resin sheet 21. Here, first, as shown in FIG. 4A, an activation surface 22 is formed by applying an activation treatment to the surface of the base material inner layer 19 of the thermoplastic sheet-like resin sheet 21. The activation surface 22 may be formed on both sides, but usually it may be formed on one side of the thermoplastic resin sheet 21.

  The activation process is a process for improving the adhesiveness to the foamed resin forming the pad portion 16, for example, forming fine irregularities on the surface of the back substrate 14, that is, the surface of the substrate inner layer 19, This can be done by implanting a reactive group capable of improving the adhesiveness with the foamed resin forming the pad portion 16. Here, activation treatment is performed by corona discharge treatment. The processing power and time can be appropriately selected according to the material of the back substrate 14 and the pad portion 16.

  After the activation surface 22 is formed, heat molding is performed. Here, as shown in FIG. 4 (b), the thermoplastic resin sheet 21 is heated by the heater 23 from the base material outer layer 18 side opposite to the base material inner layer 19 on which the activation surface 22 is formed. This is to suppress deterioration of the activation surface 22.

  At this time, the temperature is such that the base material outer layer 18 is easily deformable and the base material inner layer 19 is not excessively softened, for example, the softening point or the glass transition point of the resin constituting the base material outer layer 18, Heating is preferably performed at a temperature lower than the softening point or glass transition point of the resin constituting the inner layer 19. This is also for suppressing deterioration of the activated surface 22.

  After the heating, as shown in FIG. 4C, vacuum forming is performed immediately using the vacuum forming die 24. The vacuum mold 24 has a mold surface 24a corresponding to the back substrate 14, and the mold surface 24a from the substrate layer 18 side of the thermoplastic resin sheet 21 degassed and heated from a number of deaeration holes 24b. It is molded by pressing it with atmospheric pressure.

  At this time, since the vacuum forming die 24 is brought into contact with the base material outer layer 18 side, the activation surface 22 can be formed without coming into contact with the die surface 24a, and deterioration of the activation surface 22 can be prevented. Subsequent cooling yields a back substrate 14 as shown in FIG.

  Next, the back substrate 14 and the skin material 12 are made of foamed polyurethane by injecting a foamed resin for forming the foamed polyurethane between the back base material 14 and the aforementioned skin material 12 to perform foam molding. Integrate.

  The foam molding can be performed using a foam molding die 25 as shown in FIG. The foaming mold 25 includes a lower mold 26 capable of arranging the skin material 12 on the mold surface, and a cavity mold 28 capable of forming a cavity 27 by hermetically gripping the free end 12e of the skin material 12 with the lower mold 26. And an upper mold 29 having a supply path 29a through which the back substrate 14 can be arranged on the mold surface and a molten foamed resin can be supplied into the cavity 27.

  The lower mold 26 is provided with a vacuum chamber 26a so that the skin material 12 can be sucked and fixed from a plurality of suction holes 26b. Further, the internal pressure of the cavity 27 can be adjusted by a pressure adjusting means (not shown).

  The skin material 12 and the back base material 14 are arranged and fixed at predetermined positions of the foaming mold 25, and then the mold is clamped. Thereafter, the foam resin is fed into the cavity 27 from the supply path 29a through a through hole (not shown) of the back base material 14. Then, foaming is performed in a state where the foamed resin is in contact with the activated surface 22 of the base material inner layer 19 of the back base material 14 and the wadding material 17 of the skin material 12.

  At this time, unlike the conventional method in which a back substrate made of non-woven fabric is arranged and molded, there is no need to impregnate the back substrate 14 with foaming pressure by the foaming pressure. What is necessary is just to fill inside, and a pressure can also be selected suitably.

  At the time of the molding, the foamed resin comes into contact with the wading material 17 of the skin material 12 by the foaming pressure, so that the wading material 17 is not impregnated with the foamed resin or is slightly impregnated. Since it cools and solidifies after this shaping | molding, it is obtained as a completed body of the cushion member 10.

  If the cushion member 10 for a vehicle seat is manufactured in this way, the foamed resin is brought into contact with the activated surface 22 formed on the surface of the base material inner layer 19 of the back base material 14 to perform foam molding. 14 and the pad portion 16 can be easily joined with a sufficient joining strength to the extent that no floating, wrinkles or partial peeling occurs during use.

  Here, since the back substrate 14 can be joined without impregnating the foamed resin, the amount of foamed resin injected and the pressure during foaming can be kept low during foam molding, and the foamed resin is excessive in the skin material 12. Contact with pressure can be prevented. Therefore, the pad portion 16 is not impregnated in the wading material 17 at all or hardly, and a hard surface layer is hardly formed on the skin material 12 side. As a result, even if the skin material 12 and the back base material 14 are integrated by foam molding at the same time, the cushion member 10 having a good surface feel and good seating feeling can be produced.

  In this manufacturing process, since the back substrate 14 is formed by thermoforming the thermoplastic resin sheet 21 after the activation surface 22 is formed, even if the back substrate 14 has a three-dimensional shape, The activation surface is uniformly formed on the entire surface in contact with the foamed resin, and the pad portion 16 can be uniformly bonded to the entire back substrate 41.

  In addition, since molding is performed by heating from the side opposite to the activated surface that comes into contact with the foamed resin, heat applied to the activated surface can be suppressed to a low level, and since molding is performed from the substrate outer layer 18 side, thermoforming. Sometimes, it is difficult to lower the effect of modifying the activated surface, and it is easy to ensure sufficient bonding strength between the back substrate 14 and the foamed resin pad portion 16.

  Since the thermoplastic resin sheet 21 made of a laminated film of the base material inner layer 19 made of high density polyethylene and the base material outer layer 18 made of low density polyethylene is used as the back base material 14, the base material bonding layer 19 is The thermoplastic resin sheet 21 can be molded without being completely softened, and the effect of heating on the activated surface 22 formed on the base material inner layer 19 can be reduced, thereby further reducing the modification effect of the activated surface. Easy to prevent.

  In the above-described embodiment, the example in which the thermoplastic resin sheet 21 having the two-layer structure of the substrate outer layer 18 and the substrate inner layer 19 is used as the back substrate 14 has been described. However, the bonding strength is ensured by the activation treatment. If possible, it is also possible to use a sheet having a single-layer structure consisting only of the base material layer 18. In that case, the activation surface 22 may be formed on the base material layer 18.

Example 1: Corona discharge treatment was performed using a thermoplastic resin sheet 22 in which a base material inner layer 19 made of high-density polyethylene having a thickness of 10 μm was laminated on a base material outer layer 18 made of foamed low-density polyethylene having a thickness of 3 mm. After that, the back substrate 14 was produced by vacuum forming. Next, 1350 g of foamed resin was accommodated in the cavity 27, the foaming pressure was set to 0.3 kgf / cm ² , the foaming resin was brought into contact with the back substrate 14, and foam-molded to produce the cushion member 10.

  Example 2: Using the thermoplastic resin sheet 22 made of a polypropylene single layer having a thickness of 3 mm, performing the same as in Example 1 except that the corona discharge treatment is performed and the back substrate 14 is produced by vacuum forming. A cushion member 10 was manufactured in the same manner as in Example 1.

Comparative Example 1: Using a back substrate having a thickness of about 3 mm produced by pressure forming without applying corona discharge treatment using Borans (polyester long fiber nonwoven fabric, manufactured by Toyobo Co., Ltd.), 1450 g The cushion member 10 was manufactured in the same manner as in Example 1 except that foam molding was performed with a foamed resin at a foaming pressure of 0.39 kgf / cm ² .

  Comparative Example 2: Except that the same backing material as in Comparative Example 1 was used and the skin material 12 was not arranged in the foam molding die 25, all were foam molded under the same conditions as in Example 1, and then the adhesive was used. By adhering the skin material 12, the cushion member 10 was manufactured in the same manner as in Example 1.

  When the feeling when the cushion member 10 obtained by Examples 1 and 2 and Comparative Examples 1 and 2 is elastically deformed is compared, the cushion member 10 of Comparative Example 1 has a hard plate feeling on the skin material 12 side. Many parts were formed, and it was inferior in touch when elastically deformed than others. Further, although the feel of the cushion member 10 of Comparative Example 2 is slightly better than that of Examples 1 and 2, it takes time to manufacture the skin material 12 because it requires time to bond the skin material 12.

  When the same durability test and vibration durability test were performed on the cushion member 10 obtained in Examples 1 and 2 with a load of 70 kg, the back base material 14 and the pad portion 16 could be used in Example 2. In some cases, interfacial peeling occurs between the two. On the other hand, no interfacial peeling was observed in any test in Example 1, and it was confirmed that Example 1 was more durable than Example 2.

It is sectional drawing which shows the cushion member for sheets manufactured by embodiment of this invention. It is a fragmentary sectional view which shows the skin material of the cushion member of FIG. It is a fragmentary sectional view which shows the back base material of the cushion member of FIG. It is explanatory drawing which shows the preparation process of the back base material of FIG. It is sectional drawing which shows the foaming mold of the cushion member of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Cushion member 12 Skin material 14 Back base material 16 Pad part by foamed resin 18 Base material outer layer 19 Base material inner layer 21 Thermoplastic resin sheet 22 Activation surface 24 Vacuum molding die 25 Foam molding die

Claims (4)

A foamed resin is injected between a skin material arranged on the seat surface side and a back base material arranged on the seat frame side to perform foam molding, and the skin material and the back base material are padded with foamed resin. Is a method of manufacturing a cushion member for a seat,
An activation surface is formed on the surface of the back substrate made of a thermoplastic resin sheet to increase the adhesion to the foamed resin to form an activated surface, and the foamed resin is brought into contact with the activated surface of the back substrate A method for producing a cushion member for a seat, wherein foam molding is performed.   2. The method for manufacturing a cushion member for a seat according to claim 1, wherein the back substrate is formed by thermoforming the thermoplastic resin sheet after the activation surface is formed.   The method for manufacturing a cushion member for a seat according to claim 2, wherein the sheet is heated and molded from the side opposite to the activated surface that comes into contact with the foamed resin.   The thermoplastic resin sheet is made of a laminated film of a high-density polyethylene layer and a low-density polyethylene layer, and an activated surface that contacts the foamed resin is formed on the high-density polyethylene layer. Item 4. A method for manufacturing a cushion member for a vehicle seat according to Item 3.

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