JP2009184222A - Method for manufacturing blow molded article, method for manufacturing deck board for automobile and blow molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate the manufacture of a blow molded article having a cushioning material, which is raised from the periphery, provided to a part of its surface and to make the cushioning material of the blow molded article hard to turn up. <P>SOLUTION: The blow molded article 1 wherein the cushioning material 20 is built up from the periphery of the cushioning material 20 is manufactured by: arranging the cushioning material 20 restorable from compression by elasticity at a part of the cavity surfaces 121 and 131 of an openable mold 110 forming a cavity CA1; bonding the cushioning material 20 to the resin molding material PA1 under pressure by pressing a resin molding material PA1 expanded into a hollow shape to the cavity surfaces 121 and 131 of the closed mold 110; and restoring the cushioning material 20 in a compressed state by elasticity by opening the mold 110. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a hollow molded article such as an automobile deck board provided with a cushioning material raised from the periphery on a part of the surface, and the hollow molded article.

In an automotive deck board or the like, a cushioning material is affixed to a part of the surface of a blow molded product in order to improve the appearance and feel and to suppress the generation of abnormal noise due to vibration. The surface of the cushioning material is higher than the surrounding surface of the cushioning material. Such buffering is usually performed manually.
JP-A-9-39078

However, when manufacturing a hollow molded product provided with a cushioning material on a part of its surface, it is necessary to have a man-hour for manually attaching the cushioning material to the blow molded product.
Further, a step is generated between the surface of the cushioning material and the surface of the surrounding resin molding material, so that the cushioning material is easy to droop.

  Patent Document 1 describes a cloth-covered hollow molded product in which a decorative cloth is pasted on the surface of a hollow body having a hollow structure formed by blow molding a thermoplastic. The entire surface of the decorative fabric adhered to the cloth-clad hollow molded product is set lower toward the hollow portion than the surface of the peripheral portion. Since the decorative cloth is not higher than the surrounding thermoplastic, the decorative cloth does not function to suppress the generation of abnormal noise due to vibration of the cloth-reinforced hollow molded article.

  In view of the above, an object of the present invention is to facilitate the manufacture of a hollow molded article in which a cushioning material raised from the periphery is provided on a part of the surface, and to make the cushioning material of the hollow molded article difficult to squeeze.

  In order to achieve the above object, the method for producing a hollow molded product according to the present invention includes a cushioning material that is elastically recovered from compression and disposed on a part of a cavity surface of a mold that can be opened to form a cavity. Further, the resin molding material expanded in a hollow shape is pressed against the cavity surface of the molding die to press the buffer material against the resin molding material, and the molding die is opened to recover the compressed cushioning material by elasticity. By doing so, a hollow molded product in which the buffer material is raised from the periphery of the buffer material is manufactured.

  In addition, in the method for manufacturing an automotive deck board according to the present invention, a cushioning material that can be recovered elastically from compression is disposed on a part of a cavity surface of a mold that can be opened to form a cavity that matches the outer shape of the deck board. Then, the resin molding material expanded in a hollow shape is pressed against the cavity surface of the closed mold, the buffer material is pressed against the resin molding material, the mold is opened, and the buffer material in the compressed state is opened. A deck board in which the cushioning material is raised from the periphery of the cushioning material by being restored by elasticity is produced.

The buffer material is pressure-bonded to the resin molding material expanded in a hollow shape, and when the molding die is opened, it recovers from the compression by elasticity and rises from the surroundings. Therefore, it becomes easy to manufacture a hollow molded article in which a cushioning material raised from the periphery is provided on a part of the surface.
Further, since the surface of the cushioning material continuously rises from the surface of the surrounding resin molding material, the cushioning material of the hollow molded product is difficult to drown.

  Further, in the hollow molded product of the present invention, a cushioning material that can be elastically recovered from compression is disposed on a part of the cavity surface of the mold that can be opened to form a cavity, and the cavity surface of the mold is closed. By pressing the resin molding material expanded in a hollow shape against the resin molding material, the buffer material is pressure-bonded, the mold is opened, and the buffer material in a compressed state is recovered elastically, thereby The cushioning material is raised from the periphery.

  Furthermore, the present invention is a hollow molded article in which a cushioning material is provided on a part of the surface, the cushioning material being able to recover from compression by elasticity, and one of the surfaces of a resin molding material molded into a hollow shape. The buffer material is pressure-bonded to the portion, and the buffer material at the boundary with the resin molding material on the surface of the hollow molded product is compressed inward of the hollow molded product, and the resin molding on the surface of the hollow molded product The surface of the buffer material is raised from the boundary with the material.

  In the hollow molded article of the present invention, since the surface of the buffer material is continuously raised from the surface of the surrounding resin molding material, it is difficult for the buffer material to be rolled up.

According to the first aspect of the present invention, a hollow molded article in which a hollow molded article provided with a cushioning material raised from the periphery on a part of its surface can be easily manufactured and the cushioning material of the hollow molded article can be made difficult to squeeze. A method for producing a molded article can be provided.
In the invention which concerns on Claim 2, manufacture of this hollow molded article can be made still easier.
In the inventions according to claims 3 and 4, it is possible to manufacture a hollow molded product in which a cushioning material is provided on a part of the surface with a mold having a simple structure.
In the invention which concerns on Claim 5, manufacture of the hollow molded article which provided the shock absorbing material raised from the periphery in a part of surface is made easy, and the deck for motor vehicles which can make it difficult to squeeze the shock absorbing material of this hollow molded article A board manufacturing method can be provided.

  In the inventions according to claims 6 and 7, it is possible to provide a hollow molded article that is easy to manufacture and that makes it difficult to squeeze a cushioning material provided on a part of the surface high from the periphery.

Hereinafter, embodiments of the present invention will be described in the following order.
(1) Configuration of hollow molded product:
(2) Manufacturing method, action and effect of hollow molded article:
(3) Modification:
(4) Specific examples:

(1) Configuration of hollow molded product:
FIG. 1 is a perspective view showing a partially broken rear interior of an automobile AU1 to which an automobile deck board (hollow molded product) 1 according to an embodiment of the present invention is attached. FIG. 3 (a) is a side view showing the cushioning material 30, FIG. 3 (b) is a vertical sectional view showing the main part of the deck board 1 provided with the cushioning material 30 during molding, and FIG. 3 (c). FIG. 4A is a vertical sectional view showing the main part after molding of the deck board 1 provided with the cushioning material 30, FIG. 4A is a vertical sectional view showing the cushioning material 40, and FIG. 4B is a deck provided with the cushioning material 40. FIG. 4C is a vertical cross-sectional view showing the main part after molding of the deck board 1 provided with the buffer material 40, and FIG. 5 is a hollow molded product manufacturing apparatus 100. FIG. In addition, in order to show clearly, the hatching showing the cross section of the buffer material 40 shown in FIG. 4 is abbreviate | omitted.

  The automobile AU1 shown in FIG. 1 is a road traveling automobile designed and equipped for use on a road, and is a station wagon type passenger in which luggage compartments SP1 and SP2 for accommodating luggage are formed behind a rear seat SE1. It is said to be a car. An automotive deck board (hollow molded product) 1 shown in the figure partitions the rear space of the automobile AU1 into an upper cargo compartment SP1 and a lower cargo compartment SP2. Of course, the automobile on which the automobile deck board of the present invention can be installed is a two-row seat type motor vehicle having a front seat and a rear seat, a three-row seat type motor vehicle having a third seat, and the rear of the front seat. It may be a motor vehicle in which a luggage compartment is formed in front of the rear seat or the third seat.

  Usually, a floor of a luggage compartment of an automobile is provided with a floor box for storing luggage or formed in a concave shape for storing spare tires, tools and the like. The deck board 1 is placed on a floor surface of the cargo compartment, a support portion of the cargo compartment side wall, or the like, and is an interior material that functions as a concave lid of the floor box or the floor. The deck board 1 also has a function of flattening the cargo floor.

As shown in FIG. 2, the deck board 1 is a blow molded product in which a cushioning material 20 is provided on a part of the lower surface (surface) 4. The deck board 1 is configured such that the cushioning material 20 is disposed on a part of the cavity surfaces 121 and 131 of the mold 110 that can be opened and that forms the cavity CA1, and is hollow with respect to the cavity surfaces 121 and 131 of the closed mold. It is formed by pressing the parison (resin molding material) PA1 expanded to blow molding. Accordingly, the deck board 1 has a structure in which the buffer material 20 is pressure-bonded to the lower surface (front surface) 14 of the resin molding material portion 10. In addition, crimping | compression-bonding means fixing members mutually by applying a pressure.
Here, the buffer material 20 is made of a material that can be recovered from compression by elasticity. The buffer material 20 is compressed by the blow pressure when pressed against the parison PA1, and when the molding die 110 is opened, it recovers from the compressed state by its own elasticity and rises from the surrounding resin molding material portion 10.

As shown in FIG. 3 and the like, a hollow portion HO1 is formed inside the resin molding material portion 10 while ensuring a required plate thickness. In addition, a plurality of ribs 12 are formed in the resin molding material portion 10 at regular intervals. These ribs 12 reinforce the deck board 1. Therefore, the deck board 1 is reduced in weight while having the required rigidity.
As shown in FIG. 2, buffer materials 20 are pressure-bonded to the four corners of the lower surface 14 of the resin molding material portion, respectively. The lower surface 4 of the deck board may come into contact with other interior parts or storage items such as spare tires. For this reason, an unpleasant noise may occur while the automobile AU1 is traveling. In order to suppress this abnormal noise, a cushioning material 20 is set on the lower surface 4 of the deck board. Of course, a cushioning material may be provided on the upper surface (front surface) 3 of the deck board 1 in order to give the deck board a design or cushioning property that is preferable as an interior material for a vehicle.

The resin molding material for forming the resin molding material portion 10 may be a molding material containing a resin, and may be a material composed only of a resin or a material to which an additive is added. The resin constituting the resin molding material is preferably a synthetic resin, and a thermoplastic resin is particularly preferable from the viewpoint of facilitating molding and recycling. However, a thermosetting resin such as a phenol resin or a urea resin can also be used. .
Examples of the thermoplastic resin include olefin resins such as polypropylene (PP), polyethylene (PE), and ethylene-propylene copolymer, acrylonitrile butadiene styrene resin (ABS resin), polyethylene terephthalate (PET), polybutylene terephthalate, polystyrene, Polyamide, polyacrylonitrile, polyvinyl chloride, polycarbonate, polyphenylene ether, combinations thereof, modified resins in which a rubber component is blended with these resins, and the like can be used. A resin molding material containing a thermoplastic resin is usually a thermoplastic resin molding material. The melting point of this resin molding material is, for example, 100 to 300 ° C.

  As the additive, fillers such as talc, nucleating agents, pigments, lubricants, antioxidants, heat stabilizers, ultraviolet absorbers, antistatic agents, combinations thereof, and the like can be used. The blending ratio of the additive in the resin molding material can be set to, for example, 50% by weight or less (more preferably 35% by weight or less) from the viewpoint of sufficiently retaining the properties of the resin.

The cushioning material 20 is made of a compressible and elastic material such as a nonwoven fabric having a raised layer and a foamed material containing rubber.
As the nonwoven fabric, needle punched nonwoven fabric, thermal bond nonwoven fabric, spunbond nonwoven fabric, melt blown nonwoven fabric, and the like can be used. Examples of the foamed material include foamed rubber and a foamed material obtained by adding an additive to rubber. The foam material is preferably a closed cell material, but may be an open cell material such as sponge rubber.

FIG. 3A illustrates a nonwoven fabric 30 having a raised layer. The nonwoven fabric 30 has a structure in which a raised layer 32 is laminated on a base layer 31. Since the raised layer 32 is compressible and elastic, the nonwoven fabric 30 can recover from compression by elasticity.
The base layer 31 can be composed of a resin sheet such as a PP sheet or a PE sheet, a base fabric made of synthetic fibers, and the like. As the synthetic fiber used for the base fabric, polyolefin fibers such as PP fiber and PE fiber can be used.

  The raised layer 32 can be composed of polyester fibers such as PET fibers, polyolefin fibers such as PP fibers, polyamide fibers, synthetic fibers such as acrylic fibers, and the like. When the resin molding material and the raised layer 32 are thermoplastic materials, it is preferable that the melting point Tm1 (° C.) of the raised layer 32 is higher than the melting point Tm0 (° C.) of the resin molding material. It is preferable that Tg1 (° C.) is lower than the melting point Tm0 (° C.) of the resin molding material. The reason why Tm1> Tm0 is to prevent the raised layer from being melted by the molten resin molding material during blow molding. Further, the reason why Tg1 <Tm0 is that rubber-like elasticity is expressed in the raised layer with the resin molding material in a molten state during blow molding, and the raised layer in the compressed state is sufficiently recovered by this rubber-like elasticity. In this sense, the glass transition point Tg1 of the raised layer is preferably lower than the temperature of the raised layer at the time of mold opening.

The tensile elastic modulus of the nonwoven fabric 30 is preferably 50 to 1000 kgf / cm ² , more preferably 80 to 300 kgf / cm ^{2 in} the case of the test condition of 23 ° C. Moreover, in the case of 80 degreeC test conditions, 5-100 kgf / cm < ² > is preferable and, as for the tensile elasticity modulus of the nonwoven fabric 30, 10-30 kgf / cm < ² > is more preferable. Here, the tensile elastic modulus is the tensile elastic modulus specified in JIS K7113-1995 (plastic tensile test method). When the tensile modulus is within the above range, the blow ratio can be made sufficiently high.

Density of the nonwoven fabric 30 is preferably ^{0.02~0.6g / m 3, 0.1~0.4g / m} 3 and more preferably. When the density is set to the above lower limit or more, the nonwoven fabric can be sufficiently restored from the compression, and when the density is set to the upper limit or less, the nonwoven fabric can be sufficiently compressed at the time of blow molding and sufficiently raised after blow molding.

  The thickness of the nonwoven fabric 30 is preferably 1 to 10 mm, and more preferably 2 to 8 mm. If the thickness is equal to or higher than the lower limit, the nonwoven fabric can be sufficiently compressed at the time of blow molding so that it can be sufficiently raised after blow molding. .

FIG. 4A illustrates a foam material 40 containing rubber. The foam material 40 has a structure in which a large number of bubbles 42 are present in a molded elastic material 41. The illustrated bubble 42 is a closed cell.
The rubber contained in the foamed material 40 includes EPDM (Ethylene-Propylene-Diene Methylene linkage), styrene butadiene rubber (SBR), polybutadiene rubber (BR), synthetic rubber such as silicone rubber and polyurethane. The rubber may be a thermoplastic rubber (thermoplastic elastomer) or a rubber that does not exhibit thermoplasticity.

  As additives that can be added to the rubber, fillers such as talc, nucleating agents, pigments, lubricants, antioxidants, heat stabilizers, ultraviolet absorbers, antistatic agents, combinations thereof, and the like can be used. The blending ratio of the additive in the elastic material can be set to, for example, 50% by weight or less (more preferably 35% by weight or less) from the viewpoint of sufficiently retaining rubber properties.

  When the resin molding material and the elastic material 41 are thermoplastic materials, it is preferable that the melting point Tm2 (° C.) of the elastic material 41 is higher than the melting point Tm0 (° C.) of the resin molding material. It is preferable to make Tg2 (° C) lower than the melting point Tm0 (° C) of the resin molding material. The reason why Tm2> Tm0 is to suppress melting of the elastic material by the molten resin molding material during blow molding. Further, the reason why Tg2 <Tm0 is set is that a rubber-like elasticity is developed in the elastic material by a molten resin molding material during blow molding, and the compressed foam material is sufficiently recovered by this rubber-like elasticity. In this sense, the glass transition point Tg2 of the elastic material is preferably lower than the temperature of the foamed material when the mold is opened.

The tensile modulus of the foam material 40, if the test conditions of 23 ° C., preferably ^{50~1000kgf / cm 2, 80~300kgf / cm} 2 is more preferable. Moreover, in the case of 80 degreeC test conditions, 5-100 kgf / cm < ² > is preferable and, as for the tensile elasticity modulus of the foaming material 40, 10-30 kgf / cm < ² > is more preferable. When the tensile modulus is within the above range, the blow ratio can be made sufficiently high.

The density of the foam material 40 is preferably ^{0.02~0.6g / m 3, 0.1~0.4g / m} 3 and more preferably. When the density is set to the above lower limit or more, the foamed material can be sufficiently restored from the compression, and when the density is set to the upper limit or less, the foamed material can be sufficiently compressed at the time of blow molding and sufficiently raised after blow molding.

  The thickness of the foam material 40 is preferably 1 to 10 mm, and more preferably 2 to 8 mm. When the thickness is set to the above lower limit or more, the foamed material can be sufficiently compressed during blow molding so that it can be sufficiently raised after blow molding, and when the thickness is set to the upper limit or less, the resin molding material for crimping the foamed material is set to a sufficient thickness. Can do.

  3 (c) and 4 (c) show the main part of the deck board 1 in a cross-sectional view at a position corresponding to A1-A1 in FIG. As shown in these drawings, the buffer materials 30 and 40 are pressure-bonded to a part of the surface (lower surface 14) of the resin molding material (resin molding material portion 10) molded in a hollow shape. A part of the buffer materials 30 and 40 is embedded in the surface (14) of the resin molding material portion. The cushioning materials 30 and 40 (edge portions 36 and 46) at the boundary with the resin molding material portion 10 on the surface (lower surface 4) of the deck board are compressed in the inward direction D1 of the deck board 1. The buffer material surfaces 34 and 44 at the edge portions 36 and 46 are connected to the surface (14) of the surrounding resin molding material portion. Here, the end surfaces 36a and 46a are not included in the surfaces 34 and 44 of the cushioning material. Therefore, in the case of the buffer material 30, the surface 34 is only the surface of the raised layer 32 opposite to the base layer 31. And the surface 34,44 of a shock absorbing material is rising from the boundary part (edge 36,46) with the resin molding material part 10 in the surface (4) of a deck board.

The protruding surfaces 34b and 44b occupying the central portions of the surfaces 34 and 44 of the cushioning material are outside of the general surface (surface 14) of the resin molding material portion around the cushioning materials 30 and 40 (opposite to the inward direction D1). It is said that. From the edges 36 and 46 of the cushioning material to the projecting surfaces 34b and 44b are inclined surfaces 34a and 44a having an upward slope. The buffer materials 30 and 40 are thicker toward the projecting surfaces 34b and 44b at the inclined surfaces 34a and 44a.
As described above, the edge portions 36 and 46 are embedded in the resin molding material portion 10 and the surfaces 34 and 44 of the buffer material and the surface (14) of the resin molding material portion at the boundary portion are connected. The dripping and peeling of 30, 40 are suppressed.

(2) Manufacturing method, action and effect of hollow molded article:
Next, the manufacturing method of the deck board (hollow molded product) 1 which concerns on this embodiment is demonstrated.
A hollow molded product manufacturing apparatus 100 shown in FIG. 5 is an apparatus for blow molding the deck board 1. The apparatus 100 includes a mold 110 that can be opened and a cavity CA1, an extruder 141 that pushes out a parison (resin molding material) PA1 from an extrusion head 142, and a clamp that closes the tip of the parison PA1 that is pushed out into a cylindrical shape. 144, etc.

As the molding die 110, a pair of molds 120 and 130 that can be opened is used to form a cavity CA1 that matches the outer shape of the deck board 1. Here, the fact that the cavity CA1 is matched to the outer shape of the deck board 1 does not mean that the cavity surfaces 121 and 131 are completely coincident with the surface of the deck board 1, but the cavity surfaces 121 and 131. And the surface of the deck board 1 are roughly matched. The shape of the cavity surfaces 121 and 131 is transferred to the resin molding material portion 10 of the deck board. However, as will be described later, the surface of the cushioning material 20 is raised from the cavity surfaces 121 and 131. The cavity surfaces 121 and 131 do not completely coincide with the surface of the deck board 1.
The illustrated molds 120 and 130 can be moved toward and away from each other in the horizontal direction. Of course, the pair of molds may be able to approach and separate in a direction different from the horizontal direction, such as the vertical direction, or may be a combination of a fixed mold and a movable mold. Each mold 120 and 130 has cavity surfaces 121 and 131, and when closed, the cavity surfaces 121 and 131 are combined to form a cavity CA1. The first mold 120 that forms the upper surface side of the deck board 1 includes a slide mold 122 for forming each of the plurality of ribs 12 and a gas blowing nozzle 123 for blowing gas GA2 such as compressed air. And an exhaust hole 124 is formed for exhausting air between the cavity surface 121 and the parison PA1. The second mold 130 to be molded on the lower surface side of the deck board 1 includes a suction hole 132 for sucking and holding each of the plurality of cushioning materials 20 on the cavity surface 131, and the cavity surface 131 and the parison PA1. An exhaust hole 134 for exhausting air between the two is formed.
When the resin molding material is thermoplastic, the temperature of the molding die 110 is set lower than the melting point Tm0 of the resin molding material in order to solidify the parison PA1 in contact with the cavity surfaces 121 and 131.

  The extruder 141 is provided with a gas blowing nozzle 143 for blowing gas GA1 such as compressed air. The extruder 141 is attached to a kneading apparatus having a heating device for melting a thermoplastic resin molding material, and can extrude the molten resin molding material in a cylindrical shape from around the gas blowing nozzle 143. The kneading apparatus to which the extruder 141 is attached heats the resin molding material to a temperature higher than the melting point Tm0 of the resin molding material, but the raised layer 32 of the buffer material 30 and the elastic material 41 of the buffer material 40 are thermoplastic materials. In some cases, the resin molding material is heated at a temperature lower than the melting point Tm1 of the raised layer 32 and the melting point Tm2 of the elastic material 41.

  In the deck board 1, the cushioning material 20 is arranged on a part of the cavity surfaces 121 and 131 of the molding die, and the resin molding material PA1 expanded in a hollow shape is pressed against the cavity surfaces 121 and 131 of the closed molding die. The buffer material 20 is pressure-bonded to the resin molding material PA1, the molding die 110 is opened, and the compressed buffer material 20 is restored by elasticity. When the mold 110 is opened, the cushioning material 20 is raised from the surroundings.

The specific example of the manufacturing method of the deck board 1 is as follows.
First, the molds 120 and 130 are opened, and the cushioning material 20 is disposed on a part of the cavity surfaces 121 and 131 (only the cavity surface 131 in FIG. 5). When a negative pressure (vacuum pressure) is applied to the suction hole 132 and the cushioning material 20 is disposed on the cavity surface 131 where the suction hole 132 is formed, the cushioning material 20 is held on the cavity surface 131.
Next, the resin molding material melted by heating or the liquid resin molding material is extruded into a cylindrical shape to form a parison PA1, and is placed between the molds 120 and 130 that are opened.

  Furthermore, when the parison PA1 to be pushed out has a required length, the tip of the parison PA1 is closed with a clamp 144 as shown in FIG. Then, the parison PA1 has a hollow shape having a closed space. Here, the pre-blowing gas GA1 is blown out from the gas blowing nozzle 143 to expand the parison PA1 into a hollow shape, and the molds 120 and 130 are closed. At this time, the gas blowing nozzle 123 penetrates the parison PA1.

After clamping, the gas GA2 for blowing is blown from the gas blowing nozzle 123, and the gas GA2 is supplied into the parison PA1. The blow pressure (blowing pressure) of the gas GA2 blown into the parison PA1 can be about ² to 10 kgf / cm ² . Here, air between the cavity surfaces 121 and 131 and the parison PA1 is exhausted from the exhaust holes 124 and 134, and the parison PA1 expands into a hollow shape as shown in FIG. Pressed against. Further, the buffer material 20 is sandwiched between the parison PA1 and the cavity surface 131 and compressed in the thickness direction, and is crimped to the surface of the parison PA1. When using the nonwoven fabric 30 for the buffer material 20, as shown in FIG.3 (b), the raising layer 32 which can be compressed is compressed to the thickness direction (inward direction D1). When the foam material 40 is used for the buffer material 20, as shown in FIG. 4B, each bubble 42 becomes small, and the entire foam material 40 is compressed in the thickness direction (inward direction D <b> 1).
In addition, when providing the rib 12 in the resin molding material part 10, the slide type | mold 122 is moved while parison PA1 is melt | dissolving, and the rib 12 is formed between parison PA1.

  When a sufficient time has passed for the parison PA1 to be solidified or cured after the gas is blown from the gas blowing nozzle 123, a concave portion corresponding to the buffer material 20 in the compressed state is formed on the surface of the solidified or cured resin molding material. The surface of the cushioning material 20 is flush with the surface of the surrounding resin molding material.

After the parison PA1 is solidified or cured, the molds 120 and 130 are opened. When the foam material 40 made of the nonwoven fabric 30 having the thermoplastic raised layer 32 or the thermoplastic elastic material 41 is used for the cushioning material 20, the thermoplastic raised layer 32 and the elastic material 41 are higher than the glass transition points Tg1 and Tg2. It is preferable to open the molds 120 and 130 when the temperature is high. Then, the buffer material 20 that was in a compressed state recovers by its own elasticity and rises from the surrounding resin molding material. When using the nonwoven fabric 30 for the buffer material 20, as shown in FIG.3 (c), the raising layer 32 which has elasticity recovers in the thickness direction (outward direction). Here, the edge portion 36 of the nonwoven fabric is compressed in the inward direction D1 of the deck board, and the surface 4 of the deck board at the boundary portion between the nonwoven fabric 30 and the resin molding material portion 10 is continuous. The surface 34 of the nonwoven fabric rises from the boundary portion between the nonwoven fabric 30 and the resin molding material portion 10. When the foam material 40 is used for the cushioning material 20, as shown in FIG. 4C, the entire foam material 40 is restored in the thickness direction (outward direction) by the elasticity of the elastic material 41. Here, the edge 46 of the foam material is compressed in the inward direction D1 of the deck board, and the surface 4 of the deck board at the boundary portion between the foam material 40 and the resin molding material part 10 is continuous. The surface 44 of the foam material is raised from the boundary portion between the foam material 40 and the resin molding material portion 10.
As described above, in this manufacturing method, the cushioning material 20 is raised from the periphery of the cushioning material 20 by restoring the cushioning material 20 in a compressed state by elasticity.

The cushioning material 20 described above is pressure-bonded to a resin molding material expanded in a hollow shape, and when the molding die 110 is opened, it recovers from compression by elasticity and rises from the surroundings. Therefore, it becomes easy to manufacture a hollow molded article such as a deck board provided with a cushioning material raised from the periphery on a part of the surface.
As described above, it is possible to integrally form the cushioning material that has been post-bonded to the blow-molded product at the same time as the blow molding, thereby reducing the number of steps in which the buffer material is manually pasted. Thereby, for example, it becomes easy to take countermeasures against abnormal noise when the vehicle is running on the deck board, and the work man-hours and manufacturing costs of the hollow molded product provided with a cushioning material on a part of the surface are reduced. In order to apply the cushioning material in the post-process after molding, it was necessary to laminate the adhesive at the application position, but since this lamination is unnecessary, the material cost for manufacturing the hollow molded product should be reduced. Can do. Further, since the cushioning material has an elastic restoring force, it is possible to manufacture a molded product in which the cushioning material is raised from the general surface of the blow molded product without providing a concave shape in the molding die. For this reason, the mold structure can be simplified, and the cost of mold fabrication can be reduced.
Furthermore, the accuracy of the mounting position of the buffer material with respect to the hollow molded product is improved.

Further, since the surface of the cushioning material continuously rises from the surface of the surrounding resin molding material, the cushioning material of the hollow molded product is difficult to drown.
As shown in FIG. 3 (c) and FIG. 4 (c), the outer periphery of the cushioning material is restrained by the solidified or hardened resin molding material, and may attempt to recover the thickness in the thickness direction by elastic restoring force. It is regulated. On the other hand, the inner side portion of the cushioning material is raised in the thickness direction by its own elastic restoring force. For this reason, the outer peripheral portion of the cushioning material has a gently inclined shape, can accentuate the boundary between the general surface of the resin molding material and the cushioning material, and can make the hollow molded product a unified design, It also becomes possible to improve the appearance of the hollow molded product. In addition, since the surface of the cushioning material is formed so as to be continuous from the general surface of the resin molding material, it may cause problems such as rolling up or peeling due to interference with other parts during transportation or assembly to a vehicle. Occurrence can be suppressed.

(3) Modification:
The blow molding machine for producing the hollow molded article of the present invention may be an extrusion blow molding machine as described above, an injection blow molding machine, or a two-stage blow molding machine. The resin molding material to be expanded into a hollow shape may be a parison as described above, or a preform (preliminary product).

  FIGS. 6A and 7A are exploded perspective views showing a state in which the cushioning material is held on the cavity surface of the mold of the hollow molded product manufacturing apparatus according to the modification. FIGS. 6B and 7B are vertical sectional views showing the state in which the cushioning material is held on the cavity surface.

A plurality of protrusions 152 for fixing the cushioning material 20 are provided on the cavity surface 131 of the mold 130 shown in FIG. As shown in the figure, when the cushioning material 20 is pressed against the protrusion 152 and pierced, the cushioning material 20 is disposed on a part of the cavity surface 131. The protrusion 152 shown in the figure has a truncated cone shape, and is formed in a tapered shape whose diameter decreases from the cavity surface 131 toward the tip. The height h1 of each protrusion 152 is smaller than the thickness th1 of the buffer material 20.
In addition, it is easy by making the protrusion into a truncated cone shape, an elliptical truncated cone shape, a polygonal truncated cone shape, a cone shape, an elliptical cone shape, a polygonal column shape, a thin cylindrical shape, a thin elliptical column shape, a thin polygonal column shape, etc. It is possible to fix the cushioning material to the cavity surface with a protrusion.
By providing protrusions for fixing the buffer material on the cavity surface of the mold, a hollow molded product in which the buffer material is provided on a part of the surface with a mold having a simple structure can be manufactured.

A pair of protrusions 154 and 154 for fixing the buffer material 20 are provided on the cavity surface 131 of the mold 130 shown in FIG. That is, the interval c1 between the protrusions 154 and 154 is slightly smaller than the width w1 of the buffer material 20. In addition, the height h2 of each protrusion 154, 154 is made smaller than the thickness th1 of the cushioning material 20. As shown in the drawing, when the cushioning material 20 is fitted between the protrusions 154 and 154, the cushioning material 20 is sandwiched and fixed between the protrusions 154 and 154, and is disposed on a part of the cavity surface 131.
In addition, the protrusion for fixing the buffer material may be a protrusion that presses the left and right sides of the buffer material in addition to the protrusion that presses the buffer material up and down as shown. Further, when the upper and lower protrusions and the left and right protrusions are combined, the cushioning material can be more reliably fixed to the cavity surface. Of course, a rectangular frame connecting the upper and lower ridges and the left and right ridges may be used, and the upper and lower ridges and the left and right ridges included in this frame form a pair of ridges according to the present invention.

By providing the protrusions for fixing the cushioning material on the cavity surface of the molding die, a hollow molded product in which the cushioning material is provided on a part of the surface with a molding die having a simple structure can be manufactured.
In addition, since the ridges 154 and 154 are provided on the cavity surface 131, a recessed groove is formed in the resin molding material portion of the hollow molded product at a position in contact with the cushioning material. Thereby, a new design is given to the hollow molded article.

Of course, the cushioning material may be fixed to the cavity surface by combining the protrusion shown in FIG. 6 and the protrusion shown in FIG.
Note that the method of fixing the cushioning material to the cavity surface using the protrusions and the protrusions can be applied not only to blow molding but also to injection molding.

(4) Specific examples:
Hereinafter, the present invention will be specifically described with reference to specific examples, but the present invention is not limited to the examples.

[Specific Example 1]
An extrusion blow molding machine as shown in FIG. 5 is used for the hollow molded product manufacturing apparatus.
As the resin molding material, PP (polypropylene) having a melting point (Tm0) of 170 to 180 ° C. is used. This PP is heated to 220 ° C. to be melted and extruded as a parison from the extrusion head.
As the buffer material, a non-woven fabric having a thickness of 5 mm in which a raised layer of PET (polyethylene terephthalate) fiber is laminated on the base layer of the PP sheet is used. Here, the glass transition point (Tg1) of the PET fiber is 70 to 80 ° C, and the melting point (Tm1) of the PET fiber is 230 to 240 ° C.

With the pair of molds open, the nonwoven fabric is placed on the cavity surface, and negative pressure is applied to the suction holes of the mold to hold the nonwoven fabric on the cavity surface. Next, the melted parison is extruded from the extrusion head, the tip is closed with a clamp, and pre-blow is performed. Further, the mold is closed and compressed air is blown into the parison at a blowing pressure of 5 kgf / cm ² . When the mold is opened while the temperature of the raised layer is 81 to 169 ° C. after the parison is solidified, the hollow molded article of the present invention is formed.

[Specific Example 2]
The same apparatus as in Example 1 is used for the hollow molded product manufacturing apparatus.
PE (polyethylene) having a melting point (Tm0) of 100 to 110 ° C. is used as the resin molding material. This PE is heated to 120 ° C. to be melted and extruded as a parison from the extrusion head.
As the cushioning material, 5 mm thick EPDM foam rubber (Epto Sealer No. 6800 manufactured by Nitto Denko Corporation) is used. This foamed rubber has a closed cell structure, a specific gravity of 0.12, and a 25% compression hardness of 1.8 to 2.0 N / cm ² in accordance with JIS K6767. Here, the glass transition point (Tg2) of EPDM is about −60 to −40 ° C.

With the pair of molds open, the foamed rubber is disposed on the cavity surface, and negative pressure is applied to the suction holes of the mold to hold the foamed rubber on the cavity surface. Next, the melted parison is extruded from the extrusion head, the tip is closed with a clamp, and pre-blow is performed. Further, the mold is closed and compressed air is blown into the parison at a blowing pressure of 5 kgf / cm ² . When the mold is opened after the parison has solidified, the hollow molded article of the present invention is formed.

As described above, according to the present invention, according to various embodiments, it is possible to easily manufacture a hollow molded article in which a cushioning material raised from the periphery is provided on a part of the surface, and the cushioning material of the hollow molded article is rolled up. It becomes possible to make it difficult.
In addition, this invention is not restricted to the Example and modification which were mentioned above, Each structure disclosed in the Example and modification which were mentioned above mutually replaced, the structure which changed the combination, well-known technique, and the above-mentioned Configurations in which the respective configurations disclosed in the embodiments and the modified examples are mutually replaced or combinations are changed are also included.

The perspective view which shows a partially broken example of the rear interior of an automobile to which a deck board is attached. The bottom view which shows the deck board shown in FIG. 1 seeing from the lower surface. The side view which shows the example of a shock absorbing material, and the vertical sectional view which illustrates the principal part of the deck board during shaping | molding and after shaping | molding. The vertical sectional view which shows the example of a buffer material, and the vertical sectional view which illustrates the principal part of the deck board during shaping | molding and after shaping | molding. The vertical sectional view which shows the example of a hollow molded product manufacturing apparatus in partial cross section. The figure which shows the example which hold | maintains a shock absorbing material in the shaping | molding die which provided the processus | protrusion. The figure which shows the example which hold | maintains a shock absorbing material in the shaping | molding die provided with the protrusion.

Explanation of symbols

1 ... car deck board, 4 ... bottom surface (surface),
10 ... resin molding material part, 12 ... rib, 14 ... lower surface (surface),
20, 30, 40 ... cushioning material,
31 ... Base layer, 32 ... Brushed layer, 34 ... Surface, 36 ... Edge,
34a, 44a ... inclined surface, 34b, 44b ... projecting surface,
41 ... elastic material, 42 ... closed cell, 44 ... surface, 46 ... edge,
100 ... Hollow molded product manufacturing apparatus,
110 ... mold, 120,130 ... mold,
121, 131 ... cavity surface,
122 ... Slide type, 123 ... Gas injection nozzle, 124, 134 ... Exhaust hole,
132: suction hole,
141 ... Extruder, 142 ... Extrusion head, 143 ... Gas blowing nozzle, 144 ... Clamp,
152 ... protrusions, 154 ... protrusions,
CA1 ... cavity, D1 ... inward direction, GA1, GA2 ... gas, HO1 ... hollow part,
PA1 ... Parison (resin molding material),

Claims (7)

  Resin molding in which a cushioning material that can be elastically recovered from compression is arranged on a part of the cavity surface of the mold that can open the mold to form a cavity, and is expanded in a hollow shape with respect to the cavity surface of the closed mold The cushioning material is pressed against the resin molding material, and the cushioning material is pressed against the resin molding material, and the molding material is opened and the cushioning material in a compressed state is elastically recovered to allow the cushioning material to rise from the periphery of the cushioning material. A method for producing a hollow molded product, comprising producing a molded product. Using a pair of molds that can be opened in the mold,
Using a thermoplastic material for the resin molding material,
The cushioning material is disposed on a part of the cavity surface of the pair of molds opened, a parison is formed from the molten resin molding material, and the parison is disposed between the pair of molds. The gas is supplied into the parison and the parison is pressed against the cavity surface to be solidified, and the pair of molds are opened to restore the compressed cushioning material by elasticity, thereby surrounding the cushioning material. The method for producing a hollow molded article according to claim 1, wherein a hollow molded article in which the buffer material is raised is produced.   3. A protrusion or a protrusion is provided on the cavity surface of the mold, and the cushioning material is fixed by the protrusion or the protrusion and disposed on a part of the cavity surface. The manufacturing method of the hollow molded article of description.   A pair of protrusions are provided on the cavity surface of the molding die at a narrower interval than the buffer material, and the buffer material is sandwiched between the pair of protrusions and disposed on a part of the cavity surface. The manufacturing method of the hollow molded article as described in any one of Claims 1-3.   A cushioning material that can be elastically recovered from compression is arranged on a part of the cavity surface of the mold that can be opened to form a cavity that matches the outer shape of the deck board, and is hollow with respect to the cavity surface of the closed mold. The cushioning material is pressed against the resin molding material by pressing the resin molding material expanded into a shape, and the molding material is opened to recover the cushioning material in a compressed state by elasticity. A manufacturing method of an automobile deck board, characterized by manufacturing a deck board with raised cushioning material.   Resin molding in which a cushioning material that can be elastically recovered from compression is arranged on a part of the cavity surface of the mold that can open the mold to form a cavity, and is expanded in a hollow shape with respect to the cavity surface of the closed mold The cushioning material was pressed against the resin molding material by pressing the material, and the cushioning material was raised from the periphery of the cushioning material by opening the molding die and restoring the compressed cushioning material by elasticity. Hollow molded product. A hollow molded product provided with a cushioning material on a part of its surface,
The cushioning material is recoverable from compression by elasticity;
The buffer material is pressure-bonded to a part of the surface of the resin molding material molded into a hollow shape, and the buffer material at the boundary portion with the resin molding material on the surface of the hollow molded product is inward of the hollow molded product. A hollow molded article in which the surface of the cushioning material is raised from a boundary portion with the resin molding material on the surface of the hollow molded article.

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