JP2011131525A - Method for producing molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a molding which has a high expansion ratio when expanded secondarily, which has high cushioning property, the mold of which is excellent in shape formability, and the external appearance of which is excellent in a narrowed part when the molding has the narrowed part particularly. <P>SOLUTION: The molding comprises a laminate having: a base material layer comprising a first foamed sheet; an intermediate layer which is arranged on the base material layer and comprises a second foamed sheet; and a surface skin layer which is arranged on the intermediate layer and comprises a non-foamed sheet. The method for producing the molding comprises: a heating step of heating the laminate so that the base material layer-side surface of the laminate has the temperature higher than the surface temperature of the surface skin layer-side surface; a clamping step of arranging the heated laminate in a cavity of a sealable molding mold so that at least one surface of the laminate is not brought into direct contact with the opposed surface of the cavity of the molding mold and clamping the molding mold; a decompression step of reducing the pressure in the cavity to expand the laminate; and a cooling step of cooling the laminate expanded at the decompression step. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a molded body made of a laminate having a base material layer made of a first foamed sheet, an intermediate layer made of a second foamed sheet, and a skin layer made of a non-foamed sheet.

A laminate in which a polyolefin foam sheet is used as a base material layer and a sheet made of another resin is used as an intermediate layer or a skin layer on the surface thereof is formed into a molded body having a desired shape by a molding method such as vacuum molding. These molded bodies are used for various applications such as automobile parts materials and building materials.
As a method of shaping the laminate, for example, a foamed polypropylene sheet having a predetermined expansion ratio is used as an intermediate layer, and a molded body obtained by laminating and adhering a thermoplastic resin film as a skin layer on both sides thereof, Disclosed is a method for vacuum forming a foamed polypropylene sheet by heat-softening with a pair of hot plates heated to a temperature in the range of 160 ° C. or more and 190 ° C. or less and then vacuum forming using a pair of vacuum moldable molds. (See Patent Document 1).
Also, a method is known in which a thermoplastic resin sheet in which a skin layer is laminated, a thermoplastic resin sheet previously shaped into a desired shape, and a skin layer are attached by vacuum forming and integrated (Patent Document 2). And Patent Document 3).

Japanese Patent Publication No. 5-84729 JP-A-2-167722 Japanese Patent Application No. 11-118070

However, in the molding method described in Patent Document 1, vacuum forming is performed by uniformly heating the entire laminate in the thickness direction. Therefore, when forming a laminate having different foam layers in the base layer and the intermediate layer, It was difficult to preferentially foam the material layer preferentially, the foaming ratio of secondary foaming of the base material layer was low, and the desired foaming ratio could not be reached in some cases. At the same time, the cushioning property of the intermediate layer is lowered, and it is difficult to obtain a molded product having a high cushioning property. In addition, the shape of the mold shape is not good, and in particular, when a molded body having a drawn shape portion is produced, an appearance defect may occur.
The methods described in Patent Document 2 and Patent Document 3 are a method in which a base material layer and a skin layer that have been previously shaped into a predetermined shape are bonded together in a mold and integrated, and the base material layer and the skin layer are separated separately. It is necessary to install in a molding die, and there is a possibility that molding defects such as mixing of foreign substances and defective deaeration between the foam layer and the skin layer may occur at the time of bonding.
In view of the above problems, the present invention has a foam sheet as a base material layer, a sheet made of another resin on the surface thereof as an intermediate layer or a skin layer, and in the molding method of the laminate, the foaming ratio of secondary foaming is high, And it aims at providing the manufacturing method of the molded object which has high cushioning properties. It is another object of the present invention to provide a method for producing a molded body that has a good mold shape shapeability, and in particular has a drawn shape portion, and is excellent in the appearance of the shaped body in the drawn shape portion.

The present invention includes a base material layer made of a first foam sheet, an intermediate layer made of a second foam sheet provided adjacent to the base material layer, and a surface of the intermediate layer on the base material layer side. A skin layer made of a non-foamed sheet provided adjacent to the opposite surface, and a method for producing a molded body comprising a laminate,
A shaping step of producing the shaped body by shaping the laminate into a predetermined shape;
A heating step of heating the surface of the shaped body on the base material layer side to a temperature higher than the surface temperature of the surface of the skin layer side;
A mold in which a heated shaped body is placed in a cavity of a mold that can be sealed so that at least one surface of the shaped body does not directly contact the cavity surface of the opposite mold, and the mold is clamped The fastening process;
A pressure reducing step for expanding the shaped body by reducing the pressure in the mold cavity;
A cooling step for cooling the shaped body that has undergone the depressurization step;
The manufacturing method of the molded object which has this, and the molded object obtained by this method are provided.

  According to the present invention, in a method of forming a laminate in which a foamed sheet is used as a base material layer, and a sheet made of another resin is used as an intermediate layer or a skin layer on the surface thereof, the foaming ratio of secondary foaming is high and the cushioning property is high. It becomes possible to provide the manufacturing method of the molded object which has these. In addition, it is possible to provide a method for producing a molded body that has good mold shape shapeability, and particularly has a drawn shape portion, and has an excellent appearance of the shaped body in the drawn shape portion.

It is the figure which showed one of the embodiment of this invention.

  The present invention includes a shaping step of shaping a laminate in which a first foamed sheet, a second foamed sheet, and a non-foamed sheet are sequentially laminated into a predetermined shape, and heat-treating the shaped laminate. A heating process, a mold clamping process in which the heated laminate is placed in the cavity and clamping, a pressure reducing process in which the pressure in the cavity is reduced, and a cooling process in which cooling is performed. Hereinafter, each step will be described in detail.

<Shaping process>
In the shaping step, a laminated body described later is shaped into a predetermined shape to produce a shaped body. By shaping the laminate in advance, the first foam sheet as the base material layer can be shaped faithfully to the mold shape. The shaping method is not particularly limited, but is preferably performed by a vacuum forming method, a pressure forming method, a press forming method, or a combination of these methods. Among them, in order to achieve both transferability of a texture pattern and the like on the design surface and moldability of the mold shape on the base material, it is possible to use a molding method in which press molding is performed while vacuum-sucking at least the skin layer side serving as the design surface. More preferred. The shape of the shaped body is not particularly limited, but since it is possible to obtain a molded body having a complicated shape from a single laminate, the shape having a drawn shape portion is preferable.
The mold used in this shaping step is preferably a sealable mold that can be used in a mold clamping step and a pressure reduction step described later, and more preferably a vacuum mold having a suction hole capable of vacuum suction. .

<Heating process>
The heating step in the present invention refers to a step of heating the surface of the shaped body produced in the shaping step so as to have a temperature higher than the surface temperature of the surface on the skin layer side. By heating with a temperature difference in this way, expansion of the intermediate layer can be suppressed, and the base material layer can be preferentially expanded in the thickness direction. Further, the cushioning property of the intermediate layer can be increased.
Examples of the heating method include a method of heating using a heating device such as hot air, a far infrared heater, a near infrared heater, and a contact hot plate. It is preferable to heat using a far-infrared heater while supporting the shaped body with the mold used in the shaping process, because it can prevent drawing down of the shaped body and can be efficiently heated in a short time. In particular, it is more preferable to heat while supporting the surface on the skin layer side.

In this heating step, the temperature of the surface of the base material layer side and the surface of the skin layer side is determined from the temperature of the surface of the base material layer side from the temperature of the surface of the skin layer side from the viewpoint of preferentially expanding the base material layer. Is preferably set higher by 10 ° C. or more.
Moreover, when using crystalline resin for the 1st foam sheet which forms a laminated body, the surface temperature by the side of the base material layer in a heating process is below melting | fusing point of crystalline resin, and 35 degrees C or less higher than melting | fusing point It is preferable that the temperature is not lower than the melting point and not higher than 20 ° C. higher than the melting point. Moreover, when using an amorphous resin for the first foamed sheet, the surface temperature on the substrate layer side in the heating step is not less than the glass transition point of the amorphous resin and not more than 35 ° C. higher than the glass transition point. It is preferable that the temperature is not lower than the glass transition point and not higher than the temperature 20 ° C. higher than the glass transition point.
For example, when a polypropylene foam sheet having a melting point of 165 ° C. is used as the first foam sheet, the surface temperature on the base material layer side in the laminate is preferably 165 ° C. or more and 200 ° C. or less, 165 ° C. or more, More preferably, it is 185 ° C. or lower.
In the present invention, “melting point” and “glass transition temperature” may be values obtained by measurement using a trace melting point measuring apparatus or measurement such as differential scanning calorimetry. As the “surface temperature”, a value obtained by a method of measuring with thermocouple thermometers attached to both surfaces of the laminate or a method of measuring with a non-contact temperature sensor can be used.

  The heating time varies depending on the type of resin used for the raw material of the first foam sheet forming the surface on the base layer side, the foaming ratio and thickness of the first foam sheet, etc. What is necessary is just to set suitably so that the surface temperature of the surface at the side of a material layer may turn into desired temperature. It is preferable to set a heating temperature and a time by attaching a thermocouple to both surfaces of the first foamed sheet, measuring the temperature, examining the relationship between the temperature and the time in advance. In addition, although the 1st foam sheet before a heating process is room temperature, you may pre-heat in order to shorten heating time.

<Clamping process>
The mold clamping process in the present invention means that a heated shaped body is placed in a cavity of a mold that can be sealed so that at least one surface of the shaped body does not directly contact the cavity surface of the facing mold. And a mold clamping process for clamping the mold.
Thus, by arranging at least one surface of the shaped body so as not to contact the cavity surface, a space is formed between the shaped body and the cavity surface, and the shaped body is expanded in the thickness direction (secondary foaming). Can be made. The distance (h) in the thickness direction of the cavity can be appropriately set so as to obtain a desired molded body thickness, and is preferably 1.1 to 5 times the thickness of the laminate before the shaping step. It is more preferable that it is 1.1 times to 2 times.

The mold may be any shape as long as it can be sealed. For example, one is a storage part composed of a bottom surface and a wall surface surrounding the bottom surface, and the other is a flat plate-shaped mold that serves as a lid for the storage part, or a mold that is a pair of the storage parts, a so-called female Examples thereof include a mold formed of a combination of a mold and a male mold. Of these, the mold used in the shaping step is preferably used.
The material of the molding die is not particularly limited, and is preferably made of metal from the viewpoint of durability, thermal conductivity, and the like, and more preferably aluminum from the viewpoint of cost and lightness. Moreover, it is preferable that a shaping | molding die is a structure which can adjust the temperature which incorporated the heater, the heat medium, etc.
When placing the shaped object in the cavity, the shaped object may be sandwiched between grippers, placed on a table, or placed directly on the cavity surface with the skin layer side down I do not care.

<Decompression step>
The decompression step in the present invention refers to a step of expanding the shaped body by reducing the pressure in the cavity. The shaped body heated in the heating process expands (secondary foaming) by reducing the pressure in the cavity. At this time, in the heating step, the surface on the base material layer side of the shaped body is heated to a temperature higher than the surface temperature of the surface on the skin material side. Therefore, in this decompression step, the surface on the base material layer side The first foamed sheet that constitutes can be subjected to secondary foaming at a higher magnification than the second foamed sheet that constitutes the intermediate layer. In this decompression step, it is preferable that the laminate is expanded until at least one surface of the shaped body comes into contact with the cavity surface.
The expansion ratio of the first foamed sheet and the second foamed sheet in this step is 1.1 times to 5 times for the first foamed sheet based on the thickness of each foamed sheet in the laminate before the shaping step. It is preferably 0.0 times, and the second foamed sheet is preferably 1.0 times to 5.0 times.

As a method for reducing the pressure in the cavity, there is a method of opening a joint valve of a vacuum pump connected to the mold and vacuuming the mold. It is preferable to use a vacuum pump having a capability of exhausting the air in the space in a short time from the viewpoint of improving the expansion ratio of the base material layer of the obtained molded body.
Further, depending on the size of the mold used, it is preferable to provide a vacuum tank in order to quickly reduce the pressure in the cavity. The degree of vacuum suction is not particularly limited, but vacuum suction is preferably performed so that the degree of vacuum in the cavity is -0.05 MPa to -0.1 MPa. Here, the degree of vacuum is the pressure in the cavity with respect to atmospheric pressure. That is, “the degree of vacuum is −0.05 MPa” indicates that the pressure in the cavity is 0.95 MPa. In the present invention, the degree of vacuum of the cavity is the degree of vacuum measured using a vacuum suction hole in the cavity.

<Cooling process>
The cooling process in this invention means the process of cooling the laminated body which passed through the pressure reduction process. The laminate that has expanded (secondary foaming) to a desired magnification through the decompression step is cooled in the cavity until each layer is in a solidified state, and after the inside of the cavity is brought to normal pressure, the mold is opened and taken out.
Examples of the cooling method include cooling with outside air and cooling with a heat medium. Moreover, as a method of making the inside of a cavity into a normal pressure, the method of closing the joining valve of a shaping | molding die and a vacuum pump and opening a purge valve and making the inside of a shaping | molding die normal pressure is mentioned.
In the cooling step, it is preferable to perform cooling while reducing the pressure in the cavity from the viewpoint of maintaining the shape of the expanded laminate. That is, it is preferable to perform cooling without stopping the decompression in the decompression step.

<Laminated body>
Here, the laminated body used by this invention is demonstrated.
The laminate is a base material layer, an intermediate layer provided adjacent to the base material layer, and a skin layer provided adjacent to a surface of the intermediate layer opposite to the surface on the base material layer side, Have And the base material layer and the intermediate | middle layer are respectively comprised by the 1st foam sheet and the 2nd foam sheet.

The first foamed sheet that forms the base layer and the second foamed sheet that forms the intermediate layer use a crystalline resin or an amorphous resin as a raw material. The first foamed sheet and the second foamed sheet may use the same resin as a raw material or different resins as a raw material.
Examples of the crystalline resin include ethylene resin, propylene resin, polyacetal resin, polyethylene terephthalate resin, polybutylene naphthalate resin, polyphenylene sulfide resin, polyether ether ketone resin, ethylene-vinyl ester copolymer, ethylene- (meth) acrylic. Examples include acid copolymers, ethylene- (meth) acrylic acid ester copolymers, ionomer resins, and the like.
Examples of the amorphous resin include polymethyl methacrylate resin, polyvinyl chloride resin, acrylonitrile / butadiene / styrene copolymer resin, polystyrene resin, polycarbonate resin, and polyethersulfone resin.

Among these, it is preferable to use a propylene resin from the viewpoint of rigidity, heat resistance, and the like of the obtained molded body. These resins may be used alone or in combination with a plurality of resins.
Examples of the propylene resin include a propylene homopolymer and a propylene copolymer containing 50 mol% or more of a monomer unit derived from propylene. The copolymer may be any of a block copolymer, a random copolymer, and a graft copolymer. As an example of the propylene copolymer preferably used, a copolymer of ethylene or an α-olefin having 4 to 10 carbon atoms and propylene can be given. Examples of the α-olefin having 4 to 10 carbon atoms include 1-butene, 4-methylpentene-1, 1-hexene and 1-octene. The content of monomer units other than propylene in the propylene copolymer is preferably 15 mol% or less for ethylene and 30 mol% or less for α-olefins having 4 to 10 carbon atoms. One type of propylene resin may be used, or two or more types may be mixed and used.
Further, by using a long-chain branched propylene resin or a high molecular weight propylene-based resin having a weight average molecular weight of 1 × 10 ⁵ or more in an amount of 50% by mass or more of the thermoplastic resin constituting the foam layer, the propylene resin foam having fine bubbles is used. A sheet can be obtained. Further, among such propylene resins, non-crosslinked propylene resin is preferably used because it is difficult to form a gel during sheet recycling.

The first foam sheet and the second foam sheet can be manufactured using methods such as extrusion foaming, bead-type foaming, electron beam cross-linking and chemical cross-linking foaming, but productivity and recyclability are also possible. From the viewpoint of the above, it is preferable to produce using an extrusion foaming method. The foaming ratio of the first foamed sheet is preferably 1.2 to 5.0 times based on the thickness of the sheet before foaming, and the foaming ratio of the second foamed sheet is 10 to 30 times. It is preferable that By using a foam sheet having such an expansion ratio, both the rigidity of the substrate and the cushioning property of the intermediate layer can be achieved.
Further, the thickness of the first foamed sheet and the second foamed sheet is preferably such that the thickness of the first foamed layer is 1.1 mm to 6.0 mm, and the thickness of the second foamed layer is 1.1 mm. To 3.0 mm is preferable.

  Further, the foaming agent used when producing the first foamed sheet and the second foamed sheet may be either a so-called chemical foaming agent or a physical foaming agent, or these may be used in combination. Examples of the chemical blowing agent include a thermal decomposition type blowing agent that decomposes to generate nitrogen gas (azodicarbonamide, azobisisobutyronitrile, dinitrosopentamethylenetetramine, p-toluenesulfonylhydrazide, p, p′-oxy. -Bis (benzenesulfonylhydrazide) and the like, and thermal decomposition type foaming compounds such as a thermal decomposition type inorganic foaming agent (sodium hydrogen carbonate, ammonium carbonate, ammonium hydrogen carbonate, etc.) that decomposes to generate carbon dioxide gas. Specific examples of the physical foaming agent include propane, butane, nitrogen, water vapor, and carbon dioxide gas. Among these, it is more preferable to use water vapor or carbon dioxide.

What is necessary is just to select suitably the addition amount of a foaming agent according to the kind of foaming agent and resin to be used, and it is preferable that it is 0.5 mass part to 20 mass parts with respect to 100 mass parts of resin of a raw material.
In addition, raw material resin of a 1st foam sheet and a 2nd foam sheet may contain the additive. Examples of the additive include a filler, an antioxidant, a light stabilizer, an ultraviolet absorber, a plasticizer, an antistatic agent, a colorant, a release agent, a fluidity imparting agent, and a lubricant. Specific examples of the filler include inorganic fibers such as glass fibers and carbon fibers, inorganic particles such as talc, clay, silica, titanium oxide, calcium carbonate, and magnesium sulfate.

The non-foamed sheet forming the skin layer uses a thermoplastic resin, a thermosetting resin, a thermoplastic elastomer, cellulose fiber, or the like as a raw material. Examples of the thermoplastic resin include olefin resins such as ethylene resin and propylene resin; vinyl chloride resin and styrene resin. Examples of the thermosetting resin include urethane resin, phenol resin, epoxy resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, and thermosetting polyimide resin. Examples of the thermoplastic elastomer include olefin-based thermoplastic elastomers, styrene-based thermoplastic elastomers, acrylic-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, and the like. Examples of the cellulose fiber include cotton, hemp, bamboo and the like. Of these, a thermoplastic elastomer is preferable from the viewpoint of texture and the like. These skin layers may be provided with uneven patterns such as wrinkles, printed or dyed, and may have a single layer structure or a multilayer structure, and a skin layer provided with a cushion layer to give a soft feeling. Layers may be used.
The non-foamed sheet can be obtained by kneading the raw material resin and then extruding it using an extruder. The thickness of the obtained non-foamed sheet is preferably 0.1 mm to 1.0 mm.

  The first foamed sheet, the second foamed sheet, and the non-foamed sheet are preferably laminated by a method such as dry lamination, sand lamination, hot roll bonding, hot air bonding or the like to form a laminate.

Hereinafter, a preferred embodiment of a method for producing a molded body according to the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted.
In the present embodiment, as described in FIG. 1- (1), a polypropylene foam sheet is laminated as the base layer 11, a polypropylene foam sheet is laminated as the intermediate layer 12, and a polypropylene elastomer sheet is laminated as the skin layer 13. Use the laminate. And the skin layer side of this laminated body is press-molded while being vacuum-sucked, and is shaped into a shaped body having a drawn shape portion (shaping step). In the shaping step, a pair of male and female molds having vacuum suction holes are used.
FIG. 1- (1) is a diagram showing a heating process. As shown in FIG. 1- (1), the shaped body 1 is arranged such that the surface on the skin layer 13 side faces the cavity surface of the female die 31 of the molding die used in the shaping step. Then, both ends of the shaped body 1 are fixed by the gripping tool 4 and heated by the heating means 2. In this embodiment, a far infrared heater is used as the heating means 2. The heating temperature in the present embodiment is 370 ° C.

FIG. 1- (2) is a diagram showing a state of the mold clamping process. The male mold 32 is moved onto the female mold 31 to perform clamping. At this time, the base material layer 11 of the shaped body 1 is not in direct contact with the cavity surface 310 that opposes it. The distance h between the cavity surface 310 of the female mold 31 and the cavity surface 310 of the male mold 32 is appropriately set to a distance at which the thickness of the base material layer in the molded body becomes a desired base material thickness.
Clamping is performed by closing the male mold 32 of the mold 3.

FIG. 1- (3) is a diagram showing a state of the decompression step. The pressure in the cavity is reduced using a vacuum pump (not shown) provided on both sides of the mold 3. Depressurization starts at the same time as mold clamping or at any time within 10 seconds after mold clamping. By reducing the pressure in the cavity, the first foamed sheet and the second foamed sheet of the shaped body 1 expand (secondary foaming). Since the 1st foam sheet which forms the base material layer 11 at this time is heated at the temperature higher than the 2nd foam sheet which comprises the skin layer 13 by a heating process, it is a magnification higher than a 2nd foam sheet. Inflates with.
The expansion ratio at the time of secondary foaming is 1.1 times to 5.0 times for the first foam sheet, and 1.0 times to 5.0 times for the second foam sheet.

  FIG. 1- (4) is a view showing the shape of the shaped body after passing through the cooling step. In FIG. 1- (3), the joint valve (not shown) with the vacuum pump is closed, and the purge valve (not shown) is opened to bring the inside of the cavity to normal pressure. Take out the laminated body. The molded body thus obtained can be used for automobile interior materials and the like.

EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not limited to an Example at all.
[Example 1]
(Laminate)
An olefin-based thermoplastic elastomer sheet having a thickness of 0.5 mm is used as the skin layer, an expansion ratio of 20 times and a polyolefin-based foam sheet having a thickness of 3 mm are used as the intermediate layer, and an expansion ratio of 3 times and thickness of 3 mm is used as the base layer. A polypropylene foam sheet (trade name Sumiceller foam polypropylene sheet manufactured by Sumika Plustech Co., Ltd.) was used.
In addition, the sheet | seat layer and the intermediate | middle layer used the sheet | seat (Toray Pef Co., Ltd. product name Toraypef) by which the roll roll was previously bonded, this sheet | seat and the base material layer were bonded with hot air, and were used as a laminated body. The thickness of the base material layer at this time was measured, and it was set as “the thickness (mm) of the base material layer before the shaping step” described in Table 1.

(Manufacture of molded products)
A door trim-shaped shaped body was produced in advance from the above laminate using a vacuum forming machine (VAIM0301 manufactured by Sato Iron Works Co., Ltd.). The mold at this time is a pair of male and female aluminum molds as shown in FIG. 1- (2), which can be shaped into a door trim shape, and vacuum is formed on both cavity surfaces of the female male mold. The one having a vacuum hole for suction was used. The mold temperature during molding was adjusted to 40 ° C.
Next, the distance between the female cavity surface and the male cavity surface is set to 5.5 mm, the surface temperature on the base material layer side of the laminate is 204 ° C., and the surface temperature on the skin material side is 207 ° C. using a far infrared heater. Then, the mold was clamped. Next, the pressure in the cavity was reduced from the female vacuum hole using a vacuum pump. The degree of vacuum at this time was -0.009 MPa. The vacuum suction was stopped, the mold was opened, and the shaped body shaped into the door trim shape was taken out.

Thereafter, the mold is opened, and as shown in FIG. 1- (2), the surface temperature of the shaped body on the base material layer side is heated to 180 ° C. using a far infrared heater, and then the female mold is used. Clamping was performed by setting the distance between the cavity surface and the male cavity surface to be 9 mm, and vacuum suction was performed from both molds at a degree of vacuum of -0.09 MPa.
Thereafter, as shown in FIG. 1- (3), the molding die is sealed, a joint valve with a vacuum pump connected to the molding die is opened, and the inside of the cavity is decompressed to expand the shaped body. Cooled and solidified. The thickness of the base material layer of the obtained molded body was set to “base material layer final thickness (mm)”, and the cushioning properties and the appearance of the drawn shape portion were evaluated. The evaluation results are shown in Table 1.

[Comparative Example 1]
The same molding machine and mold as in the example were used. The temperature of the mold is adjusted to 40 ° C., the distance between the female cavity surface and the male cavity surface is set to 5.5 mm, and the surface temperature on the skin layer side of the laminate is adjusted using a far infrared heater. The mold was clamped while heating at 207 ° C. so that the surface temperature on the base material layer side became 204 ° C., and reducing the pressure in the cavity from the female vacuum hole. The degree of vacuum at this time was -0.09 MPa. The vacuum suction was stopped, the mold was opened, and the molded body shaped into the door trim shape was taken out. The thickness of the base material layer of the obtained molded body, cushioning properties, and the appearance of the drawn shape portion were evaluated. The evaluation results are shown in Table 1.

[Comparative Example 2]
The same molding machine and mold as in the example were used. The mold temperature was adjusted to 40 ° C., and the distance between the female cavity surface and the male cavity surface was 9 mm. Using a far-infrared heater, the laminate was heated so that the surface temperature on the skin layer side of the laminate was 207 ° C. and the surface temperature on the substrate layer side was 204 ° C., and the mold was clamped. After clamping, vacuum suction was started at a vacuum degree of -0.09 MPa from both the female and male vacuum holes to reduce the pressure in the cavity. The vacuum suction was stopped, the mold was opened, and the molded body shaped into the door trim shape was taken out. The thickness of the base material layer of the obtained molded body, cushioning properties, and the appearance of the drawn shape portion were evaluated. The evaluation results are shown in Table 1.

Evaluation of a molded object was performed as follows.
(Thickness of base material layer)
The thickness of the base material layer was measured using a vernier caliper after cutting the center portion of the laminate and the molded body.
(Diaphragm shape appearance evaluation)
Evaluation was performed visually. If no appearance defect was observed, it was judged as “good”, and if an appearance defect was found, it was judged as “poor”.
(Cushion evaluation)
The molded body was cut into a 50 mm square and placed on a flat stage of an autograph (manufactured by Shimadzu Corporation, AGS-500D). A load of 4 kgf was applied for 10 seconds from the skin layer side of the sample with a compression jig (φ11.85 mm), and it was visually judged whether the shape of the skin was recovered after 120 seconds. When the shape was recovered, it was judged as “good”, and when the shape was not restored, it was judged as “poor”.

  In the examples, a molded body having a thick base material layer, high cushioning properties, and no defective drawing portion appearance was obtained. In Comparative Example 1, the cushioning property was high and there was no defective appearance of the drawn shape portion, but a molded product with a thin base material layer was obtained as compared with the Example. In Comparative Example 2, a molded body in which the thickness of the base material layer was thick but the cushioning property was low and the appearance of the drawn shape portion was poor was obtained.

DESCRIPTION OF SYMBOLS 1 Shaped body 11 Base material layer 12 Intermediate | middle layer 13 Skin layer 2 Heating means 3 Mold 31 Female mold 32 Male mold 310 Cavity surface 4 Gripping tool 5 Molded body

Claims (9)

A base material layer made of the first foam sheet, an intermediate layer made of the second foam sheet provided adjacent to the base material layer, and a surface opposite to the base material layer side of the intermediate layer A skin layer made of a non-foamed sheet provided adjacent to the laminate, and a method for producing a molded body comprising a laminate,
A shaping step of producing the shaped body by shaping the laminate into a predetermined shape;
A heating step of heating the surface of the shaped body on the base material layer side to a temperature higher than the surface temperature of the surface of the skin layer side;
A mold in which a heated shaped body is placed in a cavity of a mold that can be sealed so that at least one surface of the shaped body does not directly contact the cavity surface of the opposite mold, and the mold is clamped The fastening process;
A pressure reducing step for expanding the shaped body by reducing the pressure in the mold cavity;
A cooling step for cooling the shaped body that has undergone the depressurization step;
The manufacturing method of the molded object which has.   The method for producing a molded body according to claim 1, wherein the shaping step is a step performed using a press molding method and / or a vacuum molding method.   The method for producing a molded body according to claim 1 or 2, wherein the decompressing step is a step of expanding the shaped body until at least one surface of the shaped body comes into contact with the mold cavity surface.   The said shaping process is a process of shaping the said laminated body in the shape which has a drawing shape part, The manufacturing method of the molded object in any one of Claim 1 to 3.   The said heating process is a process performed while supporting the said shaping | molding body with the shaping | molding die used at the said shaping | molding process, The manufacturing method of the molded object in any one of Claim 1 to 4.   The method for producing a molded body according to any one of claims 1 to 5, wherein the cooling step is a step of cooling while reducing the pressure in the cavity.   The method for producing a molded body according to any one of claims 1 to 6, wherein the first foam sheet and the second foam sheet are sheets made of an olefin resin.   The method for producing a molded body according to any one of claims 1 to 7, wherein the non-foamed sheet is a sheet made of a thermoplastic elastomer resin.   The molded object manufactured by the method in any one of Claim 1 to 8.

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