JP5318551B2 - Method for molding polyurethane foam - Google Patents

Description

The present invention is molded in the mold, the method for manufacturing the polyurethane foam lightweight used in a vehicle, and more particularly relates to a process for the preparation of a polyurethane foam molded lightweight along the inner shape of the body of the vehicle .

  In recent years, molded ceilings are often used for the ceilings of automobile cabins. The molded ceiling is generally provided with sound absorption or heat insulation. On the other hand, there is a strong demand for reduction of energy consumption, and high efficiency of energy consumption is also achieved in the air conditioning of the passenger compartment. Therefore, as shown in FIG. 14, a sheet material 53 made of a nonwoven fabric or the like is disposed for heat insulation between the base 51 of the formed ceiling and the roof steel plate 52 constituting the vehicle roof. . This base material 51 may be used alone as a molded ceiling. The surface facing the vehicle interior is covered with a surface material such as a nonwoven fabric, and a core material reinforced with glass fiber is used as an intermediate layer, and the back surface is subjected to hot melt. Thus, a laminated body in which resin sheets are laminated.

  The sheet material 53 is cut from a material having a uniform thickness so as to have a predetermined size. Therefore, in order to cope with a change in the gap between the base material 51 and the roof steel plate 52 (due to a difference in location), a sheet material 53 having a thickness that matches the maximum gap is used. It is also done to compress. Then, the apparent density of the portion where the sheet material 53 is compressed is increased more than necessary, and there is a problem that the weight is unnecessarily increased for an automobile that emphasizes weight reduction. Therefore, it is necessary to use a sheet material 53 having a thickness that does not require compression by adhering that a gap is generated between the base material 51 and the roof steel plate 52 and the sheet material 53. The presence is not preferable from the viewpoint of heat insulation.

  Further, brackets 52 a for supporting electric wiring and ducts are provided at a plurality of locations inside the roof steel plate 52. However, since the sheet material 53 has to be disposed avoiding the brackets 52a, a space 54 in which the sheet material 53 is not disposed is generated. Because of this space 54, a portion where heat insulation is insufficient is formed.

  In the “automobile body structure” of Patent Document 1, a vacuum heat insulating material filled with silica fiber and evacuated to the inside is disposed between the iron plate portion on the outer surface of the roof portion and the ceiling surface of the passenger compartment. A structure is disclosed. And as a result of improving heat insulation by this vacuum heat insulating material, the temperature rise at the time of parking in the summer can be effectively suppressed, and the air conditioning in the vehicle is performed by energy saving.

The “interior material manufacturing method” disclosed in Patent Document 2 is a method of manufacturing an interior material having a soft feeling and not a method of manufacturing a heat insulating material, but can be molded using a mold. It seems that it can be formed along the inner shape of the roof steel plate.
JP 2002-240740 A (see [Claims] [Effects of the invention]) JP 63-109016 A (see page 4, left column, upper row, lines 8 to 17)

  Although the vacuum heat insulating material of patent document 1 uses the coating material which consists of the resin material laminated | stacked on both sides of metal foil in order to give a vacuum barrier property, the coating material has almost no elasticity. In addition, since the silica fibers are filled inside and evacuated, the silica fibers are pressure-bonded and the displacement of the silica fibers is limited. Therefore, the vacuum heat insulating material is poor in flexibility. Therefore, it is not easy to arrange the vacuum heat insulating material while bending it between the formed ceiling and the roof steel plate or by denting a part thereof. Moreover, although this vacuum heat insulating material is lightweight and has excellent heat insulating properties, it is expensive and has a problem of increasing costs.

According to the manufacturing method of Patent Document 2, a polyurethane raw material is sprayed and foamed on the surface of the core material, and before the foam is formed and hardened, the core material is faced upward and attached to the upper mold, and the skin material is disposed. The upper mold is closed to the lower mold, and the foam is cured in the mold. Thus, when polyurethane is naturally foamed on the surface of the core material, the apparent density of the formed foam is generally 10 to 12 kg / m ³ . Incidentally, when the polyurethane raw material is foamed in a closed mold, the foaming pressure acts, so that the apparent density is generally around 15 kg / m ³ .

However, in Patent Document 2, the foam is pressed against the skin material of the lower mold and the upper mold is closed, so that the apparent density of the foam is from 10 to 12 kg / m ³ . Will increase further. Therefore, even if this manufacturing method is used to form a polyurethane foam so that the space between the formed ceiling and the roof steel plate can be filled without a gap, and the foam is used as a heat insulating material, the heat insulating material is The problem of increased weight is inherent. In addition, a soft polyurethane raw material is used for the production of an interior material having a soft feeling, but the molded foam is not suitable as a heat insulating material because it has open cells.

In addition, it is possible to use a sheet material made of a hard polyurethane foam excellent in heat insulation in place of the nonwoven fabric of the prior art, but the sheet material of the hard polyurethane foam is poor in flexibility and the slab is used as a base material. The degree of freedom of arrangement between 51 and the roof steel plate 52 is smaller than when a nonwoven fabric is used. Therefore, many gaps are generated between the slab and the base material 51 and the roof steel plate 52. Further, if the rigid polyurethane raw material is foam-molded with a molding die so that the space between the substrate 51 and the roof steel plate 52 can be filled without a gap, the apparent density of the foam is 15 kg / m as described above. Around ³ . Accordingly, it is not preferable to use a hard polyurethane molded foam because it is contrary to the weight reduction of the vehicle.

The present invention has been made in view of such problems, and an object is to provide a method for producing a polyurethane foam can be used as a lightweight heat insulating material of a vehicle, further An object of the present invention is to provide a method for producing a polyurethane foam molded along the inner surface shape of a vehicle body or the like.

In order to solve the above problem, the polyurethane foam molding method according to claim 1 has an apparent density measured in accordance with JIS A 9511 in the range of 5 kg / m ³ or more and 10 kg / m ³ or less. A method of forming a polyurethane foam, wherein a polyurethane raw material is applied to an upwardly facing cavity surface of an upper mold, and the polyurethane raw material is placed with the posture of the upper mold facing downward before the cream time of the polyurethane raw material ends. Foaming and growing downward, before the rise time of the polyurethane raw material ends, the upper mold is closed to the lower mold and molded in a cavity formed by the upper mold and the lower mold To do.

The invention of the method for molding a polyurethane foam according to claim 2 is a method for molding a polyurethane foam having an apparent density measured in accordance with JIS A 9511 in the range of 5 kg / m ^{3 to} 10 kg / m ^3. The polyurethane raw material is applied to the cavity surface of the upper mold, the polyurethane raw material is foamed and grown downward, and before the rise time of the polyurethane raw material ends, the upper mold is closed to the lower mold, Molding is performed in a cavity formed by an upper mold and a lower mold.

According to a third aspect of the present invention, in the polyurethane foam molding method according to the first or second aspect, a plurality of locking members are provided on the cavity surface of the upper mold in a direction parallel to the opening / closing direction of the upper mold. The polyurethane foam is prevented from being deformed and detached from the upper mold by the engaging member.

The invention described in claim 4 is the method of molding a polyurethane foam as claimed in any one of claims 1 to 3, wherein the lower mold is disposed a substrate, a lower mold the upper die The foam is molded in a cavity formed by the upper mold and the lower mold, and the foam and the base material are integrally laminated.

The invention according to claim 5 is the polyurethane foam molding method according to any one of claims 1 to 4 , wherein a hard polyurethane material is applied to the cavity surface of the upper mold. To do.

(Function )

In the polyurethane foam molding method of the present invention, a polyurethane raw material is applied to the cavity surface of the upper mold that is faced upward, and the polyurethane raw material is placed with the posture of the upper mold facing downward before the cream time of the polyurethane raw material ends. While making it foam, it was made to grow downward using attractive force. Then, before the rise time of the polyurethane raw material ends, the upper mold is closed to the lower mold, and the foam is molded in the cavity formed by the upper mold and the lower mold so that a predetermined shape can be obtained. . Therefore, it is possible to provide a method for molding a polyurethane foam molded into a predetermined shape and having an apparent density in the range of 5 kg / m ^{3 to} 10 kg / m ³ .

  At this time, if the cavity shape of the upper mold is made to conform to the inner surface shape of the roof steel plate of the vehicle, and the hard polyurethane raw material is applied to the cavity surface and the molded ceiling is arranged in the lower mold, the molded ceiling back surface It is possible to mold a polyurethane foam which is integrated in the above and is not bulky.

According to the present invention, it is possible to provide a molding method capable of obtaining a lightweight foam molded in a cavity of a mold.

(Embodiment)
Hereinafter, an embodiment of a polyurethane foam and a method for producing the same embodying the present invention will be described with reference to FIGS. In addition, about the same structure as a prior art, the same code | symbol used in the description shall be used.

As shown in FIG.1 and FIG.2, the shaping | molding ceiling 1 as a polyurethane foam of this embodiment is shape | molded integrally with the base material 51 and the base material 51, and the shape along the shape of the inner surface 52b of the roof steel plate 52. And the polyurethane foam 2 having the surface portion 2a. The foam 2 is formed of hard polyurethane and is adjusted so that its apparent density is in the range of 5 kg / m ³ or more and 10 kg / m ³ or less, so that the molded ceiling 1 has excellent heat insulation properties. In addition, weight reduction is realized. Moreover, since the foam 2 has rigidity as a hard polyurethane foam, it is excellent as a backup material for the base material 51. If the apparent density of the foam 2 is less than 5 kg / m ³ , the back-up material of the base material 51 is insufficient in rigidity, and if the apparent density of the foam 2 exceeds 10 kg / m ³ , it is against the weight reduction of the vehicle. This increases the weight.

  The hard polyurethane foam shown here is a mixture of a polyisocyanate having two or more isocyanate groups and a polyol having two or more hydroxyl groups together with a catalyst, a foaming agent, a foam stabilizer, etc. It is a foam obtained by carrying out the simultaneous reaction. Since this foam is formed of independent bubbles, it has excellent heat insulating properties. And although there is no restoring property, since a closed cell is hard, the rigidity of a foam is high compared with the soft polyurethane foam which consists of open cells.

  Moreover, the nonwoven fabric sheet which is not shown in figure is laminated | stacked on the back surface of the base material 51, and the base material 51 and the foam 2 are integrated through the nonwoven fabric sheet. Therefore, since the foam 2 is impregnated into the nonwoven fabric before solidifying as a foam, the foam 2 and the base material 51 are firmly integrated.

  When the formed ceiling 1 is attached to the roof steel plate 52, there is almost no gap between the roof steel plate 52 and the foam 2. However, since the end of the foam 2 is shaped so as not to interfere with the bracket 52a at the time of attachment, a slight space 54 exists above the bracket 52a.

Next, the manufacturing method of the shaping | molding ceiling 1 is demonstrated using FIGS.
As shown in FIG. 3, first, in the forming die composed of the upper die 11 and the lower die 13, the upper die 11 having a cavity surface 11 a having a shape similar to the shape of the inner surface 52 b of the roof steel plate 52, the cavity surface 11 a facing upward. Arrange so that At this time, a locking member 11b made of a plurality of plate-like bodies is erected on the cavity surface 11a. The locking member 11b has a thickness of about 2 mm.

  Then, the hard polyurethane raw material 12 is sprayed from the spray gun 10 onto the cavity surface 11a, and as shown in FIG. 4, the cream time of the hard polyurethane raw material 12 applied to a predetermined portion of the cavity surface 11a does not end. As shown in FIG. 5, the posture of the upper mold 11 is changed so that the cavity surface 11a faces downward.

  Then, the cream time of the hard polyurethane raw material 12 ends, and the hard polyurethane raw material 12 enters a rise time and starts foaming. At this time, as shown in FIG. 6, since the upper mold 11 has a downward posture, the hard polyurethane raw material 12 grows while foaming downward. The cells of the growth foam 12a that grows in this way are subjected to the action of gravity along with the foaming pressure, so that they tend to grow downward, have a vertically long shape, and become larger than when they naturally foam upward. That is, the apparent density of the growth foam 12a is smaller than the apparent density of natural foaming in the upward state.

  In addition, the blend of the hard polyurethane raw material 12 is adjusted in advance so that the viscosity in a proper range is obtained so that the growth foam 12a during the rise time in which the foam grows in a downward state does not collapse. The growth foam 12a is supported by a plurality of locking members 11b.

Then, as shown in FIG. 7, before the rise time of the hard polyurethane raw material 12 ends, that is, when the growth foam 12a is in the process of growth and is still sufficiently adhesive, the base material 51 constituting the molded ceiling The upper mold 11 is closed with respect to the lower mold 13 on which is set. A non-woven fabric sheet (not shown) is laminated and integrated on the back surface (upper surface in FIG. 7) of the substrate 51. At this time, since the growth foam 12a is supported by the locking member 11b, the growth foam 12a is brought into contact with the base material 51 without contracting and deforming in the direction along the cavity surface 11a. Further, as shown in FIG. 8, the growth foam 12 a is cured after a predetermined time has elapsed while being lightly compressed between the cavity surface 11 a of the upper mold 11 and the base material 51. Therefore, the apparent density of the cured foam 2 is slightly higher than the apparent density of the growth foam 12a in the state shown in FIG. 6, and is in the range of 5 kg / m ^{3 to} 10 kg / m ³ .

  As shown in FIG. 9, when the upper mold 11 is opened, the foam 2 is firmly bonded to the base 51, so that the lower mold 13 is joined together with the base 51 that is temporarily fixed to the lower mold 13. Remain in. And as shown in FIG. 10, the shaping | molding ceiling 1 with which the base material 51 and the foam 2 were integrated from the lower mold | type 13 can be demolded. The cavity surface 11 a of the upper mold 11 and the cavity surface 13 a of the lower mold 13 are subjected to a mold release process so as to have an appropriate mold release property with respect to the hard polyurethane raw material 12.

  Since the surface portion 2a of the foam 2 has a shape which is a transfer of the shape of the cavity surface 11a of the upper mold 11, there is no gap between the formed ceiling 1 and the roof steel plate 52 as shown in FIG. Can be attached.

  Next, the case where a recessed part or a ditch | groove is formed between the foam 2 and the roof steel plate 52 is demonstrated using FIGS. As shown in FIGS. 11 to 13, a concave portion forming portion 14 is provided on the cavity surface 11 a, and the hard polyurethane raw material 12 is sprayed and applied to the cavity surface 11 a including the concave portion forming portion 14, thereby forming a part of the foam 2. A recess 12b is formed. By doing in this way, for example, it becomes possible to pipe the drain pipe from the sunroof mounting site into the bracket 52a via the recess 12b.

Therefore, according to the above embodiment, the following effects can be obtained.
(1) In the above embodiment, the foam 2 that has been foam-grown on the cavity surface 11 a of the upper mold 11 facing downward is placed in the cavity formed by the cavity surface 11 a of the upper mold 11 and the cavity surface 13 a of the lower mold 13. Was molded into a predetermined shape to obtain a polyurethane foam. Therefore, a lightweight polyurethane foam molded into a predetermined shape and having an apparent density measured in accordance with JIS A 9511 in the range of 5 kg / m ^{3 to} 10 kg / m ³ can be provided.

  (2) In the above embodiment, since the molded ceiling 1 is formed by integrating the base material 51 and the foam 2 made of the rigid polyurethane raw material 12, the molded ceiling 1 has excellent heat insulation properties and the foam 2 It is possible to have rigidity by backing up.

  (3) In the said embodiment, the surface part 2a of the foam 2 was formed so that the shape of the inner surface 52b of the roof steel plate 52 might be met. Therefore, when the formed ceiling 1 is attached to the roof steel plate 52, it is possible to prevent a gap from being formed between the foam 2 and the roof steel plate 52.

  (4) In the said embodiment, the nonwoven fabric sheet was laminated | stacked on the back surface of the base material 51, and the base material 51 and the foam 2 were integrated through the nonwoven fabric sheet. Therefore, since the foam 2 impregnates the nonwoven fabric before solidifying as a foam, the foam 2 and the base material 51 can be firmly integrated.

(5) In the above embodiment, the hard polyurethane raw material 12 is applied to the cavity surface 11a of the upper mold 11 that is turned upward, and the posture of the upper mold 11 is turned downward before the cream time of the hard polyurethane raw material 12 ends. . Then, the hard polyurethane raw material 12 is foamed and grown downward, and before the rise time of the hard polyurethane raw material 12 ends, the upper die 11 is closed to the lower die 13 and formed by the upper die 11 and the lower die 13. The foam 2 having a predetermined shape is molded in the cavity to be formed. In this way, it is possible to provide a method of molding a polyurethane foam apparent density was measured according to JIS A 9511 is in the range of 5 kg / ^{m 3} or more 10 kg / ^{m 3.}

  (6) In the above embodiment, the plurality of locking members 11 b are erected on the cavity surface 11 a of the upper mold 11 in a direction parallel to the opening / closing direction of the upper mold 11. Therefore, when the rigid polyurethane raw material 12 is foamed and grown downward to become the growth foam 12a, the growth foam 12a can be supported by the locking member 11b so that the growth foam 12a does not fall off the upper mold 11. it can.

  (7) In the above embodiment, the upper mold 11 and the lower mold 13 are closed by closing the upper mold 11 in which the rigid polyurethane raw material 12 is foamed and grown into the growth foam 12a on the lower mold 13 on which the base material 51 is arranged. The foam 2 is molded in the cavity formed by the above, and the foam 2 and the substrate 51 are laminated together. Therefore, it is possible to provide a method for molding a polyurethane foam as a molded ceiling 1 in which the foam 2 having the surface portion 2a formed in a predetermined shape and the base 51 are integrated by the adhesive force of the hard polyurethane raw material 12. it can.

(Example of change)
In addition, the said embodiment can also be changed and actualized as follows.
-Although the locking member 11b is a plate-like body, it should be a columnar body.
The hard polyurethane raw material 12 is applied to the cavity surface 11a of the upper mold 11 that is directed upward, and the posture of the upper mold 11 is set downward before the cream time of the hard polyurethane raw material 12 is finished, but the downward cavity surface 11a The hard polyurethane raw material 12 is applied to the base material, and the hard polyurethane raw material 12 is directly foamed and grown downward.
・ Although the base 51 is arranged on the lower mold 13 and integrated with the foam 2, the foam 2 itself is molded by the cavity formed by the upper mold 11 and the lower mold 13 without arranging the base 51. To do.
・ Use soft polyurethane material without using hard polyurethane material.

Sectional drawing which shows the polyurethane foam by embodiment of this invention. The schematic diagram which shows the state which attached the shaping | molding ceiling by embodiment of this invention to the roof steel plate. The schematic diagram which shows a part of process of the shaping | molding method in embodiment of this invention, and shows the state which sprays a polyurethane raw material on the cavity surface of an upper mold | type. The schematic diagram which shows the upper mold | type with which the polyurethane raw material was apply | coated. The schematic diagram which shows the state which changed the attitude | position of the upper mold | type downward. The schematic diagram which shows the state by which a polyurethane raw material foams and grows downward. The schematic diagram which shows the state immediately before an upper mold | type is closed with respect to a lower mold | type. The schematic diagram which shows the state which is mold-closed and waits for hardening of a foam. The schematic diagram which shows the state which opened the upper mold | type from the lower mold | type. The schematic diagram which shows the state which removes a shaping | molding ceiling from a lower mold | type. The schematic diagram which shows the state which sprays a polyurethane raw material on the cavity surface of the upper mold | type in a modification. The schematic diagram which shows the upper mold | type with which the polyurethane raw material in the modification was apply | coated. The schematic diagram which shows the state which attached the shaping | molding ceiling in a modification to the roof steel plate. The schematic diagram which shows the state which attached the shaping | molding ceiling of the prior art to the roof steel plate.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 1 ... Molded ceiling, 2 ... Foam, 11 ... Upper mold | type, 11a, 13a ... Cavity surface, 11b ... Locking member, 12 ... Hard polyurethane raw material, 13 ... Lower mold | type, 51 ... Base material, 52b ... Inner surface.

Claims (5)

A method for molding a polyurethane foam having an apparent density measured in accordance with JIS A 9511 in a range of 5 kg / m ³ or more and 10 kg / m ³ or less, wherein a polyurethane raw material is applied to an upwardly facing cavity surface of an upper mold The polyurethane mold is foamed and grown downward with the posture of the upper mold facing down before the cream time of the polyurethane raw material ends, and before the rise time of the polyurethane raw material ends, the upper mold A method for molding a polyurethane foam, wherein the molding is closed in a lower mold and molded in a cavity formed by the upper mold and the lower mold. A method for molding a polyurethane foam having an apparent density measured in accordance with JIS A 9511 in a range of 5 kg / m ³ or more and 10 kg / m ³ or less, wherein a polyurethane raw material is applied to a cavity surface of an upper mold, and The polyurethane raw material is foamed and grown downward, and before the rise time of the polyurethane raw material ends, the upper mold is closed to the lower mold and molded in a cavity formed by the upper mold and the lower mold. A method for molding a polyurethane foam characterized by the following. On the cavity surface of the upper mold, a plurality of locking members are erected in a direction parallel to the opening / closing direction of the upper mold, and the locking members prevent deformation of the polyurethane foam and dropping from the upper mold. The method for molding a polyurethane foam according to claim 1 or 2 , wherein: A substrate is disposed in the lower mold, the upper mold is closed to the lower mold, and a foam is formed in a cavity formed by the upper mold and the lower mold. The method for molding a polyurethane foam according to any one of claims 1 to 3 , wherein the layers are laminated together. The method for molding a polyurethane foam according to any one of claims 1 to 4 , wherein a hard polyurethane raw material is applied to the cavity surface of the upper mold.

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