JPH01200945A - Preparation of blow molded product including polyurethane foam - Google Patents

Abstract

PURPOSE:To provide a lightweight blow molded product having a skin excellent in softness and having sufficient rigidity and strength, by a method wherein a skin obtained by blow molding is set to an urethane injecting mold and long glass fibers are set to the skin before or after an urethane raw solution is injected and an upper mold is closed to perform curing. CONSTITUTION:A cylindrical parison is held between porous blow molds and air is blown in the molds from an air blow nozzle to obtain a skin 9. Then, the skin 9 is set to the lower mold 8 of a mold consisting of an upper mold 7 and the lower mold 8 and a semihard urethane foam raw solution 10 is injected on the skin 9 from a mixing head 11 and long glass fibers 12 are rapidly set to the upper part of the lower mold. After the completion of setting, the upper mold is closed and the urethane foam raw solution is cured under heating to perform demolding. By this method, a polyurethane foam having a blow molded skin is obtained. Therefore, cost down is attained by eliminating necessity for using a core material and excellent softness is held on the skin side of the foam layer and sufficient rigidity and strength can be held on the back surface side of the foam layer.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is applied to interior parts used in transportation facilities such as automobiles, railway vehicles, aircraft, ships, etc., such as compound hooks, door trims, instrument panels, and seven consoles. The present invention relates to a method for manufacturing a T71 blow molded product containing polyurethane foam, which is used for interior parts such as T7 and A type houses, or toys.

(Prior Art) Conventionally, for example, the material composition of interior material parts for automobiles can be roughly divided into two types.

1.67 (M innoection type) In this case, the filler material is polybutylene (
PP), acrylonitrile butanoene styrene (
Common materials include ABS, acrylonitrile-styrene-glass-reinforced resin (ASG), and ABS, and have been used primarily for console boxes, door trims, instrument panels, and the like.

However, these molded products do not have a soft feel and lack flexibility, so it is difficult to say that they are sufficient in terms of safety.

2. Padded type In view of the above problems, interior parts have recently been equipped with a padded type.
In order to provide molded products with flexibility and excellent decorative properties, various interior material parts in which cushion pads are laminated between the skin material and the core material have been devised and put into practical use. . For example, a molded product is obtained by applying a durable non-yellowing urethane paint to a mold and injecting a foaming polyurethane stock solution between a pre-formed skin layer and a core material.

There is also a type in which a foaming polyurethane stock solution is injected between a skin material manufactured by vacuum forming, blow molding, slush molding, etc. and a core material made of resin or iron.

In addition, a type in which a facing material pre-laminated with a polyurethane cushioning material is vacuum-formed and molded onto a core material has also been put into practical use.

Each of these types consists of three layers: a skin material, a cushion material, and a core material, and requires a step of injection molding or press molding the core material, which has the disadvantage that the cost of the core material is high. The padded interior material parts described above are mainly used for consoles, instrument panels, door trims, armrests, etc.

As for a simpler material structure, there is also a type in which a foamable polyvinyl chloride composition is injected and foamed onto a rigid core material. Recently, a type that does not use the above-mentioned rigid core material has also appeared, in which a rigid polyurethane foam is injected and foamed on the back side of a facing material in which a cushion pad is laminated to the facing material.

This mainly includes door trims and console boxes (Koishi II+).

In addition, it is desirable to have a skin with a good appearance, especially one with deep markings such as natural leather, but when trying to obtain such a skin by vacuum forming, squeezing flow occurs in areas where the rJ and aperture ratio are large. The disadvantage is that the pattern becomes shallow and the appearance is poor, and that the cost is high when obtained by slush molding.

In addition, in normal blow molding, the blow mold has an appropriate diameter of 0.3 m.
+Although air vent holes of the same size are provided, the disadvantage is that the air in the four tiny parts of the mold cannot be exhausted, making it impossible to perform fine drawing transfer, resulting in poor appearance.

(Problems to be Solved by the Invention) The purpose of the present invention is to create a blow-molded product containing polyurethane foam that does not use a core material made of resin or iron, has a simpler material composition, and can reduce costs. The purpose is to provide a manufacturing method.

Another object of the present invention is to provide a method for manufacturing a skinned polyurethane foam molded product that is lightweight, has excellent texture and softness, has deep markings such as natural leather, and at the same time has sufficient rigidity and strength.

(Means for Solving the Problems) The present invention involves blow molding a thermoplastic synthetic resin material using a porous mold to create a skin, setting this blown skin in a foaming mold for urethane injection, The present invention relates to a method for manufacturing a blow-molded product containing polyurethane foam, characterized by setting a positive fiber before or after injecting a urethane foam stock solution onto the epidermis, and closing and curing the upper mold.

In the present invention, when the plus long glass fibers are set on the upper part of the lower mold or the inner surface of the upper mold, the glass long fibers are unevenly distributed mainly near the back side of the foamed pad layer of the molded product obtained after curing. In addition, for example, in molding armrests,
Place the plus long fibers perpendicularly to the center of the upper mold. ! J
It is also possible to set the long glass fibers, in which case the long glass fibers will be embedded in the longitudinal holes of the foamed Para 1 scraps of the armrest after molding.

In the present invention, as described above, even without using any core material, by using a special composite single material consisting of a semi-rigid polyurethane foam and long glass fibers unevenly distributed in specific parts thereof, a 7-layer structure can be used. The polyurethane foam interior material with a skin that maintains excellent softness on the skin side of the 7-ohm layer and at the same time has sufficient rigidity and strength in specific areas of the 7-ohm layer, such as the back layer on the opposite side, is used in a smaller amount. It can be manufactured with any material composition.

In the present invention, conventionally known skin materials can be used as the skin material made of thermoplastic synthetic resin, such as polyvinyl chloride (PVC), polyurethane, acrylonitrile butadiene styrene resin (AB S ).
Synthetic resins such as polyethylene, polypropylene, polyester, nylon, etc., molded by blow molding can be used.

The thickness of the epidermis is preferably about 0.2 to 4.0 parts. A known method can be used for skin molding. That is, using a blow molding method, a cylindrical parison is lowered and enclosed in a mold, and air is blown into the mold to form a bag-shaped outer skin. In this blow molding, in addition to blowing, a method is also used in which air is forcibly removed through air vent holes in the edges of the parison to improve the degree of adhesion of the parison to the mold and improve the transferability of the pattern.

In the present invention, a porous mold is used to almost completely remove air from the uneven parts of the fine patterns on the inside of the mold during blow molding.
It is possible to obtain an epidermis in which the uneven shape is well transferred.

In the present invention, the foam pad l'' scrap to be laminated with the skin material is made of semi-rigid polyurethane foam reinforced with fibers, and the long glass fibers are mainly used on the back side of the 7-ohm layer (on the opposite side to the skin side). However, depending on the use of the molded product, it can also be embedded in the center of the 7-ohm layer or other specific parts.A single composite in which such special long glass fibers are arranged By using this material, it is possible to obtain a polyurethane foam molded product with a skin that simultaneously has a soft feel as described above and sufficient rigidity and strength.

Known semi-rigid polyurethane stock solutions can be used for the foam pad layer. The properties of semi-rigid polyurethane foam include a density of approximately 0.02~0, IOH/
cI63, reactivity is Cream Time 30±Jos
t departure, del time 120 ± 30 sec, rise time +
50±: (Os e c is appropriate. It is preferable to design the foam type clearance so that the thickness of the 7-ohm layer is approximately 5al111 or more. As the long glass fiber, a known one is used. However, in particular, long glass fiber mats made by layering continuous long glass fibers in a spiral shape on one or more layers of scrap and forming them into a mat shape with a binder (for example, Continuous Strand Mat manufactured by Asahi Fiberglass Co., Ltd.) , abbreviation C8M, etc.) can be particularly preferably used.ff
It is preferable that the lath woven fibers are mainly present in the vicinity of the back side of the pad layer opposite to the outer skin side, but it is of course possible that some of the fibers are present on the outer skin side. Furthermore, as described above, there are cases where it is preferable to have it in the center of the pad layer, as in the case of an armrest.

Next, the present invention will be explained with reference to the drawings. FIG. 1 is a partially enlarged sectional view of the blown polyurethane foam molded product with a skin of the present invention, in which long glass fibers 3 are mainly unevenly distributed near the back side of a foam pad layer 2 laminated on a skin 1.

Next, an example of a rear console door being manufactured as an example of the molded product of the present invention is shown in Figure 2 and Figures 3 (1) to (6). A cylindrical parison 6 is sandwiched between porous blow molds 4 shown in FIG. 2, and air is blown from an air blowing nozzle 5 to obtain a skin. A skin 9 is set in the lower mold 8 of a mold consisting of an upper mold 7 and a lower mold 8 in FIG.
The long glass fibers 12 are quickly set on the upper part of the lower mold. After the setting is completed, the upper mold 7 is closed, the mold is cured by heating, and the mold is demolded to obtain a polyurethane foam with a blown skin as shown in FIG. 4 (1). Next, this is removed and trimmed to obtain a rear console door with a blown skin having a cross-sectional configuration as shown in FIG. 4(2).

(Effects of the Invention) The polyurethane foam molded product with a blown skin of the present invention conventionally had a V# structure made of separate members of a foam pad layer and a core material, but was reinforced by the presence of long glass fibers in specific parts. The use of a single composite material, semi-rigid polyurethane foam, eliminates the need for the core material used in the shell, simplifies component construction, and reduces costs.

In addition, by using a special composite single material made of long glass fibers unevenly distributed in specific areas of the semi-rigid polyurethane foam layer, an excellent soft feel is maintained on the skin side of the 7-ohm layer, and at the same time, the 7-ohm layer maintains an excellent soft feel on the skin side. It is possible to obtain a polyurethane foam molded product with a blown skin that has sufficient rigidity and strength in the back layer on the opposite side of the single layer.

Furthermore, in the present invention, since the skin is created by blow molding using a porous mold, the transferability of minute marks is good, and the skin with deep marks, such as natural leather, which has a good appearance, can be produced at low cost. It is possible to obtain a better skin than vacuum forming or slush forming.

[Brief explanation of the drawing]

FIG. 1 is a partially enlarged sectional view of a polyurethane foam molded product with a blown skin according to the present invention, and FIGS. 2 to 4 are schematic diagrams showing a procedure for manufacturing a rear console door as an example. 1.9... Blown skin, 2... Foamed pad layer, 3.
DESCRIPTION OF SYMBOLS 12... Glass long fiber, 4... Porous blow mold, 5... Air blowing nozzle, 6... Cylindrical parison, 7... Upper mold, 8... Lower mold, 10 ... Semi-rigid urethane foam stock solution. (The above) Applicant: Toyo Rubber Industries, Ltd. Applicant: Kanto Jidosha Kogyo Co., Ltd. Agent
Patent Attorney 1) Iwao Mura Figure 1
Figure 2

Claims (2)

[Claims] (1) Create a skin by blow molding a thermoplastic synthetic resin material using a porous mold, set this blown skin in a foaming mold for urethane injection, and before injecting the urethane foam stock solution onto the skin. Alternatively, a method for producing a blow-molded product containing polyurethane foam, which comprises subsequently setting long glass fibers, closing the upper mold, and curing the product. (2) The manufacturing method according to claim (1), wherein continuous glass long fibers are laminated in one or more layers in a spiral shape and formed into a mat shape with a binder.