JP3679395B2 - Manufacturing method of resin molded body reinforced with back surface - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a container-shaped resin molded body such as a bathtub, a wash bowl, a water tank, and the like. The present invention relates to a method for producing a molded resin product.
[0002]
[Prior art]
In general, synthetic resin molded products whose back side is reinforced with fibers, such as bathtubs and wash bowls, are pre-formed by vacuum molding or compressed air molding, such as acrylic resin, which constitutes a high-quality textured surface. Then, in order to improve the strength of the thermoplastic resin molded product, a reinforcing fiber material such as a synthetic resin and glass fiber (glass preformed product: may be a preform) is placed on the back surface of the male mold. The molds are clamped between the back molds, and further molded by heating and integrally molded.
[0003]
With reference to FIG. 4 and FIG. 5, the manufacturing process of the resin molding reinforced with FRP is demonstrated concretely.
[0004]
First, the thermoplastic resin plate (not shown) of the material is subjected to vacuum forming or pressure forming using the designed mold 10 and the front side of the molded body such as a bathtub is produced as a thin thermoplastic resin molded article 11. Next, both the thermoplastic resin molded article 11 and the reinforcing fiber material 14 and the like are accommodated in a casting mold (cavity) made up of a separately prepared female mold 12 and male mold 13, and a female mold. A well-known FRP laminate in which the mold 12 is clamped in combination with the male mold 13, a polymerization curable resin raw material is injected into the formed sealed space (cell) from the gate 15, polymerized and cured, and then demolded. It is manufactured by a molding process (see, for example, Patent Document 1).
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-291333 (paragraphs “0009” and “0021”, FIGS. 1 and 3)
[0006]
[Problems to be solved by the invention]
However, in the conventional FRP lamination molding process described above, a thermoplastic resin molded article and a reinforcing fiber material are accommodated, and the back mold and the male mold are combined and clamped, and the formed sealed space (cell) is formed. Since a process of injecting a polymer curable resin raw material from the gate and pressurizing the preform is necessary, a pair of molds consisting of a high-strength back mold and a male mold is required. Since a manufacturing process of a preform or the like in which a glass reinforcing fiber material is pre-impregnated with a resin is costly, it is difficult to simplify the manufacturing process.
[0007]
Further, when manufacturing a large molded product such as a bathtub, it is difficult to move while using a large mold, so that the line production process is difficult and mass production is not easy.
[0008]
In addition, because it is difficult to change the design of the back mold and male mold with high strength, the responsiveness to respond quickly to the new design is not sufficient, and it is necessary to prepare a new mold even if the thickness of the molded product is changed. We were unable to respond to the request easily and quickly.
[0009]
Therefore, the object of the present invention is to solve the above-mentioned problems, reduce the number of molds for molding in the manufacturing process, and can quickly respond to a request for a design change, and impregnate the reinforcing fiber material. It is a method for producing a resin molded body reinforced with a back surface that is uniform in amount and can be reliably cast, and that is useful for reducing the production cost.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, a front side resin molded body is provided, and a back mold is superimposed on the back surface of the front side resin molded body via a reinforcing fiber material. After sealing the peripheral edge of the mold and the peripheral edge of the front side resin molded body, and then reducing the gap between the sealed back mold and the front side resin molded body, a liquid resin material is injected into the reduced gap, This is cured to provide a method for producing a resin molded body reinforced with the back surface comprising integrating the front-side resin molded body and the reinforcing fiber material.
[0011]
In the method of manufacturing the back side reinforced resin molded body according to the above-described process, the gap between the sealed back mold and the front side molded resin body is reduced in pressure, and then a liquid resin material is placed in the gap. Since the injection is performed, the liquid resin material quickly infiltrates the reinforcing fiber material having a small volume due to the reduced pressure, so that the liquid resin material can be easily and surely injected into the narrow gap and uniformly filled. Moreover, unlike the conventional molding method, it is not necessary to pressurize the liquid resin material, so there is no need for a heavy and strong male / female mold, and only a relatively low-strength thin mold is used for front side resin molding. The back surface can be reinforced by backup casting by integrating the body and the reinforcing fiber material.
[0012]
Accordingly, the resin molded body reinforced on the back surface can be efficiently manufactured while moving the mold in the manufacturing line process.
Further, in this manufacturing method, since the back-up casting is performed only with the thin back mold, the mold followability or tolerance is appropriate for the expansion and contraction of the molded body at the time of molding and curing, and at the time of demolding Can be said to be a production method that does not damage the molded body, and does not have partial cracks or distortions in the molded body that is a product, can produce a high-quality and stable molded body, and improves the yield.
[0013]
In addition, in order to fill a liquid resin material uniformly over the entire surface of a molded body such as a bathtub having a relatively large area, the liquid resin material is injected in the above-described method for producing a resin molded body reinforced with back surface. A belt-like ridge that narrows the gap between the back mold and the front side resin molded body is provided in a portion closer to the center than the periphery of the back die, and the back of the periphery is formed so as not to cross this belt-like ridge. It is preferable to provide a method for producing a back-reinforced resin molded body according to claim 1, wherein the liquid resin is temporarily retained in a gap between the mold and the front-side resin molded body.
[0014]
In this way, when the liquid resin material is injected, the resin material does not immediately flow into the center of the back mold at random, and the resin material once dams up the belt-like ridge that narrows the gap between the back mold and the front side resin molded body. It is stopped and temporarily stays in a gap of a predetermined volume between the back mold and the front side resin molded body, and then when the resin is fully filled in the gap, it goes over the belt-like ridges at once, and then Flows from the entire periphery toward the center at almost the same flow rate, and the cavity is uniformly filled.
[0015]
Further, in order to surely exhibit such an action, the front side resin molded body is a container-shaped front side resin molded body having an upper surface opening, and the peripheral edge of the opening portion is folded outwardly along the outer wall of the container. It is preferable to provide a method of manufacturing a resin molded body reinforced with a back surface, in which a liquid resin material injection port is disposed at the periphery of the back mold along the flange.
[0016]
In addition, in order to obtain a method of manufacturing a back-side reinforced resin molded body in which the thickness of the resin molded body can be easily adjusted in a request for a design change, manufacture of any of the above-described back-side reinforced resin molded bodies. In the method, the sealing between the peripheral edges of the back mold and the front side resin molded body is to bring an annular elastic packing provided on the peripheral edge of the back mold into close contact with the front side resin molded body, and the elastic packing is tubular Thus, the thickness of the resin molded body can be adjusted by adjusting the pressure of the hollow portion.
[0017]
In this way, when the pressure of the tubular hollow portion of the elastic packing is increased, the gap between the peripheral edges of the back mold and the front side resin molded body can be widened and sealed, and a thick resin molded body is manufactured. be able to. Further, when the pressure in the tubular hollow portion of the elastic packing is lowered, the elastic packing becomes thin and flat, and a thin resin molding can be manufactured.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
[0019]
As shown in FIGS. 1-3, the manufacturing method of embodiment first produces the resin molded object 1 for front sides, such as a bathtub which is a tank (large-sized container of upper surface opening) shape previously by vacuum forming or pressure forming. The reinforcing fiber material 3 made of a mat-like glass fiber is accommodated in substantially the entire area of the cavity of the back mold 2 that covers the back surface of the front side resin molded body 1 (not shown in FIG. 1, (See FIG. 3).
[0020]
The resin molding 1 for the front side is not particularly molded by limiting the material thereof, and is made of a known resin such as an acrylic resin, a polystyrene resin, a polypropylene resin, or an ABS resin according to the purpose of the molded product. Can be used.
[0021]
Then, the front-side resin molded body 1 is overlaid on the back mold 2, and the entire peripheral edge of the back mold 2 and the entire peripheral edge of the front-side resin molded body 1 are annular rubber elastic packing 4 and a pair of frames 5. And a clamp (not shown) is closed and sealed, and then the gap between the sealed back mold 2 and the front side resin molded body 1 is evacuated from an exhaust hole 6 with a chamber at the bottom to a vacuum pump (not shown). The air is exhausted and depressurized.
[0022]
Next, a liquid resin material such as urethane resin is injected from the injection port into the gap (cavity) that has become substantially vacuum at less than 1 atm, using a pressure difference, filled with an appropriate amount, further heated, etc. Is cured by integrating the front-side resin molded body 1 with the reinforcing fiber material 3 and the resin to obtain a resin molded body reinforced on the back surface.
[0023]
As the liquid resin material, well-known resins such as unsaturated polyester resins, acrylic resins and vinyl ester resins can be selected in addition to the urethane resins described above, and those having good adhesion and integration with the above-mentioned resin molding for the front side can be selected. Adopt it.
[0024]
The resin molded body 1 for the front side of the bathtub has a flange-like portion 1a formed by folding the peripheral edge of the opening from the downward direction to the horizontal direction and outward, and an inlet 7 for the liquid resin material is formed in the flange-like portion 1a. Provided.
[0025]
The liquid resin material injection ports 7 may be formed in a suitable number by arranging them at appropriate intervals on the periphery of the back mold 2 (four locations are formed in FIG. 2). A belt-like ridge portion 8 that makes a round along the periphery of the back mold 2 is provided, and when the liquid resin material is injected, a liquid resin is formed in the gap between the back mold 2 outside the belt-like ridge portion 8 and the front-side resin molded body 1. Is temporarily retained, and then the liquid resin material flows from the entire periphery to the center of the back mold 2 at a substantially uniform flow rate when it passes over the belt-like ridge 8 provided on the entire periphery. .
[0026]
Further, in order to seal the peripheral edges of the back mold 2 and the front side resin molded body 1, the annular elastic packing 4 provided on the peripheral edge of the back mold 2 is replaced with the front side resin molded body 1 and the elastic packing 4 on the upper surface thereof. And a clamp (not shown) through a pair of frames 5.
[0027]
The elastic packing 4 is made of tubular rubber, and it is possible to adjust the thickness of the resin molded body by adjusting the thickness of the elastic packing 4 by injecting compressed air or the like from the valve not shown in the drawing to the air pressure of the hollow portion. .
[0028]
【The invention's effect】
As described above, the present invention accommodates the reinforcing fiber material in the back mold cavity covering the back surface of the front side resin molded body, overlaps the front side resin molded body, and depressurizes the sealed gap. In this way, a liquid molded material is injected and cured to produce a resin molded body that is reinforced on the back surface. Therefore, the resin material is uniformly and quickly filled into the cavity, and the amount of impregnation is uniform and the quality of the reinforcing fiber material. There is an advantage that a good casting can be surely performed, and this provides a method of manufacturing a resin molded body reinforced with a back surface that is useful for improving quality and reducing manufacturing costs.
[0029]
In addition, this manufacturing method does not require a pair of strong molds for compression molding, can be easily manufactured by reducing the number of molds for molding, and a thin-walled mold can be used to meet a design change request. It can respond promptly, and the molded product that has become a product has no cracks or distortion, and can produce a high-quality and stable molded product, which improves the yield. Moreover, the back side-reinforced resin molded body can be mass-produced with high production efficiency while moving the mold in the production line process.
[0030]
In addition, when a method is adopted in which the hollow elastic packing is tightly sealed to the front side resin molded body with a clamp and the thickness of the hollow elastic packing is adjusted by the hollow internal pressure, the thickness of the resin molded body can be simplified. There is an advantage that it is a manufacturing method of a resin molded body whose back surface is reinforced that can be adjusted.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a sealed back mold and a front side resin molded body for explaining a manufacturing method of an embodiment. FIG. 2 is a plan view of FIG. 1 for explaining a manufacturing method of the embodiment. FIG. 4 is a cross-sectional view showing an enlarged main part of FIG. 1 for explaining the manufacturing method of FIG. 1. FIG. 4 is a cross-sectional view of a mold and a thermoplastic resin molded product for explaining a conventional manufacturing method. Sectional view of resin moldings reinforced with male and female molds [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Front side resin molding 1a Flange-shaped part 2 Back mold | type 3 Reinforcing fiber material 4 Elastic packing 5 A pair of frames 6 Exhaust hole 7 Inlet 8 Band-shaped protruding part 10 Mold 11 Thermoplastic resin molded product 12 Female mold 13 Male mold 14 Reinforcing fiber material 15 Gate

Claims (4)

A front-side resin molded body is provided, and a back mold is superimposed on the back surface of the front-side resin molded body via a reinforcing fiber material, and the periphery of the back mold and the periphery of the front-side resin molded body are After sealing, and then reducing the gap between the sealed back mold and the front side resin molded body, a liquid resin material is injected into the reduced pressure gap and cured to cure the front side resin molded body and the reinforcing side In the manufacturing method of the back side reinforced resin molding that integrates the fiber material ,
The liquid resin material is injected from the periphery of the back mold, and a belt-like ridge that narrows the gap between the back mold and the front side resin molded body is provided in a portion closer to the center than the periphery of the back mold. A method for producing a back-reinforced resin molded body, characterized in that a liquid resin is temporarily retained in a gap between a back mold on the periphery and a resin molded body for front side so as not to exceed. The front-side resin molded body is a container-shaped front-side resin molded body having an opening on the upper surface, and the periphery of the opening is folded outward to form a flange along the outer wall of the container. The method for producing a back-reinforced resin molded body according to claim 1 , wherein an injection port for the liquid resin material is arranged at the periphery and injected. A front-side resin molded body is provided, and a back mold is superimposed on the back surface of the front-side resin molded body via a reinforcing fiber material, and the periphery of the back mold and the periphery of the front-side resin molded body are After sealing, and then reducing the gap between the sealed back mold and the front side resin molded body, a liquid resin material is injected into the reduced pressure gap and cured to cure the front side resin molded body and the reinforcing side In the method for producing a resin molded body integrated with a fiber material
Sealing between the peripheral edges of the back mold and the front side resin molded body is to bring the annular elastic packing provided on the peripheral edge of the back mold into close contact with the front side resin molded body, and the elastic packing is tubular, method of manufacturing and adjusting the air pressure in the hollow part molded resin thickness of adjustable and the back surface reinforced resin molded body. The sealing between the peripheral edges of the back mold and the front side resin molded body is to bring the annular elastic packing provided on the peripheral edge of the back mold into close contact with the front side resin molded body, and the elastic packing is tubular, The method for producing a back-reinforced resin molded body according to claim 1 or 2 , wherein the thickness of the resin molded body can be adjusted by adjusting the pressure of the hollow portion.

Images