JPH0631800A - Method and device for molding ultraviolet-curing synthetic resin sheet - Google Patents

Abstract

PURPOSE:To mold an oversize product out of a sheet-form, fiberreinforced, and ultraviolet-curing synthetic resin by a simple device in a small manhour. CONSTITUTION:A mold 1 provided with air vent holes 3 is placed on a vacuum suction plate 4. On the surface of the mold 1, a molding sheet 16 is fixed. The molding sheet is heated by being irradiated with an infrared light emitted from an infrared light emission part 18 of a transport device 17 from above. The molding sheet is vacuum formed by actuating a vacuum pump 9. Lastly, the molded item is cured by being irradiated with an ultraviolet light emitted from an ultraviolet light emission part 20 of the transport device. In this manner, a device is simplified and capable of easily dealing with the molding of even a remakably oversize product. Furthermore, there is no need for a transport manhour for putting in and taking out the item from a furnace in heating and curing processes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a synthetic resin and a molding apparatus therefor, and more particularly to a method for molding a fiber reinforced synthetic resin sheet using an ultraviolet curable resin as a matrix resin and a molding apparatus therefor.

[0002]

2. Description of the Related Art Synthetic resin products reinforced with fibers such as glass fibers or carbon fibers, so-called FRP products, have been widely used in various fields.

[0003] Such FRP products are molded by injection molding using pellets or compression molding using bulk prepregs when they are relatively small, and when they are large, such as polyester and epoxy. It was formed by handlay-up or filament winding using a liquid thermosetting resin.

Since a large number of man-hours are required to form a large FRP product by handlay-up or filament winding, recently, a sheet-like SMC which uses a thermosetting resin prepreg has been used. Then, it has become popular to perform molding.

Since the matrix resin of SMC is a thermosetting resin, if the sheet is softened by heating for molding, it must be molded within a short time so that the curing does not proceed. Is exclusively used for press molding.

However, the press molding has a problem that the molding time is greatly shortened, that an expensive mold is required as a mold for molding, and that the press machine is expensive, resulting in a product. If the size is large, the die cost and equipment cost are very high, and in the case of high-mix low-volume production, the product cost is very high because of the die cost.

In order to overcome the drawbacks of the FRP sheet using a matrix resin as a thermosetting resin such as SMC which can be applied only to press molding, an FRP sheet using a matrix resin as an ultraviolet curable resin has recently been developed.

In the case of a UV-curable FRP sheet, even if it is heated to soften the sheet during molding, the curing of the resin does not proceed as in the case of thermosetting, so that it takes a sufficient time for molding. Vacuum molding has become available in inexpensive molds such as wood, gypsum, and ceramics.

[0009]

However, when vacuum forming an ultraviolet curable FRP sheet, a heating furnace for heating the sheet to the forming temperature and an ultraviolet curing furnace for ultraviolet curing the molded product are required. Will be needed.

For this reason, when the product is large, the equipment cost becomes high, and at the same time, the sheet is taken in and out of the heating furnace, set in the vacuum forming apparatus, taken out of the formed product from the molding die, and put in the ultraviolet curing furnace. In order to take it in and out, a lot of man-hours are required for molding, and in some cases special carrying equipment is required.

The present invention solves the above-mentioned drawbacks of the prior art, and UV curable F-curing with simple equipment and a small number of steps.
The purpose is to be able to mold an RP sheet.

[0012]

That is, according to the present invention, a molding sheet is fixed on a molding die having a ventilation hole placed on a vacuum suction plate, and a heat ray is applied to the molding sheet from above. Irradiate and heat to the molding temperature, the vacuum pump operates to evacuate the molding die, and the vacuum suction force causes the molding sheet to be adsorbed on the cavity surface to mold, and the molded product is irradiated with ultraviolet rays from above to cure. A method of molding an ultraviolet-curable synthetic resin sheet, which is characterized in that after processing, it is taken out from a molding die, and a vacuum suction plate to which a vacuum exhaust device is connected, and a vacuum suction plate mounted on this vacuum suction plate. It comprises a molding die having an air-permeable hole, and a conveying device provided with an infrared radiation part composed of a plurality of infrared lamps rotating above the molding mold and an ultraviolet radiation part composed of a plurality of ultraviolet lamps. Characteristic purple It is a line-curable synthetic resin sheet forming apparatus.

[0013]

The present invention is constructed as described above, and the sheet can be heated to the molding temperature in a state where the molding sheet is set in the vacuum forming mold, and the molded product can be ultraviolet-cured while being set in the mold. Therefore, molding requires almost no man-hours for transportation.

Further, since the molding apparatus is provided with the infrared radiation portion and the ultraviolet radiation portion, and only the conveying device which is rotated above the die, can be manufactured at a very low cost, and the infrared radiation is generated by driving the conveying device. Section or UV radiating section is conveyed to a position facing the mold and then the lamps provided in each are turned on to easily irradiate the sheet with infrared rays to heat it, or irradiate the molded article with UV rays for curing treatment. .

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a state in which a molding sheet is set in a molding apparatus. First, the structure of the molding apparatus will be described. 1 is a molding die, and this molding die 1 has a cavity 2 and a cavity 2. , A plurality of ventilation holes reaching from the cavity 2 to the bottom surface are provided.

Since the molding die 1 has only to withstand a molding temperature of about 70 ° C., it may be made of any material such as wood, gypsum and ceramics.

Reference numeral 4 denotes a vacuum suction plate on which the molding die 1 is placed. The vacuum suction plate 4 has a vacuum exhaust groove 5 of a predetermined depth and vacuum exhaust gas reaching the bottom surface from the vacuum exhaust groove 5. A hole 6 is provided.

Reference numeral 7 denotes a cylinder device, and a cylinder 8 of the cylinder device 7 supports the bottom surface of the vacuum suction plate 4, and the operation of the cylinder device 7 moves the molding die 1 up and down.

Reference numeral 9 is a vacuum pump, and this vacuum pump 9 is connected to the vacuum exhaust hole 6 of the vacuum suction plate 4 by a vacuum exhaust pipe 10 in which an accumulator 11 and a solenoid valve 12 are provided.

13 is a molding sheet 1 having openings on both upper and lower sides.
6, the holding frame 13 is supported by the cylinder 15 of the cylinder device 14.
It is moved up and down by the operation of 4.

Reference numeral 17 is a support rod 2 which is erected on a base 22.
3 is a conveying device which is supported by 3 and rotates above the molding die 1. The conveying device 17 includes an infrared emitting portion 18 including a plurality of infrared lamps 19 and an ultraviolet emitting portion 20 including a plurality of ultraviolet lamps 21. Has been deployed.

Next, a molding method will be described based on an example in which a glass fiber reinforced UV curable resin sheet (polyurethane chemical conversion, Optol LHZ) having a thickness of 2 mm and a molding temperature of 70 to 80 ° C. is molded.

First, the molding sheet 16 is held and fixed by the holding frame 13, and then the conveying device 17 is driven to move the infrared radiating portion 18 to a position facing the molding die 1, and all the infrared lamps 19 are provided. Lights up.

Next, when the cylinder device 15 is operated, the distance between the molding sheet 16 and the infrared lamp 19 is 15 to 2
The holding frame 13 is moved so as to be about 0 cm, and infrared rays are irradiated until the molding sheet 16 reaches a molding temperature of 70 to 80 ° C.

Of course, it is preferable that the distance between the infrared lamp 19 and the molding sheet, the irradiation time, and the like be determined in advance by experiments.

When the molding sheet 16 reaches the molding temperature, the cylinder device is operated again to lower the holding frame 13 so that the molding sheet 16 covers the surface of the molding die 1, and the vacuum pump of the vacuum exhaust pipe 10 is operated. The electromagnetic valve 12 for the accumulator 11 holding the vacuum state by 9 is opened, and the molding die 1 is evacuated through the vacuum suction plate 4.

When the molding die 1 is evacuated to vacuum, the molding sheet 16 is adsorbed by the cavity 2 to form a molded product 24 as shown in FIG.

When the molded product 24 is completely vacuum-formed, all the infrared lamps 19 of the infrared radiating part 18 are turned off, and the conveying device 17 is driven to bring the ultraviolet radiating part 20 to the position facing the molding die 1. When the cylinder device 7 is operated, the vacuum suction plate 4 is moved upward so that the distance between the molding die 1 and the ultraviolet lamp is 20 to 30 cm.

After that, all the ultraviolet lamps 21 are turned on and the molded product 24 is irradiated with ultraviolet light for about 10 minutes to cure the molded product 24.

When the curing process is completed, all the ultraviolet lamps 21 of the ultraviolet radiating part are turned off, the electromagnetic wave 12 is closed, and the molded product 1 is taken out from the molding die 1 whose atmospheric pressure has been returned to complete the molding operation.

[0032]

EFFECT OF THE INVENTION The present invention has the constitution and effects as described above, and a large-sized FRP product can be manufactured almost at a low cost by using a mold which can be easily manufactured at a low cost by an extremely simple device with a low equipment cost. It can be molded without multiplying man-hours.

[Brief description of drawings]

FIG. 1 shows a state of a molding sheet set of a molding apparatus,

FIG. 2 shows the state of formation of a molded product.

[Simple explanation of symbols]

 1 Mold 2 Cavity 3 Vent 4 Vacuum suction plate 9 Vacuum pump 10 Vacuum exhaust pipe 13 Holding frame 16 Sheet for molding 17 Conveying device 18 Infrared emitting part 19 Infrared lamp 20 Ultraviolet emitting part 21 Ultraviolet lamp

Claims (2)

[Claims] 1. A molding sheet is fixed on a molding die having a ventilation hole placed on a vacuum suction plate, and the molding sheet is irradiated with heat rays from above to heat it to a molding temperature. The vacuum of the molding die is evacuated by the operation of the vacuum pump, and the vacuum suction force causes the molding sheet to be adsorbed to the cavity surface for molding.
A method for molding an ultraviolet-curable synthetic resin sheet, which comprises irradiating a molded product with ultraviolet rays from above to cure the molded product, and then removing the molded product from a molding die. 2. A vacuum suction plate to which a vacuum exhaust device is connected, a molding die having air-permeable holes placed on the vacuum suction plate, and a plurality of infrared lamps which rotate above the molding die. An apparatus for forming an ultraviolet-curable synthetic resin sheet, comprising: an infrared radiating section made of ????????? and a conveying apparatus provided with an ultraviolet radiating section made of a plurality of ultraviolet lamps.