JPH05147030A - Manufacture of fiber reinforced resin molding material - Google Patents

Abstract

PURPOSE:To provide a method for preparing a fiber reinforced resin molding material capable of preventing the fiber breakage by eliminating the necessity of a scraper roller which causes the fiber breakage. CONSTITUTION:Two supporters 2, 2' of a long film form is introduced into a clearance 3 formed between a pair of rollers 1, 1' in which the supporters 2, 2' are faced each other at intervals. A fibrous material 4 cut into a short size and a thermosetting resin paste 5 are supplied respectively between the supporters 2, 2' to impregnate the thermosetting resin 5 into the fibrous material 4 by passing through the clearance 3 formed between the rollers, and at the same time the fibrous material 4 is pressed to produce a sheet 6. Moreover, the film-shaped supporters 2, 2' are stuck on both surfaces of the sheet 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fiber-reinforced resin molding material called a so-called sheet molding compound (SMC), and more particularly, to prevent breakage of fibrous materials and obtain fiber-reinforced resin. The present invention relates to a method for producing a fiber-reinforced resin molding material, which does not reduce the mechanical strength of the molding when a molding having a desired shape is molded using the resin molding material.

[0002]

2. Description of the Related Art Conventionally, as a method of producing a fiber-reinforced resin molding material called so-called SMC, a short-cut fibrous material and a paste-like thermosetting resin are respectively supplied between a pair of rolls to form a roll. After impregnating the fibrous material with the thermosetting resin by passing through the gap, the fibrous material impregnated with the thermosetting resin adhering to the roll surface is scraped off with a scraping roll rotating at high speed, There is a method for producing a fiber-reinforced resin molding material by depositing it on a film-like support located below (Japanese Patent Publication No. 55-518).
(See Japanese Patent No. 13).

[0003]

According to the above conventional method for producing a fiber-reinforced resin molding material, since the thermosetting resin-impregnated fibrous material adhered to the roll surface is scraped off by the scraping roll rotating at a high speed, The fibrous material is damaged by the pressing force and frictional force generated at the time, and when the molded product of the desired shape is formed by press molding using the obtained fiber reinforced resin molding material, the fibrous material is molded at a place where the damage is significant. There is a risk that the strength of the product may decrease. For example, when the molded product is a bathtub, press molding is usually performed by supplying the fiber-reinforced resin molding material to the portion corresponding to the bottom wall of the bathtub, but the mechanical strength decreases at the portion where the fibrous material is significantly damaged. However, there was a case where a bathtub of good quality could not be obtained due to a serious problem.

The present invention eliminates the above-mentioned drawbacks in the conventional method for producing a fiber-reinforced resin molding material, and eliminates the need for using a scraping roll, which was the cause of damage to the fibrous material. To prevent damage to the product and to obtain a molded product of good quality without lowering the mechanical strength even when the desired molded product is molded by press molding using the obtained fiber reinforced resin molding material. It is an object of the present invention to provide a method for producing a fiber-reinforced resin molding material, which is capable of

[0005]

The method for producing a fiber-reinforced resin molding material according to the present invention introduces two long film-shaped supports into a roll gap formed by a pair of rolls, and the gap is set in the roll gap. In the above, the film-like support is made to face each other, and the fibrous material and paste-like thermosetting resin cut into short pieces are supplied between the film-like supports and are passed through the roll gap to obtain the thermosetting property. The fibrous material is impregnated with the resin and the fibrous material is pressed to form a sheet-like body, and the film-like support is attached to both surfaces of the sheet-like body. This achieves the above object.

Next, the present invention will be described in more detail with reference to the drawings. 1, 1'is a pair of rolls, the diameter of which is preferably 10 to 100 cm,
It is usually rotated at 1 to 200 rpm. The pair of rolls 1, 1'are installed so as to form a roll gap 3, and the roll gap 3 is preferably 0.5 to 5 mm.

Reference numerals 2 and 2 ′ are two long film-like supports, which are introduced into the roll gap 3. Film-like support 2,
2 ′ guides the fibrous material 4 impregnated with the pasty thermosetting resin 5 to the roll gap 3 and is attached to both surfaces of the sheet-like body 6 formed by the pressing force when passing through the roll gap 3. The sheet-like body 6 is coated with the sheet-like body 6 to make it convenient to handle. For example, a polyethylene film, a polypropylene film, a nylon film, a polyester film or the like is used. Further, the thickness of the film-shaped supports 2 and 2'is preferably 25 to 100 μm.

The film-like supports 2 and 2 ′ introduced into the roll gap 3 face each other in the roll gap 3 with a gap. Next, the fibrous material 4 and the paste-like thermosetting resin 5 which are cut into short lengths are supplied between the film-shaped supports 2 and 2 ', respectively.

As the fibrous material 4, for example, glass fiber,
Examples thereof include synthetic resin fibers and mineral fibers. To form the short fibrous material 4, for example, the roving fiber 7 can be cut by passing it through the roll cutters 8 and 8 '. Further, the length of the fibrous material 4 is preferably 12 to 50 mm.

Examples of the thermosetting resin 5 used in the present invention include unsaturated polyester resin, epoxy resin, melamine resin, phenol resin and the like. If necessary, a curing catalyst, a thickener, a filler, Various additives such as colorants, release agents and stabilizers can be added. The thermosetting resin 5 is used in the form of a paste that is a viscous liquid. For this purpose, a thermosetting resin which is originally in a liquid or paste form may be used and a mixture of various additives may be prepared into a paste form, or it may be dissolved in a solvent to form a liquid or paste form. A thermosetting resin may be mixed with various additives and may be prepared into a paste.

The blending amount of various additives is appropriately determined according to the purpose, and for example, per 100 parts by weight of the thermosetting resin,
0.5 to 5 parts by weight for the curing catalyst, 0.1 to 10 parts by weight for the thickener, and 20 to 600 for the filler.
It is preferable to use parts by weight.

The thermosetting resin 5 is discharged from the discharge ports provided in the resin supply pipes 9 and 9'and supplied to the roll gap 3. It is preferable that the fibrous material 4 and the thermosetting resin 5 are supplied between the film-shaped supports 2 and 2 ′ separately from the viewpoint of stability in feeding, etc. You may supply it after that.

The fibrous material 4 and the paste-like thermosetting resin 5 cut into short pieces are formed into a fibrous thermosetting resin 5 by the pressing force of the rolls 1, 1'when passing through the roll gap 3. The fibrous material 4 is formed into a sheet-like body 6 while being impregnated with the material 4. The thickness of the sheet-like body 6 is regulated by the roll gap 3, but is preferably 0.4 to 5 mm.

The film-like supports 2 and 2'are attached to both surfaces of the sheet-like body 6 by the pressing force of the rolls 1 and 1'when passing through the roll gap 3. The fiber-reinforced resin molding material thus obtained is cut into a predetermined size if necessary and supplied to a press molding machine. At this time, the film-shaped supports 2 and 2 ′ can be appropriately peeled off.
At the time of press molding, the fiber reinforced resin molding material is put in a molding die heated to 130 ° to 160 ° C.
After molding with a pressing force of 0 to 120 kg / cm ² for 3 to 30 minutes, the molding die is opened and the molded product is taken out.

[0015]

In the present invention, the short cut fibrous material 4 and the paste-like thermosetting resin 5 are supplied between the long film-like supports 2 and 2'which are opposed to each other at a distance, and the rolls are rolled. Since the fibrous substance 4 is impregnated with the thermosetting resin 5 by passing through the gap 3 and the fibrous substance 4 is pressed to form the sheet-like body 6, the conventional fiber-reinforced resin molding material of this kind is used. The viscous paste thermosetting resin 5 does not adhere to the roll surface as in the manufacturing method, and it is not necessary to perform scraping with a scraping roll, so that the fibrous material 4 is less likely to be damaged. ..

[0016]

EXAMPLES In order to more specifically describe the present invention, examples will be described below. In addition, for convenience of explanation,
Each part will be described with reference to the drawings. (Example 1) Rolls 1 and 1'having a diameter of 40 cm were used, and a roll gap 3 was set to 4 mm. Thickness 120
Two long polyethylene films 2 and 2 ′ of μm are introduced into the roll gap 3 so as to face each other, and roll cutters 8 and 8 ′ are passed between the polyethylene films 2 and 2 ′ to be cut into a length of 25 mm. Glass fiber 4 was sprayed and supplied. Also this polyethylene film 2, 2 '
In the meantime, the paste-like unsaturated polyester resin 5 was supplied from the discharge ports of the resin supply pipes 9 and 9 '.

As the paste-like unsaturated polyester resin 5, 1.0 part by weight of a curing catalyst, 1.0 part by weight of a thickening agent, and 100 parts by weight of an unsaturated polyester resin,
A paste-like material prepared by adding 120 parts by weight of a filler was used. The pasty unsaturated polyester resin 5 was pressed into the glass fiber 4 by passing through the roll gap 3 and impregnated into the glass fiber 4. Further, the sheet-like body 6 is formed by the pressing force of the rolls 1 and 1 ′ when passing through the roll gap 3.
Furthermore, the polyethylene film 2 is provided on both sides of the sheet-like body 6,
2'was attached.

The fiber-reinforced resin molding material thus obtained was placed in a press mold heated to 150 ° C.
The bath body was molded with a pressing force of 20 kg / cm ² for 3 minutes.

After molding, a sample piece was taken from the bath body, and the state of the glass fiber was observed by soft X-ray photography. As a result, it was found that the glass fiber was not damaged and remained a fiber of a constant length. Further, the bending strength was measured according to JIS K 6911 and found to be 12 kgf / mm. (Comparative Example 1) As in Example 1, the diameter is 40 cm.
Rolls 11 and 11 'are used, and scrapers 20 and 20' are attached to the cores 11 and 11 ', and the roll gap 13
The glass fiber 14 cut to a length of 25 mm obtained in the same manner as in Example 1 was sprinkled on the paste-like unsaturated polyester resin 15 having the same composition as in Example 1 and the resin supply pipe 1 was added.
It is supplied by being discharged from the discharge ports 9 and 19 ', and the roll gap 1
3, and the glass fiber 14 was impregnated with the paste-like unsaturated polyester resin 15 by pressing force, and the sheet-like body 16 was formed. Since the sheet-like body 16 is attached to the rolls 11 and 11 ', the scraping roll 2
Scraped with 0, 20 ', polyethylene film 12
A polyethylene film 12 'was deposited on the upper surface of the film so as to have a thickness of about 4 mm.

Using the fiber-reinforced resin molding material thus obtained, a bath body was molded by press molding in the same manner as in Example 1. After molding, a sample piece was taken from the bath body, and the state of the glass fiber was observed by soft X-ray photography. As a result, it was found that the glass fiber was significantly damaged and the fiber length was irregular. Further, the bending strength was measured according to JIS K 6911 and found to be 6 kgf / mm.

[0021]

According to the present invention, a short cut fibrous material and a pasty thermosetting resin are supplied between two long film-shaped supports facing each other in a roll gap,
Since the fibrous material is impregnated with the fibrous material by passing through the roll gap and the fibrous material is pressed to form a sheet-like material, a paste-like thermosetting resin having viscosity on the roll surface is used. Since it does not adhere and it is not necessary to scrape with a scraping roll, the fibrous material is less likely to be damaged. Therefore, when a molded product is molded using the fiber-reinforced resin molding material obtained by the present invention, the fibrous material does not cause a decrease in mechanical strength of the molded product due to breakage, and a good quality is obtained. It becomes a molded product.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an example of a production mode of a fiber-reinforced resin molding material in Example 1.

FIG. 2 is an explanatory diagram showing a production mode of a fiber-reinforced resin molding material in Comparative Example 1.

[Explanation of symbols]

 1, 1 ', 11, 11' Roll 2, 2'Film-shaped support (polyethylene film) 3, 13 Roll gap 4 Fibrous material (glass fiber) 5 Thermosetting resin (unsaturated polyester resin) 6, 16 Sheet Form 9, 9 ', 19, 19' Resin supply pipe 20, 20 'Scraping roll

Claims (1)

[Claims] 1. Two long film-like supports are introduced into a roll gap formed by a pair of rolls, said film supports are opposed to each other at intervals in this roll gap, and cut into short lengths. A fibrous material and a paste-like thermosetting resin are supplied between the film-shaped supports, and the fibrous material is impregnated with the thermosetting resin by passing through a roll gap, and the fibrous material is pressed to form a sheet. A method for producing a fiber-reinforced resin molding material, characterized in that the film-shaped support is adhered to both surfaces of the sheet-shaped body.