JPH085691B2 - Manufacturing method of chopped strands - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing glass fiber chopped strands by spinning molten glass, applying a coating agent, and immediately cutting the bundle after bundling.

[Prior Art] Conventionally, a strand formed by bundling glass fibers withdrawn from a spinning furnace and coated with a coating agent is wound up,
A manufacturing method called direct cutting is performed in which chopped strands are immediately cut without drying to produce chopped strands.

FIG. 2 shows a conventional example of such a manufacturing method. For example, JP-B-62-3697 and JP-A-61-163136.
No. 6,086,045.

It is believed that in the conventional production of glass fiber chopped strands by direct cutting, reducing the equipment used in the cutting and drying process of strands containing many filaments leads to improved efficiency and cost reduction. Several large strands drawn from the furnace are cut by a single large cutting device.

In these manufacturing processes, glass fibers drawn from a plurality of spinning furnaces are coated with a coating agent by an applicator mechanism installed under the spinning furnace to form bundles, and these multiple strands are fed through a guide mechanism to a feed roller. The strand is cut into chopped strands of a certain length by a cutter roller, which is a known cutting device, that is stretched by and is pressed against the peripheral surface of the feed roller. The cut chopped strands in a wet state are conveyed to a drying device or a storage container by a belt conveyor, a vibration type conveyor or the like, and dried to obtain a product.

[Problems to be Solved by the Invention] However, there are various problems in the manufacturing method in which a plurality of strands are cut by one large cutting device to form chopped strands.

For example, breakage of the glass fiber strand easily occurs at the nozzle portion and the coating agent coating roller portion, and the glass fiber strand is also cut by the guide winding, sample measurement, and the like.

At this time, the heat balance is lost on the nozzle surface of the broken spinning furnace, and even if the spinning is restarted, the diameter of the drawn filament becomes thick and the product of desired quality is not immediately obtained, and this portion is discarded. Also, the reconnection work of the broken strands is dangerous in a high-speed motion state, so the cutting device is stopped or rotated at a low speed, and the glass from the spinning furnace is not broken by the conventional method of cutting a plurality of strands with a single cutting device. The amount of fiber drawn out is the same as in the broken spinning furnace, and the same thermal history fluctuations occur, and the maintenance diameter changes in the strands from all spinning furnaces, resulting in poor quality and product quality problems. It does not become.

However, when the spinning furnace and the cutting device are one set as in the present invention, the influence of breakage is limited only to the spinning furnace,
Even if one spinning furnace is stopped, the other spinning furnaces are not affected by it, and good quality products can be produced. As a result, the amount of inferior quality products is greatly reduced along with the operation loss time.

The number of glass fiber filaments forming the chopped strand is usually about 800 to 2,000. Therefore, for example, in the case where the strands spun from the bushings of 3,000 holes attached to each spinning furnace are concentrated and simultaneously cut, the cutting device is inevitably divided into 6-10 strands, and therefore the cutting device is inevitable. Wide and large.

When the wet chopped strands are put into a drying device or a storage container by a conveyor, a vibration conveyor, or the like that is generally used as a conveying means for the wet chopped strands, the wet chopped strands adhere to the belt or trough, and the adhered substances are peeled off and mixed into the product glass. The inconvenience that appears as a stain on the surface of the fiber reinforced plastic product occurs.

The present invention prevents the production amount and quality from deteriorating due to the thermal imbalance of the bushing portion due to the breakage of the strand, which occurs in the production process of the chopped strand by the direct cut method, and is mixed in the product of the deposit of the conveying device. The purpose is to prevent.

[Means for Solving the Problems] The present inventors have studied various methods for solving these problems, but the method of cutting a plurality of strands from a plurality of spinning furnaces with a single large cutting device is efficient. Contrary to popular belief, it is possible to solve these problems by cutting one glass fiber strand with one cutting device attached to one spinning furnace and drying it, and see that productivity and product quality are improved. The present invention has been completed after various investigations.

In the present invention, for example, as shown in FIG. 1, one unit of an apparatus for producing chopped strands is a bushing 10a, a coating agent application roller 12a, a focusing roller 13a, a guide roller 21a as a cutting device 20a, a rubber surface; synthetic resin, etc. A freely rotatable feed roller 22a, a cutter roller 23a pressed against the feed roller 22a and driven by a motor, in which a large number of cutter blades are planted so as to project radially from the surface, and chopped The strand vibrating / conveying device 40a and other accessory equipment (not shown) necessary for spinning are included. These facilities may be the same as those used for the conventional direct cut method,
The cutting device 20a includes a guide roller 21a and a feed roller 22.
Since the cutter roller 23a and the cutter roller 23a can be made narrow and small in size, the entire apparatus becomes compact equipment.

The operation of these facilities is carried out as follows. The glass fiber pulled out from the bushing 10a is a coating agent application roller 1
A coating agent (sometimes referred to as a sizing agent or a sizing agent) is applied by 2a and then divided into a required number of glass fibers, which are converged by a converging roller 13a to form strands 14a. The strand 14a passes through the guide roller 21a and is wound around the feed roller 22a. The feed roller 22a is rotated by a cutter roller 23a that is pressed against the feed roller 22a.
The glass fiber drawn from 0a is drawn, and the strand 14a is cut into a length determined by the cutter blade interval by biting the strand 14a at the pressure contact with respect to the surface of the feed roller to form a chopped strand 30a.
Chopped strand 30a is usually about 1 for glass fiber.
It contains 0-15% by weight of coating.

The other two sets of production equipment shown in FIG. 1 are operated in the same manner, and in this figure, one set of wet chop strands produced from three sets of glass fiber strand production equipment is collected. Although it is shown as being put into a drying device, the number of glass fiber chopped strand manufacturing facilities can be further increased.

Since the glass fiber strands from each spinning furnace are cut by different cutting devices, the resulting wet chopped strands need to be fed into the drying device 50 from the feeding port 51 by some conveyance means for drying. As the conveying device and the drying device, known devices such as a belt conveyor and an aeration drying device can be used. However, in the present invention, it is preferable to use a vibrating transfer device described below as this transfer device to prevent the glass fiber or coating material from adhering to the transfer device and peeling off the deposited material and mixing it into the product. You can get quality products.

Installed at the bottom of the cutting device 20a, a trough (vibration) for vibrating and transporting wet chopped strands has an installation angle of 20.
-60 degrees, the frequency is 1200-1600HZ, using the vibration transfer device 40a with an amplitude of 0.2-3mm, after cutting, the wet chopped strands 30a that fall are put into the vibration drying device 50 from the input port 51 without depositing. .

When the installation angle of the trough is 20 degrees or less, the fibers adhere to the trough, and when it is 60 degrees or more, the wet chopped strands, which are aggregates of filaments, cause a "deviation" phenomenon, which is not preferable because the shape is deteriorated. If the frequency is low, the fibers will stick to the trough, and if the frequency is high, the wet chopped strands will tend to come apart. Further, when the amplitude is 0.2 mm or less, there is a problem in the carrying capacity, and when the amplitude is 3 mm or more, the wet chopped strands are likely to come apart.

The vibrating and conveying device may be vibrated individually by a known vibrating means, but if the vibrating aeration drying device and the vibrating source are shared, it is effective for downsizing the device.

One vibration dryer 50 is attached to a plurality of chopped strand manufacturing machines.

Embodiment An embodiment of the present invention will be described below with reference to the first drawing.

A glass fiber filament with a fiber diameter of 13 μm drawn out from a bushing with a nozzle of 2800 holes and coated with an epoxy resin binder by a coating roller is divided into 3 by a focusing roller at the bottom of the coating roller, and about 900 glass fiber strands Three pieces are introduced into the cutting device and drawn at a speed of 1100 m / min to form chopped strands with a cutting length of 3 mm.

A chopped strand divided in the same manner is manufactured with a bushing similar to this, and the vibration aeration drying device is arranged immediately below the central bushing by using these three bushings as a group of manufacturing units. This vibrating aeration drying device was arranged directly below the cutting device located in the center, and a vibrating trough was installed as a conveying device for introducing the wet chopped strands into the drying device below the cutting devices located on the left and right. The vibration trough has a length of 660 mm and a width of 240 mm.
It was mounted at an angle of 30 degrees downward, and was vibrated at the same amplitude of 2 mm and the frequency of 1450 Hz as the vibration aeration dryer by the rotary vibrators mounted on the left and right sides of the dryer. Moisture content 12 wt% wet chopped strands cut by the cutting devices located on the left and right sides of the drying device are thrown into the drying device without dropping and depositing on the vibrating trough mounted 1000 mm below the cutting point, and The wet chopped strands cut by the cutting device located directly above the drying device were introduced from directly above the drying device.

The dryer is a vibration / ventilation type, and the aperture ratio of the perforated baffle plate is 3
%, Amplitude 2 mm, frequency 1450 Hz, and small hole passing wind speed 5 m /
The heating air temperature at that time was set to 160 ° C in sec.

The wet chopped strands supplied from each cutting device were 60 Kg / Hr each, and were dried and cooled and taken out as a product.

Comparative Example Glass fiber strands drawn out from three bushings were collected and cut by one large cutting device, and reconnection after breaking of the strands was performed by stopping the operation of the cutter, and otherwise the same as the example. It was manufactured under the conditions.

Table 1 shows the results of measuring the number of breaks, the product yield, and the properties of the chopped strands of Examples and Comparative Examples.

As can be seen from this result, the product yield is good even though the number of breaks is larger than that of the conventional one. It has a large bulk density and good fluidity.

[Effects] In the present invention, since a cutting device is installed for each spinning furnace, the spinning furnace for stopping the cutting is limited to the one in which the glass fiber breaks, unlike the conventional manufacturing method. The furnace allows continuous production without being affected by this, which improves the product yield.Because the number of strands that can be cut with one cutter roller is small, the cutting device can be downsized, and the narrow spinning operation is possible. The environment can be improved.

Further, since the mounting angle and the amplitude of the vibration trough are set to specific conditions, the deposition of the glass fiber and the coating material adhering to the trough is eliminated, and the deposit is not mixed into the product.

[Brief description of drawings]

 FIG. 1 is a front view of an embodiment of the present invention. FIG. 2 is a front view of a conventional manufacturing method. 10a …… Bushing (lower part of spinning furnace) 11a …… Filament 12a …… Coating roller 13a …… Converging roller 14a …… Strand 20a …… Cutting device 21a …… Guide roll 20a …… Feed roller 23a …… Cutter roller 30a …… Wet chopped strand 40a …… Vibration transfer device 50 …… Drying device, 51 …… Inlet 52 …… Rotary vibrator

Claims (2)

[Claims] 1. In the production of chopped strands in which glass fibers are spun from a plurality of spinning furnaces, bundled, and immediately cut, a single cutting device is provided for each spinning furnace and the wet chopped strands are dried. Of glass fiber chopped strands characterized by: 2. A trough that vibrates and conveys wet chopped strands has an installation angle of 20-60 degrees and a vibration frequency of 1,200-1,6.
The method for producing glass fiber chopped strands according to claim 1, characterized in that the glass fiber chopped strands are introduced into a drying device by means of a vibration transfer device having an oscillation frequency of 00HZ and an amplitude of 0.2-3 mm.