JPS648738B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for forming highly homogeneous spread sheets from continuous fiber bundles.

More specifically, the present invention relates to a method and apparatus for splitting and expanding a continuous fiber bundle using a liquid fluid to form a sheet, and by controlling the flow of the liquid fluid to spread the fiber bundle highly uniformly. .

Conventionally, methods for forming sheets from continuous fiber bundles include methods in which melt-spun continuous fiber bundles are separated and collected using static electricity, and continuous fiber bundles are separated using air flow, spread, and captured. A method of collecting fibers, and a method of splitting and spreading a continuous fiber bundle using a water stream to form a sheet on a net are known.

Among these methods, in the method of splitting and spreading a continuous fiber bundle using a liquid flow such as a water stream to form a sheet, the entanglement of single fibers causes uneven spreading, and the twisting of the continuous fiber bundle itself causes the spread. Since opening itself becomes impossible, it was necessary to pay sufficient attention to the manufacture and handling of the continuous fiber bundle to be supplied.

Moreover, it is difficult to stabilize the liquid flow even when using a continuous fiber bundle adjusted in this way, and when supplying the fluid flow, air is taken into the continuous fiber bundle, making it difficult to spread uniformly. I couldn't keep it running for a long time.

For this purpose, as disclosed in JP-A No. 50-121568, a slit-shaped opening is opened at the lower end of a part of the side wall of the liquid tank, and a slit-shaped opening is opened at the bottom of the slit-shaped opening side in a direction substantially perpendicular to the flow direction of the liquid flow. A continuous fiber bundle expanding device is provided in which a tapered expanding groove having a plurality of extending protrusions is connected to each other. However, in this device, the flow direction of the liquid in the inclined expansion groove has enough room to spread freely in the width direction of the expansion groove. Due to differences in the degree of partial overlap, etc., there is a difference in the resistance to the flow of liquid in the width direction of the expansion groove. Strict process control was required to form highly homogeneous sheets that were prone to cracking.

The inventor of the present invention has further conducted research to solve these problems and has improved the inclined expansion device to control the flow of liquid across the width of the expansion groove. The present inventors have invented a method and device that can split and spread a continuous fiber bundle extremely uniformly using a dogleg-shaped slanted spreading groove.

The gist of this is that multiple continuous fiber bundles are separated and expanded individually in advance using an inclined expansion groove that widens toward the end, and then, while being made one or more U-turns, they are homogenized using another inclined expansion groove. In this method, a slit-shaped opening is opened at the lower end of a part of the side wall of the liquid tank that supplies a plurality of continuous fiber bundles, and a plurality of slit-shaped openings are formed on the slit-shaped opening side extending in a direction perpendicular to the flow direction of the liquid flow. A plurality of protruding portions are provided on the lower plate and/or the upper plate, and a plurality of tapering grooves are arranged in a row in the width direction, and a plurality of protruding portions extending in the flow direction of the liquid flow are provided on the downstream side thereof. A continuous fiber bundle expanding sheet forming device is provided in which a plurality of inclined expanding grooves provided on a plate are connected vertically in a dogleg shape.

The present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a perspective view showing an example of the expanding device of the present invention, and FIG. 2 is a side sectional view thereof.

In FIGS. 1 and 2, a liquid tank 1 maintained at a constant liquid level includes a plurality of continuous fiber bundles 2, 2',
2'', etc. are supplied via guide rollers 3, 3', 3'', etc., and a constant amount of liquid is supplied from an inlet 4, filling the liquid introduction tank 5 in a spreading shape. A slit-shaped opening 6 is formed between the lower end of the side wall of the liquid tank 1 and the lower part of the liquid introduction tank 5, and this slit-shaped opening 6 increases the flow rate of the liquid in the liquid introduction tank 5. The continuous fibers 2, 2', 2'', etc. inside are drawn into the inclined expansion groove.

From the entrance of the inclined expanding groove to the lower end, separating plates 7, 7', 7'' form inclined expanding grooves 8, 8', 8'', etc., which widen toward the end, corresponding to each continuous fiber bundle. are formed in the expansion grooves 8, 8', 8'', and the continuous fiber bundle is separated and expanded by the flowing liquid flow.At this time, the expansion grooves 8, 8', 8'''' upper plate 9 and lower plate 10 are provided with a plurality of protrusions 11, 12, 13 extending perpendicularly to the flow direction of the liquid flow, and the fiber bundles 2, 2', 2'' pass through the liquid flow direction. Pass with the flow.

Furthermore, a weir plate 14 is installed downstream of the inclined expansion grooves to control the flow rate and discharge amount of the flowing liquid, and is connected to the lower plate 17 downstream of the inclined expansion grooves 8, 8', 8''. A plurality of protrusions 16, 16', 1 are provided on the lower plate 15.
An inclined expansion groove 17 having a diameter of 6" or the like is provided, and furthermore, at the tip of this inclined expansion groove 17, a gap is formed between the bottom plate 19 of the next inclined expansion groove 18 for several m/m in the vertical direction. The expanded groove 18 is provided, and the next inclined expanded groove 20 is also connected in a similar positional relationship, and the liquid flow flows through each inclined expanded groove 1 along with the continuous fiber bundle.
From the tips of 7 and 18, they flow in opposite directions. The continuous fiber bundle from the inclined widening groove 20 is collected on a net 21 which moves at a constant speed along with the liquid flow.

To explain further, the liquid tank 1 is always filled with liquid, and the air trapped between the single fibers of each fiber bundle of continuous fiber bundles 2, 2', 2'' is discharged while passing through the liquid. As a result, the liquid is filled between each single fiber, which helps eliminate fine fiber unevenness.Therefore, it is desirable to keep the liquid level in the liquid tank 1 constant. Transfer the liquid from tank 5 to liquid tank 1
If the amount of liquid received is large, the liquid level can be easily kept constant by overflowing from the liquid tank 1, or if the amount of liquid is insufficient, additional liquid can be injected into the liquid tank 1 from the outside and overflowing. can be maintained.

Each continuous fiber bundle 2,
2', 2'', etc., the fiber bundles are guided into the respective tapered slanted expansion grooves 8, 8', 8''. At this time, each inclined expansion groove 8, 8',
In order to uniformly introduce the amount of liquid flow into each of the inclined expansion grooves, the liquid introduction tank 5 needs to have a large volume and be filled with liquid. Each inclined expansion groove 8, 8',
8", a uniform amount of liquid is introduced, and it takes care of only the spreading width required for each continuous fiber bundle to be supplied. Therefore, the diffusion of the flowing liquid stream is also finely controlled, so that it is possible to create a widening shape at the end. The separation and expansion of each continuous fiber bundle 2, 2', 2'', etc. in each inclined expansion groove 8, 8', 8'', etc. is extremely uniform, and it is possible to form a sheet with a uniform expansion width. Each of the tapering grooves has a plurality of protrusions 11, 12, 1 in a direction perpendicular to the direction of liquid flow.
3, etc. are provided on the lower and upper plates, so that when the continuous fiber bundles 2, 2', 2'', etc. flow up and down in a wavy manner with the liquid flow, they are uniformly split and expanded. Furthermore, at the downstream outlet of the inclined expansion grooves 8, 8', 8'', etc., the lower plate 10 forming each inclined expansion groove is
A slit-shaped opening is formed by the weir plate 14 and the weir plate 14. This slit-shaped opening has a mechanism in which the cross-sectional area of the slit-shaped opening can be adjusted by vertically moving the weir plate 14. , 8'', the flow rate is controlled and the spread width of the continuous fiber bundles 2, 2', 2'', etc. is controlled. Therefore, each continuous fiber bundle 2, 2',
The amount of liquid passing through this slit-shaped opening can be appropriately set depending on the total denier of 2" and the expansion width required for each fiber bundle. In this way, the fibers can be separated and expanded uniformly. When even a continuous fiber bundle is directly collected on the net 21 along with the liquid flow, gaps 23, 23' are created between the continuous fiber bundles 22, 22', 22'' obtained as shown in FIG. In this way, a sheet with gaps is formed. The reason for this is that the continuous fiber bundles 22, 22', which are separated and expanded immediately after the expansion width is regulated by the separating plates 7, 7', 7'', etc.
This occurs because 22'' is collected on the net as it is, and there is no diffusion of the liquid flow.

Furthermore, if the continuous fiber bundles 2, 2', 2'' are still insufficiently spread out even by the inclined expansion grooves 8, 8', 8'', this is mainly due to the single fibers constituting the continuous fiber bundles. A subpopulation of fibers twists, inverts, and inverts within a continuous fiber bundle.
This is often caused by the properties of the continuous fiber bundle, such as the fibers running diagonally. Providing a squeezing effect inside is an essential condition for obtaining a more homogeneous spread sheet.

In the present invention, a plurality of protrusions 16, 16', and 16'' are provided on the bottom plate so as to connect the inclined expansion groove to the bottom plate 10 immediately after the slit-shaped opening, and there is no separating plate. An inclined expanding groove 17 is provided in a direction perpendicular to the flow direction, and an inclined expanding groove 18 having a similar shape is provided.
, the lower plate 19 of the lower plate 1 of the inclined expansion groove 17 is
5, and the continuous fiber bundle opened with the liquid flow is allowed to flow down in the direction opposite to the direction of flow in the inclined expansion groove 17. The continuous fiber bundle opened at the tip of the lower plate 15 of the opening groove 17 is subjected to straining. Furthermore, the inclined expansion groove 20 is also similar to the expansion grooves 17 and 18.
The continuous fiber bundle that has been opened is placed in the same positional relationship as the fiber bundle and subjected to straining. By repeatedly subjecting the spread tow to squeezing multiple times in this way, and by allowing the spread tow to flow down for a long period of time along with the liquid flow through the multiple protrusions on the lower plate of each inclined expansion groove, single fibers within the continuous fiber bundle are Strong twisting, inversion and oblique movement of a partial group of fibers are also spread out extremely uniformly. Moreover, since it is an inclined expansion groove without a separating plate, there is no resistance to the diffusion flow of the liquid flow, and the separated and expanded continuous fiber bundles 22, 22', 22'' are expanded slightly further throughout, thereby eliminating the gap. It is possible to obtain an extremely homogeneous sheet without causing any formation of particles.
FIG. 4 shows this state. Furthermore, since the inclined expansion grooves 17, 18, 19, etc. are installed in multiple stages in the vertical direction, it is extremely compact and can lengthen the residence time of the opening tow in the liquid flow, making it easy to install the device. It also has the great advantage of reducing space.

As explained above, by using the method and apparatus of the present invention, it is possible to subdivide and control the diffusion flow of the liquid flow, and furthermore, the continuous fiber bundle that has been opened is given multiple strokes and the fiber bundle is kept in the liquid flow for a long time. The major feature of this method is that it is possible to perform a fiber-spreading process, so that regardless of the properties of the fiber bundle, highly homogeneous sheets can be obtained in the width and longitudinal direction, from sheets with extremely low to high basis weights. Yes, the industrial value is extremely large.

[Brief explanation of the drawing]

1 and 2 are a perspective view and a side sectional view showing an example of an apparatus for carrying out the method of the present invention,
FIG. 3 is a plan view of a spread sheet obtained by the conventional method, and FIG. 4 is a plan view of a spread sheet obtained by the method of the present invention.

Claims (1)

[Scope of Claims] 1. A plurality of continuous fiber bundles are supplied into a liquid stream flowing down an inclined expansion groove, and the fiber bundles are produced by the flow of the fluid that spreads downward in an expanding shape. In this method, multiple fiber bundles are separated in advance by a separating plate and spread out in an inclined expansion groove that widens at the end, and then U
A method for forming a continuous fiber bundle into a sheet by expanding it into a homogeneous sheet while turning the fiber bundle in another inclined expansion groove. 2 A slit-shaped opening is opened at the lower end of a part of the side wall of the liquid tank that supplies a plurality of continuous fiber bundles, and a plurality of protrusions extending in a direction substantially perpendicular to the flow direction of the liquid flow are provided at the bottom of the slit-shaped opening side. A plurality of tapering grooves provided on the plate and/or the upper plate are arranged in a row in the width direction with a separation plate interposed therebetween, and a plurality of protrusions extending in the direction of fluid flow on the downstream side thereof. This is a continuous expansion sheet forming device in which a plurality of inclined expansion grooves provided in the lower plate are arranged vertically in a dogleg shape.