JPH022980B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for opening a fiber bundle and an apparatus therefor. More specifically, the present invention relates to a novel method and apparatus for charging fibers and opening them using the repulsive force.

Conventionally, various methods have been proposed for applying static electricity to fibers to open them. For example, Tokuko Sho 48-34544
In the publication, the fiber bundle is fed between a pair of opposing belt conveyors to which a high voltage is applied at a faster speed than the belt conveyor, and the fiber bundles carrying an electrostatic charge are repelled from each other to open the fibers. A method has been proposed in which the waste is accumulated on the lower belt. Also, JP-A-55-
In Publication No. 80566, an untwisted filament bundle is charged, then introduced into a roller whose core is grounded and whose surface is coated with elastomer, and the lower high voltage pole is projected onto a belt on the back side to open the filament. A method of creating a web has been proposed.

The method of opening fibers using electrostatic force is industrially preferable because it consumes less energy than methods that utilize air flow or mechanical methods (rubbing, relaxation, tension).

However, in Japanese Patent Publication No. 48-34544, the number of belts used is too large, special consideration must be taken regarding belt meandering and wear during continuous production, machine maintenance is complicated, and fiber bundles are It has the disadvantage that it tends to get wrapped around the rollers used to feed between opposing belts. Furthermore, Japanese Patent Application Laid-Open No. 55-80566 has the drawbacks of high equipment costs for high-voltage electrodes and rapid friction of the elastomer.

As a result of intensive research into a method that does not have the above drawbacks, the inventors of the present invention have found that the above drawbacks can be overcome, and the fiber opening property is extremely good, the fiber spread is large, and the strength and bulk of the resulting web are improved. We discovered a major method and arrived at the present invention.

That is, the present invention is a method of spreading fibers by applying static electricity to a fiber bundle, in which the fiber bundle is brought to the surface of a rotating belt conveyor and the fiber bundle is separated by friction between the surface of the belt conveyor and the fiber bundle. The fiber bundle is moved along with a rotating belt conveyor while being electrically charged, an electric field is formed at a predetermined location to cause the fiber bundle to separate from the belt conveyor, and at the same time, the fiber bundle is opened and collected by electrostatic repulsion. A method for opening fiber bundles, and a device for opening fibers by imparting static electricity to the fiber bundles, comprising: a belt conveyor that charges the fiber bundles while transporting them; and a belt conveyor that charges the fiber bundles while transporting them; This is a fiber bundle opening device consisting of an electric field application device that causes the fiber bundle to separate more easily.

The fiber bundle used in the present invention is preferably one with little twist and relatively low interaction between single fibers. For example, a synthetic fiber tow with a number of crimps of up to 20 crimps/inch is tensioned and relaxed with a notched roller and then pre-opened, or a tow that is pre-opened by being rubbed with a pair of toothed rollers is used. It will be done.

Furthermore, the tow obtained by the manufacturing method described in JP-A-55-128062 is a preferred fiber bundle because it has little twist and extremely good parallelism between the fibers.

The present invention will be described below with reference to the accompanying drawings. The fiber bundle is either charged in advance with a friction rod such as 2 or a discharge electrode, or is introduced onto the surface of the rotating belt conveyor 3 without being charged. The material of the belt conveyor 3 is preferably one that is easily charged with an opposite charge to that of the fiber bundle due to friction with the fiber bundle. That is, it is preferable that the positions of the charging series of the material of the belt conveyor 3 and the material of the fiber bundle are apart. For example, for polyethylene terephthalate fiber bundles, polyvinyl chloride,
Conveyor belts made of polyethylene, polytetrafluoroethylene, polypropylene, polycaprolactam, etc. are preferred, and polyvinyl chloride is particularly preferred. Although the effects of the present invention can be exhibited even with a conveyor belt made of polyethylene terephthalate, which is the same material as the fiber bundle, polyvinyl chloride is better.

The belt conveyor 3 is rotated slightly faster than the introduction speed of the fiber bundle, thereby causing friction between the two. Preferably 1.05 to 1.05 of the introduction speed of the fiber bundle
A 1.5 times higher circumferential speed is advantageous. This relatively fast rotation causes friction between the belt surface of the belt conveyor and the fiber bundle, and the fiber bundle and the belt are charged to opposing potentials. A preferable charging potential is about 1 kV to 30 kV.
Since the belt is charged with a sign opposite to that of the fiber bundle, the belt acts to attract the fiber bundle being introduced into the belt conveyor, and the fiber bundle is introduced very smoothly. There are very few problems during the process. This is one of the advantages compared to the proposed method.

While the fiber bundle is being conveyed by the belt conveyor, it is sufficiently charged as described above, and an electric field is applied to the fiber bundle at a predetermined location in a direction that causes the fiber bundle to separate from the belt. In the drawing, an electrode plate to which a high voltage having the same sign as the charged potential of the fiber bundle is applied, such as 5, is installed on the back side of the belt conveyor at a predetermined location, and the collection location of the fiber bundle is grounded. By doing so, the electric field is formed. The high voltage applied to the electrode plate is a voltage that does not change sign, such as a half wave obtained by rectifying direct current or alternating current, and preferably has a potential of 5 kV to 50 kV. The collection site may be grounded and may also be equipped with an air suction device.

By applying such an electric field to the fiber bundle, the fiber bundle is automatically separated from the belt conveyor 3, and the fiber bundle is shaped into a spindle due to the electrostatic repulsion between the single fibers of the fiber bundle. It spreads, is attracted to collection sites, and is deposited. Since the location where the single fibers constituting the fiber bundle leave the belt conveyor 3 varies slightly within a certain range (usually within the range of the electrode plate 5), random accumulation of fibers is facilitated. This is a desirable phenomenon since it is advantageous when producing a bulky web and also contributes to improving the strength of the produced web or the nonwoven fabric formed by pressing the web into a sheet.

According to the method of the present invention, long-fiber thermal batting, sheet-like nonwoven fabrics, etc. can be produced in an energy-saving manner, and the physical properties of the products exceed those of conventional products. Specific examples will be explained below in Examples, but the scope of the present invention is not limited thereto.

Example Single yarn denier approximately 3 de, total denier approximately 100,000
A fiber bundle of polyethylene terephthalate produced by the method disclosed in Japanese Patent Application Laid-open No. 55-80566 of 1983, and stretched approximately 2.5 times while maintaining the parallelism of the fibers, is connected to three polyvinyl chloride rods 2 as shown in the attached drawing. belt conveyor made of polyvinyl chloride film 3
lead to. The introduction speed of the fiber bundle is 20 m/min,
The peripheral speed of the belt conveyor 3 is 23 m/min, and the diameter of the fiber bundle introduced into the belt conveyor 3 is approximately
It was conveyed on a belt for 1.5 m, and when it separated from the belt at the position of the 10 cm wide pole plate 5 to which +20 kV was applied, it was collected on the collecting belt 6 about 40 cm below while forming a spindle shape. The collection belt 6 was made of 200-mesh stainless steel wire mesh, and its circumferential speed was about 1/4 that of the belt conveyor 3. Further, the collection belt 6 was grounded. Approximately 15% polyacrylic acid ester is applied to the nonwoven fabric deposited on the collecting belt, and it is temporarily pressed and wound up as shown in the drawing.
The nonwoven fabric obtained by main pressing at 200℃ has a basis weight of 82g/m ²
It had excellent strength and elongation properties.

[Brief explanation of drawings]

The accompanying drawings show specific examples of the device of the invention. 1 is an introduction, 4 is a roller for gripping and rotating the belt (normally kept electrically neutral), 5
Reference numeral 1 indicates an electrode plate that forms an electric field to separate the fiber bundles, 6 indicates a belt (usually made of conductive material) that collects the fiber bundles, and 7 indicates an air suction device that collects the fiber bundles. (does not necessarily need to be used),
6 may be replaced with one roller with a large diameter, a pair of rollers, etc.

Claims (1)

[Claims] 1. In a method of spreading fibers by applying static electricity to a fiber bundle, the fiber bundle is brought to the surface of a rotating belt conveyor and the fiber bundle is spread by friction between the belt conveyor and the fiber bundle. The fiber bundle is moved along with a rotating belt conveyor while being electrically charged, and an electric field is formed at a predetermined location to cause the fiber bundle to separate from the belt conveyor. At the same time, the fiber bundle is opened and collected by electrostatic repulsion. Characteristic method for opening fiber bundles. 2 A device for opening fibers by applying static electricity to the fiber bundle, which comprises an electric field application device that causes the fiber bundle to be separated from a belt conveyor that moves at a circumferential speed of 1.05 to 1.5 times the introduction speed of the fiber bundle. textile equipment.