JPS60119258A - Opening of continuous filament group - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for opening polyester continuous filaments. More specifically, it is a continuous filament spreading method that can stably produce a uniform web with good single filament opening properties and less uneven filament density from polyester continuous filaments.

In the so-called spunbond method, in which a group of continuous filaments is drawn using an air sucker or the like and then dispersed and deposited on a collecting surface to directly produce a nonwoven web, the continuous filaments are sufficiently opened and spread uniformly. It is an important technical challenge to create a nonwoven web with uniform filament density distribution. Various proposals have been made to obtain a uniform nonwoven web, one of which is to charge the filaments and use the electrical repulsion between the filaments to improve opening properties. Are known. Various techniques have been proposed for charging the filament, such as corona discharge and forced charging, but the simplest method with good operability and stability is A method of imparting an electric charge to a filament by colliding it with another substance having a different value and contact frictional charging has been considered, and a device for imparting an electric charge to a filament using this method is disclosed in Japanese Patent Application Laid-open No. 118068/1983. and disclosed in Japanese Patent Application Laid-open No. FjFi52-118069.

Furthermore, in this method, it is known that the amount of charge imparted to the filament varies greatly depending on the material of the contact plate, resulting in a large difference in the opening and dispersibility of the filament.

For example, JP-A No. 56-101938 discloses that zinc-plated zinc oxide or a metal mainly composed of copper is a material suitable for opening a fibrous material made of polyethylene terephthalate. When a metal mainly composed of zinc, zinc oxide, or copper is used for the contact plate, the effect of improving the opening rate and dispersibility of the polyester filament group is smaller than when other metals are used for the contact plate. However, the use of these contact plates alone is an inefficient means of obtaining a uniform nonwoven web.

Furthermore, Japanese Patent Application Laid-Open No. 57-89635 discloses that a metal mainly composed of lead is a material suitable for making 11 fibers of a fibrous material made of polyethylene terephthalate. Even in the conventional ridge dividing method of the present inventors, if a metal mainly composed of lead is used as a contact plate, not only will the spreadability and dispersibility of the polyester yarn filament group be the same as above, but due to the toxicity of lead, it will be difficult to work. From an environmental perspective, it has been found that various problems arise in industrialization, such as the possibility that lead may be mixed into the nonwoven subweb.

In view of the above-mentioned problems of the prior art, the present inventor conducted extensive research on an excellent contact plate material in order to obtain a uniform web with good single fiber spreadability and less uneven filament density. This has led to the present invention.

That is, the present invention provides a method for opening a group of continuous polyester filaments by colliding the group with a contact plate to generate contact frictional electrification. - A method for opening polyester continuous filaments, characterized by using a bismuth alloy or mixture containing the above.

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

FIG. 1 is a partial sectional view of a feeding device for a continuous filament group used in the present invention, and is a partial cross-sectional view of a feeding device for a continuous filament group used in the present invention.
This device is the same type as the device disclosed in Japanese Patent No. 8069.

In FIG. 1, 1 is a thread guiding groove wall for forming a group of filament passages, and 2 is a contact plate which forms an inclination angle θ with respect to the groove wall 1 and has a length t and a width d. When the filament group 3 running while being towed at high speed collides with the contact plate 2, the filaments are triboelectrically charged and spread and dispersed.

Regarding the contact plate 2 used in the present invention, the material of at least the surface that contacts the filament group must be made of a single bis, or a bismuth alloy or mixture containing bismuth in an amount of 50% by weight or more.

That is, by using bismuth alone or an alloy or mixture containing bismuth in an amount of at least 50 fi % for the contact plate, it is possible to obtain a charging voltage sufficient to sufficiently open the filament group. The bismuth content of this contact plate is 5
If the Oi amount is less than 1, a sufficient band pressure cannot be obtained, and the filament group has poor opening properties, resulting in only a web having large filament density irregularities.

Further, in the bismuth alloy or mixture, injucum, tin, antimony, copper, silver, nickel, etc. are generally used as metals combined with bismuth. The seventh effect will be evaluated based on specific examples described later.

In addition, in the present invention, there is no problem even if other means for opening the fibers, such as the conventionally known filament charging method using corona radiation tK, are used in addition to the means for opening the fiber ruts by collision with the contact plate. No problem. In addition, it is also possible to provide contact plates in multiple stages as necessary.
It includes filaments made of polyesters such as talate, polybutylene terephthalate, and copolymers thereof.

Next, the present invention will be specifically explained with reference to Examples.

Examples 1 to 6 Polyethylene terephthalate was spun at a discharge rate of 400 f/ak from a rectangular integral movable yarn head having 400 spinning holes, and was pulled at a yarn speed of 500 m/- by high-speed airflow to form a group of traveling filaments. After none tc, inclination angle θ - 45° shown in Figure 1 Length t = 30% Width 300% Thickness d = 101
A nonwoven web of 50 f/lri' was produced by impinging on a contact plate of X and collecting it on a moving conveyor placed below the contact plate.

Table 1 shows the filament charging voltage, area weight fluctuation rate, and apparent quality when the material of the contact plate was variously changed in the above method.

The filament voltage in the table is an average value measured in the width direction by a current collecting potential measuring device KS-325 manufactured by Kasuga Denki. In addition, the basis weight variation rate was used as a measure for evaluating the uniformity of web weight distribution, and samples were taken from 30 locations on the web in a size of 25% width and 100× length, and the weight of each sample was measured. This is a value determined by a formula, and the smaller the value, the more uniform it is.

Furthermore, the apparent quality refers to the appearance of the nonwoven web in five grades, including the state of opening of the filaments, poor dispersion due to web blow-off, localized mottling, etc. This is a visual judgment evaluation, and the larger the value, the better the apparent quality.

As is clear from Table 1 below, according to the Gilfa method of the polyester continuous filament group of the present invention (Examples 1 to 6), both the basis weight fluctuation rate and the apparent quality were as low as that of Comparative Example 1.
This shows excellent results compared to Example 3, and it is possible to form an extremely uniform web with good single filament opening properties and less uneven filament density.

[Brief explanation of the drawing]

FIG. 1 is a partial side sectional view of a filament group feeding device used in the method for opening polyester continuous filaments according to the present invention. 1...QUID 2Ment group passageway thread guiding groove wall 2...
... Inclined plate 3 ... Filament group patent applicant Asahi Kasei Industries, Ltd.

Claims (1)

[Claims] In a method of opening a group of continuous filaments by colliding a group of running polyester continuous filaments with a contact plate to generate contact frictional electrification, the contact plate contains bismuth alone or bismuth containing 50% by weight or more of bismuth. Spreading method for polyester continuous filament group using alloy or mixture as /Nj characteristic