FR2468678A1 - Three-dimensional random-orientation fibre web - produced by re-orientation of fibres by electric field during deposition (SE 13.4.81) - Google Patents

Abstract

In the formation of fibrous webs, pads, etc., partic. of mineral or inorganic fibres, the fibres are deposited from an air stream onto a conveyor in a chamber within which is an electric field of at least 50 kV/m, which so orients the fibres that at least one-third of them make an angle of between 20 and 60 deg. with the plane of the web, and retain the orientation within the web. The web is treated with a binding agent after leaving the chamber. Within the plane of the web, the fibres form an angle of 0-180 deg. with the edges thereof. The process gives voluminous webs of relatively low fibre content which have high resistance to compression and deformation. The web is formed in a single, non-complicated process without the need for complex machinery and gives economies in raw material, power, and labour requirements.

Description

The present invention relates to a process for the manufacture of fibrous textile articles such as strips, mats and sheets of fibrous fabric preferably having a high resistance to pressure and to deformation, from mineral fibers, glass fibers as well as from other organic and inorganic fibrous materials.

I1 is known that fibrous textile articles whose fibers are oriented perpendicularly to the extent of the card web, have a high resistance to pressure and deformation.

In known processes for the manufacture of fibrous textile articles, the fibers of which are in the upright position, the carding veil first produced and the fibers of which are oriented in the plane of the extent of the carding veil, is subjected to a subsequent and expensive treatment in order to modify the fibrous structure.

We know, for example, a process according to which the fibers, after their manufacture on a spinning machine, are moistened with a binder and introduced, using a stream of air into a room where, thanks to a device suction, they are deposited with their larger surface of attack on a means of transport which constitutes the support for the sail of carding in formation.

As a result, the fibers of the carding veil are first oriented parallel to the plane of the extent of the carding veil. the fibrous structure it is cut into parallel strips which are turned by 900 and glued to a support material, for example a sheet of paper or aluminum (Information 105 - Anwendungstechnische Mitteilung-en der Deutschen Rockwool GmbH, Gladbeck
FRG) o
This known method has the drawback that the modification of the fibrous structure requires one and its implementation, which increases the operating and maintenance costs which have repercussions on the cost price of the textile articles thus produced. As a result of this method of depositing the fibers, the card web has an insufficient volume and it is necessary to bring in a large quantity of material in order to remedy this defect.

Another method is also known according to which the carding veil produced in an identical manner to the preceding method, is sectioned after leaving the formation chamber, and is compressed by folding the edges, the binder then being hardened (Ser. Prom. Polymernych. ..

mater, Moscow 13 (19763 9, pages 31 and 32).

 The disadvantage of this process lies in the high energy consumption and in the significant expense to be considered for the equipment and the implementation.

 Furthermore, this process does not make it possible to obtain a sufficiently high resistance to pressure and to deformation because the horizontal fibrous structure is preserved.

 The object of the present invention is to create a process which makes it possible to reduce the expenditure in technical equipment, in manpower as well as the consumption of material and the operating and maintenance costs during the manufacture of fibrous textile articles. with high resistance to pressure and deformation.

The defects inherent in the known solutions come from the fact that the fibers, after their production, are sucked inside the chamber in the card web during formation, by their larger surface of attack which has the effect of create a card sail, the fibers of which extend parallel to the support of the card sail. This is why the object of the present invention is to create a process which makes it possible to dispense with the subsequent modification of the fibrous structure during the manufacture of fibrous textile articles.

 These problems are solved in accordance with the invention by a method for the manufacture of fibrous textile articles in which the fibers produced in the spinning chamber are brought by a stream of air into a chamber inside which they are deposited. on a transport device for forming a carded sail, this process being characterized in that the fibers are introduced, in the dry state and free of binder, into an electrostatic field of at least 50 KV / m, in that '' at least a third of the fibers is oriented by this field to form an angle between 20 and 600 with the plane of the carded sail and in that the fibers are introduced in this position into the carded sail which is then treated with using a binder after leaving the formation chamber. In the electrostatic field the fibers are oriented relative to the plane of the extent of the carding sail so that they form an angle between 0 and 1800 relative to the longitudinal sides to and across the card sail.

 Various other characteristics of the invention will also emerge from the detailed description of the embodiment which follows.

The fibers produced by a spinning machine are brought to the dry state and free of binder in a deposition chamber by an air stream. In this chamber, an electrostatic field with an intensity of at least 50 KV / m is created by means of a pair of electrodes. The fibers introduced by the air current into the electrostatic field are turned inside the latter in the direction of the field so that they occupy an upright position and substantially perpendicular to the plane of the carding sail. As a result of the cooperation of the electrostatic field, the air stream and the suction device located below the carded sail, the fibers are oriented and introduced into the carded sail so as to form an angle between 0 and 1800 with respect to the longitudinal and transverse sides of the carded sail and that at least one third of the fibers form an angle with respect to the plane of the carded sail, which can reach 600. This gives a bulky carded sail and heavily felted, the fibers of which are in the upright position but without being aligned, this card web is then treated with a binder outside the chamber.

 This process is used to manufacture fibrous textile articles having a high resistance to pressure and to deformation, from mineral fibers, glass fibers, as well as from other organic and inorganic fibers but without being limited to this type. fiber. The process according to the invention makes it possible to produce fibrous textile articles resistant to pressure and to deformation without it being necessary to subsequently modify the fibrous structure because the fibers of the carding sail are already in the upright position. . It is thus possible to save additional equipment and labor which are necessary when it comes to modifying the structure of the card sails produced according to the known prior processes. The greater volume of the carded sail produced by the process according to the invention also makes it possible to save on fibrous material.

Claims (2)

1 - Process for the manufacture of fibrous textile articles in which the fibers produced in the spinning chamber are brought by a current of air into a chamber inside which they are deposited on a transport device to form a web card, characterized in that the fibers are introduced, in the dry state and free of binder, into an electrostatic field of at least 50 KV / m, in that at least one third of the fibers is oriented by this field to form an angle of between 20 and 60 with the plane of the carding veil and in that the fibers are introduced in this position into the carding veil which is then treated with a binder after leaving the formation chamber. 2 - Process according to claim 1, characterized in that in the electrostatic field the fibers are oriented relative to the plane of the extent of the carded sail so that they form an angle between 0 and 1800 relative to at the longitudinal and transverse sides of the card sail.