Process for producing fiber aggregate

#1. Field of the Invention

#The present invention relates to a process for producing fiber aggregate, and more particularly, it relates to a process for producing fiber aggregate in which most fibers are about one-dimensionally oriented. "One-dimensionally oriented" means that many fibers are oriented in substantially the same direction. This definition is applied not only to the fiber aggregate but also to the orientation step mentioned later.

#2. Prior Art

#These and other object, as well as features of this invention will become apparent by reading the following description referring to the accompanying drawings, wherein:

#FIG. 1 is a schematic sectional view illustrating the process for producing fiber aggregate, said process including the step of filtering the dielectric fluid through a porous filter;

#FIG. 2 is a photograph showing the state of one-dimensional orientation of fibers in Example 1. Fibers disposed in the dielectric fluid are oriented and becomes strong between the positive and negative electrodes;

#The first step of the process of the present invention for producing fiber aggregate is the dispersion step in which short fibers, whiskers, or a mixture thereof are dispersed into a dielectric fluid.

#The fibers used in the dispersion step are short fibers, whiskers or a mixture thereof. Short fibers and whiskers of any kind can be used. They are not specifically limited in diameter and length. Also, they are not limited in material so long as they are capable of static orientation in the dielectric fluid when a high voltage is applied across the positive and negative electrodes. The material of the fiber includes, for example, alumina, silica, alumina-silica, beryllia, carbon, silicon carbide, glass, and metals. Either fibers of single material or a mixture of fibers of different materials may be used.

#The dielectric fluid means a fluid which exhibits the dielectric properties upon application of a high voltage. Examples of the dielectric fluid include carbon tetrachloride, fluorine- and chlorine-substituted hydrocarbon, n-hexane, and cyclohexane. Preferable among them is carbon tetrachloride. Fluorine- and chlorine-substituted hydrocarbons are preferable from the standpoint of handling safety.