Polymeric strands with high surface area and methods for making same

• Main Author: LEE KIRBY JAMESON
• Format: Patent
• Language: English
• Published: 05.12.1997
• Edition: 6
• Subjects: MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OFARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES ORRIBBONS; NATURAL OR ARTIFICIAL THREADS OR FIBRES; SPINNING; TEXTILES

A melt-extrudable polymeric strand with altered physical properties formed by extruding an emulsion comprising a melt-extrudable polymer and an immiscible component while subjecting the emulsion to ultrasonic energy. In one embodiment, a melt-extrudable polymeric strand has a plurality of fissures in the surface of the strand such that the strand has a B.E.T. surface area to six times the B.E.T. surface area of an otherwise identical strand lacking the plurality of fissures. Desirably, the strand of this embodiment has a B.E.T. surface area of within a range from about 0.10 to about 0.18 m2/g. In a method for making such a strand, the immiscible component of the extrudable emulsion comprises a substance that is an expandable gas upon extrusion. The expandable gas forms the fissures in the strand. According to another aspect, a polymeric strand has a continuous phase which is a melt-extrudable polymer and a disperse phase which is immiscible with the continuous phase. The disperse phase forms discrete pockets of material in the extruded strand and can include a variety of components which alter the physical properties of the strand. Suitable components of the disperse phase include water, aqueous solutions, oils, low melting point metals, and other physical property altering materials.