Method and apparatus for ultrasonically assisted melt extrusion of fibers

• Main Author: JAMESON LEE KIRBY
• Format: Patent
• Language: English
• Published: 28.05.2002
• Edition: 7
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBONFILAMENTS; APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL; ATOMISING APPARATUS; BLASTING; BRAIDING; BURNERS; CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS,THREADS, FIBRES, BRISTLES OR RIBBONS; COMBUSTION APPARATUS; COMBUSTION ENGINES; COMBUSTION PROCESSES; COTTON-WOOL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS,NON-WOVEN FABRICS; GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGHVELOCITY, e.g. GAS-TURBINE COMBUSTION CHAMBERS; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; KNITTING; LACE-MAKING; LIGHTING; MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARYMATERIAL; MECHANICAL ENGINEERING; MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OFARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES ORRIBBONS; MIXING, e.g. DISSOLVING, EMULSIFYING, DISPERSING; NATURAL OR ARTIFICIAL THREADS OR FIBRES; NON-WOVEN FABRICS; NOZZLES; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; SPINNING; SPRAYING APPARATUS; SPRAYING OR ATOMISING IN GENERAL; SUPPLYING COMBUSTION ENGINES IN GENERAL, WITH COMBUSTIBLEMIXTURES OR CONSTITUENTS THEREOF; TEXTILES; TRANSPORTING; TRIMMINGS; WADDING; WEAPONS; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

An apparatus and a method for the melt extrusion of a molten thermoplastic polymer, e.g., as fibers and nonwoven webs, which apparatus and method utilize ultrasonic energy to assist in the melt-extrusion process. The apparatus includes a die housing which defines a chamber adapted to receive the molten thermoplastic polymer and a means for applying ultrasonic energy to a portion of the molten thermoplastic polymer. The die housing includes a chamber adapted to receive the molten thermoplastic polymer, an inlet orifice adapted to supply the chamber with the molten thermoplastic polymer, and an extrusion orifice adapted to receive the molten thermoplastic polymer from the chamber and extrude the polymer. The means for applying ultrasonic energy is located within the chamber. The method involves supplying a molten thermoplastic polymer and extruding the molten thermoplastic polymer through an extrusion orifice in the foregoing apparatus to form a threadline. The means for applying ultrasonic energy is at least partially surrounded by molten thermoplastic polymer and is adapted to apply the ultrasonic energy to molten thermoplastic polymer as it passes into the extrusion orifice. While extruding the molten thermoplastic polymer, the means for applying ultrasonic energy is excited with ultrasonic energy. The resulting threadline then is attenuated to form a fiber. The means for applying the ultrasonic energy may be an ultrasonic horn.