Fiberweb North America, Inc.

Leon M Zeldin

John V Francis

Lloyd E Trimble

Jean-Pierre R Vuillet

Ronald E Lamkin

Joseph E Werner

William J Grubbs

A slot draw attenuator apparatus and method are provided for producing webs of spunbonded thermoplastic filaments having improved cover even at low basis weights. The filaments are introduced to a slot draw attenuator having corona electrodes mounted in an elongate insulator bar and staggered and spaced along one wall of the attenuator slot near the exit end thereof. The corona electrodes are electrically connected to a high voltage source. The opposing wall of the slot is grounded. A corona is created in the attenuator slot so that the filaments are charged as they exit the attenuator. The electrostatic charge induces repelling forces in the filaments so that the filaments spread before they are randomly deposited upon a forming belt.

Apparatus and method for producing a web of thermoplastic filaments

An apparatus and method are disclosed for forming a nonwoven fabric web, such as a spunbond web. The apparatus comprises a spinneret for downwardly extruding a curtain of filaments, and an underlying air drawing unit for drawing and attenuating the filaments as they move downwardly therethrough. A conveyor belt receives the drawn filaments and forms the filaments into a nonwoven fabric web. In the drawing unit, the filaments pass downwardly through a slot, and a pair of air nozzles are positioned in the slot, with one nozzle being positioned adjacent each side wall of the slot. The nozzle outlets are oriented so as to introduce each of the air streams into the slot in a direction which is parallel to the side walls of the slot, and the introduced air streams act to draw additional air into the open upper end of the slot. The drawn-in air and the air introduced by the two nozzles collectively form a substantially non-turbulent flow at their juncture and along the remainder of the vertical length of the slot, and this smooth air flow serves to draw the filaments without imparting turbulence to the filaments, which in turn produces filaments which are uniformly drawn and thus of uniform denier.

Apparatus for producing nonwoven fabric

A method and apparatus for providing uniformly distributed filaments from a spun filament bundle and a process for forming spunbonded fabric having superior uniformity and a favorable ratio between machine and cross direction tensile strengths. The apparatus includes a fiber transfer tube and a pair of adjustable deflector plates. The deflector plates form a channel having a tapering width for transporting the filaments in a stream of high velocity air. The apparatus may also include an electrostatic charging means for applying an electrostatic charge to each individual filament after it exits the channel. The method for providing uniformly distributed filaments includes a first stage of separating the filament bundle by the high velocity stream of air and may also include a second stage of electrostatically charging the filaments to achieve a uniform filament separation. The process for forming spunbonded fabric enables a fabric to be produced having a machine direction to cross direction tensile strength ratio less than about 1.5.

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Greer, SC, United States of America

Leon M Zeldin