Patent ID: 7571524

Claim:
A method of producing a spread multi-filament bundle comprising the steps of: subjecting a multi-filament bundle in carriage to fluctuation of a tensile force applied to said bundle alternatively between tension and relaxation by locally and reciprocally pressing said bundle fed from a yarn supplier crosswise with regard to a moving course of said bundle; passing in suspension said multi-filament bundle moving under said fluctuation through a plurality of fluid flowing portions in succession comprising a fluid flowing spreader, said portions being disposed in series along a moving course of said multi-filament bundle; subjecting said multi-filament bundle to fluidal resistance while said bundle moves through said respective fluid flowing portions so as to bend said bundle towards a direction to which a fluid in use flows; and flowing said fluid through an interstice between any adjacent monofilaments of said bundle whose bonding is slackened due to said fluidal resistance so as to widen said interstice, thereby, promoting spreading operation on said bundle, wherein said multi-filament bundle to be subjected to said spreading operation is continuously passed through said fluid flowing portion located in an upstream side of the spreader to said fluid flowing portion located in a downstream side of the spreader in succession to gradually enlarge contact area between said bundle and said fluid so as to widely spread said multi-filament bundle in a progressive manner.