Apparatus for the manufacture of crimped bulky filaments

Claim 1

In an apparatus for preparing crimped bulky filaments including a feed roll for feeding continuous non-crimped thermoplastic synthetic filaments having a total denier of 40 5,000 at a rate of at least 250 m/min. to a jet nozzle having an open end for projecting a heated jet stream accompanying the filaments fed to said jet nozzle, the jet stream being held at a temperature of from 200* C. to a point 40* C. higher than the melting point of the filaments and a pressure of from 3 to 12 kg/cm2 gauge, a moving screen upon which the heated jet stream impinges allowing the heated jet stream to pass therethrough while leaving the filaments on the screen, and a take-up roll for removing the crimped filaments, wherein the value (x) expressed by the following formula is at least 60,000 de.meter/min. (x) (D) X (R) in which D is the total denier of the filaments fed to the jet nozzle and R is the filament feeding rate, the improvement comprising said moving screen being an assembly screen having a perforation ratio of from 20 to 60 percent and including at least a perforated upper screen and a perforated lower screen, said upper and lower screens being spaced by a distance up to 2mm., the plane perforation area of each portion of said lower screen overlapping each perforation of said upper screen being smaller than the plane area of each perforation of said upper screen, said overlapping portions of said lower screen providing an open space sufficient for the jet stream to pass through said portions and freely escape from said assembly screen, and said open end of said jet nozzle being spaced from said upper screen by a distance of up to 3 mm.