Steam jet crimping method and apparatus

Claim 1

In a process for texturizing yarn which comprises contacting yarn with a current of heated fluid in a pre-heat zone to heat the yarn, directing the heated yarn under the action of the fluid against a yarn plug contained in a texturizing zone, said texturizing zone having a larger cross-sectional area than the cross-sectional area of said pre-heat zone and disposed with relation to said pre-heat zone such as to form an annulus between the inner periphery of said texturizing zone and the outer periphery of said pre-heat zone, maintaining said texturizing zone under reduced pressure with respect to the pressure in said pre-heat zone, continuously exhausting said fluid through a plurality of passageways in said annulus in a direction substantially opposite to the direction of yarn travel through said texturizing zone, causing the heated fluid to escape from the texturizing zone through said passageways whereby a major portion of the pre-heat zone is surrounded with said exhausted fluid, and continuously discharging said texturized yarn from said texturizing zone at a lower linear rate than the feed rate of said yarn to said texturizing zone, the improvement comprising exhausting said fluid through a screen having myriad small apertures and having an effective open area of at least 35%, and assisting exhaust of said fluid by means of a conduit under vacuum.