Apparatus and method for stuffer box crimping a synthetic yarn

An apparatus for stuffer box crimping a synthetic multifilament yarn comprising

• a yarn conveying nozzle which includes a yarn duct having an inlet end and an outlet end, and a passageway for introducing a pressurized fluid into the duct so as to advance a yarn which is introduced into the inlet end of the duct through the duct and the outlet end thereof,
• a stuffer box disposed adjacent the outlet end of the duct for receiving the advancing yarn exiting from the duct and forming the same into a yarn plug, the stuffer box comprising a perforated circumferential wall which defines an internal passage therethrough which extends from an inlet end to an outlet end and which is positioned to receive the advancing yarn in the inlet end and form the yarn into a yarn plug, with the cross section of the passage increasing in the direction of advance such that no significant cohesive force is imparted to the yarn by the passage wall, and such that the yarn plug leaving the stuffer box passage at the outlet end thereof has a predetermined plug diameter,
• a pair of rolls rotatably mounted adjacent the outlet end of the passage of the stuffer box, with said rolls defining a conveying gap for receiving the yarn plug therethrough, and
• wherein said conveying gap of said rolls is less than the plug diameter.