Abstract: An apparatus providing a hot section in a continuously moving synthetic yarn wherein at least one jet of hot fluid obliquely is directly across the moving yarn. The jet intersects the yarn at an obtuse angle to the approaching yarn. The apparatus also produces drawn yarn by passing undrawn yarn into the jet and tensioning the yarn as it passes through the jet. The apparatus includes a body member formed with a chamber formed with yarn entry and exit passages and a fluid ejecting nozzle. The body member may be additionally formed with a cavity opening from the chamber opposite the nozzle.

Abstract: A method of providing a hot section in a continuously moving synthetic yarn comprises directing at least one jet of hot fluid obliquely across the moving yarn. The jet intersects the yarn at an obtuse angle to the approaching yarn. The method also produces drawn yarn by passing undrawn yarn into the jet and tensioning the yarn as it passes through the jet. Apparatus for performing the method includes a body member formed with a chamber formed with yarn entry and exit passages and a fluid ejecting nozzle. The body member may be additionally formed with a cavity opening from the chamber opposite the nozzle.

Abstract: A method of producing commercially usable textured synthetic multifilament yarn from commercially produced undrawn multifilament synthetic yarn of a type which has normally a limited operational life and which has exceeded the normal operational life for undrawn yarn in which the overage undrawn yarn is fed continuously without pause through two discrete successive treatments with hot fluid at a temperature high enough to plasticize the yarn. The yarn is drawn to a chosen ratio of extension while it is passing through the first treatment with hot fluid. Next the yarn is jet textured while it is passing through the second treatment with hot fluid. The yarn may be subjected to a cooling action between the two successive treatments with hot fluid.

Abstract: A bulked multifilament yarn having filaments of polymeric material has alternating points of maximum polymeric density and minimum polymeric density occurring along the length of each filament with a maximum spacing of 10 meters. The yarn may have a crimped structure in which the crimps are of undulating form with more than 50% of the filaments having maximum amplitudes of undulation less than the diameter of the yarn and more than 50% of each filament lies on one side of a diametral plane of the yarn particular to that filament. A process of producing the yarn includes the steps of jet bulking yarn and projecting it against one end of an elongated package during which the pressure prevailing at said one end of the package fluctuates. The pressure varies between a maximum value and a minimum value with a frequency related to the rate of feed of the yarn.

Abstract: Apparatus for producing bulked multifilament yarn incorporates a high pressure fluid passage debouching into an intermediate pressure expansion chamber. The high pressure fluid passage is formed with entries for yarn and high pressure fluid and the intermediate expansion chamber is formed with a yarn-deflecting surface and yarn-discharge passage both located across the chamber from the point where the high pressure fluid passage enters the chamber.

Abstract: Bulked and crimped yarn is produced by a process comprising driving heated yarn forward to form an elongated package of compressed yarn, to which yarn is continually added at one end and withdrawn from the other end. The magnitude of the deviation of the position of the take-off end from a predetermined position is measured and used as a control parameter to control the temperature of the heated yarn.

Abstract: Bulked and crimped yarn is produced by a device comprising yarn feed means arranged to form a yarn package, means for taking off yarn from an end of the package and heat exchanging means arranged to be in heat-exchanging relation with the yarn on its way to the package. Means capable of sensing the position of the take-off end of the package is arranged to send a control signal controlling operation of the heat exchanging means. The yarn feed means may be a fluid jet or feed nip rollers. A stuffer tube or a movable surface may be provided to receive the yarn package. The take-off position sensing means may be optical, electrical, acoustical, pneumatic, or mechanical.