US 4,051,699 AGranted

Liquid ammonia mercerization

AssigneeBurlington Industries, Inc.

InventorJohn B. Carpenter, Jr.

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Abstract

Apparatus for mercerization of cellulosic fabrics with liquid ammonia. Denim fabrics and the like, especially those made from open-end spun yarn, have liquid ammonia for mercerization applied thereto by a metering roller while tensioned. The metering roller has a number of deep engravings formed in the periphery thereof, which may be in the form of a truncated cone or a tetrahedron. Pile or ribbed fabrics are treated by application of liquid ammonia with a metering roller to the back of the fabric, while tension is maintained by relatively gentle apparatus, such as a pinned drive cylinder. When fabric direction is changed, soft rollers engage the fabric face to change the direction, and the fabric face is brushed with rotary driven brushes of Nomex or the like. Final ammonia removal from the fabric is facilitated by passing the fabric over a large cylinder with a perforated surface, steam transfer occurring across the fabric in the steam chamber.

Claims8

Dependent claims

Apparatus for mercerization of a cellulosic pile or ribbed fabric, the fabric having a pile or ribbed face and a back, said apparatus comprising

means for applying a predetermined amount of liquid ammonia to said fabric less than the amount that would be picked up by said fabric if immersed in liquid ammonia, said means including a metering roller partially disposed in a pan of liquid ammonia and having a surface for engaging the back of said fabric, and means for rotating said metering roller at a predetermined rate, said metering roller having a plurality of deep engravings formed in the surface thereof,
means for tensioning said fabric so that the face thereof is not disturbed after application of liquid ammonia to said fabric, said means including a first cylinder having a plurality of pins associated with the peripheral surface thereof for engaging the back of said fabric,
means for facilitating the removal of ammonia from said fabric by changing the direction of fabric movement without damaging the fabric face and drying said fabric, said means including a plurality of guide rollers for engaging the fabric face and changing the direction of fabric movement, and a second, heated, cylinder for engaging the back of said fabric,
means for brushing the fabric face to substantially restore the original appearance thereof, and
means for further treating said fabric as necessary to remove all of the ammonia therefrom.

2 more elements

Dependencies are inferred from the claim text.