Low weight pick up processing for the 80S

BYDHANRAJ DESAI

UNDER THE GUIDANCE OFDR. SUJATA PARITI

Introduction One of the main theme of ITMA 79 exhibition in Hanovar was energy conservation. The wet processing sectors of the textile industry consume vast quantities of energy, a great deal of which is used in the drying processes. Many of machinery manufacturers made attempts to modify their machines to reduce energy consumptions but they are successful upto certain limit.

DEVELOPMENT REVIEW The IIC provides incentive to encourage the development of low wet pick up processing of cotton fabric. Although the process advantages in terms of energy and chemical savings are at least as important. The careful attention must be paid to a number of key factors to prevent a reduction in product performance and to achieve optimum results.

MINIMAL APPLICATOR Tritex International AG, Zurich They had developed independently a low wet pick up applicator, primarily for use with polyester/cotton blends. The Tritex MA system is based on the well known technique of a lick roller or kiss roller.

CONT….The main difference is that the speed of the lick roller and the fabric are controlled independently which enables the wet pick-up level to be adjusted.

For the technique to be used it is essential that the finishing formulation will produce a film of uniform thickness across the width of the roller, otherwise variable pick will occur.

ALTERNATIVES TO MA system The various alternatives to the pad mangle for applying finishing agents to fabrics fall into one of the following categories.A. LICK ROLLERSB. SPRAY APPLICATORSC. LIQUOR METERING BY ENGRAVED or SPIRALLED

ROLLERSD. FOAM APPLICATORS

Commercially available foam applicators

MACHINE MANUFACTURERFFT GASTON COUNTY

JANUS EDWARD KUSTERS

AUTOFOAM DINTING ENGINEERING

HORIZANTAL PAD KNIFE-OVER-ROLLER UNITED MERCHANTS

RSF ROTARY SCREEN STORK BRABANT

ROTARY SCREEN JOHANNES ZIMMER

VACU-FOAM MONFORTS

FOAM APPLICATORS

DIRECT (Pressurized Foam)In this category the foam is applied directlyto the substrate while held under pressure in the distribution box or manifold.Gaston County FFTWith the FFT unit the fabric passes over a slot of variable size, which is the open end of the foam distribution box.

CONT… Stork RSF In the stork system the foam is applied through A rotary screen with the fabric pressed against a backing roller. Zimmer Unit The Zimmer unit is basically similar but use is made Of the magnet-roll squeegee,

DIRECT (non-pressurized foam) In this system a pressure is exerted to apply and to destroy the foam, but the foam reservoir is not maintained under pressure.Dinting Engineering Auto Foam Unit It is developed and refined version of a Knife-on-air unit. The foam generation unit has been speciallyDesigned so that, once the required details of fabric weight and pick-up are set, foam delivery will be controlled automatically to compensate for changes in stenter speed

Cont.… United Merchants It is generally requires fairly stable foam, which have to be destroyed after the applicationstage. This is because the gap setting is the majorcontroller of pick-up. And therefore the foammust not collapse and wet the fabric prior to the doctor knife, otherwise a higher wet pick up could be obtained

Cont.… United Merchants or Tubetex This manufacturers uses horizontal pad technique to apply foam liquor to the fabric. With this technique a foam with differentproperties and stability required.

Indirect Some of the more expensive and larger machines use the principle of indirect metering of the foam onto a carrier roller or belt.

Kusters In this machine the foam is doctored ontoa drum and transferred by contact with thefabric. The Janus Version has two applicators fortreatment of both sides of the fabric, witheither the same or different formulations.

CONT…. Monforts This machine uses a knife-over-roller to meter a foam layer onto a rubber blanket. Transfer of the foam onto and into a fabricis assisted by vacuum as the fabric passes round a perforated drum. Only a low vacuum is required to collapsethe foam but it is claimed that the vacuumgreatly improves liquor distribution.

Factors influencing wet pick up value

CONCLUSIOn There can be no doubt that low wet pick up finishing is here to stay. Big advances have already been made in developing alternative techniques to the padder, and further development will obviously come with the introduction of more units into the trade and a gradual build-up of experience.

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