Delivering perfect bleaching results

Introduction

After washing and scouring, the cotton fibre still has its natural yellowish colour and contains multiple contaminations. This can influence dyeing and printing processes and does not meet the requirements for a full white. Therefore the next process of decolorization of greige material into a suitable material for next processing is called bleaching.

Most important for the bleaching process are continuous open-width bleaching ranges with best cost-efficiency and highest reproducibility. The process itself takes place in the following steps: application of bleaching agent, steamer with a capacity of for 1-2min tight strand guiding and 10-20min in the Roller-bed section washing off.

Generally most of the continuous desizing and bleaching-ranges are consisting of a pre-washing section to remove the cracked size, followed by a wet-on-wet impregnation and steamer, and finally the washing off after bleaching. The exact dosing of the chemicals is essential for the bleaching result. Multiple controls and computerized dosing with sophisticated mixing facilities result in an excellent process capability with best reproducibility and highest quality. Besides peroxide or hypochlorite, the following chemicals are essential for bleaching: wetting agent, complex builder, stabiliser, activator and corrosion inhibitor (if using chloride)

Salient Features

  • Unique Centering configuration at outlet of combi steamer with provision for E+L stainless steel centering device.
  • Five-stage flowmeter controlled auto-dosing station with proportionate valve configuration for accurate dosing and final bleaching results.
  • Steam conditioning station for combi steamer for optimal steam generation of suitable temperature and saturation for perfect bleaching results.
  • Reisky-Dhall hydraulic deflector controlled roll (S-roll) finishing padder for uniform moisture & high squeeze before chemical impregnator.
  • Highly efficient double loop Closed Washing Tank for optimal washing results in compact footprint.
  • Large 200 mm dia stainless steel guide rolls in entire range for absolutely creaseless run.

Configuration

1. Continuous Bleaching Range running two superimposed ends

2. Continuous Singeing and Bleaching Range in single operation for yarn dyed shirting fabrics

3. Continuous Bleaching Range running two superimposed ends

4. Continuous Bleaching Range

5. Continuous Singeing, Desizing and Bleaching Range in single operation

Collage

Continuous Bleaching Range (running two superimposed ends)

Voils, Cambrics and Bottom-weights

Continuous Bleaching Steamer

With horizontal tight-strand and roller-bed sections

S-type Washing Compartment with Intermediate S-Roll Squeezer

Forms the foundation of all wet processing and finishing lines

Vertical Drying Range

5-Stage Automatic Dosing Station

Flowmeter controlled proportional valve configuration for accurate dosing calibration