Open width processing

Williams unit A wet-processing unit for open-width processing of fabric. The fabric passes up and down over rollers in the liquor. The unit is widely used for dyeing, washing, pretreating, and aftertreating. 

Open width processing - processing without fibrillation... 

Lyocell can be processed in conventional open width systems. Because the mechanical action on the fabric is virtually eliminated the result is a flat classical fabric. Aesthetical differentiation is reduced against cotton, but the lyocell (or blend) will still be softer and more fluid than a cotton comparison. No fibrillation occurs on lyocell fabrics that have been open width processed, but they still retain a soft handle with an imderlying bounce and resilience. 

This is an extension of the open width processing principles in combination with causticisation. The fabric construction should be devised so that there is space to allow yam crimp to develop. Causticisation will cause the crimp development and impart a memory which together with the fibre s high modulus and resilience will allow stretch with high degrees of recovery, equal to that achievable with elastane containing fabrics. It should be borne in mind though, that this is a comfort stretch rather than the power stretch associated with elastomerics. 

As with any fabric, chemical finishing is an important aspect of the process and this is especially true when considering the finishing of open-width processed lyocell fabrics. In such processing, resination is the method of controlling fibrillation. If too little resin is fixed then fabrics will fibrillate on subsequent washing, too much and physical performance deteriorates. It is also important to include appropriate softeners and auxiliary products into the chemical finish so that performance and handle are appropriate to the customer s requirements. 

As mechanical agitation is important to effect the bio-fmishing, only selected processes and machines can be used, for example tubular fabric preferably cut to open width and treated in open width washers. In the rope form the loosened fibre particles are filtered out by the fabric and cannot easily be removed. The pad-batch process, jig or package dyeing machines are not effective in bio-fmishing. 

Fabrics can be desized and scoured in open width form using a jigger, which is one of the oldest and most universal machine in textile finishing. A centrally controlled fully automated jigger (Fig. 5-7) to secure improved processing quality with... 

In this process goods are padded through the scouring solution and then batched open width onto rolls which rotate slowly for several hours ranging from 6 to 24 h depending upon the type of cloth. The goods are then washed and rinsed in open width washers. 

Scouring machines of wool depend on the kind of wool to be scoured i.e. raw wool, hank form or woven fabrics. Scouring of wool can be carried out in batch or continuous process, aqueous or solvent media and rope or open width form. 

The main purpose of the continuous bleaching system, whether in the rope form or in open-width form, is to reduce the time of bleaching and the cost of labour involved. Continuous bleaching in J-Box in rope form was started in the late in 1930s with the introduction of hydrogen peroxide [10, 11] and plant scale equipment had been built and a suitable procedure was developed [12]. In 1942, the unit used in the bleach range was called a J-Piler [13], but by 1952 the name had become J-Box and bleacher s dream of one-step process had finally come true [14]. 

As ASISA shock system for continuous desizing, scouring and bleaching in open width gives result within few minutes without any need for previous pad-batch process. The reaction time is only 2 min. 

---