Santex Energy Saving Chamber: Higher Productivity – better ROI

Santex is primarily involved with the finishing of knit fabrics. However, every stage from spinning, knitting to dyeing, affects the behaviour of the fabric and determines the fabrics characteristics and how the finishing machines need setting in order to achieve the best results. 

Reference to “best results” not only refers to fabric quality but also optimization of machine usage and minimising of costs.

The primary goal for any manufacturer is to produce on time, within specification and at the predicted cost. “Right First Time” is an often used term for the goals of a manufacturer but unless there is a high level of understanding of the materials that need processing, the process itself and the capabilities of the processing machines, this is unrealisable. To this end choosing the right partner as machine supplier will place the textile producer on a fast track to success.

Historically, in markets where the textile industry was less organised Santex Switzerland set out to provide a complete solution and technology transfer in order to enable the required results to be achieved quickly. As the markets became more organised the focus has moved to not only higher quality fabrics but also savings in process costs despite ever tightening environmental regulations.

The term “Right First Time” is mostly associated with the processing of the product itself and often ignores aspects such as power consumption, steam usage, maintenance and even staff. Although the term “Right First Time” hints also at the goal of “at minimal cost” clearly if all aspects involved in the process are not taken into consideration opportunities for minimising cost may be overlooked.

As an example, steam consumption for drying a single jersey fabric of between 160 to 200 gsm may vary from less than 1 kg steam per kg fabric to around 1.25kg steam per kg fabric. Differences may include whether it is a bleached or dyed fabric, whether the fabric is a dark or light shade and whether the stitch density is high or low.

The differences seen in drying performance between dark and light shades may in part be attributed to such factors as whether the fabric is well scoured or not. Some processes omit an intensive scour for dark fabrics with the intention to save chemicals and process time, but it is useful to analyse whether this affects batch repeatability as well as other issues, such as energy consumption during drying. For example, a good scouring may help to break the barriers of the outer surface of the cotton fibre and thereby improve both wetting, as well as evaporation of the moisture in the fibre. This is important for both drying as well as re-humidification during compacting. In this way an additional cost in one process may lead to an overall reduction in both time and cost for the finished fabric, so it is necessary to investigate where you can spend a little more in order to achieve a greater return overall.

Similarly the choice of machinery shouldn’t only look at installed power or heat exchanger capacity, but ultimately at what is the productivity and what the energy costs per kilo fabric are. In the end the cost of machinery is a lesser part of the overall cost of purchasing a machine particularly when future costs of power and fuel are likely to rise. In addition, features such as the high lofting action of Santashrink may also lead to less softener being necessary to achieve the required fabric feel.

Longer process times during dyeing tend to cause elongation of the knit loop structure and make restoring the loop structure to its fully relaxed state more difficult. Santastretch (for tubular fabrics) or Santashrink progress (open width) will help restore the loop structure so that further processing in Santashrink relax dryer will relax the fabric to the correct state for further processing.

Technologies for reducing process costs are readily available, but despite overwhelming benefits the Textile Industry can remain very conservative. Nova is one example.

NOVA uses dry cleaning fluid to remove oils (including silicon oils) waxes, and in the case of polyester also oligomers. The need for water, detergent chemicals and effluent treatment is avoided.

Compared with water scouring, Solvent scouring has six major benefits.

  1. It’s scouring effectiveness is 6 times higher than using detergents!
  2. NOVA is a dry in, dry out process, so fabrics can be scoured and stored for later processing if desired.
  3. The solvent used needs only about 10% of the energy that water requires for heating, which makes it very economical.
  4. There is no water used for scouring and therefore no corresponding effluent to treat.
  5. It needs water for cooling but this is completely uncontaminated with the additional benefit of being pre-heated.
  6. The solvent is almost completely recycled so chemical costs are extremely low.

Health and safety is often sited as a reason for non acceptance of such technology, but much is to do with a lack of understanding. NOVA is already well established and operating worldwide and in countries with the strictest legislation such as Switzerland, Germany, Italy, China and India, etc. so why is there so much resistance to such technology in some countries? Failure to embrace such advantageous technology restricts both process flexibility as well as process cost reduction.

In the near future more such advantageous technology will be released to the market, and a failure to truly understand such technology will only reduce the opportunities for an advantage over the competition. It is clear that further development in the technical ability of the workforce will be required in order to fully appreciate and take advantage of these emerging technologies, and of the machinery suppliers, such as Santex, who have the in house competence to assist their customers reach the next level.

Efficiency in the finishing house has still a lot of potential for improved machine usage and cost savings. Batch scheduling software is already well established in the Dyehouse, but is virtually unknown in the finishing section. If the finishing dept has machines from many different suppliers it is not possible to provide scheduling software and as some manufacturers may only make one or two types of finishing machine they have no incentive to developing a batch scheduling program. As a supplier of the full range of finishing machines Santex are able to provide a full solution including Santaccess, software which enables scheduling and historical data gathering for every batch that is processed through the Santex line, including maintenance tools which minimise machine maintenance costs.

With increased pricing pressure from buyers, ever increasing utilities costs and environmental constraints from governments the more efficient use of current equipment and the adoption of new technologies will enable textile manufacturers meet the new challenges of the market and a higher level of “Right First Time”.