A newly developed enzyme technology for more efficient dyeing, printing & finishing-Gentle bleaching

A newly developed enzyme technology has been successfully initiated that provides an improved & sustainable bleaching process. Gentle Power Bleach system is said to be the latest innovative pre-treatment process. Enzyme-based peroxide bleaching process allows low-temperature bleaching of textiles at a neutral pH range. By avoiding use of harsh chemicals & achieving its potential at low treatment temperatures, process meets goal for environmentally friendly products & processes. This new system excels in its capability to process textiles more sustainably than conventional bleaching systems while delivering textile fabrics with enhanced quality.

Switzerland-based Huntsman Textile Effects is constantly developing new platforms to improve fabric performance & reduce energy & water consumption in textile industry. Palo Alto, Calif.-based Genencor, a division of Denmark-based Danisco A/S, focuses on discovering, developing & delivering highly innovative, eco-friendly, efficient enzyme technologies. Both companies see this new process as a contribution to a more sustainable textile industry.

Perfect preparation New gentle bleaching process is truly innovative. Traditional bleaching requires a high water temperature, while new gentle bleaching takes place at a low temperature of 65C & almost neutral pH conditions, making it especially suitable for all delicate fibres that are temperature & pH-sensitive. Even after bleaching under these gentler conditions, cotton is perfectly prepared for dyeing all shades.

By applying the latest enzyme technology as a core component of solution, it is now possible under these mild conditions to prepare cotton with very good results for dyeing. On regenerated cellulosic fibres, excellent full white levels can be obtained as well. One recipe is enough for all fibres sensitive to temperature & pH. A multitude of fibres can be treated, including regenerated cellulosic fibres such as viscose, MicroModal, lyocell, bamboo & blends with cotton, elastane, acetate, acrylic, silk & wool. Similar bleaching recipes for all fibres & blends result in simple recipe management & reduced sources of errors.

Although technology is completely new, process flow remains similar to current Smart Prep pre-treatment system. Process is applicable on all closed discontinuous equipment such as jets, jiggers, overflow & cheese dyeing machines. A liquid system is offered that is suitable for automatic dosing systems.

Gentle Power Bleach enzyme-based peroxide bleaching process requires a water temperature of only 65C for bleaching & fewer rinsing cycles than traditional bleaching systems

Soft hand In case of cotton, fabrics pre-treated with new bleaching technology are said to have a superior hand compared to that of conventionally bleached goods. Main characteristics are: Very soft, bulky and natural hand; Fast and permanent effect; Excellent crease recovery properties; Improved needle resistance, or sewability, and stretch; and Very durable elastane properties.

Very mild process conditions also should ensure maximum strength of textile material, with the lowest degree of chemical damage on cotton compared to goods processed using traditional bleaching methods.

Improved colour yield Optimal bleaching is a prerequisite for true colours. Compared with traditional bleaching systems, Gentle Power Bleach system brings following advantages to subsequent dyeing process: Better colour yield with more vivid & intense shades that have excellent fastness properties; Brighter shades; Possible cost savings in dyeing process; & Improved wash-, water- & rubbing-fastness properties.

Energy Savings ... Energy consumption savings by almost half are possible owing to considerably lower treatment & rinsing temperatures compared to conventional bleaching systems. No neutralization is required, & at least one or two rinsing baths can be omitted, leading to a substantial reduction in water usage.

When treating cotton, savings over traditional bleaching are attainable thanks to fact that weight loss is reduced considerably. As material remains naturally soft & bulky, possible savings in softening may be obtained, & previously unattained softness levels may be realized.

New bleaching process further enables improvements in right-first-time production, reducing costly re-works & second-quality products, & offering following: Improved reproducibility in reactive dyeing by avoiding risk of excessive residual alkalinity at beginning of dyeing cycle; Reduced swelling of natural fibre & avoidance of a channeling effect in yarn cheese/package dyeing machines, leading to more uniform results; and Reduced risk of crease marking in piece-goods and garment processing.

... And Water Savings Primarily, reduced use of water & energy makes this process environmentally friendly. By lowering treatment temperature from boiling down to 65C, new bleaching technology is said to be unique in field of energy reduction. Even rinsing is conducted below this temperature. Additionally, effluent salt load is reduced by eliminating harsh chemicals such as caustic soda. All auxiliaries used exhibit excellent bio-elimination, & are free of alkyl-phenol ethoxylates & adsorbable organic halogen. In case of cotton, reduced weight loss leads to a considerable reduction of both biochemical oxygen & chemical oxygen demand in wastewater stream. Enzyme-based peroxide bleaching technology is a way forward. It can help textile industry make better use of scarce natural resources & contribute to a more sustainable environment - also for future generations.

A newly developed enzyme technology for more efficient dyeing, printing & finishing-Gentle bleachingCompiled by: M. Rezaul Karim Tutul