**6. References**

258 Textile Dyeing

The optimized process performed at lower temperature and time than conventional dyeing

The results of rubbing fastness in dyed fabrics with and without treatment are very good.

The DBD treatment used the following parameters: power - 1500 W, number of passage - 2,

The cost to treat one kilogram of polyamide 6.6 fabric (weight : 105 g.m-2) is calculated

Dosage (kW.min.m-2) kW.h.m-2 Price kW.h (€) Cost per m2 (€) Cost per kg (€)

Despite the cost of the treatment DBD is around 0.036 €.kg-1, several benefits are achieved such as: reduction of 30ºC in the temperature of dyeing with an excellent bath exhaustion; reduction of dyeing time of around 25%; reduction of the quantities of dyeing auxiliaries

A relatively low plasma dosage (DBD), around 2400 W.min.m-2, can be used to modify the surface of polyamide textile materials, leading to enhanced hydrophilicity and dyeability. Due to these modifications, dyeing of polyamide 6.6 fiber is now possible using nonconventional dyes for this fiber, such as direct and reactive dyes for cotton and wool. The results suggest that the change in exhaustion and dyeing yield in different dyeing conditions closely correspond with the roughness´s creation and the changes in chemical oxidative properties induced by DBD treatment in polyamide fabrics. These results reflect directly on dyeing ability of the fiber providing more terminal groups to make dye

The application of anionic dyes in discharged polyamide 6.6 shows extensive improvement of dye exhaustion from baths easily achieving 100% in shorter dyeing times. The kinetics of

It should be noted that deeper dyeing is a great advantage for all anionic dyes since darker shades are obtainable using less amount of dyestuffs. Using plasmatic treatment in polyamide substrates it is possible to obtain decisive energetic gains by dyeing at lower temperatures, to have quite pH independent processes similar to a buffer effect and to

The DBD plasma treatment has an high industrial potential, because it is an environmental friendly dry process. Including a plasma treatment in the processing of the substrate, dyeing properties obtained by using anionic dyes are improved, namely yield, dyebath exhaustion, washing and rubbing fastness, providing a cheap, clean and high quality option for the

dyeing in every case is quicker, but leveled results are obtained.

reduce dyes and auxiliaries with deeper colors and less pollutant charges.

Table 10. Cost of DBD plasma treatment (\* mean value of kW.h - Portugal 2010).

**2.400 0.040 0.094\* 0.0038 0.036** 

of untreated polyamide did not change the washing fastness results.

**3.8 Cost of DBD plasma treatment** 

and the possibility to get more intense colors.

velocity - 2.5 m.min-1.

according to table 10.

**4. Conclusion** 

bonding.

dyeing of polyamide materials.

The value of 4/5 or 5 in the gray scale was obtained for all the samples.


**13** 

*1Switzerland 2USA* 

*3,4The Netherlands* 

**Surface and Bulk Modification of** 

*3Engineering of Fibrous Smart Materials,* 

*Saxion University of Applied Sciences, Enschede,* 

**Synthetic Textiles to Improve Dyeability** 

*1Department of Chemistry and Biochemistry, University of Bern, Bern 2Fiber and Polymer Science Program, Department of Textiles Engineering, Chemistry and Science, North Carolina State University, Raleigh NC,* 

*Department of Engineering Technology, University of Twente, Enschede, 4Knowledge Centre Design & Technology, School of Applied Art & Technology,* 

Mazeyar Parvinzadeh Gashti1, Julie Willoughby2 and Pramod Agrawal3,4

Synthetic fibers, mainly polyethylene terephthalate (PET), polyamide (PA), polyacrylonitrile (PAN) and polypropylene (PP), are the most widely used polymers in the textile industry. These fibers surpass the production of natural fibers with a market share of 54.4%. The advantages of these fibers are their high modulus and strength, stiffness, stretch or elasticity, wrinkle and abrasion resistances, relatively low cost, convenient processing, tailorable performance and easy recycling. The downside to synthetic fibers use are reduced wearing comfort, build-up of electrostatic charge, the tendency to pill, difficulties in finishing, poor soil release properties and low dyeability. These disadvantages are largely associated with their hydrophobic nature. To render their surfaces hydrophilic, various physical, chemical and bulk modification methods are employed to mimic the advantageous properties of their natural counterparts. This review is focused on the application of recent methods for the modification of synthetic textiles using physical methods (corona discharge, plasma, laser, electron beam and neutron irradiations), chemical methods (ozone-gas treatment, supercritical carbon dioxide technique, vapor deposition, surface grafting, enzymatic modification, sol-gel technique, layer-by-layer deposition of nano-materials, micro-encapsulation method and treatment with different reagents) and bulk modification methods by blending polymers with

Nowadays, the bulk and surface functionalization of synthetic fibers for various applications is considered as one of the best methods for modern textile finishing processes (Tomasino, 1992). This last stage of textile processing has employed new routes to demonstrate the great potential of nano-science and technology for this industry (Lewin, 2007). Combination of physical technologies and nano-science enhances the durability of textile materials against washing, ultraviolet radiation, friction, abrasion, tension and fading (Kirk–Othmer, 1998). European methods for application of new functional finishing

different compounds in extrusion to absorb different colorants.

**1. Introduction** 

