Laser-treated polyester

Dyeing properties (a) the exhaustion rate and (b) the colour reflectance of untreated and laser treated polyester fabrics. Source Adapted from Lan et al., 1997.)... 

In another study, Shaohua et al. (2003) used a UV-laser (10 pulses of 150 mJ/cm ) to improve the dyeability of polyester fabric. They used three disperse dyes (red,blue and navy), and Fig. 2.15 shows the change in K/S values versus the red-dye concentration (% owf) of the untreated and laser-treated PET fabrics. It can be seen that the laser (ablated)-treated PET has a higher K/S than the untreated (non-ablated) fabric, indicative of greater uptake of the disperse dye. 

The polyester material has been analysed using 3D-Laser profilometry. The laser profilometer measures the texture, form and topography profile of the fabric, creating 3D images of the fabric surface. (Fig. 3) This technique can be used to compare the surfaces of treated textiles and visualise the effect that the finishes have on the surface profile of the polyester. 

Abstract The use of two environmentally friendly technologies, the plasma and laser approaches, in treating the surface of textiles is discussed in this chapter. The surface of fibrous materials can be functionalized and structured on the nano- and micro-scales, and the results of the treatment of natural and synthetic fibres such as wool, cotton, polypropylene, polyester and polyamide which have been treated by different plasmas and lasers are detailed and are found to be similar to morphological modification of a textile surface using the ripple/roll-structure technique. 

The dyeability of polyester fabric is poor compared to that of other synthetic fibres, due to the lack of polar molecules and pendent groups. Lan et al. (1997) used an exdmer laser at 248 nm, 1 Hz and fluence range (20-150 mJ/cm ) to treat the surface of polyester fabric in order to improve both the hydrophobicity and dyeability. Rgure 2.13 shows that the contact angle for a water droplet on an untreated surface (Hg. 2.13a) is less than 90° while, after... 

The trial runs were performed on a bare roll corona treatment system as well as on an atmospheric plasma treatment system, resident at the same pilot line. For all runs, two PVdC-coated polyester films were post-treated, one in the APT system with a helium/oxygen plasma, the other by means of a corona treater. Another sample constituted the control reference and was not treated. The samples were then printed at 90 mpm on a PCMC press with aqueous ink (Flint Ink) using a laser-engraved anilox roll to 300 lines per inch (Ipi) and a cell volume of 4.8 billion cubic microns (bcm)/sq.in. The printed image provided solid (100%) ink coverage. The calculated ink transfer (thickness) to the film, based upon this cell volume, was approximately 1.9 microns. The printed web drying temperature occurred at 121 °C, with a web temperature of 77 °C. 

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