Dyeing of PLA Fibers

When concentrations of auxiliaries (NaOH and Na2S203) are kept at constant and dye concentration is ca. 5% owf, K/S value turns into the maximum. And then the color yield decreases at higher concentration of dyes. These results are quite different from the dyeing behaviors of conventional dyeing processes. Stoichiometric relationship between the dye and the auxiliaries seems to determine the dyeability of dyes in this system. In order to evaluate the effects of the auxiliaries on dyeing PLA fabrics, similar investigations have been carried out 

Disperse dye Dye exhaustion (2% owf) (PLA/PET) (%) Gray scale rating for Gray scale rating for dry crockfastness wet crockfastness (PLA/PET) (PLA/PET) 

One variant of dry spuming is known as electrospinning which utilizes an 

PLAhas been successfully electrospun into fibers primarily for tissue engineering and biomedical applications. For instance, a number of studies show that scaffolds 

Core-sheath nanofibers of PEG-PLA and PEG can be prepared by electrospinning a water-in-oil emulsion in which the aqueous phase consists of a PEO solution in water and the oily phase is a chloroform solution of an amphiphilic PEG-PLLA diblock copolymer. The fibers obtained are composed of a PEO core and a PEG-PLA sheath with a sharp boundary in between. By adjusting the emulsion composition and the emulsification parameters the overall fiber size and the relative diameters of the core and the sheath can be changed. As shown in Fig. 5.15, a mechanism is proposed to explain the process of transformation fi-om the emulsion to the core-sheath fibers, i.e., the stretching and evaporation induced de-emulsification. In principle, this process can be applied to other systems to 

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