IMPROVEMENT OF DYEING PROPERTIES AT PRODUCTION OF PET YARNS BY ADDITION OF PBT(2)

2. State of knowledge

To the property profile of polyester fibers in the direction of said appearance change, one can in principle follow two different paths. Either you modified the polymer or the process of fiber production. Both paths lead to so-called carrier-free -. That is, without Additional ecologically unsound Aids- and dyeable yarn at boiling temperature. This will in principle reached in that the mobility of the amorphous chains will zoom. Since long, the long chain industrially by the incorporation of diols, aliphatic dicarboxylic acids or polyether in the PET chain achieved Despite the clear advantages, such as the uses simpler, since no pressure dyeing machines working and lower energy costs by Use of lower dyeing temperatures, this version has a crucial drawback: the wet fastness properties the dyeings are not acceptable . In this regard, much better cut materials from, the spun from a mixture (blend) of PET and PBT are . If such Mixtures at high filament linear and high spinning speeds (POY Bedingungen) processed, the dyeing temperature can be lowered to cooking temperature, the brings above advantages, without compromising the fastness [6]. This particular behavior is on the specific structure formation in the fiber at the nozzle and the crystallization inducing action of PBT recycled [6, 11].If, as now increasingly common for the leisure sector, processed and colored microfiber yarns, so show this through the fiber due to the stronger scattering effect with the same dye uptake of thinner filaments to a lighter shade. If, therefore, textiles, different from yarn Filament titer were prepared to be colored in the same color depths, so must satisfy the are comparatively thin filaments worn by adjusting the bill Färberezepte [12-15], as well as the very dense beaten tissues that one only on certain machines, may be sufficient flow optimally colored by the dye liquor [16-18]. With View of the optimal Färberezept should be noted here that microfibers compared to Normal fibers show a higher dye consumption in the dyeing and the withdrawal speed increases, which may result in Egalitätsprobleme [19]. In addition to the increased dye consumption and the increased rate of exhaustion is for the dyeing of microfibre yarns but also a decrease in the washing and rubbing Hitzefixier-, for which on the one hand, the larger specific Surface and on the other hand, the higher dye concentrations must be held responsible.

Writen by R.Gutmann ICF,Institut Fur Chemiefasern der Deutschen Institute Fur Textil-und Faserforschung Stuttgart