PROJECT DESCRIPTION
BACKGROUND
Sizing is one of the steps in textile processing. Threads are prepared for weaving by coating them with chemicals (sizing agents) which reduce the roughness of the surface. In this way sizing enables the weaving process and improves the processing behaviour of yarns. The quality of woven fabrics as well as the efficiency of the weaving process are influenced by sizing. It also minimises the yarn breakage rate and, therefore, the down-time of weaving machines. However, in addition to these positive aspects of sizing, the negative environmental effects must also be considered. Sizing agents have to be removed from the fabrics by washing, which results in considerable pollution of effluents from textile finishing plants with sizing agents. The application of ultrasound to the sizing processes leads to a more efficient utilisation of sizing agents, thereby reducing the amount of environmental pollution.
OBJECTIVES
The project aimed to develop and disseminate new knowledge about the application of ultrasonics to reducing waste water pollution from textile finishing plants, which is due to the washing of textile auxiliaries during the production process. Simultaneously, it aimed to improve the processing behaviour of the yarn. All research and development, as well as materials’ testing, was to be performed as a practice oriented co-operation with industrial users. In order to study the influence of ultrasound on the sizing process, the project would investigate not only the sizing bath and its viscosity, adhesion behaviour and molecular mass distribution function but also the textile physical properties of the yarns after sizing.
RESULTS
The successful implementation of the project required co-operation with specialists in the development of sizing agents. For this reason the Austrian company Zuckerforschung Tulln was involved in the project. Laboratory tests showed that difficult biologically decomposable synthetic sizing agents can be substituted by starch. The fibre specific adhesion force of starch is increased by the application of ultrasound to the sizing bath. A complete arrangement of machinery with integrated ultrasonic devices was installed at the Textilforschungsinstitut Thuringen-Vogtland e. V Greiz (TITV) for demonstration purposes. The advantageous effects of applying ultrasonics covered all steps of textile processing, from sizing via weaving to textile finishing. Due to its modular construction, the ultrasonic device can be inserted in newly developed as well as in existing machinery. By reducing the amount of sizing agents required, treatment with ultrasound resulted in a process with a lower environmental impact. The chemical and biological oxygen demand was used to measure the extent of this: reduction of chemical and biological oxygen demand values by approximately 500 and 250 mg 02 per litre effluent respectively were achieved. Costs for sizing agents and fees for treatment of waste water pollution were therefore reduced. Return on investment of the ultrasonic module is achievable after two years. Contact between experts in the development of sizing agents, textile plants and suppliers of ultrasonic devices were intensive throughout the project. In addition, to implement the results of the project the TITV got in touch with a leading European supplier of sizing equipment. Therefore, the project was also instrumental in bringing together industrial users and technology providers. The successful implementation of the project required co-operation with specialists in the development of sizing agents. For this reason the Austrian company Zuckerforschung Tulln was involved in the project. Laboratory tests showed that difficult biologically decomposable synthetic sizing agents can be substituted by starch. The fibre specific adhesion force of starch is increased by the application of ultrasound to the sizing bath. A complete arrangement of machinery with integrated ultrasonic devices was installed at the Textilforschungsinstitut Thuringen-Vogtland e. V Greiz (TITV) for demonstration purposes. The advantageous effects of applying ultrasonics covered all steps of textile processing, from sizing via weaving to textile finishing. Due to its modular construction, the ultrasonic device can be inserted in newly developed as well as in existing machinery. By reducing the amount of sizing agents required, treatment with ultrasound resulted in a process with a lower environmental impact. The chemical and biological oxygen demand was used to measure the extent of this: reduction of chemical and biological oxygen demand values by approximately 500 and 250 mg 02 per litre effluent respectively were achieved. Costs for sizing agents and fees for treatment of waste water pollution were therefore reduced. Return on investment of the ultrasonic module is achievable after two years. Contact between experts in the development of sizing agents, textile plants and suppliers of ultrasonic devices were intensive throughout the project. In addition, to implement the results of the project the TITV got in touch with a leading European supplier of sizing equipment. Therefore, the project was also instrumental in bringing together industrial users and technology providers.