Thesis Details

Thesis Title: Relating results of a new test for yarn aerodynamics to air requirements in pneumatic filling insertion
Thesis Author: Ruth-Ann Breitler
Abstract: Air-jet weaving machines continue to attain widespread use in today's textile operations. As their popularity increases, greater demands are placed on the performance of the machine and the ability to predict that performance relative to changes in fabric style and filling insertion system configuration. One of the foremost demands being placed on this type of machine is the ability to weave a greater variety of filling yarns. A quick and clean test which can be used for making predictions about filling yarn weavability can be a vital asset to the air-jet weaving operation and the suppliers of filling yarn to that operation. The objective of this thesis was to develop and evaluate a testing instrument which could be used to make such predictions. In addition to developing a tester, this thesis aimed to evaluate one possible method for applying the results on the tester to any particular filling insertion system configuration (within the realm of multi-nozzle air-jet weaving machines) without lengthy weaving trials. Yarns of varied structural composition were used to evaluate the relationship of the tester and a quick filling insertion system test. The yarns were evaluated by the tester named the Yarn Air-Friendliness Tester (YAFT) u in a non-weaving on-loom filling insertion system test of the same character as the YAFT, and through actual weaving trials. The Ruti L5100 air-jet weaving machine at the Institute of Textile Technology was used as a sample loom for testing the theories of this thesis. Theoretical acceleration values were generated from tension values measured by the YAFT and filling insertion system test were correlated to the Minimum Airflow Threshold, which was used as an indication of weavability based on filling stops per one hundred thousand picks and compressed air consumption. Conclusions drawn from the results of this experiment were: 1. A simple tester which is capable of evaluating the aerodynamic characteristics of filling yarn in a quickly performed test has been developed. This instrument has been named the Yarn AirFrienBliness Tester. 2. There is a high correlation between the results of the Yarn Air-Friendliness Tester and the results of the Filling Insertion System Rating Test used in this study for all yarns tested in both these methods. In accounting for the observation that one of these tests is poor at assessing the air-friendliness of medium to fine open-end spun rayon yarns, the correlation between all test results increases. 3. The Yarn Air-Friendliness Tester is able to predict Minimum Airflow Threshold as an indicator of weavability. The correlation between the two sets of results is very strong for all yarns tested and is highly significant and reliable. 4. The results of this study revealed that the Yarn Air-Friendliness Tester is useful for evaluating the extent of filling yarn weavability and for facilitating predictions of compressed air consumption in air-jet weaving for many types of filling yarn. However, there were indications that the accompanying filling insertion system rating test has weaknesses especially in the area of reproducability as it yielded values with greater variability thaN the Yarn Air-Friendliness tester.