Application Of Stretch-breaking In Ramie Spinning Process

Over-length in ramie fibre does have great harm to ramie spinning. The appliance of stretch-breaking can dramatically cut down the number of over-long fibre and achieve the economic purpose in ramie textile industry.This thesis focuses on the researches in the following aspects. Firstly, according to the man-made fibre and wool stretch-breaking machine, develop ramie stretch-breaking machine.Secondly, optimize and adjust the technical parameters of the machine according to the characteristics of ramie and the experimental results.Finally, establish mathematic model and analyze the relationship between the technical parameters of the ramie stretch-breaking machine and the quality of the ramie stretch-breaking strip.The experimental results are as follows. Firstly,' ramie stretch-breaking machine adopt that the front field is the drafting field and the back field is the stretch-breaking field, total drafting multiples are above 7 and below 10. The front drafting multiples are 1.5 and the back drafting multiples are 4.5-6.5. The feed quantum of BR221 strip is 100.9g/m, and CZ191 strip is 134.4g/m. The schopper hardness of the top roller is 90. The average length of the gripping arc is 13.5mm.Secondly, as to three different materials, the errors between theoretic average length got by the stretch-breaking model and actural numbers got by the experiments are fluctuating. With an error range, the model and hypothesis are correct.Thirdly, optimize degummed ramie and BR221 strip stretch-breaking process. As to degummed ramie, technical parameters are as follows.Stretch-breaking guge is 122.2mm. Stretch-breaking pressure is 0.48Mpa. Back field stretch-breaking multiple is 5.1. The experimental results are as follows. Mean length is 62.8mm. Irregularity of length is 67.3%. Staple rate is 34.3%. Over-length fibre rate is 2.9%.Nep number is 12. String rate is 1.9%. As to BR221 strip, technical parameters are as follows. Stretch-breaking guge is 128mm. Stretch-breaking pressure is 0.4Mpa. Back field stretch-breaking multiple is 4.8. The experimental results are as follows. Mean length is 55.3mm. Irregularity of length is 75.2%. Staple rate is 39.4%. Over-length fibre rate is 8.7%.Nep number is 59. String rate is 0.31%.Finally, compared degummed ramie with BR221 strip stretch-breaking, degummed ramie stretch-breaking is more economical and the experimental effect is more notable. The ramie stretch-breaking machine can carding degummed ramie continuously and dose less harm to the fibre. After stretch-breaking, the fibre has a better straightness and parallelization and over-length fibre, nep and string are reduced dramatically.