Characterisation of fibre lengths and breakage behaviour of cotton fly in knitting process
Alok Kumar, Dr. B. R. Ambedkar, National Institute of Technology, Department of Textile Technology, Jalandhar-144011, Punjab, India, Niranjan Bhowmick, Subrata Ghosh, Dr. B. R. Ambedkar, National Institute of Technology, Department of Textile Technology, Jalandhar-144011, Punjab, India, Dr. B. R. Ambedkar, National Institute of Technology, Department of Textile Technology, Jalandhar-144011, Punjab, India
2018
Tekstilec
In this research work, the fi bre fl y from diff erent zones in the knitting process, such as the cone unwinding, guide and the knitting zones, were collected and characterised. The results show that in the cone unwinding zone were formed 18% of shortest (i.e. ≤1 mm), 40% of shorter (i.e. 2-6 mm), 32% of short (i.e. 7-11 mm) and 10% of long (i.e. ≥12 mm) fi bres, followed by shortest (14%), shorter (38%), short (30%) and long (18%) in the guide zone, and shortest (30%), shorter (36%), short
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... ) and long (6%) in the knitting zone. The surface characteristics and breakage behaviour of fi bre fl y collected from three diff erent zones were studied using a scanning electronic microscope. The majority of fi bre fl y are highly twisted, with kink bands with longitudinal and transverse cracks, and twist break in the form of ductile, granular and individual fi bril break due to torsional fatigue under high tensile stress in the cone unwinding zone. The majority of fi bre fl y are found in twisted form with a fl at surface, are bent with kink bands, surface peeling, a long axial crack and twist break, and either fi bril failure or independent fi bril failure due to the combination of fl ex and torsional fatigue under tensile stress in the guide zone. Surface peeling, bent along with the kink bands, and twist break, either with two and multiple splits or granular and ductile form, were observed in the fl y of the knitting zone due to the combined eff ect of torsional, fl ex and abrasion fatigue under tensile stress. Keywords: fi bre fl y, unwinding zone, guide zone, knitting zone, weft knitting, cotton Izvleček V tej raziskavi so bila v različnih območjih pletenja, tj. v območju odvijanja preje z navitka, v območju dovajanja preje in v območju zapletanja, zbrana in analizirana leteča bombažna vlakna. Rezultati so pokazali, da je v coni odvijanja preje z navitka nastalo 18 % najkrajših vlaken, dolgih ≤1 mm, 40 % krajših (2-6 mm), 32 % kratkih (7-11 mm) in 10 % dolgih (≥12 mm) vlaken. V coni dovajanja preje je nastalo 14 % najkrajših, 38 % krajših, 30 % kratkih in 18 % dolgih vlaken, v coni zapletanja pa je nastalo 30 % najkrajših vlaken, 36 % krajših, 28 % kratkih in 6 % dolgih vlaken. Lastnosti površine in pretrgov zbranih letečih vlaken so bile proučene s pomočjo rastrskega elektronskega mikroskopa. Pokazalo se je, da je bila večina letečih vlaken visoko vita, imela so lokalne prečne zdrse v strukturi, vzdolžne in prečne razpoke, pretrge v obliki duktilnih, zrnatih in fi brilnih poškodb, kar je bilo posledica torzijskih obremenitev in visokih nateznih napetosti pri odvijanju preje. Večina letečih vlaken je imela poškodbe, od zasukov, zravnih površin, ukrivljenosti, lokalnih zdrsov, površinskega pilinga, do dolgih aksialnih razpok in torzijskih pretrgov, kjer so zaradi kombinacije upogibnega in torzijskega utrujanja ter nateznih obremenitev v coni dovajanja preje nastali pretrgi fi brilov ali neodvisni pretrgi fi brilov. V območju zapletanja so nastala leteča vlakna s poškodbami v obliki pilinga površine, upogibov in zdrsov strukture, pretrgov zaradi vitja z dvema ali več razcepi, zrnatih in duktilnih pretrgov kot posledica kombiniranega učinka torzijske, upogibne in natezne napetosti vlaken. Ključne besede: tvorba puhka, poškodbe vlaken, pretrg vlaken
doi:10.14502/tekstilec2018.61.272-279
fatcat:lpar2cf2ufhuneps5rd6qjl2ku
