| 摘要 |
<p>1,139,418. Core-yarn; drafting apparatus. KURASHIKI RAYON K.K. 2 Feb., 1966 [21 April, 1965], No. 4561/66. Headings D1D, D1F and D1W. Core yarn is made in a spinning-frame having a drafting-head with a pair of apron rollers by simultaneously feeding to the rear of the apron rollers, an elastic thread and a non-elastic roving of larger diameter than the thread whereby the roving is drafted and the thread remains undrafted. Drafting of the roving without drafting the thread is ensured by spacing the apron rollers or providing a recess in one of them, the depth of the space or of the recess being greater than the diameter of the thread and smaller than the diameter of the roving. In Fig. 1, rovings 9, 9<SP>1</SP> are fed together into the drafting-head comprising five sets of rollers. The elastic thread is fed through tension-guides 7, 7<SP>1</SP> to the rear of the penultimate pair of rollers 4, 41 which are provided with aprons 5, 5<SP>1</SP>. The upper roller has a circumferential recess (10, Fig. 2, not shown). The roving(s) may be of natural or artificial fibres, and the elastic thread may be a monofilament of polyolefine or polymethane polymer diol, an organic isocyanate and a diol chain-extender (examples given). The polyurethane has a molecular weight between 200-8,000 and a melting point below 80‹C. The filament is stretched and heat treated at above 50‹C for between 1 second and 30 minutes whereby the elongation is set to less than 150%; after which it may be similarly heat treated before it is spun. It is then supplied to the drafting head at a tension of between 0.8 and 1.3 grammes per denier.</p> |
