GB1507535A - Method of and apparatus for producing plied spun staple yarn - Google Patents

Abstract

1507535 Making yarns UNIROYAL Inc 9 June 1975 [11 June 1974] 24646/75 Heading D1F In order to produce plied spun staple yarn 41 one spun staple yarn 11 is ballooned around a second spun staple yarn 31 at a ballooning station 6. Each yarn 11. 31 is withdrawn from the respective supplies 4, 30 by respective pairs of nip-forming rolls 13, 14 and 26, 27 at equal linear speeds. The roll pairs isolate the tensions on the yarns such that the tension on each yarn before it reaches the respective roll pair is different from the tension after it has passed the roll pair. A roll 28 draws the plied yarn 41 and the respective yarns 11, 31 at a speed greater than and, as a result, at a tension greater than that imparted to each yarn by the roll pairs 13, 14 and 26, 27 to maintain the stability of the balloon. The ballooning operation imparts a false twist on the yarns 11, 31 and the plied yarn 41. The plied yarn is then guided via a roll 34' to a heat-treatment zone 7 where it enters a steam-heated tube 62 and exits from another heated tube 63 so that the already twisted yarn 41 is heat-set to retain the twist. The twist-set yarn is guided around rolls 36, 37, pigtails 38, 39, rolls 42 and 34" so that it dries and cools before being passed under increased tension to a yarn take-up means 8. The roll 34" is smaller in diameter than its original roll 34' whereby the yarn travelling speed around the roller 34" is decreased. Therefore the tension imparted to the yarn 41 inside the tubes 62, 63 is small compared to the tension on the yarn 41 as it leaves the roll 28. The tension subjected to yarn 51 after it has left the drying and cooling zones is increased. The heating in the zone 7 may be in the form of moist heat or dry heat. The rolls 13, 26 and 18 are driven at equal rotational speeds and the rolls 13 and 26 have a high friction slippage-preventing surface which in the case of the roll 26 is made of aluminium oxide. The rolls 34' and 34" have also a high friction surface similar to the rolls 13, 26 and 18. The plying and ballooning of the yarn 11 around yarn 31 is promoted by a disc 24 rotating about a housing 74 at the plying station 6.