SPINNING 



641 



as to separate the short fibres the ' noils ' from 

 the long or ' top ' fibres. The ' top ' afterwards 

 passes through a long series of operations, the 

 principal object of which is to lay every single 

 fibre as nearly as possible parallel and level with 

 its neighbour. For woollen yarn, on the other 

 hand, short staple and wavy wools are used. 

 These are cardea together so that the fibres may 

 as far as possible cross each other and interlace 

 before being spun, and these peculiarities form the 

 essential distinction between woollens and worsteds. 

 Apart from worsteds, however, there is a general 

 sequence in the treatment of all fibres which may 

 lie here briefly outlined. 



The object of all operations preliminary to the 

 actual spinning is ( 1 ) to free the fibres from all 

 extraneous matter ; (2) to lay them side by side in 

 level parallel order ; (3) to pull them out in a con- 

 tinuous strand or sliver of uniform thickness ; and 

 (4) i to attenuate this sliver till the quantity re- 

 quired to form the yarn is reached. The operations 

 necessary for these purposes, combined with a pro- 

 perly regulated amount of twist, constitute the 

 conditions necessary to produce sound, level, and 

 uniform yarn. 



Taking the case of cotton, the opening and 

 partial cleaning of the matted fibres are secured by 

 passing the material through two machines called 

 respectively the opener and the scutcher. In these 

 machines are cylinders revolving at a high rate of 

 speed, with their surfaces studded with stout teeth 

 which seize separate locks of the fibre and carrying 

 it round form a broad uniform teased mass which 

 is called a lap. In the first of these machines it is 



Fig. 5. Sections of Carding-engine. 



also submitted to a strong current of air which 

 blows dust and dirt out of the cotton. From the 

 scutcher a well opened and spread lap of the fibre 

 is delivered to the carding-engine (fig. 5), in which 

 a series of cylinders of various sizes, and rotating 

 at different velocities, further open and tease the 

 fibre. The cylinders are covered with teeth of 

 fine wire (fig. 6) bent at about half their length, 



Fig. 6. 

 a, card wire ; b, card settiig. 



of which there may be from six to seven millions 

 in a single machine. According to the direction 

 in which the cylinders rotate, and the rate of their 

 revolution, the wire points may meet each other, 

 or the points and flat sides of the wires may meet 

 and pass ; and in this way certain cylinders lift 

 the fibres from their neighbours and pass it on to 

 others, so that the fibre is gradually teased, 

 brushed, and spread out in a uniform manner. 

 From the carding-engine the fibre is delivered in 

 a broad lap ; bnt by passing it through a ring or 

 457 



tube it is compressed into a soft rounded coil or 

 sliver. This sliver is taken to the drawing-frame, 

 which consists of say four successive pairs of 

 rollers, each pair in succession going at a greatly 

 accelerated rate, so that the last pair may be going 

 six times quicker than the front pair. In this way 

 a sliver is drawn out six times its original length, 

 and six slivers fed in come out the thickness of 

 one. This drawing out ultimately brings the 

 slivers to a very uniform thickness, and places the 

 fibres in a parallel order. It may be repeated 

 many times, and thereby the fibres which lay 

 together in the original strand may be drawn out 

 to a great length. Thus, passing a sliver of one 

 yard three times through the drawing-frame elon- 

 gates it 6 x 6 x 6 = 216 yd., or four times passed 

 through it is stretched out to 1296 yd. For fine 

 yarns this drawing out frequently repeated may 

 represent an elongation many thousandfold. In 

 the slubbing-frame comes the beginning of the 

 spinning process ; the sliver being here further 

 drawn out and twisted sufficiently to enable it to 

 be wound on a bobbin. The intermediate frame 

 draws out two slubbings to the thickness of one, 

 again slightly twists it, and winds it on a l>obbin. 

 In the roving frame the slubbing is drawn out 

 further, slightly twisted, and wound on a bobbin. 

 The rovings or bobbins of rove are then ready for 

 the spinning-frame, which in the case of heavy 

 stout yams is invariably the throstle, but when 

 fine counts are spun the spinning is done on the 

 mule. In throstle-spinning the roving is attenuated 

 by passing between rollers increasing in speed till 

 the desired tenuity is attained, at which point the 

 final twist is given, and the yarn is wound on the 

 bobbin or pirn ready to receive it. 



There are three methods of twisting practised 

 in throstle-spinning. The first and oldest is with 

 spindle, bobbin, and flyer, in principle precisely 

 the same as the arrangement in the spinning- 

 wheel. The second method is cop-spinning, in 

 which the spindle is stationary, but the bobbin 

 which revolves around it is caused at once to 

 give the twist and wind the yarn on its own 

 surface. This is effected by fitting over the bob- 

 bin a steel cop or cover of sufficient dimensions 

 to cover a filled bobbin. The cop has a smooth 

 steel edge which keeps the yam free from the 

 bobbin while the twist is being put on, and which 

 by its motion up and down regulates the winding 

 of the finished yarn on the bobbin. The third and 

 most recent development of throstle-spinning is the 

 ring and traveller frame. In this both spinale and 

 bobbin revolve together and give the twist ; but 

 the yarn passes to the bobbin through a traveller 

 or eye of steel set on a flanged steel ring wliich 

 encompasses the spindle and bobbin. The traveller 

 keeps the yarn free from the bobbin while the twist 

 is beinfj put in, and being carried round by the 

 bobbin it winds the yarn on the bobbin, the filling 

 of which is regulated by an up-and-down motion 

 communicated to the rail on which ring and 

 traveller are fastened. In mule-spinning the 

 bobbins of rove are mounted on a fixed frame, and 

 corresponding yam bobbins or paper cops are 

 attached to the spindles, which are mounted on 

 a carriage made to travel back and forward over a 

 space of two yards or thereby. The spinning in 

 this apparatus is intermittent. The drawing rollers 

 at the fixed frame give out a certain length of 

 roving; and simultaneously the carriage begins 

 to move away, and the spindles rotating rapidly 

 put twist on the rove. At a certain point the 

 rollers cease to give off roving, but, the carriage 

 still travelling backward and the spindles rotating, 

 the yarn is further drawn out and correspond- 

 ingly more twist is imparted. The twist becomes 

 hardest at the points where the yarn is weakest, the 



