CHAPTER VIII

THE PREPARING AND SPINNING MACHINERY FOR MANILA AND OTHER HARD FIBRES

The method of producing yarns from the hard fibres involves the use of quite different machines in the preparatory processes; this departure is necessary on account of the nature of the material and the length of the raw fibre.

The bales of raw material, Manila, Sisal, New Zealand, or the like, but all from one type in general, are arranged in a convenient position near the feed of the first machine which is called a “Hackler and Spreader,” and one type of which is illustrated in Fig. 25. The bales which are grouped together for this first treatment are chosen from different “marks” or grades of fibre in order to mix them to secure uniformity and to produce yarns of a given quality at the desired price.

[Illustration: FIG. 25 HACKLER AND SPREADER]

The heads of material are split up into suitable and uniform stricks, and when various classes are to be mixed it is essential that proportionate quantities should be drawn from the various bales in the “batch” or blend, and fed proportionately and uniformly on to the feed sheet of the machine. The feed sheet conveys the stricks slowly towards and ultimately between a pair of retaining and feed rollers, and when the material emerges from these rollers it is acted upon by a series of large hackle pins fixed in a chain of fallers or bars. These pins move at twice the speed of the feed and retaining rollers, and this relative movement enables the pins to hackle and open out the stricks. The partially-hackled stricks are now conveyed to a second chain of fallers and hackles which move at a much greater speed than that of the first hackles; it is here where most of the drawing takes place, and the material as it leaves these hackles is in the form of a thin sheet of fibres which enters a pair of drawing rollers. Finally, the material is delivered on to the floor in the form of a sliver and at the opposite end of the machine.

The bundles of sliver are conveyed to another machine, termed the intermediate machine, where further processes of equalization and drawing take place. In this, and in any subsequent machine of the same type, of which there may be three or four, the slivers are fed as illustrated on the left of Fig. 26, while several lengths of slivers appear in the foreground. After the drawing and hackling operations, the sliver is delivered as illustrated. These processes prepare suitable slivers for the remainder of the operations which are somewhat similar to those which are used for the soft fibres, although the “reach” in the machines for the hard fibres is very much longer than that necessary for the soft fibres. In the final preparing machine, the sliver is delivered into sliver cans which are then taken to the automatic spinning frame.

[Illustration: FIG. 26 INTERMEDIATE MACHINE]

AUTOMATIC SPINNING MACHINES.--A row of automatic spinning machines is illustrated in Fig. 27. The slivers from the last drawing frame are placed at the feed, one sliver can with its length of sliver for each machine. The sliver is passed through the first conductor, situated about a yard above the sliver can, and then between a pair of feed rollers seen to the right of the machine. From here the sliver is deflected to the proper bell-mouth conductor and to the long stretch or reach of gill pins shown clearly in the view. On emerging from the gill pins, the sliver passes through a nipping die and thence to the enclosed flyer from which it is wound on to the bobbin.

[Illustration: FIG. 27 AUTOMATIC SPINNING MACHINE]

The drafting is accomplished by a series of rollers or pulleys which draw the fibres through the gill pins and the nipping die, while the twist is imparted as usual by the flyers which revolve at about 1,400 revolutions per minute. The flyers are now enclosed in a safety cage of about the same width as the name plate.

The yarns thus spun are built upon large steel-ended bobbins which, when filled, may be conveyed direct to the transferring or warping machines where the yarns are prepared for further treatment, if and when any further treatment is necessary, or to the rope machines. Thus, if the yarns are to be made up into a tarred rope, it is necessary to prepare them into a suitable form for the tarring operation. This usually takes the form of a warp, and such warps are most satisfactorily made on a warping mill or winding reel. It is usual to run twelve threads from twelve bobbins and to make the warp a suitable size by continuing the operation of warping in the same way as is done for warps which are to be woven in a loom.

The warp is then passed through a tarring machine in which the tar, usually Russian or Swedish, is kept warm during the operation. After the necessary amount of tar has been applied, it is usual to store the warps of yarn for a lengthened period, say up to six months, to condition them. The individual yarns from these warps are then rewound on to twelve large bobbins in what is known as a 12-bobbin vertical spindle-winding machine.