Читать книгу Textiles, for Commercial, Industrial, and Domestic Arts Schools - William H. Dooley - Страница 15

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Carding. After the wool is washed it undergoes a number of operations before it is finished into worsted or woolen yarn.[12] The first step in the manufacturing of worsted yarn is to pass the washed wool through a worsted card which consists of a number of cylinders covered with fine wire teeth mounted on a frame. The effect of these cylinders on the wool is to disengage the wool fibers, make them straight, and form a “sliver” or strand. It is now ready for the combing machine.

Combing. The process of combing consists of subjecting the card sliver to the operations of the automatic wool comber, which straightens the fibers and removes all short and tufted pieces of wool. Combing is a guarantee that every fiber of the wool lies perfectly straight, and that all fibers follow one after the other in regular order.

Comb. A comb is a complicated machine. The principal feature is a large metal ring with rows of fine steel pins (pin circles), which is made to revolve horizontally within the machine. By various devices the wool is fed into the teeth of the ring in the form of tufts. The fibers of the tufts by an intricate process are separated into long and short lengths, and a set of rollers draws each out separately and winds it into a continuous strand called “tops.” On leaving the comber, the wool is free from short fibers, specks, and foreign substances, and presents a fine, flowing, and lustrous appearance. The short combed-out wool is called noils, and is used in making carpet yarns, ground up into shoddy stock, or utilized in spinning fancy yarns.

Worsted Tops. American textile manufacturers are finding it advantageous to have their combing done by those who make the work a specialty rather than to do it themselves. In the manufacture of tops all varieties of combing wools are used: Australian, Merino, and Crossbred wools, South American Merino and Crossbred wools, Cape Merino wools, Merino and Crossbred wools grown in the United States, the lustrous wools of pure English blood, Mohair from Asiatic Turkey, and Alpaca from the Andes. Tops are sold to worsted spinneries.[13] Many mills or worsted spinneries send their wools, either sorted or unsorted as they may desire, to a combing mill, where the wool is put into top at a lower price than that at which most spinneries can do their own combing. By means of the naphtha process a larger amount of top from a given amount of wool can be secured than by any other process, and in addition, a top in better condition for drawing and spinning.

COMB ROOM

1. Driving pulley on horizontal shaft (2).

3. Boxes containing bevel gears.

4. Pillars.

5. Driving pulley for dabbing motion.

6. Boxes containing dabbing-brush mechanism.

7. Dabbing brushes.

8. Star or stroker wheels.

9. Large circle containing rows of pins.

10. Drawing-off apron and rollers for large circle.

11. Brass boxes or conductors.

12. Guides for comb ball ends.

13. Comb balls (4 ends each).

14. Fluted wooden rollers on which comb balls rest.

15. Comb leg (4 in number).

16. Foundation plate.

In a strand of combed wool, called top, no single fiber lies across the strand; all lie in the direction of the length. This order is preserved until the fibers have been converted into yarn, which is accomplished by passing through “gill boxes.” These gill boxes are machines with bars of iron having upon their surface two rows of minute steel pins, by this means kept perfectly straight. The bars on which they are placed are worked on screws between two sets of rollers. The wool enters between the first set of rollers, and, as it passes through, is caught by one of these gills that is raised up for the purpose, being succeeded by others as the rollers revolve. These gills are moved forward on screws in the direction of the other set of rollers, and the pins in the gills always keep the fiber perfectly straight. The second set of rollers is termed the draught rollers, since by them the wool, after passing through the front rollers, is drawn out and reduced in thickness. This is accomplished because the second rollers revolve at a higher rate of speed than the first rollers, the speed being regulated according to the length of the wool, and the thickness of the yarn to be produced. These gills are used in the production of worsted yarn until the size of the rope of wool has been so reduced and twisted that there is no chance of any fiber getting crossed or out of the order of straightness. A worsted yarn is, consequently, a straight yarn, or a yarn produced from perfectly straight fibers.

GILLING

1. Cans containing Comb Ends or Sliver.

2. Balling Head.

3. Stock from Balling Head No. 2.

4. Screws for applying pressure to Back Rollers.

5. Screws for applying pressure to Front Rollers.

6. Faller Screws situated between No. 4 and No. 5.

7. Guard for covering gears which drive Back Rollers.

8. Guard covering gears which drive Balling Head.

9. Balling Head.

The combing of wool may be dispensed with in some cases, although such a yarn is not in common use. When combing is dispensed with, the gills, in connection with the draught of the rollers, make the fibers straight, and produce a worsted yarn, although such a yarn has a tendency to be uneven and knotty.

Before the wool can be spun it must be made into roving of a suitable thickness. This is done by passing it, after being combed, through a series of operations termed drawing, whose functions are to produce a gradual reduction in thickness at each stage. Although the number of machines varies according to the kind of wool to be treated, still the same principle applies to all.

Spinning. The process of spinning is the last in the formation of yarn or thread, the subsequent operations having for their object the strengthening of the yarn by combining two or more strands and afterward arranging them for weaving or for the purpose for which the yarn is required. It is also the last time that the fibers are mechanically drawn over each other or drafted, and this is invariably done from a single roving. The humidity and temperature of the spinning room must be adjusted to conditions. Each spinner is provided with a wet and dry thermometer so that the best temperature can be ascertained. The most suitable heat and humidity can only be obtained by comparison and observation. A dry and warm atmosphere causes the wool to become charged with electricity and then the fibers repel each other.

WORSTED SPINNING. “BRADFORD SYSTEM”

1. Bobbins containing Worsted Yarn.

2. Conical shape caps placed on top of spindles.

3. Tin Wings fastened to Eyeboard.

4. Eyeboard containing pot eyes, through which yarn passes to the bobbin.

5. Scratch fluted front rollers.

6. Leather covered Pressing Rollers for No. 5 Rollers.

7. Smooth metal Pressing Rollers for Back Rollers.

8. Large Front Roller Gear.

9. Pulley for driving Twist gear.

10. Spools of Roving held by a series of pegs.

11. Spindle bands.

12. Sifter plate or rail.

Worsted yarn is spun by two different methods known respectively as the Bradford or English system and the French system. The difference in these systems of spinning worsteds lies principally in the drawing and spinning processes, a radically different class of machinery being used for each. The combing process is practically the same in both cases, but the wool is combed dry for the French system, and by the English method the stock is thoroughly oiled before being combed. The result of the English method is the production of a smooth level yarn in which the fibers lie nearly parallel to each other. The yarn made according to the French system is somewhat fuzzier and more woolly. On account of the absence of oil, the shrinkage of French spun worsted is considerably less than that made by the Bradford system.

Characteristics of Worsted Yarn. The unique structure of worsted yarn makes it invaluable in the production of textile fabrics in which luster and uniformity of surface are the chief characteristics. The methods by which worsted is formed render it capable of sustaining more tension in proportion to its size than the pure woolen yarn. This feature, combined with its lustrous quality, gives it a pre-eminent position in the manufacture of fine coatings, dress goods, etc. The method of arranging the fibers in the formation of a woolen yarn is such as to produce a strand with a somewhat indefinite and fibrous surface, which destroys to a large degree the clearness of the pattern effect in the woven piece. In the construction of worsted yarn the fibers are arranged in a parallel relationship to each other, resulting in the production of a smooth, hard yarn having a well-defined surface; hence weave-ornamentation of a decided or marked type is possible by its use. There is, in a word, more scope for pattern effects, since the level and regular structure of the yarn imparts a distinction to every part of a woven design. From this peculiarity arises the great variety of effects seen in the worsted dress fabrics, coatings, trouserings, etc., both in colored patterns and in fabrics of one shade throughout.

SPOOL ROOM

1. Jack Spooler frame.

2. Drum upon which Jack Spool rests.

3. Jack Spool.

4. Guides for spool ends.

5. Spools containing yarn.

6. Pressers which rest on spools to prevent slack ends.

7. Spool creel.

FRENCH SPINNING

1. Balling heads.

2. Bobbins upon which stock is wound.

3. Rub or condenser aprons.

4. Gearing for driving rub motion.

5. Shipper rod and handles.

6. Bobbins held in place in creel by skewers.

7. Weights with system of levers for applying pressure to rollers.

Worsted yarn can be made of pure wool; and as a rule, the wool used in the English system is of fairly good length and uniform staple, for if otherwise it is only with difficulty that the yarn can be spun straight. Shorter wool can be combed and spun under the French system, and this is the reason why the French system of spinning is being introduced. On the other hand, in the spinning of woolen yarns great length of staple is not essential, for the machinery employed will work the small fibers.

Uses of Worsted Yarn. Worsted yarn may be used in any of the following fabrics:

1. Combed wool yarn for ornamental needlework and knitting, as Berlin, Zephyr, and Saxony wools.

2. Cloth made from combed wool not classified according to material.