Rags which contain a mixture of cotton and wool have the cotton separated out by a process of carbonization. The rags are treated with dilute acid, usually sulphuric, dried, crushed to destroy the weakened fibers, neutralized, and dried. The rags are then torn to pieces to produce a grade of fibers known as extract.
The last and poorest class of shoddy consists of the very short clippings from tailor establishments or mills, called flocks. These are too short to weave alone, but may be felted into the surface of woolen cloth to add weight.
Spinning and weaving shoddy, mungo, or extract does not differ from other woolen spinning, except that the poorer grades of shoddy, and practically all mungo and extract, must be mixed with a longer fiber, either wool or cotton, in order that it may be spun.
The especial value of shoddy lies in the fact that it has greatly increased the supply of woolen cloth on the market, thereby reducing the cost of good wool, as well as providing a cheap wool. It brings woolen cloth within the reach of many who could not otherwise afford it. While ordinarily material made up entirely or in part from shoddy has not the wearing quality of new wool, it has warmth, and the best grade may be even better than the poorest grade of new wool.
Microscopically, shoddy may be distinguished from new wool in that the fibers are not as uniform in size or general character. The color of the different fibers often varies considerably, the ends may be broken and uneven, and often the scales are gone in parts of the fiber. Cotton fibers are not infrequently found with shoddy.
Some shoddy is longer than the shortest wool, so the length of the fiber is not a true test. The poorer grades of shoddy will make a thread which breaks easily, like rotten string. One needs to guard against this grade if durability in the finished cloth is a consideration.
The fibers called flocks, felted into the surface of cloth, rub out after some wear, collecting in the linings of coats, the hems of dresses, etc., and leaving the surface of the cloth threadbare.
Woolen fibers, because of their ability to hold together, may be made into cloth without the processes of spinning and weaving.
The wool used to make felt is cleaned, then carded into sheets several feet wide and very thin. These sheets are put one on top of another until the pile is about one inch thick, and are then passed through a series of rollers submerged in water. One roller is of wood, the other of tin filled with steam. The motion of the rollers is from side to side, as well as revolving, and the combined action of heat, moisture, and pressure opens the scales of the wool, tangles and mats it until felt is the result. This material is then dyed or printed, if so desired, is tentered and pressed, and then goes to the market.
Hair and cotton may be mixed with wool in limited quantities. This is done either before carding, as in case of cotton, or layers of hair may be mixed with the layers of wool, and the whole felted.
By these varied processes the dirty mass of wool which comes to the factory is transformed into many kinds of cloth to suit the needs and demands of a novelty-loving public.
With the changes in conditions of living, with warm houses, overheated public buildings, cars, trains, etc., the requirement for woolen underclothing has decreased. Although cotton, linen, and silk have replaced wool in many uses, for some purposes it is almost indispensable. For use in babies' flannels, underclothing for men working in places of extreme heat or cold, for protection from the wind, and for many other purposes, wool is the best material known, and the demand for it increases continually.
Barker, A. F. Textiles.
Beaumont, Robert. Woolen and Worsted Cloth Manufacture.
Bowman, Fred H. Structure of the Wool Fibre.
Burnley, J. History of Wool and Wool Combing.
Clapham, J. H. The Woolen and Worsted Industries.
MacLaren, W. S. B. Spinning Woolen and Worsted.
Matthews, J. M. Textile Fibres.
Posselt, E. A. Wool, Cotton, Silk, from Fibre to Finished Fabric.
Priestman, Howard. Principles of Woolen Spinning.