THE SPINNING OF "SILK WASTE" The term silk waste includes all kinds of raw silk which may be unwindable, and therefore unsuited to the throwing process. Be fore the introduction of machinery applicable to the spinning of silk waste, the refuse from cocoon reeling, and also from silk wind ing, which is now used in producing spun silk fabrics, hosiery, etc., was nearly all destroyed as being useless, with the exception of that which could be hand-combed and spun by means of the distaff and spinning wheel, a method which is still practised by some of the peasantry in India and some Eastern countries.
The supply of waste silk is drawn from the following sources: ( ) The silkworm, when commencing to spin, emits a lustreless and uneven thread with which it suspends itself from the twigs and leaves of the tree upon which it has been feeding, or from straws provided for it by attendants in the worm-rearing establish ments: this first thread is unreelable, and, moreover, is often mixed with straw, leaves and twigs. ( 2) The outside layers of the true cocoon are too coarse and uneven for reeling ; and as the worm completes its task of spinning, the thread becomes finer and weaker, so both the extreme outside and inside layers are put aside as waste. (3) Pierced cocoons—i.e., those from which the moth of the silkworm has emerged—and damaged cocoons. (4) During the process of reeling from the cocoon the silk often breaks; and both in finding a true and reelable thread, and in joining the ends, there is unavoidable waste. (5) Raw silk skeins are often re reeled ; and in this process part has to be discarded : this being known to the trade as gum-waste. The same term—gum-waste is applied to "waste" made in the various processes of silk throw ing; but manufacturers using threads known technically as organ zines and trams call the surplus "manufacturer's waste." Finally we have the uncultivated varieties of silks known as "wild silks," the chief of which is tussur. The different qualities of "waste," of which there are many, vary in colour from a rich yellow to a creamy white ; the chief producing countries being China, Japan, India, Italy, France and the countries in the Near East; and the best known qualities are: steam wastes, from Canton; knubs, from China and from Italy and other Western countries; frisons, from various sources ; wadding and blaze, Shanghai ; China, Hang chow, and Nankin buttons; Indian and Szechuen wastes; punjum, the most lustrous of wastes ; China curlies ; Japan wastes, known by such terms as kikai, ostue, etc. ; French, Swiss, Italian, China,
Piedmont, Milan, etc. There are yellow wastes from Italy, and many more far too numerous to mention.
A silk "throwster" receives his silk in skein form, the thread of which consists of a number of silk fibres wound together to make a certain diameter, the separate fibres having actually been spun by the worm, and this fibre may measure anything from 500 to i,000yd. in length. The silk-waste spinner receives his silk in quite a different form : merely the raw material, packed in bales of various sizes and weights, the contents being a much-tangled mass of all lengths of fibre mixed with much foreign matter, such as ends of straws, twigs, leaves, worms and chrysalides. It is the spinner's business to straighten out these fibres, with the aid of machinery, and then to so join them that they become a thread, which is known as spun silk.
There are two distinct kinds of spun silk—one called "schappe" and the other "spun silk" or "discharged spun silk." All silk pro duced by the worm is composed of two substances—fibroin, the true thread, and sericin, which is a hard, gummy coating of the "fibroin." Before the silk can be manipulated by machinery to any advantage, the gum coating must be removed, really dissolved and washed away—and according to the method used in achieving this operation the result is either a "schappe" or a "discharged yarn." The former, "schapping," is the French, Italian and Swiss method, from which the silk when finished is neither so bright nor so good in colour as the "discharged silk"; but it is very clean and level, and for some purposes absolutely essential, as, for instance, in velvet manufacture.