Silk threads

Of all the materials used in the manufacture of fabrics, silk is certainly the most valuable by the many qualities it possesses naturally.

The length of the strands varies between 400 and 600 meters and the strength is such that a few strands of cocoon assembled are sufficient to make it a weaving thread.
The fineness of the strands, although variable according to provenance, varies between 19 and 32 thousandths of a millimeter (microns).
Its elasticity, its regularity, its whiteness once washed and its brilliance are remarkable. These qualities are not equal for all silks, from various sources. They depend on the food and the mode of rearing silkworms.
The breeding is done in magnaneries arranged for this purpose. This industry is of interest to the fabric manufacturer only in a purely documentary way, since it buys the yarn all prepared, however it is good to know that the Asian silks are the finest.
The thread provided by the silkworm is called a cocoon strand and is composed of two drops secreted together by the silkworm, together with a gelatinous material called sandstone, which more or less sticks the two drool.
This sandstone will be eliminated later. The color goes from white to yellow, but it is the sandstone that is colored. Once decrusted, ie rid of its sandstone, the silk of the Bombyx mori is white. Uncoiled silk contains 20 to 25% of sandstone and foreign matter.
Because of its constitution, silk is a very absorbent material and one avails of its greed to incorporate foreign bodies. This is what is called silk charging. The purpose of this load is to magnify the silk by giving it weight. The percentage of charge is variable and ranges from 20 to 25% up to 150% and more. It is evident that an exaggerated load will produce a weave which breaks through the folds and is pulverized in time. It is the dyer who performs this operation in wire or piece. If it returns to the silk the weight that was lost during the decreasing, it is said that it made a load weight for weight.
The silkworm provided by the silkworm can not be used alone. Several strands are assembled to form the first wire. The first yarns thus assembled comprise at least 2 or 3 strands of cocoons (often more) joined to one another by the sandstone which has resolidified by drying after the reeling of the cocoons. These threads are greaves. It is this operation which is called the drawing or spinning of silk.
The douppion is a large grate characterized by its irregularities of size. It comes from the reeling of double cocoons, spun by two silkworms that have been locked in the same cocoon.
The other threads, that is to say, not greige, undergo the silk milling which gives them a twist which makes them more solid and able to withstand the decay without inconvenience.
According to this twist, the threads will take different names. Those are :
Milled silk or hair is simply raw material that has been twisted after spinning. This twist is called primer. This makes it possible to dye this silk into fleets or skeins. It is sometimes used as a chain to replace the much more expensive organsin.
The weft is composed of several pieces of raw wood twisted together at a rate of 75 to 150 turns per meter. Used in weft as its name suggests, when one wants to give gloss and cover (tightening) to the fabric.
The crêpe is composed of one or more twisted hoofs, on the contrary, several thousand turns, which gives it powers of narrowing and tendencies to twist if one does not take the precaution of winding it as it goes. It is used in weaving crepe.
The organsin is formed of two (sometimes three or more) hair yarns twisted separately in straight torsion (Z), then twisted together in left torsion (S). The torsion S is 500 to 600 turns per meter, the torsion Z varying according to the destination of the organsin: 300 rpm for the velvet yarns, 400 rpm for the satins and 500 for the taffetas. The more turns are given, the less the wire is shiny and the stronger it is. The organsin is mostly used for the chain.
Grenadine is a large organsin very crooked or overturned with a grainy and dull appearance.
The cord is made up of two coarse threads (sometimes more) twisted together and showing the turns in relief. It is mainly used in embroidery.
The rondelette is a cordonnet whose hairs come from douppions.
The oval or oval silk is composed of greaves more or less large assembled and twisted at 70 or 80 turns per meter. It is used in weft in brocades and in embroidery for its brilliance and its cover.
The wave is formed of two hairy threads, one of which stands straight and taut, serving as a winding support for the second, much larger coiled loosely around it. The first is the soul, and the second the body. The body receives a very strong tension and the soul is not twisted at all. The two threads are twisted together in the opposite direction to the torsion of the body after they have been assembled, so that the body loosens and stretches as the core twists, shrinks and tightens. The willow is used in weft in embroidery and embroidery.
Special yarns or fancy yarns, very varied.
Tussah is the silk that comes from the spinning of cocoons produced by different breeds of caterpillars stronger than those of the Bombyx-mori, living in the wild in India, China and Japan, and feeding on oak leaves , Of ailante, of castor, and so on. The tussah comes from three breeds of anthéroea caterpillars. The tussah of Japan is the most beautiful. This silk is about 4 times larger than that of Bombyx-mori and contains on average 8% sandstone and 92% fibroin. Its strength is less great and its gray-red color more or less dark does not allow to obtain beautiful white even after decreasing. The cocoons are 2 folds big. The tussah finds many uses as a weft in united and shaped fabrics. The Japanese have used it extensively in fabrics for shirts and printed dresses. These so-called Japanese tussor paintings were reproduced in Lyon and then imitated by schappe articles.
The cocoons of Bombyx-mori are not all unrecoverable, and those that are inevitably give waste. The schappe or fantasy is obtained by the combing and spinning of this waste.
The bourette is the product of the carding and the spinning of the waste, in short the waste of waste ...
The schappe is obtained with the waste from the cocoons of Bombyx mori. It is not a silky tube like silk but a thread spun like cotton or wool. It can be compared to a beautiful mercerized cotton or a Scotch thread.