The manufacture of silk

The manufacture of silk

Origins - Legend and antiquity

A Chinese legend attributes the discovery of the reeling of the silk cocoon to the Chinese princess Si-Ling-Chi who - around 2600 BC - dropped a butterfly cocoon into her hot tea. By wishing to remove it, she would have discovered fine filaments that could be pulled continuously.

The Empire of China will remain the exclusive producer of silk for 2,000 years. Its trade extending to Greece i.e. the silk road around 200 years before J.C. The Japanese and the Indians end up unraveling the mystery of sericulture and also become great producers, so much so that the Romans call the region east of the Ganges: Sericium.

Much later - in the 6th century AD - sericulture was finally mastered by the Byzantine Empire, which jealously guarded its secret. It was a waste of time since the Muslim conquest of the Iberian Peninsula and Silica massively disseminated all the techniques of silk production in the Mediterranean basin, mainly in France, Italy and Spain.

 

Modern history in France

It was with the arrival of the popes in Avigon in the 14th century that the cultivation of mulberry trees began in this region. Simultaneously Louis XI will motivate many Greek and Italian craftsmen to emigrate to Tours in order to promote sericulture there. A century later, Tours became a more important sericulture center than Paris, Lyon or Montpellier. This is followed by various actions and royal orders by François I, Henri IV - Olivier de Serres and Louis XIV - Colbert which will really anchor the manufacture of silk in the French artisanal fabric.

A particularly harsh winter in 1709 froze most of the olive trees in the south as well as the chestnut trees in the Cévennes. This devastating frost will lead to the massive planting of mulberry trees in the Cevennes and more slightly in Provence. This results in a respectable annual production of around 7,000 tons of silk cocoons.

Production will then drastically accelerate from the 1760s - 1780s to the 1850s, going from 7,000 tons to 26,000 tons annually. Of course, this strong increase in production comes at the cost of the increase in the breeding density of silkworms, which end up being victims of numerous diseases. Around 1856 production dropped from 26,000 to 7,500 tons per year, nearly 80 years of production optimization evaporated.

Several attempts to stem diseases of mulberry plants and silkworms will be undertaken. Note, among others, the work of de Quatrefages, Béchamp, Balbiani and Louis Pasteur on two diseases: pebrine and flacherie. After 5 years of research and the implementation of new breeding measures, the spread of these two diseases has been stopped. Production dates back to 8,000 - 10,000 tons annually. From this moment on, sericulture will gradually decrease in France, in particular because of the flacherie which will increasingly resist the measures taken previously and the opening of the Suez Canal which makes the silk trade with Asian countries much easier. more interesting than before.

It is sericulture that will give birth to confetti. In 1891, the breeding of silkworms uses perforated paper and Mr. Lué, administrator of the Casino de Paris will use scraps of breeding paper to generate small pieces of paper used as festive projectiles during a ball. hidden within the casino. Confetti was born and will spread globally in just a few years.

The 4 stages of silk production

Sericulture

Cette première étape est précisément décrite dans son propre article : sériciculture.
Elle consiste en l'élevage du Bombyx du mûrier dont le cycle de vie passe par la production de cocons afin d'effectuer sa métamorphose. Les cocons sont faits d'un matériau matriciel composé de fils de soie sont ensuite collectés en vue d'en extraire la soie. Comme précisé dans l'article, l'intégralité du cocon contient un unique fil de soie, si la métamorphose n'aboutit pas alors ce fil peut-être extrait c'est le dévidage du cocon.

Spinning - reeling of the cocoons

Spinning describes the process of unwinding the cocoon in order to extract the silk thread. The cocoons are placed in a bath of boiling water, softened and shaken with a small broom to see one of the two ends of the thread that makes up the cocoon emerge.

Each loose thread is collected then attached to a spinning machine which groups several threads of silk into a thicker fiber made up of several threads rolling up on themselves. Without it, the silk thread would be too fine to weave.

Artisanal spinning is done manually using a spinning loom on wooden lathes, with the invention of the steam engine, spinning looms are dehumanized and spinning can become industrial.

Grinding

This step is necessary in order to once again increase the resistance of the silk thread. Although after spinning the silk thread is made up of a dozen silk fibers rolled up on themselves, this thread is still not strong enough to be woven in a traditional loom. or industrial.

Moulinage therefore takes care of this increase in resistance by grouping several silk threads by twisting them around each other. Depending on the twisting method used, several yarns can be created: organzin, crepe, grenadine, veil, etc.

Weaving

Weaving is the step to obtain the finished textile. Like any other textile, silk fabric is woven by interweaving weft threads (width of the fabric) with warp threads (length of the fabric).

The weft thread or threads pass through the warp threads using a shuttle. The weaving pattern, defined by the setting of the loom, determines the nature of the fabric: muslin, crepe, velvet, satin, brocade, etc. but also the pattern if several yarns of different colors or types are used.

We will mention the Jacquard loom which was the first loom allowing weaving with a single artisan. The weaving network is "programmed" by the perforation of several cardboard or wooden plates which determines the sequence of the raised warp threads and therefore the weaving by the weft threads at each passage of the shuttle.

 

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