Depending on the climatic zone, harvests can be 2/3 up to 8/10 per year. During its larval phase, the silkworm only eats mulberry leaves, which need to be finely chopped. In about 27 days, these insects grow from few millimetres up to 7/8 cm.
From each spinneret, a very thin and mellow filament gets out. This is called floss. During the spinning, the two flosses weld together thanks to sericin (silk’s gum) and assume a solid state as soon as they meet air.
The silk filament is produced passively, as it is not due to the compression of the sink glands, but by the circular and repetitive movements of the silkworm head. Therefore, thanks to its movements, it can continuously produce the filament.
Comme nous l'avons dit, la « spelaia » est la première partie du fil extrudé du ver à soie, environ 40/50 mètres, après quoi elle commence à construire le cocon proprement dit. La partie externe du cocon, appelée « strusa », a une longueur classiquement mesurée en cent mètres. La partie centrale, dite « filable », est celle qui intéresse la filature car elle représente la partie dans laquelle le titre de la « bavelle » est plus régulier, la longueur varie selon les races et les facteurs climatiques et d’élevage ; il peut varier de 450 à 1 000 mètres.
For the industrial use of cocoon in the reeling mill, the chrysalis needs to be dried before the silkworm completes its metamorphoses, transforming itself into a butterfly and holing the cocoon irreparably. For this reason, in the past, the cocoons were treated in steaming stoves, where they were steamed through hot water’s vapours. Then, the humid cocoons were placed on wide, well ventilate stands. Here they could be dried up until they lose 1/3 of their weight. At this point, the cocoons can be commercialized, as they are completely dry. Nowadays, quicker and more efficient techniques have been developed, such as dry stoves, in which specific dryers are used. This also allows to dramatically decrease the appearance of molds.
Company specialized in the processing of silk yarns
Via Castello, 27/29
23843 Dolzago LC
TEL: (+39) 0341 451 320
FAX: (+39) 0341 451 404