These are the very long proteinic fibers obtained from the cocoon of silkworm. Due to its strength, silk is used as carpet wrap or for waving floral patterns as piles of the carpet. Occasionally as well, in weaving very fine and precious carpets, silk is used as wrap and weft; all silk carpets are mainly decorative.

Weaving silk carpets requires specialty. In Iran, such carpets are mainly woven in Qom, Naein, Isfahan, Tariz and Kashan and compared with other types of carpet, silk carpets are produced in limited numbers.

Identifying Natural Silk

A-    By burning :
From the burning view point, silken fibers are like woolen ones and once burnt, they produce a smell like that of burnt feather.
B-    Chemical procedure : 
Natural silk completely dissolves in boiling 5% sodium chloride solution. Cold and concentrated hydrochloric acid and sulfuric acid as well dissolve silk thoroughly.

Important Centers of Production

Silk worm breeding factories are active in the provinces of Khorassan, Guilan and some other parts of the country.

 

Silk Yarn Production

Silk is either spun by hand using elementary instruments or in factories employing wheels and tens of spindles. Amongst the important hand-made silk production centers Guilan and Mazandaran could be mentioned. Also, the biggest silk spinning factory of Iran has been established in Rasht.

Grading (Numbering) of Silk Yarns

For grading silk yarns the denier system is employed which is the weight of 9000 m silk fiber/gram. Conversely to metric number, the higher the denier, the thicker will be the silk fiber. In carpet-weaving, deniers 60-160 are common and deniers 60-80 are used for wrap and deniers 100-160 are employed for carpet flowers.

                        Den = W/L x 9000