A Nonwoven Composite Model Based on Silkworm Cocoon （Bombyx MOri）

The cocoon of the commercial silkworm Bombyx mori is used as a model natural nonwoven composite to formulate a model for structural properties of nonwoven composites. The model is based upon open cell foam structures for the intrinsic undamaged elastic properties using the component materials in the cocoon, combined with the effect of gradual loss of connectivity in the interfiber bonding as the cocoon is damaged by increased stress or strain loading. At a critical strain, the bonding connectivity it falls below a percolation threshold, and strength falls rapidly to a point where the cocoon is held together by loosely interwoven silk fibres.