Fleece Preparation Technology for Obtaining Fabric from Defective Cocoons

Abstract

The efficient utilization of silk-processing waste is essential for improving the resource efficiency and environmental sustainability of the textile industry. This study investigates a technology for producing silk fleece from defective cocoons of the Jingsong × Haoyue hybrid as a raw material for nonwoven fabrics. Unreelable cocoons were processed into silk fleece using an HL100 automatic silk wadding machine. The effects of alkaline soap-soda treatment and different boiling solutions on sericin removal and fibre quality were evaluated. The cocoon waste and prepared fleece were characterized by sorting statistics, microscopic examination of fibre arrangement, and fibre length analysis after cutting to staple lengths of 30, 35, and 40 mm. The results showed that double-dome, spotted, white-patch, and stalk-marked cocoons constituted the major defective fractions. Although unsuitable for conventional silk reeling, these cocoons proved suitable for fleece production. The optimal soda-soap boiling regime removed approximately 6-7% of sericin while preserving fibre integrity. Fibre length analysis revealed a predominance of very short (1 -10 mm) and very long (≥70 mm) fibres, indicating limited suitability for spinning bu t good potential for nonwoven manufacturing. Two processing routes for nonwoven silk materials were proposed: incorporation of thermoplastic binder fibres and needle punching followed by heat pressing. The proposed technology enables the conversion of defective cocoon waste into value-added raw material for environmentally sustainable nonwoven silk products, contributing to waste valorization and circular resource utilization in the silk industry.