Biodegradable staple fiber nonwovens calendered with the assistance of an aqueous solvent : $btheir fabrication, properties, and structural characteristics

Biodegradable cotton/cellulose acetate thermal calendered webs were consolidated with the assistance of an aqueous acetone solvent. Existing patent literature cited lower acetate binder softening temperatures could be achieved because of the plasticization, hence microstructural changes brought on by the localized interruption of hydrogen bonds between adjacent molecular chains in the acetate fibers associated with acetone treatment. Acetate fibers softened at temperatures far below their typical 230°C melting temperature, fiber coalescence could be achieved between 177 and 191 °C. Microstructural responses to solvent modification include solvent induced crystallization, surface and internal cavitation and shrinkage, that ultimately cause suppression of the fiber second order glass transition and softening temperatures. Two different blend systems were treated with 20 and 40% acetone and consolidated at 150, 170 and I 90°C using thermal calendering rolls. Fabric mechanical integrity, web dimensional stability and fabric hand were evaluated, the performance of the different fabric combinations was compared statistically using the General Linear Model.