The Study On The Separation Of Waste Polyeaster/Cotton Textiles And Their Recycling Technology

With people living consumption level increasing,the textile life-time is shorten,Post-consumer textiles grow significantly.Because of the oil resources and the environmentle pressure,recycling of waste textiles is becoming the research focus.Polyester/cotton textiles account for a large part of the waste textiles.Therefore,the research on the separation of the polyester or polyester-cotton blend fabrics and their reuse are of great theoretical and practical significances.Firstly,post-consumer polyester/cotton uniforms were used as raw materials and separation process was carried out using dilute acid of hydrochloric acid,sulfuric acid,nitric acid.The parameters such as mass concentration of acid,reaction time and reaction temperature were studied.The products were characterized by SEM,FT-IR,DSC,XRD and GPC.Under the experimental conditions,the best separation were obtained,for hydrochloric acid the mass concentration of hydrochloric acid was 10%,reaction temperature was 90℃ and reaction time was 90 min;for sulfuric acid the mass concentration of acid was 20%,reaction temperature was 95℃ and reaction time was 90 min;for nitric acid,the mass concentration of acid was 9%,reaction temperature was 95℃ and reaction time was 100 min.The test results showed that the chemical structure of polyester remained unchanged as well as its tensile properties,while the orientation and modulus dropped significantly.The cotton powders desolved from the blends were still cellulose in chemical structure and crystallinity increased.Secondly,re-use of the polyester fiber and cotton powder after the separation was studied.For cotton powder the parameters such as spinning speed and mass concentration were systematic studied.The recycled PET chips were prepared by using the glycolysis plus re-polymerization process.The corresponding fibers were prepared using lab-scale melt spinning.The products were characterized by SEM,tensile tester,DSC,XRD and GPC.The results showed that optimal spinning technology were obtained when mass concentration of cotton powder was 11%,spinning speed was 60 m/min,the fiber strength was 0.42 GPa and.crystallinity increased with the increase of spinning speed.The intrinsic viscosity of recycled polyester chips could reach the value of 0.68dl/g which reached fiber-class standard.The recycled PET chips have good spinnability with certain cotton power uneven distribution along the fibers.