What About Waste Wool, Polyester And Viscose Blended Fabrics? -- Dissolution Recovery

In the waste textiles, the proportion of pure textiles is very small, relatively speaking, it is more feasible to recycle wool fabrics.

The main ways to recycle polyester fiber by chemical methods are hydrolysis, alcoholysis, pyrolysis and supercritical fluid. The products obtained by different degradation methods are different.

Because the solubility of polyester is poor and the dissolution technology is difficult, the wool is chosen to dissolve.

The waste polyester and viscose fabric is recovered and recycled by viscose fiber. Finally, the remaining polyester is washed and dried and used directly.

Viscose fiber has good alkali resistance, and polyester and wool fiber have good acid resistance.

In recent years, many new solvents for the dissolution of cellulose have appeared, such as N- methyl morpholine oxide, NaOH/urea (sulfourea), DMAc/LiCl, NH3/NH4SCN, ionic liquids, and phosphoric acid / polyphosphoric acid mixed solvents.

At present, there are few studies on the dissolution of cellulose by phosphate solvent at home and abroad. Only a small number of patents have reported that phosphate / polyphosphate composite solvent can completely dissolve cellulose in a relatively short time.

Based on a large number of experiments in China, it was found that only P2O5 72%~76% content in mixed acid system could effectively dissolve cellulose.

Therefore, this study first dissolves the viscose component in the fabric with phosphoric acid / polyphosphoric acid system, then filters it and dissolves the wool through the reduced C system.

Finally, the remaining polyester fiber.

The wool fibers and viscose fibers obtained after dissolving are used to prepare recycled fiber powder, and polyester fiber is used to prepare nonwovens.

The optimized solution of the phosphoric acid / polyphosphate mixed acid system for viscose fiber in wool polyester viscose blended fabric is: P2O5 content of 74%, solid content 14% and temperature 25 degrees.

By means of electron microscope analysis and infrared spectrum analysis, it is found that the mixed acid system of phosphoric acid and polyphosphoric acid can rapidly dissolve viscose fiber without damaging wool and polyester fibers.