Recycling of cellulosic textiles
US11891725B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 2023 |
| Grant date | Feb 6, 2024 |
| Priority date | — |
| Expiry date | Feb 27, 2043 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/62
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A method for recycling textiles comprising cellulose with the following steps of: optionally disintegrating the textile, swelling the cellulose, under reducing conditions, wherein at least one reducing agent is present at least during a part of the swelling, and then performing at least one of the following two bleaching steps in any order: i) bleaching the material with oxygen at alkaline conditions with a pH in the range 9-13.5, and ii) bleaching the material with ozone at acid conditions below pH 6. An advantage is that the yield is improved at the same time as excellent decolourization is achieved. If the recycled material is used in viscose manufacture, the risk of clogging nozzles and so on is reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.