Green Machine using Hydrothermal Separation Treatment


A post-consumer blended textile separation and recycling system by using hydrothermal treatment is developed to recycle and reuse textiles made of cotton polyester blends, achieving closed-loop textile recycling.

  • Green Machine using Hydrothermal Separation Treatment 0
  • Green Machine using Hydrothermal Separation Treatment 1
  • Green Machine using Hydrothermal Separation Treatment 2
Technical name of innovation
Hydrothermal treatment to recycle cotton polyester blends
Research completion
Commercialisation opportunities
Technology licensing
Problem addressed

Cotton and polyester blended-fibre are extensively used by clothing manufacturers today to meet garment preferences in fit, style, and comfort. Currently, there is absence of a textile recycling solution that can completely recycle these blended-fibre. The huge amount of textile waste imposes great pressure on landfill and fibre supply chain.

  • Developing a complete hydrothermal treatment process to decompose cotton into cellulose powder and to recover separated polyester fibres, whose the quality of the polyester fibres is maintained
  • Involving only water and a tiny amount of non-harmful chemical throughout the treatment
  • The Green Machine has been upscaled for industrial operation with a daily processing capacity of 1.5 tonnes
Key impact
  • A non-harmful chemical and energy-saving textile recycling treatment of cotton-polyester blended fabrics
  • Fulfilling the goal of "end-to-end recycling" where post-consumer textiles are recovered as the raw materials in circular supply chains
  • Reducing environmental damage and demand for virgin fibres in the textile industry
  • 2022 R&D 100 Awards - Winner (2022)
  • ITMF Awards 2022
  • Gold Medal in the 46th International Exhibition of Inventions of Geneva (2018)
  • Gold Award in the Asia International Innovative Invention Award (2019)
  • Silver Award in the Hong Kong Green Innovations Awards (2017)
  • Textile recycling 
  • The separated fibres with no depolymerisation are ready for spinning and manufacturing of new fashion items.
  • While the cellulose powders, decomposed from the cotton, can be applied to functional products such as super-absorbency materials and regenerated cellulose fibres.


  • 305183721
  • EP19181129.8
  • EP19181128.0
The Hong Kong Research Institute of Textiles and Apparel (HKRITA)

Established in 2006, The Hong Kong Research Institute of Textiles and Apparel (HKRITA) is funded by the Innovation and Technology Commission of the HKSAR government, and hosted by The Hong Kong Polytechnic University. 

HKRITA has achieved research deliverables over the years around our research clusters targeting in sustainability, industry advancement and social benefits through our centre-owned research teams and laboratories as well as collaborations with industry partners and institutions.