EP4: Philippe Colignon, Centexbel, Recycling of textile waste streams, the Retex project

For this Ellie.Talks episode, we invited Philippe Colignon, from Centexbel, to talk about Retex, an ambitious partnership for circular economy in the textiles industry in the EU region. The aim of RETEX was to Rethink, Redesign, Reuse, and Reduce textile waste and Stimulate Innovation.

About Retex

  • Aim: the transformation of textile waste streams into prime material for the local textile industry by recycling.
  • Focus on textile waste streams in 100% Cotton, 100% Polyester, or Polyester/Cotton
    • Domestic & Industrial End Of Life
    • Industrial waste from the textile processing and production industry
  • Defined Action Areas :
    • Chemical Recycling: Technology Watch
    • Thermoplastic Recycling
      • Semi-industrial trails
      • Test value chains for polyester
    • Mechanical Recycling: Industrial trials
      • Test value chains polyester/cotton
      • Test value chains 100% cotton

Action Area: Technology Watch for Chemical Recycling

This has not been discussed during the call but for more details, you can visit the Retex website: https://www.dotheretex.eu/

Action Area: 2: Thermoplastic Textile Recycling of 100% Polyester

  • Aim: Transform textile waste into raw material for extrusion via mechanical and thermal processes
    • Research the technical feasibility to go from fibre-to-fibre
    • Spin yarns intended for weaving and knitting
    • Use 100% polyester waste material
    • Focus on meltable materials
    • From waste to pellets to granulates
  • Process
    • Preparation is very important: removing labels & tags, sorting in colors, washing, cleaning
    • Shredding to get bits and pieces of fabrics
    • Compacting into pellets (plastic bullets)
    • Thermogranulation / compounding: to make pellets stronger and more homogeneous
    • Extrusion into mono or multifilament
    • Important: you tend to lose properties during the process, you need to correct these. Solve by injecting virgin materials into recycled ones. Or, you need to use additives like viscosity boosters.
    • End result:
      • Tapes
      • Mono filaments
      • Plastic Moulding
  • Challenges
    • Requires well-identified types of waste
    • Shredding and compacting: most equipment is designed for recycling hard plastics
    • Mechanical and thermal processes result in the degradation of properties
    • Low viscosity leads to reduced processability
    • High brittleness
    • Tensile strength and elongation
    • Presence of impurities and additives
    • Colour change
    • Cost of the use of properties enhancers

Action Area 3: Mechanical Recycling Tests

  • Project set-up – Blend Cotton/polyester
    • Looked at different possibilities for the textile feedstock
    • Partners & process
      • Collection of 2T EOL jackets and trousers via industrial laundry company
      • Removal of buttons and tags via social employment company
      • Minot Recycling: unraveling of the fabrics into fibers
      • Utexbe: spinning of the fibers into a yarn
      • Utexbel: weaving & finishing -> fabric
      • Van Moer: assembling of the new garments
  • Insights – Blend Cotton/Polyester
    • Started with polyester and cotton but ended with only polyester
      • Cotton degrades by industrial washing (10% instead of 35% in the original content)
    • Important to learn from the process in order to adapt and optimize
      • Collection via industrial laundries presents a big advantage
      • Removal of the buttons and tags by the social employment company
        • ECO CONCEPTION speeds up the process and lowers the cost
      • The final composition of the yarn: only 33% virgin materials
      • Industrial symbiosis to make a value chain work. Create mutual benefits: waste for one company as raw material for the other.
    • This first trial has really served as a starting point now the value chain is further developing itself.
  • Project Set-up 100% Cotton
    • Production scraps from Petit Bateau
    • Procotex for the recycling
    • ESG for the spinning
    • Degeest for the knitting of the new garment
  • Insights: 100% Cotton
    • Existing machinery for cutting, tearing, and unraveling should be improved to reduce the aggression of the tearing.
    • The best result is obtained from unwashed industrial cotton
    • Industrial laundries should work at reducing the damage to the cotton
    • Removal of hard points requires eco-conception is a must
    • Recycling per material type and colour requires further automation of the sorting process
    • Industrial waste cotton is technically feasible… What about unsold clothes?

Textile Recycling in Future

  • Huge quantities of textile waste available = problem or opportunity
  • Waste streams availability and quality are key
  • EU Textile Strategy in preparation, what’s next?
  • Extended Producer’s Responsibility (EPR of UPV) is on its way
  • Increasing demand for recycled fibers, yarns, fabrics
  • A circular Economy is the way
  • Recycling rather than downcycling

Textile Recycling Technologies

  • Mechanical: recycling available
  • Thermo-Mechanical Recycling in progress
  • Chemical recycling breakthrough, now, 2023, 2024
    • Purpose: get as close as possible to the original material
    • Development in progress, with promising results
    • Industrial scaling-up required for meaningful capacity
  • Sorting technology in progress

Key Take-Outs

  • Recycling is no Magic, no easy recipe is available yet
  • The same material can not be indefinitely recycled
  • The quality of recycled material depends on waste stream quality
  • In the mechanical process, virgin/better material must be added
  • In the thermoplastic process, additives must be used, bringing the cost up


  • The Circular Economy approach is there to help
  • There are opportunities out there for mechanical processes
  • The future of recycling has a huge potential, with several options currently in development or in industrial scaling up.