Products of Recycling

Our holding started work on tires recycling market 10 years before.

One of the main product of recycling process is the rubber crumb.

Production of Rubber Crumb – Starting Material for Many Recycling Processes

  • Rubber crumb – types
  • Whole tyre (possible fabric/metal contamination)
  • Tyre tread only (very low contamination – premium product)
  • Other crumb rubbers commercially available – Nitrile, EPDM, FKM etc
  • Grinding technologies
  • Cryogenic grinding (<150 mesh)
  • Water jet grinding (<150 mesh)
  • Ambient grinding (down to ~100 mesh)
  • Specialist systems (e.g. semi-cryogenic)
  • Sieving stage – after grinding
  • Grades crumb into particle sizes
  • e.g. 40 mesh (~400 μm)

Rubber Crumb – Quality Standards

  • WRAP Quality Protocol (2009)
  • Defines what point rubber fully recovered and no longer waste
  • Defines categories based on size
  • BSI PAS 107:2007 (ambient crumb only)
  • Collection of raw material, e.g. tread tyre buffing’s
  • Storage of raw material, manufacture and storage of final product
  • General properties of crumb
  • ASTM D-5603-2008 (grades 1 to 6 – mesh size, bulk density etc)
  • Particle size and particle size distribution
  • ASTM D-5644-2008 (Ro-tap sieve test method)
  • Chemical properties
  • ASTM D-297-2006 (sulphur level, ash composition)

Uses of Rubber Crumb

 

•Plastic products
•Wide range of plastics investigated – PE/PP, Nylon, Polystyrene etc
•Properties dependent on – level, type of compatibiliser etc
•Rubber products
•Up to 50% reported if activated/small particle size used
•EPDM compounds, Large tyres etc
•Other products
•Wood/crumb blends – sound insulation products
•Better than pure wood products
•Concrete – for construction products
•Bitumen and aggregate – road and path surfacing materials
•Gypsum plaster – improves elastic behaviour stops cracking
•Adhesives – improves elasticity
Rubber Crumb – Construction Products

Rubber Crumb – Construction Products

Rubber Crumb – Barrier Products and Large Tyres

Rubber Crumb – Recreational Surfaces

Cryosintering using Rubber Crumb

 

  • Cryosinter process to manufacture products
  • High pressure sintering of crumb directly into products
  • e.g. Shoe soles
  • Surface of crumb activated to improve interfacial adhesion
  • Quality of end product very dependent upon :
  • quality of crumb and effectiveness of surface treatment
  • Tensile strengths above 10 MPa are possible
  • Active area for Research
  • EU funded Cryosinter project (2006 to 2008)
  • Workers at Universities (e.g. Massachusetts and Florida)

Rubber Crumb – Adhesive and Underlay

Rubber tiles