Rubber Recycling Dierkes
Rubber Recycling Dierkes
Rubber Recycling Dierkes
Rubber Recycling
Joint seminar
Kumi-instituutti & MOL
2
Contents
- Introduction
Reclaim / devulcanizate
- Future
3
Introduction
Used tires
EU countries:
2000: ca. 2,700,000 tons
2006: ca. 3,200,000 tons
4
Introduction
Legislation
Rubber powder
Surface
Granulate
Vulcanized activation Rubber
rubber product
Powder
Regeneration
10 m 2 m
7
Surface
Granulate
Vulcanized activation Rubber
rubber product
Powder Regeneration
Biological treatment
Chemical treatment
8
Surface
Granulate
Vulcanized activation Rubber
rubber product
Powder Regeneration
Biological treatment
Chemical treatment
9
Surface activated rubber powder
Chemical treatment
Coating:
+ Polymer
Latex, low-molecular liquid polymer, polymer-oil blends
+ Curing additives
Swelling:
+ Oligomer, evtl. with functional groups
+ Oil with (curing) additives
Grafting:
+ Silanes
+ Ethylacrylate
10
(Surface activated) rubber powder
Influence on compound properties
10 0
Tear strength [N] Tear strength [N]
100
50
50
25
0 0
0 10 20 30 40 50 0 10 20 30 40 50
-
Concentration rubber crumb [%] Concentration rubber crumb [%]
100 100
50 0
Compression set (70) [%] Compression set (70C) [%]
75 100
50 50
0
25
Rebound resilience (70C), [%] Rebound resilience(70) [%]
60 50
50 40
40 30
0 10 20 30 40 50 0 10 20 30 40 50
-
Concentration rubber crumb [%] Concentration rubber crumb [%]
Reclaim
Surface
Granulate
Vulcanized activation Rubber
rubber product
Powder
Reclaiming
Definition reclaim:
Crosslink
A process in which vulcanized rubber is scission
converted into a material which can be
blended, processed, and cured again by
using mechanical, thermal or chemical
processes
Polymer
Devulcanization: scission
Crosslinks
http://www.coe-nr.org
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Reclaim
Processes
Mechanical
reclaiming
Granulate
Reclaim
Powder
Thermal Chemical
reclaiming devulcanization
14
Reclaim
Thermomechanical breakdown
Softeners Polymers
mechanical thermal
Viscosity decrease
Molecular weight
120C Temperature Initial MWD
MWD after thermal breakdown
MWD after mechanical breakdown
Thermal: Mechanical:
- non-selective in terms of chain length + selective for longer chains
- non-selective for polymer chains and crosslinks - non-selective for polymer chains and crosslinks
- reactive chain ends - reactive chain ends
Polymer degradation
15
Reclaim
Processes
Mechanical
reclaiming
Granulate
Reclaim
Powder
Thermal Chemical
reclaiming devulcanization
16
Reclaim
Chemical devulcanization aids
Mechanical
reclaiming
Granulate
Reclaim
Powder
Thermal Chemical
reclaiming devulcanization
18
Reclaim
Effect of temperature, reclaiming aid and concentration
200C 225C
(): HDA
CH3 (CH2)15 NH2
(): DPDS
S S
250C 275C
(): BAFD
N CO
S H
S
N CO
H
N CO
S H
(): HDA CH3 (CH2)15 NH2 (): DPDS S S (): BAFD S
N CO
H
EV cured
- Temperature
- Time
- Shearing forces
- Devulcanization aid
- Restoration of double bonds
Shifting to devulcanization:
- Low temperatures
- Low shearing forces
- Appropriate devulcanization aid
Rubber Recycling