Hierarchy classification:

1. top of the aat hierarchies
2. Activities Facet
3. Processes and Techniques (hierarchy name)
4. [processes and techniques by specific type]
5. physicochemical processes

Anotations

Scope note:

Processes for treating crude or synthetic rubber or similar plastic material to give it useful properties including elasticity, strength, or stability. The term originally referred exclusively to the treatment of natural rubber with sulfur. Currently, the term may be applied to the hardening of other synthetic materials through a variety of means.