Kinematics and Wear of Tool Blades for Scrap Tire Shredding

Abstract

The wear of tool blades for cost-effective scrap tire shredding is investigated. Rotary disk cutters are widely used for cutting scrap tires into small pieces. The hard, wear-resistant tool blades mounted on the periphery of disk cutters maintain a narrow gap between blades and generate the cutting action. The kinematics of the relative motion of two adjacent disk cutters is derived to model the overlap region on blades during cutting. The model predictions match well with the actual shapes of the worn regions on used tool blades. The wear of tool blades made of AISI D2 and CRU-WEAR (CW) tool steels for scrap tire shredding is evaluated. A coordinate measurement machine was used to measure the tool wear. The wear on the blade surface is not uniform. Regions with high wear rate are explained using the kinematics analysis. The CW blades show a lower wear rate, about half of that of D2 blades, and a potential choice for cost savings.

Keywords:

• Scrap tire processing
• Kinematics
• Tool wear

Acknowledgments

The authors acknowledge supports from the Solid Waste Division of North Carolina Department of Environment and Natural Resource, particularly the project management of Pam Moore and Paul Crissman, and the National Science Foundation (Grant #0099829). Technical assistances form Mark Diemunsch of Barclay Roto-Shred Inc., Robert Hinger of US Tire Recycling, and Edward Tarney of Crucible Materials Corp. are also gratefully acknowledged.