Environmentally Conscious Design & Manufacturing

1. Environmentally Conscious Design & Manufacturing Class19: Reuse Prof. S. M. Pandit

2. Agenda • Needs and Benefits • Elements • Limits • Implementation • Evaluation • Example

3. Reuse and Life Cycle Analysis

4. End-of-life Product Recovery Strategies • Repair • Refurbishing • Remanufacturing • Reuse of components • Material recycling and disposal • Energy recovery

5. Needs and Benefits - 1

6. Needs and Benefits - 2 • Design for reusability (Technology) • Better quality - ease of reuse • Bookkeeping and control over effect of • Design • Materials • Manufacturing • Use

7. Needs and Benefits - 3 • Costs are reduced because: • Consistent guidelines are established for all • mechanics • When the part can and cannot be reused • Forms the basis for a quality control program • that lowers redo & warranty costs

8. Elements - 1 • New Product Design • Developing guidelines • e.g. small project:reusability limitations and • salvage procedures for a shaft or a gear • e.g. Large project: reusability limitations and • salvage procedures for all the piece parts in • a family of components such as a • turbocharger

9. Elements - 2 • Defining the project • grouping • Setting priorities • Costs of parts/ components • Field population • Wear or failure rate

10. Element - 3 • Define reusable • Life? (80 % -100 %) • Used only on the same machine? • Risk of failure? • Fatigue life? • Remaining failure is often impossible • to determine

11. Limits • Approximate reusable limits • Salvaging options • Second life probability • Laboratory tests • Field tests • Historical data

12. Implementation - 1 • Measuring • Inspection tools • Visual, transducers, machine optics • Applications • severity factor

13. Implementation - 2 • Failure analysis • Credibility of guidelines • Standardizing failure interpretation • Improves service quality • Sells more parts and service

14. Evaluation • Maintain historical data on • Repair • Performance • Life • Failure modes and effects • Correlation with product batch

15. Example: Motor Reuse - 1 • Today’s automobiles carry up to 100 electric • motors • There are two brushless and two stepping motors • and one or two brushless fan motors in a laptop • computer. • It is estimated for an average North American • household to have 60-80 electric motors, without • accounting for automobiles. Source: Klausner et al., 1998, Journal of Industrial Ecology, 2(2), pp.89-102.

16. Example: Motor Reuse - 2 • Commutator motors mainly consist of steel, copper, and plastics. These materials cannot be easily separated at end of life. • Revenues of only some $22 per ton or $0.02 per motor (1998).

17. Example: Motor Reuse - 3 • Reuse Potential • Not compromise product quality • Meet functional requirements of new motors • Need a thorough understanding of used motors’ failure mechanisms and causes

18. Example: Motor Reuse - 4 • Assessment of the Reuse Potential • Need information on the degradation of the • motors • Approaches to assess reuse potential • Testing parameters after product return • Recording parameters during product use

19. Example: Motor Reuse - 5 • Testing parameters after product return • Requires the identification of parameters that indicates degree of degradation (e.g., noise, torque. • Shortcoming: • Long time required for testing • High labor cost • Hard to identify the parameters that • reliably shows the degree of degradation

20. Example: Motor Reuse - 6 • Recording parameters during product use • The temperature of certain spots on the motor • The number of starts and stops of the motor • The accumulated runtime of the motor • The power consumption

21. Example: Motor Reuse - 7 • Changes in Design • Introduce one electronic data log (EDL), which records the history of the product’s usage and shows the degradation of the product when product is recovered. • Design for disassembly to allow the old motor to be removed intact.

22. Example: Motor Reuse - 8 • EDL records and analyzes the following data • The number of starts and stops of the motor • The accumulated runtime of the motor • Motor temperature and the power consumption • Peak and average values of all parameters of interest

23. Example: Motor Reuse - 9 • Economic efficiency • Additional cost incurred by EDL • Return rate • - Depends on consumers’ willing etc. • Recovery rate • - Determined by the return rate of old products • and the yield in the product recovery stage

24. Big Picture - 1 • Less resources used • Resources diverted from waste stream • Savings in cost

25. Big Picture - 2 • Setting up: • Classification • Clustering, group theory • Design for reuse • Tolerances, nominal dimensions, effect on performance • Failure mode and effects analysis