An Assessment and Prioritization of “Design for Recycling” Guidelines for Plastic Components

1. An Assessment and Prioritization of “Design for Recycling” Guidelines for Plastic Components Eric Masanet, University of California, Berkeley Rudolf Auer, Dani Tsuda, Thomas Barillot, Andrew Baynes, Apple Computer Inc.

2. Introduction • Design for Recycling (DFR) is an important environmental strategy for Apple • DFR efforts require a significant investment of time and resources Study purpose: To assess the effectiveness of DFR strategies for plastic components based on direct feedback from computer recyclers so that both product recyclability and design productivity can be maximized • Focus on plastics: highly visible, high degree of Apple design input, important for brand identity

3. Interviews • 24 site visits and telephone interviews with recyclers and recycling experts in the United States and Europe • Feedback on current recycling methods and effectiveness of DFR for plastics • Feedback on plastic recycling trends for the future • Both manual and automated recycling systems were investigated: Number of Interviews by Disassembly and Sorting Method

4. DFR Guidelines Assessed R = required for certification, S = suggested

5. Definitions • A DFR strategy improves the recyclability of a plastic part if it increases the number of potential recycling applications for that part at the end of life stage • A DFR strategy is effective if it provides guaranteed improvements in recyclability for plastic parts

6. Mixed Polymer Applications Limited Mixed Polymer Applications Sorting Detail Value Single Polymer, Multicolor Applications Single Polymer, Single Color Applications Recycling Options for Plastics

7. General Findings • Typical batch of computers highly heterogeneous • Only the highest volume plastics in a given batch are typically sorted for recycling

8. Manual Sorting Systems Used extensively by those sorting plastic parts by polymer type Up to 20% of existing ISO labels are incorrect! Effectiveness: High Automated Sorting Systems Polymers are sorted based on mechanical and chemical properties, thus ISO labels have no effect Effectiveness: None Use of ISO 11469 Labels • Intent: To allow a human laborer to identify polymer • type by visual inspection

9. Use of One Polymer Type for All Large Plastic Parts • Intent: To increase the volumes of a given polymer • for recycling Manual and Automated Sorting Systems • Recycling of a given polymer depends on batch volumes of that polymer • Choosing one polymer only effective if that polymer occurs in high volumes in a given batch • Polymer choice for any one computer model found to have little effect on batch polymer composition • Effectiveness: Low

10. Limiting the Use of Paints to <1% of Total Part Mass • Intent: To minimize the potential adverse effects of • paints on plastic recycling • Manual Sorting Systems • Most painted plastic parts were not being sorted manually for recycling • Effectiveness: High • Automated Sorting Systems • Painted plastics can be sorted and recycled into higher grade uses if paint levels are pre-screened • Effectiveness: High

11. Avoiding Molded-in or Glued-on Metal Parts • Intent: To ensure metal parts can be easily removed • from plastic components before recycling • Manual Sorting Systems • Plastics with molded-in metal parts not sorted • Glued-on metal parts not problematic if easily removable • Effectiveness: High* *for molded-in metal parts only • Automated Sorting Systems • Both molded-in and glued-on metal parts can be removed during the automated process • Recent study accepted up to 25% metals • Effectiveness: Low

12. Use of One Color per Polymer • Intent: To increase the volumes of single polymer, • single color plastics for recycling • Manual and Automated Sorting Systems • Due to heterogeneity of the typical batch, likelihood is small for choosing color/polymer combinations that will occur in high enough batch volumes for recycling • Only black and “computer beige” sorted • Recycler advice: do not worry about color • Effectiveness: Low

13. Use of Snap-fits • Intent: To allow for ease of disassembly for plastic parts • Manual Disassembly Systems • Snap-fits vs. threaded fasteners a matter of preference • 6 of 14 prefer fasteners • Effectiveness: Medium • Automated Disassembly Systems • Plastic parts separated via destructive techniques, thus fastening method has no effect • Effectiveness: None

14. Prioritization of DFR Guidelines Effectiveness for: * for molded-in metal parts only

15. Future Trends • Based on interview results and literature review • Findings: • Increasing levels of automation for disassembly systems • Rising labor rates, less resale, decreasing precious metals profits • Will necessitate automated plastics sorting • Increasing use of automated plastics sorting systems • Economic difficulties for manual sorting systems in the USA • Delphi study predictions: 80% say attractive by 2010

16. Conclusions • Using ISO labels, avoiding molded-in metals and minimizing paint levels were found to be the most effective DFR strategies • The effectiveness of DFR strategies depends on the recycling technology employed • For the automated systems of the future, minimizing paint levels will be most important • The results of this study have helped Apple better understand and communicate DFR priorities to its design engineers