4. Why care about Sandwich Vehicles?
According to a Wall Street Journal article,
Americans are packing their lunches now more
than ever. They do it to watch their wallets and
their waistlines. But they are also creating less
waste.
This study’s objective is to determine which
sandwich vehicle for the average American’s lunch
is indeed saving money and reducing waste over a
lifetime of working lunches.
3
5. Functional Units
SANDWICH
DAY
Ziploc Bag Tupperware Box
1 bag 1 box
5 uses 6500 uses (260 uses/year x 25
4
6. Functional Units
SANDWICH
DAY
Ziploc Bag Tupperware Box
1 bag 1 box
5 uses 6500 uses (260 uses/year x 25
4
7. Raw Material Use &
Extraction Manufacturing Transport Reuse End of Life
Input Energy for
Transport
Polycarbonate Closure Wrap Bag
Petroleum Manufacture To store Bag Use
Production Manufacture Assembly
To home
Output
Recycled Cardboard Box Manufacture
Production
Ziploc® Plastic Sandwich Bag
System Boundary
5
8. Raw Material
Extraction Manufacturing Transport Use & Reuse End of Life
Input
Energy for
propylene gas Polypropylene, Box Box To Store
Manufacture Box use Landfill
Polyethylene Assembly To Home
Output
Tupperware® Plastic Sandwich Box
System Boundary
6
19. Use Phase
Dishwasher is full (box = 3%), 4.5 gallons/
wash, 300kwh/year
Handwashing: 0.75 gal to wash a baggie, wash
4 times, then throw away
Wash in dishwasher 2x/week, 2x by hand
0.5 gal to wash a box
Gas hot water heater
11
20. End of Life
Don’t recycle anything at end of life
Throw away box after 25 years
12
21. End of Life
Don’t recycle anything at end of life
Throw away box after 25 years
12
22. Cost Analysis
Box = $3.00 ($12.00 for 4-pack)
Baggie = $0.07 ($8.91 for 125 ct box )
13
23. Cost Analysis
Box = $3.00 ($12.00 for 4-pack)
Baggie = $0.07 ($8.91 for 125 ct box )
13
24. Energy Usage
Ziploc® Tupperware®
Throw away - raw material Use phase is THE energy usage
extraction dominates
Wash – Use phase dominates So, what do these
14 numbers mean?
26. Acidification/SMOG Formation
Acidification
Ziploc®- Manufacturing and Use
Tupperware®- All use phase
• Electrical generation dominates machine wash scenario
16
30. Conclusion
Consider what you DON’T see –
Personal water use vs industrial water use
Assumptions are very important!
Hand-washing vs dishwashing
• Energy efficiency
• Energy source
20