Update on Project No Drip
Jacqueline Greene
Michelle Dufalla
Tania Chan
February 22, 2007
Initial Design Schematic
H2O container
cork
Inside
container
Container
wall
Clamp
with
attached
rubber
plug
Tap Design Considerations
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Gravity driven tap- need to ensure water-tight
seal, grit resistant, easily produced, easy to
distribute water
2-hole Jerry Can- one removable for water refill,
one permanent for water access
Can be assembled with cheap, bought materials
(PVC tubing, cork, etc.) or by processing
recycled plastics (we plan to try and test out
both options)
Jerrycans in Kenya
•For use at grade schools
in Kenya
•Durable, can endure many
cycles, up to 1,000,000 a
year
•Suitable for different types
of jerrycans
Designs Considered
Pumping System
Pros:
•Basic pumping system
•Does not require water proof sealing
Cons:
•High cost
•Impurities in water may lead to clogging
•Durability?
Designs Considered
Gravity Driven System
Pros:
•Water flows from gravity
•Simple design
•Durable
Cons:
•Low water pressure when water is
running low
•Needs sealing around tap
Designs Considered
Water Swelling Grommets
Pros:
•Grommet made of water swelling
polymers
•Swelling acts as sealing even when
grommet is not a perfect fit
Cons:
•Polymers lose mechanical properties
after swelling
•Structurally strong swellign polymers
are expensive
Materials Costs –
PVC Pipe
½” - $0.52/foot
¼” - $0.76/foot
http://www.usplastic.com/catalog/product.asp?catalog%5Fname=USPlastic&cate
gory%5Fname=13669&product%5Fid=16587&gclid=COzC4PfhwIoCFQx1VAodu
iiekw&cookie%5Ftest=1
Materials Costs –
Clamps
$1.10
-or* 6 Gauge Brass
Wire ~ $1 /foot
http://www.schoolmasters.com/science4.html
http://www.rjleahy.com/Store/wire/bwi.htm
Materials Costs –
Cork
Self-Expanding - $78.26/
1”x36”x24”
http://www.corkstore.com
Materials Costs –
Bulk Rubber
Pure Gum - $57.64/
1”x36”x12”
Closed Cell
Neoprene Blend$183.90/ 1”x70”x
42”
http://www.rubbercal.com
Major Materials Costs –
Approximations
PVC Pipe – 2 inches of ½” diameter ~ $0.09
-or- 2 inches of ¼” diameter ~$0.13
Closed Cell Neoprene Blend – 4 sq. in. ~ $0.25
-or- Pure Gum Rubber – 4 sq. in. ~ $0.54
-or- Expanding Cork – 4 sq. in. ~ $0.37
Clamp - 1 - $1.10
TOTAL ~ $1.44-1.77
Advantages of Recycling Plastics in
Developing Countries
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Lower labour costs
existing culture of reuse and recycling, & collection of these
materials
Possibilities to create small businesses, opportunities to earn a
small income are rarely missed by members of the urban poor.
Fewer laws to control the standards of recycled materials. (i.e. in
the US recycled plastics can not be used to package food- must
be virgin plastic)
Lower transportation costs, hand or ox carts often being used.
Innovative use of scrap machinery often leads to low entry costs
for processing or manufacture.
http://practicalaction.org/practicalanswers/product_info.php?products_id=190
Disadvantages of Recycling
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Cost: “May not be economical to recycle small quantities of
plastics.
Training of waste generators will be required, so they can
separate the wastes properly.
Market prices for recycled plastic are currently $200 to
$1000/ton from local recycling centers based on recent surveys
in selected regions. As presented below, a recycling program,
dedicated only to plastic container recycling, is not likely to be
cost effective unless large quantities of plastic containers are
collected and sold. This is primarily a function of the market
price for plastic. It will however be cost effective if incorporated
into an existing program that includes glass and aluminum
recycling.
Joint Service Pollution Prevention Opportunity handbook, US Navy
http://p2library.nfesc.navy.mil/P2_Opportunity_Handbook/7_I_A_7.html
Recycling vs. Disposal costs
According to the Institute for Lifecycle
Environmental Assessment
(http://www.ilea.org/lcas/Tellus.html),
“Though there is no decisive research on the
environmental impacts of recycling plastic,
relating the economic cost of disposal to
recycling shows that the cost to recycle plastic is
$360 per ton while normal disposal cost is $250
per ton. “

How Plastics are Recycled
1. Inspection
Workers inspect the plastic trash for contaminants like rock and glass, and for plastics that the plant
cannot recycle.
2. Chopping and Washing
The plastic is washed and chopped into flakes.
3. Flotation Tank
If mixed plastics are being recycled, they are sorted in a flotation tank, where some types of
plastic sink and others float.
4. Drying
The plastic flakes are dried in a tumble dryer.
http://www.eia.doe.gov/kids/energyfacts/saving/recycling/solidwaste/plastics.html
How Plastics are Recycled cont’d
5. Melting
The dried flakes are fed into an extruder, where heat and pressure melt the plastic.
Different types of plastics melt at different temperatures.
6. Filtering
The molten plastic is forced through a fine screen to remove any contaminants that
slipped through the washing process. The molten plastic is then formed into strands.
7. Pelletizing
The strands are cooled in water, then chopped into uniform pellets. Manufacturing
companies buy the plastic pellets from recyclers to make new products. Recycled
plastics also can be made into flowerpots, lumber, and carpeting.
http://www.eia.doe.gov/kids/energyfacts/saving/recycling/solidwaste/plastics.html
Manufacturing Techniques for
Recycled Plastics
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Extrusion: the product is usually in the form of a continuous 'tube' of plastic such as
piping or hose. The reclaimed plastic is forced along the heated tube by an archimedes
screw and the plastic polymer is shaped around a die. The die is designed to give the
required dimensions to the product and can be interchanged.
Injection moulding. The first stage of this manufacturing process is identical to that of
extrusion, but then the plastic polymer emerges through a nozzle into a split mould.
The quantity of polymer being forced out is carefully controlled, usually by moving the
screw forward in the heated barrel. A series of moulds would be used to allow
continual production while cooling takes place. This type of production technique is
used to produce moulded products such as plates, bowls, buckets, etc.
Blow moulding. Again the spiral screw forces the plasticised polymer through a die. A
short piece of tube, or 'parison' is then enclosed between a split die - which is the final
shape of the product - and compressed air is used to expand the parison until it fills
the mould and achieves its required shape. This manufacturing technique is used for
manufacturing closed vessels such as bottles and other containers.
Film blowing. Film blowing is a process used to manufacture such items as garbage
bags. It is a technically more complex process than the others described in this brief
and requires high quality raw material input. The process involves blowing compressed
air into a thin tube of polymer to expand it to the point where it becomes a thin film
tube. One end can then be sealed and the bag or sack is formed. Sheet plastic can also
be manufactured using a variation of the process described.
Gantt Chart
2/6/07
2/16/07
2/26/07
3/8/07
3/18/07
3/28/07
4/7/07
4/17/07
4/27/07
5/7/07
5/17/07
Background Research
Recycling
Processing C ost
Material C ost
Target User
Design of Tap on SolidWorks
Materials Economic Analysis
Materials Testings
Materials in C hlorinated Water
Production of Prototype #1
Testing of Proposed Designs
Leak Test
Mechanical Test
Recycling and Processing of Plastic Bags
Troubleshoot Problems of Prototype #1
Overall Evaluation of Prototype after Improvements
Production of Final Product
Increase Efficiency and Decrease C ost of Production
Troubleshoot Defects in Final Product
Preparation for Final Presentation
Completed
Remaining