SafeSource : Designing a Better Safe Water Storage System Robin Davis Meryl del Rosario Joanna Natsios Paul Saindon

CDC – Safe Water System Approx. 20L water vessel Ships efficiently – Tough, robust material – Nests and stacks on palate for easy shipping Easily carried with hands or on head Lid – Difficult to remove – With opening large enough for filling but small enough to prevent contamination from hands Tap for dispensing—on/off/hold All citations: Current CDC standard water vessel

Alternative Designs: TiO 2 as antibacterial agent Pros – Tasteless – No risk of overdose – No harmful disinfection byproducts – TiO 2 photo-oxidation is a renewable process – Purification process integrated into vessel – SH must be kept at pH11 Cons – Requires longer periods of time for purification – Requires high surface area to volume ratio – More costly than SH ($2.40/yr per family) – Is not more effective than SH at killing bacteria  Considered using TiO2 –based water purification system instead of current sodium hypochlorite (SH) system. When exposed to UV light, TiO2 exhibits bactericidal effects.

Last Year’s Design Thermoforming Selected Jolivert style tap Recommended HDPE, but used ASB No work on lid design Dimple for head is uncomfortable Cylindrical BucketSquare Bucket Jolivert Tap

Planned Improvements Selection of ideal polymer material Modifications to square design Elimination of “webbing” in areas of high curvature Easy-to-secure, hard-to-remove lid with ergonomic handles

3D Printing a Male Mold Form solid ceramic mold from SolidWorks design – 0.1 to 0.2 mm layers of material – Layers composed of binder printed into powder – Infuse cyano-acrylate into finished product increase strength – Can withstand intense heat of thermoforming process

Large 3D Mold Process The full production size is too large to create a 3D mold from the printer. Instead several interlocking parts will be designed to fit together into a single mold that is large enough to create our piece.

Thermoforming Process by which a sheet of plastic is shaped. Has low startup cost versus other methods such as injection molding. Is meant for small or medium scale production. Animation from:

Material Requirements Able to be thermoformed Machinable UV and weather resistant Safe to drink from Resistant to chlorine and preferably other chemicals Inexpensive

Material Solutions ABS Polycarbonate VHMW PE UHMW PE PVDF Image from:

Comparisons MaterialThermoformable Chemical ResistanceWeatheringSafeCost ABS Yes - Great Avoid Gas, alcohol, toluene Poor UV stability. UnsureCheap $30sheet Polycarb onate Yes – Good Avoid Methylene Chloride, dioxane YesSome forms Cheap ~$35 VHMW Yes – Good Avoid toluene, xyleneGreat stabilityYes, FDA Mid range UHMW Yes – Great Avoid strong acids, hydrocarbons YesYes, FDA, USDA Mid range PVDF Yes – Good Avoid acetone methyl ethyl ketones, NaOH Great UV and Gamma, Wet Environment Yes, FDA Highest Data from: McMaster-Carr

Feb 12 Mar 1 Mar 15 Apr 2 Apr 15 May Learn SolidWorks 2.Create compressive elements on SolidWorks 3.3D print compressive elements 4.Conduct compressive strength tests 5.Determine physical limits of mold geometry 6. Design mold of interlocking parts 7. Print 3D scale models of bucket and lid 8. Thermoform scale prototypes with various materials 9. Choose material for final bucket and lid 10. Make full-sized bucket and lid Project Timeline