SafeSource: Formal Design Review Team 3: Robin Davis Meryl del Rosario Joanna Natsios Paul Saindon

Product Design Specifications Bucket – 20 L capacity – Head dimple on bottom – Stackable for shipping – Spigot Lid – 4 in. fill port with cap General – Durable – Thermoformable material – Inexpensive

Thermoforming Process Heat thermoforming apparatus Insert mold and plastic Heat plastic Turn on vacuum and push mold up into plastic Cool plastic-mold slightly Remove mold Allow for complete plastic cooling

Material Selection- Thermoforming Thermoplastics – Amorphous Lower thermoforming temperature Forgiving of temperature variations Forms well with wooden molds Creeps over time under load – Crystalline No creep, but warpage Totally stiff until softening temperature is reached Must be formed around aluminum mold

Our Materials Requirements: – food grade – UV resistant – cheap – clear/translucent – no reaction with kerosene or NaOH Polycarbonate (Lexan 9440) – GE Polymershapes UHMW Polyethylene – McMaster-Carr ABS

Property Comparison

Design Limitations Constrained thermoforming size Draw ratio Avoiding undercuts Preventing webbing Bucket needs to be 20L – 14”x11”x8”

Thermoforming Experience Wooden mold for lid – Made from scrap using simple tools Thermoformed successfully – Nearly fits bucket – Observations: Warpage and lack of undercut

Revisions and Returns A second mold was designed to correct the problems of the first Fill port added Triangular feet to improve undercutting Our design process will be iterative! Top View Bottom View

Mold Design: Bucket

Mold Design: Lid Wood for easy creation Triangular shape to improve removability from mold Undercut and feet to provide snap for attaching to bucket. Biggest challenge: design of fill port cap

Looking Towards Production Would want a Steel or Aluminum Mold with cooling channels – Increased consistency of parts – Increased rate of production – Longer mold life – Better thermal properties Develop jig cutting technique

Compressive Testing of 3DP Material Mold must withstand 15psi 9 2-inch cubes – 4 cubes w/ new glue, 5 cubes w/ old glue – Tested each direction 3X Results – Compressive strength greatly exceeds 15psi – Strongest in X-direction, weakest in Z (binding) direction – Stronger when infiltrated w/ new glue New Glue σ y (psi)Old Glue σ y (psi) X824X609 Y567Y488 Z534Z396 AVG641AVG498

Future Testing 3-point Beam Bending – ASTM for a ceramic 0.25” thick 1.5” long – 3D print specimens in different orientations – Printer problems

Further Investigation Deformation Mapping Shrinkage Analysis Impact Tests Drop Strength Analysis (ANSYS or ASTM) Non-Newtonian Flow

Design Variables Plastic thickness Tapering Snap mechanism Ribbing

Feb 12 Mar 1 Mar 15 Apr 2 Apr 15 May Learn SolidWorks and ANSYS 2.Create compressive elements on SolidWorks 3.3D print compressive elements 4.Conduct compressive strength tests and 3pt beam bending 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