Novel Material and Mechanical Design for Shipping Pallets

Justin Gallagher, Taylor Hopkins, Craig Leslie, Niko McMurray, Kevin Rebellino Advisor: Dr. Daehn Partner: Alcoa Foundation

Background • Global packaging market – Over $459 billion* • Wooden pallets ▫  Cost $20 each** ▫  Weigh 50 lbs.** ▫  Not environmentally resistant ▫  Non-recyclable ▫  Potential for invasive species

*:"Pallet Trends." Solutions For Wood. FP Innovations. Web. 1 Dec. 2011. <http://www.solutionsforwood.ca/_docs/reports/PalletTrends09.pdf>. **: Pallet Sizes and Dimensions. http://www.palletsunlimited.com/pallets_size.html. ***: "Aluminum pallets." Aluminum pallets. N.p., n.d. Web. 4 Dec. 2011. <http://www.aluminum-pallets.com/>.

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Background • Wooden pallets ▫  Occupy 4% solid waste in

landfills* ▫  Deforest up 100 million

acres of forest each year* ▫  Short life span- generally

single use*

*: Loadek - the First 100% Corrugated Pallet. Web. 01 Dec. 2011. <http://www.loadek.com/index.htm>. **: "Aluminum pallets." Aluminum pallets. N.p., n.d. Web. 4 Dec. 2011. <http://www.aluminum-pallets.com/>.

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Background

•  Plastic pallets ▫  Cost $60-100 each* ▫  Weighs between 30-50 lbs.* ▫  Lack rigidity ▫  Low creep resistance at high loads ▫  Recyclable

*: Premier Pallets FAQ. http://www.premier-pallets.com/faqs.asp. **:"Aluminum pallets." Aluminum pallets. N.p., n.d. Web. 4 Dec. 2011. <http://www.aluminum-pallets.com/>.

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Background • Aluminum pallet ▫  Cost at least $200 each* ▫  Weigh ~35 lbs.* ▫  Longer life span ▫  More visual appealing

*: National Wooden Pallet and Container Association. http://www.palletcentral.com/. 2010. **:"Aluminum pallets." Aluminum pallets. N.p., n.d. Web. 4 Dec. 2011. <http://www.aluminum-pallets.com/>.

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Background • Aluminum pallet ▫  Recyclable/ .97 cents per lb.* ▫  Environmentally resistant ▫  Do not carry insects/bacteria

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*: National Wooden Pallet and Container Association. http://www.palletcentral.com/. 2010. **:"Aluminum pallets." Aluminum pallets. N.p., n.d. Web. 4 Dec. 2011. <http://www.aluminum-pallets.com/>.

Motivation of Project

• Design an sustainable shipping pallet to fulfill a market need

•  Produce at a lower lifetime cost than currently available options

• Use manufacturing processes that can be highly automated, and therefore, cost will be close to that of raw material at high volume.

Design Criteria

• Aluminum pallet ▫  Dimensions*: 48”x42”x6” ▫  Minimize weight/increase strength ▫  Decrease cost (under $100) ▫  Possess a load bearing capacity of 2000 lbs

(Dynamic) & 6000 lbs (Static)** ▫  May be transported by standard forklifts* ▫  100% recyclable

*: ISO 6780, Flat pallets for intercontinental materials handling-Principal dimensions and tolerances **: ISO 8611-2, Pallets for materials handling-Flat pallets-Part 2: Performance requirements and selection of tests

Technical Approach

• Widely available material – Al alloy 6061-T6 • Each group member contribute designs • Use various manufacturing methods – maximize

automation • Determine at least two viable designs • CAD – meet weight and design standards •  FEM – meet ISO standards •  Prototype – viability of manufacturing

Industrial Origami

• Rapid, simple manufacturing process •  Perforations made along fold lines •  Shapes folded in sequence

*: Industrial Origami. Design and Technology Overview. Middleburg Heights, Ohio. 2012. http://www.industrialorigami.com/technology/science.cfm.

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Joining Methods-Welding •  Welding Aluminum ▫  Heat input ages

material rapidly ▫  Leads to

overcoarsening of precipitates, massive grains* ▫  IWSL process uses

water cooled electrode   Focuses current at

weld site

*Mathers, Gene. The Welding of aluminum and its Alloys. Woodhead Publishing. 2002. London.

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Joining Methods-Adhesive

• High strength adhesives for structural applications ▫  Example: Lotus Elise/

Exige chassis ▫  Important properties   Peel and shear strength,

corrosion resistance

*Lotus Exige, body and bare chassis. http://www.europeancarweb.com/firstlook/0603_ec_2006_lotus_exige/photo_04.html

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Industrial Origami Design

•  6061-T6, 48”x42”x4”, under 29 lbs.

Industrial Origami Stress Analysis • Basic finite element

analysis • High stress regions

where top is bonded to middle sections

Industrial Origami Fabrication

•  Shapes formed with hydraulic shear, manual bend press

•  Pieces were bonded using Loctite E-120HP •  Substituted U-channels for expansion formed

channels

U-Channel Design

•  6061-T6, 48”x42”x5”, 21.9 lbs • Requires only two distinct pieces •  0.065” channel thickness •  0.010” tube thickness

U-Channel FEM

• Modeled in Solid Works

•  0.14 cm deflection at max. loading

•  107 MPa VonMises stress at max. loading

•  6061-T6 yields at 276 Mpa at room temp.*

* http://www.matweb.com/search/DataSheet.aspx?MatGUID=1b8c06d0ca7c456694c7777d9e10be5b&ckck=1

U-Channel Fabrication

• Water Jet holes in sheets

• Bend cut out patterns • Use electromagnetic

expansive forming

U-Channel Fabrication

•  Some issues in conformal joining, adhesives also used in prototype

Interference Fit Extrusions Background

•  This design relies on two types of pieces • Very similar to U-Channel design produced • Number of required parts reduced for decreased

costs

Interference Fit Extrusions Design •  6061-T6, 48”x42”x5”,

23.4 lbs • Holes cut in T-beams

to reduce weight • Varied wall thickness

to reduce weight

Interference Fit Extrusions FEM •  Stress concentrations

are a limiting factor • VonMises stress of

196 MPa at max. loading

• Max. displacement 0.15 cm in dynamic loading

Design Comparison

•  U-channel is the lightest and cheapest design •  The origami design allows 4-way entry •  T-Beam has deflects more than U-channel ▫  Equivalent FEM was not run for both, however

loads are roughly comparable

Design Weight Material Cost Entry Deflection

Industrial Origami 28.8 lbs $57.6 4-Way 0.061”

(6000lb Static Load)

T-Beam 23.4 lbs $46.8 2-Way 0.055” (2000lb Dynamic Load)

U-Channel 21.9 lbs $43.8 2-Way 0.057” (2000lb Dynamic Load)

Testing

•  ISO Standard 8611-2 ▫  Static and Dynamic Load ▫  Deflection

• A large test frame must be found or designed to allow the maximum load to be determined both statically and dynamically ▫  Nominal load is defined as the load at which the

maximum deflection is less than 20mm, or 0.787”

Results

•  3 viable options ▫  All weigh < 30lb ▫  Estimated cost < $75

•  3 different manufacturing methods ▫  All manufacturing methods commercially viable

•  FEM analysis – Passed Requirements ▫  2000lb Dynamic and 6000lb Static Loads

Design Conclusions

• U-Channel is lightest at 21.9 lbs • All components are easily manufactured ▫  Can be available in larger quantities

•  Simple Construction ▫  Expansive forming must be optimized for large

scale production ▫  Spot welding is also an option

Future Recommendations

•  Testing ▫  Based on ISO standards

• Develop a process for fabrication ▫  Automatable, as much so as possible

• Address other design aspects ▫  Aesthetics, Stackability, Design optimization

Acknowledgements •  Advisor: ▫  Dr. Glenn Daehn

•  Department of Mechanical Engineering Advisors: ▫  Dr. Tony Luscher and Dr. Leo Rusli

•  Industrial Partners ▫  Bill Shepard from Die Matic, ▫  Dr. Dr. Anthony Ananthanarayanana from Innovative

Welding Solutions Ltd. •  The Aluminum Company of America (ALCOA) •  Dr. Daehn’s Lab: ▫  Geoffrey Tabor and Ryan Brune

•  Dept. of Mechanical Engineering machine shop: ▫  Chad Bivens and Matt Little