PACKAGING SOLUTIONS NewNew UnitUnit LoadLoad designdesign TrendsTrends andand TheirTheir ImpactImpact onon SystemsSystems IntegrationIntegration
April 7, 2009 The unit load is the form by which most consumer and industrial products are stored and distributed. Exclusive of the product being distributed, the unit load supply chain consists of three basic components.
Packaging
Pallet Interface
Unit Load Material Handling Equipment The design of the unit load impacts the operating efficiency of unit load handling equipment
Distribution Pallet Unit Load Package Handling Equipment
Operating expense The unit load is a complex engineered structure
Stretch wrap $1.80 Pallet $8 - $9.00 Corrugated cases $45.00 HDPE 32 oz bottles $324.00 The three component unit load supply chain is designed by three independent design communities, all focusing on the cost reduction of that component for which they have responsibility.
Packaging
Pallet
Equipment This “component” based method of designing a unit load materials handling “system” leads to avoidably high supply chain operating costs.
Item Annually in the US
Supply chain operating costs $970 billion or 9.5% of GDP Transportation energy costs $28.5 billion Product damage costs $1.6 billion grocery & un-saleables beverage
Natural resource consumption 70 million dry tons of wood fiber
Human health and safety and 25% of all occupational injuries are associated worker productivity with materials handling 22.1 MMTCE green house gases from 34% of Environmental impacts municipal solid waste To reduce supply chain costs, a true “systems” based design procedure must be developed that optimizes the efficiency of the shipping unit based on an understanding of how the three components mechanically interact during storage and distribution.
Packaging Designer
Unit Load Pallet Handling Designer Equipment Designer Supply Chain Component Interactions
• Distribution vibration and unit load resonance • Load Bridging and unit load deformation • Equipment spans and unit load deflections • Interfacial friction and load stability • Compression stress redistribution and product protection • Vertical stabilization versus horizontal stability Vibrations During Shipping of Unit Loads Stiffer pallets result in more stable unit loads and better protect certain vibration sensitive products.
Pallet Deck Resonant Transmissibility Stiffness Frequency EI (Hz) Output g’s (N-M2) Input g’s 202 13 2.4 860 16 1.8 2391 17 1.6 Load slip and COF during unit load handling and storage
Forklift Braking
40 0.6 0.55 0.56 35
0.5 0.45 0.46 30 0.43 Distance A 0.38 0.4 25 COF 20 0.3 Pallet Displacement 0.23 0.24 0.21 15 0.2
10 Pallet Displacement Coefficient of Friction 0.1 5
0 0 OSB GE Pal GMA GMA Grade A GE Noryl Plywood Chep M55 EPC HDPE New Green Chep Plastic Unit loads are beams. The larger any span the stronger and stiffer the beam must become
Span Span Spans within unit load handling equipment
Span Span Spans in unit load handling equipment Load Bridging During Storage of Unit Loads The redistribution of the load or stresses on the pallet as a function of packaging design, stacking pattern, and unit load stabilizers.
Certain Loads on Pallets will “Bridge” across the Pallet Deck. In Warehouse Racks, Some Loads will Shift Stresses from the Center of the Pallet to the Rack Supports Load bridging is significant and reduces unit load deformation. This principle can be used to reduce pallet and packaging costs when warehouse rack storage is used.
Case Goods, Average Deflections at 4.5 kN Pai ls, Average Deflections at 4.5 kN
25.0 25. 0 Low Low
20.0 20. 0 Medium-Low Medium-Low ) 15.0 mm 15. 0 (
Medium High 10.0 10. 0 Me di um High Deflection Deflection Deflection (mm) 5.0 5.0
0.0 0.0 Airbag Airbag Airbag Airbag Airbag Airbag Airbag Airbag Colum n Column Colum n Column Column Column Column Column Interlock Interlock Interlock Adhesive Interlock Adhesive Adhesive Tie Sheets Tie Sheets Tie Sheets Tie Sheets Interlock,ST Interlock,ST Column, ST Column, Colum n, ST Column, ST Column, Colum n, ST Interlock, ST Interlock,SW Interlock,SW Interlock,SW Interlock,SW Interlock,ST Column,SW Column,SW Column,SW Column,ST Column,ST Column,ST Column,ST Column, SW Column, Column,SW Column,SW Column,SW Column,SW Stretch Tape Stretch Tape Stretch Tape Column, Tape Column, Tape Column, Colum n, Tape Distance between rollers and direction of unit load movement Spans throughout unit load handling systems Design Equipment to handle “real” unit loads “Real” unit load in a storage rack The I.Q. of the Supply Chain Shall Increase
I.Q. > 0 I.Q. = 0
Automation To increase the I.Q. of automatic supply chains we must design and use smarter unit loads
• More consistent geometry • More uniform size and shape • Flat surfaces • Stiffer MHIA/ANSI MH1 Pallets, Slip Sheets, and other bases for Unit Loads, Part 10 “Performance Specification for Pallets to be Used in Automated Unit Load Material Handling Equipment” Pallet design trends
Stringer to block
Uni-directional to perimeter bottom decks Stringer class pallets are stiffer than block class pallets Pallet Design Trends
Wood to Plastic
?
Perimeter base
To cruciform base Why are pallets 5 inches high? A Powered Pallet Truck (Jack) at 2.5 inches? To achieve significant improvements in supply chain operational efficiencies in the future, a more systematic approach to supply chain design is necessary • Develop strategic partnerships
Packaging Designer
Unit Load Pallet Handling Designer Equipment Designer Transition from component to systems based design
• Educate and train professionals across design disciplines • Continue the study of supply chain component interactions • Develop design tools which model these interactions. Virginia Tech Packaging Science Option in the College of Natural Resources
• Packaging design and performance • Pallet design and performance • Unit load design and performance • Warehouse design and layout • Design and performance of unit load storage, handling, and shipping equipment. Unit Load Modeling Tools
• TOPPS • CAPE • PDS Pallet Design System • BEST LOAD