The Basics of Wooden Pallets

The pallet industry in the United States:

1.9 billion pallets are in use in the U.S. each year.
Solid wood pallets make up 92% of the U.S. market.
441 million new wood pallets were manufactured in the U.S. in 2006.
321 million pallets were recovered/repaired/remanufactured in the U.S. in 2006.

Common Pallet Sizes in the U.S. (2011):

48" x 40" = 24.4%
42" x 42" = 4.8%
40" x 48" = 2.8%
48" x 36" = 1.5%
36" x 36" = 1.8%
48" x 48" = 3.8%
44" x 44" = 3.0%
800mm x 1200mm (Euro) = 0.7%
Other (Custom) = 57.1%

Plastic Pallets:

Paperboard Pallets:

Wood Pallets:

Pallet design by entry method:

Two-way entry wood pallet:

Partial four-way entry wood pallet:

Four-way entry wood pallet:

Pallet design by base configuration:

Unidirectional base wood pallet:

Perimeter base wood pallet:

Cruciform base plastic pallet:

Solid Wood Pallets

79% of the U.S. market consists of solid wood pallets and 92% of pallet users use them

Advantages:

Inexpensive
Easy to prototype
Strong
Stiff
Recyclable
Can be designed using PDS
Existing equipment and packaging is designed for the best performance using wood pallets.

Disadvantages:

Fasteners
Can harbor bugs
Splintering
Gaps between boards
Give off moisture
Variations between pallets
Different lumber specs for different locations

Plastic Pallets

11% of the U.S. market consists of plastic pallets and 37% of pallet users use them.

Advantages:

Bug free
Durable
Washable
No fasteners
Weather resistant
Design potential
Custom colors

Disadvantages:

High purchase price
Expensive to prototype
Low friction
Low stiffness
Fire safety rating
Not repairable
Slower production times

Composite Pallets

18% of pallet users use composite pallets.

Advantages:

Smooth deck
Dry
Bug free
Good product protection
Durable
Design flexibility
Can be designed using pallet design software

Disadvantages:

High purchase price
Expensive to repair
Splintering
Less recyclable
Less water resistant
Fasteners

Paper Pallets

11% of the U.S. market consists of paper pallets and 8% of pallet users use them.

Advantages:

Lightweight
Ergonomic
Smooth deck surface
Recyclable
Lower freight cost
Dry
Bug free

Disadvantages:

High purchase price
Susceptible to moisture
Poor performance with flexible loads
Not durable
Less product protection

Metal Pallets

0.8% of the U.S. market consists of metal pallets and 7% of pallet users use them.

Advantages:

Strong and stiff
Durable
Recyclable
Fire resistant
Bug free
Sanitary
Dry
No Fasteners
Impervious to extreme temperatures
Excellent product protection

Disadvantages:

High purchase price
Weight
Sharp edges
Low friction
Susceptible to rusting

Fundemental pallet design parameters:

Strength
- Racking
- Static (floor stacks)
- Dynamic (fork tine movement)

Functionality
- Stiffness
- Durability
- Size
- Weight

COST!!!

Cost breakdown of packaging within a typical unit load...

$ 1.80 = Stretch wrap
$8-$9 = Pallet
$45 = Corrugated cases
$324 = HDPE 32oz bottles

$ 1.80 = Stretch wrap
$8-$9 = Pallet
$210 = 3.5 gallon plastic pails

Best practices for stiffer pallets:

Always know the stiffness of your pallet design!
Measure the increase in stress distribution before you make a decision.
Consider the stiffness change of the pallet before modifying the support conditions.
Stiffer is better!

When pallets aren't stiff enough, unit load failures can happen!

Best practices for more durable pallets:

The life of the pallet is specified in number of trips.
Expendable pallets need to last only 1 trip.
Reusable pallets need to last more than 1 trip.
Use butted double nominal 6" boards as lead-edge boards.
Use hardwood boards for the lead-edge of a pallet.
Use better fasteners.
Protect the lead-edge blocks or stringers from impacts.
Don't design pallets for more than 10 years.
Don't design pallets for longer than you can retain ownership.

When pallets aren't durable enough, board failures can happen!

Technology used to improve pallet durability:

The below image shows a pallet protector attached to fork tines which helps to distributes the load on a larger area.

The below image shows a pallet protector attached to the front of the pallet reduces the severity of impacts on blocks, stringers, and lead-edge boards of the pallet.

Potential ways to improve durability:

5-6% increase in the number of fasteners used = 56% durability improvement in pallets.
Butting lead-edge deckboards = 38% durability improvement in pallets.
Split-inhibitors in lead-edge boards = 48% durability improvement in pallets.
Use dense hardwood instead of medium density hardwoods = 38% durability improvement in pallets.
Use dense hardwood instead of Douglas Fir = 165% durability improvement in pallets.
Use air-dry pallets instead of green pallets = 43% durability improvement in pallets.

When pallets aren't durable enough, board splitting can happen!