Banner for LabNotes
From Lab Notes
Contact Information
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53726-2398
Phone: (608) 231-9200
Fax: (608) 231-9592
Email

 

You are here: FPL Home  / Information Products & Services  / Publications

Requested Product

Title: Evaluating shrinkage of wood propellers in a high-temperature environment

Source: Research Note FPL-RN-0309. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 7 pages.

Author(s)Bergman, Richard; Ross, Robert J.

Publication Year: 2008  View PDF »

Category: Research Notes
Associated Research Project(s):   FPL-4714-1A  FPL-4851-MA

Abstract: Minimizing wood shrinkage is a priority for many wood products in use, particularly engineered products manufactured to close tolerances, such as wood propellers for unmanned surveillance aircraft used in military operations. Those currently in service in the Middle East are experiencing performance problems as a consequence of wood shrinking during long-term storage at low equilibrium moisture content conditions prior to installation. To evaluate the extent of shrinkage, seven sugar maple (Acer saccharum) veneer propellers were dried from 11% to 3% moisture content in a controlled environment of 150F (65C) for 3 days. Two of these wood propellers were encased in polyethylene bags. Results showed 5 to 20 times more shrinkage for the thickness of the propeller hub and the hub face perpendicular to the propeller blades (across the grain), respectively, compared with the hub face parallel to the blades (along the grain). Two hubs, coated with aluminum oxide paint, showed dimensional changes similar to those observed for uncoated hubs. For the two wood propellers encased in polyethylene bags, moisture loss was slowed during the course of the experiment by roughly 46%. Wrapping the wood propellers prior to shipping would slow moisture desorption, thereby minimizing shrinkage during short-term storage. Processing the propellers at a lower equilibrium moisture content would minimize shrinkage during long-term storage.

Keywords: wood, propeller, shrinkage, sugar maple, veneer, equilibrium moisture content, EMC

File size: 1 kb(s)

This publication is also viewable on Treesearch:  view
RITS Product ID: 26106
Current FPL Scientists associated with this product (listed alphabetically)
Bergman, Richard
Research Forest Products Technologist
Ross, Robert J.
Supervisory Research Gen. Engineer
 

Additional items that might interest you
View the video celebrating FPL's 100 years of public service in 2010, from the producers of the Greatest Good....view

Research Highlights from FPL....view

Termite Eradication: A search for the Holy Grail.... view

Moisture Management in Residential Construction Series videos...view

Wood Floor Systems in Residential Construction Series videos....view
- FPL's Mission and Strategic Plan -

FPL's mission is to identify and conduct innovative wood and fiber utilization research that contributes to conservation and productivity of the forest resource, thereby sustaining forests, the economy, and quality of life. ... ..more »

- FPL Research Emphasis Areas -
Advanced Composites

As an integral part of the FPL mission, we improve the long-term sustainability of our Nation's forests by creating valuable composite products from biobased materials ... ..more »


Advanced Structures

The FPL has been in the forefront of wood-frame housing research since 1910 and has long been recognized as a world leader in such housing-related areas as engineered wood ... ..more »


Forest Biorefinery

We all know the compelling reasons that the United States needs to reduce its dependence on fossil fuels. Historically, the greatest increases in energy demand have been for transportation fuels ... ..more »


Nanotechnology

A leader in wood products research for over a century, the FPL is positioning itself to become the lead Federal research facility for the application of nanotechnology in forest products ... more »


Woody Biomass Utilization

Forests in the United States contain a substantial amount of small-diameter, overstocked, and underutilized material.FPL research projects are exploring the potential of the small-diameter ... ..more »