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


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

Requested Product

Title: Changes in wood flour/HDPE composites after accelerated weathering with and without water spray

Source: Proceedings of the 2nd Wood Fibre Polymer Composites Symposium : Applications and Perspectives : March 24-25, 2005, Bordeaux, France. [S.l. : s.n., 2005]

Author(s)Stark, Nicole M.

Publication Year: 2005  View PDF »

Category: Journal Articles

Abstract: Wood-plastic lumber is promoted as a low-maintenance high-durability product. After weathering, however, wood-plasticcomposites (WPCs) often fide and lose mechanical properties. In the first part ofthis study, 50%wood-flour-filled high-density polyethylene (HDPE) composite samples were injection molded or extruded. Composites were exposed to two accelerated weathering cycles in a xenon-arc type weathering apparatus; either ultraviolet (UV) light only or UV light and water spray. The composites lightened less when they were exposed to only UV light compared with exposure to UV light and water spray. The change in modulus of elasticity(MOE) and strength was also much less when the composites were exposed to UV light only. The second part of the study involved stabilizing the WPCs with an ultraviolet absorber and or pigment. The stabilized composites were also exposed to the two weathering cycles. Again the amount of lightening and loss in mechanical properties was less when the composites were exposed to UV light only compared with exposure to UV light and water spray. The pigment was more effective than the ultraviolet absorber retaining composite properties. The pigment had a larger impact on property retention when the composites were exposed to UV light and water spray. The results of this study demonstrate that exposing WPCs to water spray in combination with UV light is more severe than exposing WPCs to only UV light. This is likely a result of the water spray washing away the degraded layer and wood extractives during weathering, as well as causing the wood-plastic interface to be compromised through dimensional changes in the wood particles.

Keywords: Composite materials, mechanical properties, deterioration, polyethylene, injection molding of plastics, wood flour, modulus of elasticity, elasticity, ultraviolet radiation, accelerated life testing, weathering, pigments, ultraviolet absorber, photostabilizers, surface properties, accelerated testing, wood-plastic composites, discoloration, HDPE, color fading, plastics, extrusion, plastic lumber

File size: 360 kb(s)

This publication is also viewable on Treesearch:  view
RITS Product ID: 16623
Current FPL Scientist associated with this product
Stark, Nicole M.
Research Chemical 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 »


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 »