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: Improving the color stability of wood-plastic composites through fiber pre-treatment

Source: Wood and fiber science. Vol. 40, no. 2 (2008): Pages 271-278

Author(s)Stark, Nicole M.; Mueller, Scott A.

Publication Year: 2008  View PDF »

Category: Journal Articles
Associated Research Project(s):   FPL-4706-1A

Abstract: Wood-plastic composites (WPCs) continue to make inroads into the decking market. One of the main drawbacks from the consumer's perspective is that they can fade during weathering. It has been shown that WPCs fade more when exposed to a combination of light and water spray than when exposed only to light. This suggests that the loss of the color-imparting extractives from the wood could be partly to blame for color fade. Pigments are routinely added to only the plastic matrix to combat WPC color fade despite the fact that change in color could be due primarily to changes in the wood component of WPCs. In this study, we investigated two methods of fiber pretreatment in an attempt to improve the color stability of WPCs. The first was to remove water-soluble extractives from wood flour through a series of washes. Washed wood flour was then compounded with high-density polyethylene and injection-molded into test specimens. The second method involved coloring wood flour with either a water-based dye or an oil-based stain. Colored wood flour was also compounded with high-density polyethylene and injection-molded into test specimens. Pigments were added to half of the composites containing colored wood. The composites underwent accelerated weathering in a xenon-arc weathering apparatus, and were monitored for changes in color. Washing wood flour and coloring wood flour with a water-based dye were ineffective for improving composite color stability during weathering. However, coloring wood flour with an oil-based stain resulted in a more color stable WPC.

Keywords: Wood-plastic composites, weathering, color, extractives, pigments, dyes, dyeing, accelerated life testing, composite materials, deterioration, color fading, polyethylene, injection molding of plastics, wood flour, wood-plastic materials, stains, staining, wood extractives, HDPE, surface properties, accelerated testing, discoloration, photostabilizers, pigments

File size: 222 kb(s)

This publication is also viewable on Treesearch:  view
RITS Product ID: 4219
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 »