Wood Plastic Composite Overview
Wood-plastic composites (WPCs) are composite materials made of wood fiber/flour
and plastic(s). In addition to wood fiber and plastic, WPCs can also contain
other ligno-cellulosic and/or inorganic filler materials. WPCs can also be
referred to as natural fiber plastic composites or natural fiber reinforced
plastics.
Wood-plastic composite lumber is composed of wood from recovered saw dust (and
other cellulose-based fiber fillers such as pulp fibers, peanut hulls, bamboo,
straw, digestate, etc.) and virgin or waste plastics including high-density
polyethylene, PVC, PP, ABS, PS and PLA. The powder or fibers are mixed to a
dough-like consistency and then extruded or moulded to the desired shape.
Additives such as colorants, coupling agents, stabilizers, blowing agents,
reinforcing agents, foaming agents, lubricants help tailor the end product to
the target area of application. The material is formed into both solid and
hollow profiles or into injection moulded parts and products. With the diversity
of organic components used in wood/plastic composite processing, there is no
single answer to reliably handling these potentially difficult materials. In
some applications standard thermoplastic injection moulding machines and tools
can be utilized.
A major advantage over wood is the ability of the material to be molded to meet
almost any desired spatial conditions. It can also be bent and fixed to form
strong arching curves. With up to 70 percent cellulose content (although 50/50
is more common), wood-plastic composites behave like wood and can be shaped
using conventional woodworking tools. At the same time, they are
moisture-resistant and resistant to rot, although they are not as rigid as wood
and may slightly deform in extremely hot weather. The material is also sensitive
to staining from a variety of agents by virtue of its porosity. A major selling
point of these materials is their lack of need for paint as they are
manufactured in a variety of colors, but are widely available in grays and earth
tones. |