08-02-2013, 10:57 AM
WOOD PLASTIC FIBER COMPOSITES
1WOOD PLASTIC.ppt (Size: 807 KB / Downloads: 70)
INTRODUCTION
First Generation WPCs
Recycled woodchips / flour & binder
Designed for undemanding applications
New Generation WPCs
High Performance products
Good mechanicals
High dimensional stability
Complex shapes
Extruded products with high dimensional tolerance
RAW MATERIALS
Wood
Wood is filler material
Fillers can be classified into two major groups, particulate and fibrous
Particulates are generally classified as fillers or reinforcing fillers if interphase addition is high
Fibers are considered reinforcing because they bear a majority of the load applied and their length is much greater than the cross sectional dimension
The wood is generally in the form of short fiber, particulate or flour
Thermoplastics
There are a variety of thermoplastics available for composite manufacturing although a few can be used for WPCs.
The primary selection criteria for a thermoplastic used in WPCs is a melting or softening temperature less than thermal degradation temperature of wood.
Thermoplastic having softening or melting temperatures that are suitable for WPC processing include polystyrene(PS),low- and high- density poly ethylene (LDPE & HDPE), polypropylene(PP), and polyvinyl chloride(PVC)
Applications
Fiber reinforced polymeric composites have been used for a variety of structural applications. Because of their high specific strength and modulus compared to metals.
Current applications of WPCs, lay in the automotive, construction, marine, electronic and aerospace industries.
The first major application of wood-plastic composites was in the construction industry.
CONCLUSION
Although wood has long being used as filler in thermoplastics, wood plastic fiber composites have developed primarily over the last decade.
One of the primary forces driving this development has been the need for durable wood composites.
The processing advantages thermoplastics have, however present considerable opportunities in direct manufacture of products.