By external look wood-polymer composite profile with a high content of wood is most border on wood-based panels - MDF or solid fiberboard. The high content of polymers makes it look like plastic.
The material has a number of important consumer properties.
1. Technological effectiveness:
- Ability to extrusion of hollow profiles, which reduces its weight and lower use of material. Complex profiles are obtained in a single processing step perfectly flat, smooth, matte uniform surface without knots, burrs and distortion along the length;
- Wood-polymer composite can be sawed, planed, drive in nails.
- Some composites can be welded, like plastic, and bended in a heated state.
2. Aesthetic properties: "liquid wood" can be painted, in the mass subjected to conventional paint finish paints and enamels; can be faced with synthetic films or natural veneer.
3. Durability: Many WPC manufacturers provide warranty for 10-50 years of serviceability of finished goods in the open air, without special protection from moisture, light, fungi and insects. Standard warranty period for WPC decking in the United States is 20 years.
4. Moisture resistance: majority of WPC can take a small amount (0.1-4%) of moisture, without losing shape and strength, and after drying restore the former properties without warping.
5. Environment friendly: wood-polymer composites are suitable for reuse in the same process. The material does not lose its properties during 3-4 processing cycles. (Various agents-modifiers may be used in WPC compound: antioxidants, antimicrobial agents, binders, shock modifiers, lubricants, thermal stabilizers, pigments, flame retardants, light stabilizers). There are examples of the use of blowing agents that reduce density of WPCs.
In conclusion, we present a summary table of physical and mechanical properties of "liquid wood" in comparison to wood-based panels. Characteristic values for WPC are averages. Depending upon the formula and manufacturing process it’s possible to obtain a suitable characteristic values. .
|Characteristic, unit||Light WPC||Heavy WPC||Flake board, GOST 10632-89||Solid fibreboard, GOST 4598-86||MDF, DIN EN 622-5|
|Flexural strength, MPa||30-35||25-60||18||33-47||15-34|
|Flexural modulus, MPa||3500-4000||3000-6000||1700-4000||-||1700-3000|
|Impact strength, kJ / m2||6-14||3-4||4-8||-||-|
|Swelling in thickness in H2O for 24 hours,% not more||8-12||8-12||22-33||13-23||6-45|