Short Fibers of Natural Origin

Typical Properties of (Short) Synthetic Fibers Compiled from Various Sources (Manufacturers Data Sheets, Scientific Publications) 

Fiber Type Specific Gravity (g/cm ) Tensile Strength (GPa) Tensile Modulus (GPa) Elongation at Break (%) Poisson s Ratio (n) Maximum Working Temperature (°C) 

Considering synthetic fibers in terms of specific tensile strength and modulus specific properties are obtained by dividing the tensile property by the product (density times the gravitation constant g = 9.807 m/s ). 

Typical length of the thread of raw silk from one cocoon. 

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Whilst finely grinding wood material may considerably hide the fiber aspect of wood particles, WPC exhibit properties which are typical of systems filled with short fibers of natural origin. As WPC is a rich subject in itself, only a few basic aspects will be discussed hereafter. It is obvious that not all thermoplastics can be used to prepare WPC. Indeed the polymer component melts or at least softens at or below the degradation point of the wood component, normally 200-220°C but must be rigid at normal usage temperatures (i.e., up to around 65°C). Practically, this reduces the choice to polypropylene, low-and high-density polyethylenes, polystyrene, and vinylics (essentially PVC). 

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