Content The Ability to Absorb Water

Neat plastics (except nylons), which are used in composite materials, practically do not absorb water (hundredth or thousandth percent by weight). Incorporation of cellulose fiber into plastic significantly increases water absorption (0.5-2% for 24 h underwater), which is still much lower compared to wood itself (typically more than 20% w/w for 24 h underwater). 

Cellulose and lignocellulose fiber absorbs water in amount up to 200% and higher. Ground rice hulls particles absorb 220% of water by weight. 

Moisture content in cellulose fiber typically reaches 2-12%, depending on origin of the fiber and air humidity at the storage. Moisture content of ground rice hulls supplied for WPC manufacturing varies between 8.5 and 9.5% throughout the year. 

Ramie and cotton hbers reportedly can reach their moisture absorption capacity in ambient conditions up to 17 and 25%, respectively however, those conditions are often not clearly dehned. 

---