Biodegradable lightweight construction boards based on tannin/hexamine bonded hemp shaves

Interior grade hemp shave lightweight construction boards of about 0.260 g/cm(3), with a dry I.B. strength of up to 0.34 MPa, a formaldehyde release well within the emission class E1 and certificate as normal flammable and not burning dripped off (DIN 4102-B2) were fabricated by mixing hemp shaves with a borate-modified mimosa tannin-hexamine binder and press the masses as fast as 6 s/mm thickness at 70degreesC to one-layer boards. Different drying processes indicate that fast drying at similar to100degreesC is needed both for satisfactory strengths and for a sufficient dimension stability performance of soaked samples, but, as well for a lower boron leaching during soaking. For dry environments the resistance to fungal attack is sufficient enough to have boards for interior application.