The fibre orientation was predominantly
in length direction, parallel to the machine direction. To
avoid damage of fibres due to carding, the fibres were conditioned
for at least 24 h at 20 C and 65% relative humidity.
After carding, the webs were cut into parts of 323 9
223 mm. The initial weighing of the pre-cut parts took
place in consideration of the density of the tested fibres in
relation to the volume of the fabricated boards. Cotton/PLA
boards with and without lignin were produced. For the
boards with lignin content, 5 g powdery lignin was filled
equal into the webs by a sieve.
The dimensions of the boards are 323 9 223 9 2 mm.
As a spacer an aluminium frame with external dimensions
of 343 mm 9 243 mm was used. For easier removal of the
composite panel from the mould, the frame was treated
with a parting compound from the company Marbocote
Ltd. (Cheshire, UK). Prior compression moulding, the
multilayer webs were dried for 3 h at 105 C in a forcedair-
oven (Memmert, Germany). After drying, the multilayer
web was centred on the bottom pressure plate in the
aluminium frame. Compression moulding was done with a
hydraulic press type KV 214.01 (Rucks Maschinenbau
GmbH, Glauchau, Germany) capable of applying pressure
and controlled heating to both upper and lower plates. The
press has a nominal pressure force of 1,000 kN, a maximum
temperature of 330 C and a pressure table of