During sintering natural particles are completely burned out, so that pores remain. Pore volume, pore structure and pore size distribution are controlled.
Advantages of higher porosity are
Correlation between porosity and flexural strength:
Flexural strength decreases with an increase of porosity. With JRS cellulose particles the stability is still on a high level even for porosities up to 60 %. The lower the particle size of the pore creator, the lower its impact on flexural strength; as a result especially micro porosity becomes attractive for applications with high stability requirements.
Pore size distribution*:
The pore channel is defined by the contact area of the single pores. For fibrous particles the contact area corresponds to the pore diameter. This diameter is uniform and therefore results in a unimodal pore size distribution. For granules and spheres the contact area varies. This leads into a wide pore size distribution (bimodal or even multimodal).
* according to mercury intrusion porosimetry and micro tomography (µCT) measurements