The external surfaces and internal structures of particles of milled pine bark ( Pinus taeda L. and P. elliottii Engelm.) were examined with scanning electron microscopy. Numerous external openings, cracked cell walls and internal cellular connections, that might allow water penetration were observed. Periderm surfaces were without pores, and contained rough surfaces and apparently waxy substances that might resist water penetration or absorption.
No takes yet. Share an insight, caveat, or question.
Airhart et al. (1978) studied this question.