Application of non-symmetrical drying tests for assessment of drying behaviour of ntholo (Pseudolachnostylis maprounaefolia PAX)

Experiments concerning drying behaviour of ntholo (Pseudolachnostylis
maprounaefolia PAX) were conducted to find
a suitable drying schedule. Two non-symmetrical drying
(NSD) tests were carried out to determine the drying behaviour
of ntholo in terms of drying rate and stress behaviour.
A tentative drying schedule was selected for comparison of
the test results with those of similar tests with other known
species. The schedule was tested in a laboratory kiln on 28-
mm thick boards. According to both NSD tests and laboratory
tests, ntholo dries easily but slowly. The laboratory
drying lasted 266 h and achieved standard drying quality
characterised by 8.9% moisture content, a moisture gradient
of 1.2% and a case-hardening (gap) of 1.2 mm. Twist was
the largest deformation with 3.4 mm per 1000 mm on average.
The assigned schedule provided standard drying quality
and it could be tested further in industrial kilns.