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The paper is focused
upon alder wood (Alnus glutinosa Gaertn.),
aiming a presentation suitable to impel
the interest of foresters and specialists
from wood industry, in order to rehabilitate
the status of this wood species and to
promote it due to its properties.
A data synthesis, as
a result of the documentary research performed,
especially upon the aspects regarding
forestry, microscopic and macroscopic
structure, chemical composition, colour
changes during wood-air contact, physical
and mechanical properties, workability
and technological properties, domains
of use, is presented.
The experimental studies
were focused upon the colour modifications
during the wood-air contact, as well as
upon the processing by milling and sanding.
The orange colour, specific
to the cross section of logs and timber
exposed to air contact after cutting,
did not appear in the case of freshly
cut veneers. The phenomenon can be capitalized
for technological and aesthetic purposes
and can be controlled by thermal treatments.
Roughness measurements
on the surfaces obtained by milling and
sanding were performed and they had as
a result the specification of optimal
processing schedules, based on the criterion
of minimum roughness value.
Longitudinal milling
generated good quality surfaces. It was
noticed that cross milling produced surfaces
with high roughness, similarly to sawn
surfaces. Therefore, cross milling is
not recommended.
Surfaces obtained bu sanding presented
different values for roughness depending
on the processing direction, parallel
sanding being prefered. It was noticed
that wetting the surfaces before sanding
did not positively influence the roughness.
For final sanding, the use of grit sizes
over 120 is not justified.
The conclusions of these research highlight
the qualities of alder wood, pointing
out some aspects
concerning its aesthetic
value and workability by milling and sanding,
including the recommendation of optimum
processing schedules, thus contributing
to a better capitalization of this secondary
resource in furniture manufacturing.
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