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ŠUMARSKI LIST 7-8/2003 str. 57     <-- 57 -->        PDF

J. Ištvanić: PILANSKA OBRADBA BUKVE (Fagus sylvatica L.) U HRVATSKOJ Šumarski list br. 7-8, CXXVII (2003), 373-387


SUMMARY: Today, beech is of prime importance for the sawmill industry
in Croatia with respect to its overall quantity in the forests and the quantity of
sawmill logs processed. Beech wood has a series of positive, as well as, negative
characteristics that are important for sawnwood production. Beech
wood´s positive characteristics such as its fine texture and workability are of
particular importance for beech sawmill technology. However, beech has certain
negative characteristics such as large coloured fault hearts, subjection to
micro-organism decomposition, suceptibility to fustiness and rotten wood,
dimensional instability and splitting during manipulation and drying.
Technological development, particularly in the past few decades, has in large
measure, overcome the majority of beech wood s negative characteristics,
and has therefore become one of the most sought-after material in wood processing
industry. Today, with certain exploitation methods coordinated with
processing rhythm and log preservation, sawmills successfully prevent fustiness
and rotten wood. With certain hydro-thermal processing regiments (drying
and steaming), defects that result from drying can be diminished, and a
reduction of the difference between sapwood and heartwood can be achieved.
With specific log sawing methods, it is possible to considerably reduce the
dej´ormation of sawmill products. Today, more and more beech wood, with its
numerous defects, as well as, logs and round wood of smaller dimensions are
processed at sawmills. With certain techniques and technology, they can be
more or less successfully processed. Raw material delivered to sawmills can
have different specific characteristics. This depends on the overall organization
and technological production concept at the sawmill, type of sawmill
products, the characteristics of forest exploitation, methods and options for
transporting raw material to the sawmills etc. Depending on the norms implemented,
beech raw material is classified according to the purpose, dimension
and quality criterias. Bouls, the most valuable and qualitative sawmill product,
were once manufactured from prime quality beech. Today, these products
are high quality unedged, half edged and edged boards. In addition, lower
quality boards that are re-sawing into dimension stocks and flooring. Railway
sleepers and heart-boards are also made from beech. In Croatian sawmills,
beech logs are most frequently sawn in the live sawing, cant sawing and
round sawing techniques, while the Slavonian and quarter sawing methods
are rarely used. Frame saw proved to be better suited for processing thinner
and lower quality beech logs with dispersed defects. In contrast to this, qualitative
and thicker logs or logs with individually dispersed defects can be
processed more successfully with the band saw due to advantages in the individual
sawing approach. Researching particular criteria for successful beech
wood processing at sawmills also yielded results. Further development in
beech wood processing at sawmills can be expected in Croatia as well as an
increase in the production of wooden dimension stocks at greater processing
stages. Some sawmills are already manufacturing products such as finished
parquet and solid glued boards. For further development in beech wood processing
at sawmills, as well as processing other types of wood, more attention
will need to be dedicated to the so-called integral log yield, which would, in
addition to finding a rational solution for sawmill residues, increase the overall
production value.


Key words: common beech (Fagus sylvatica L.), sawmilling technology,
sawmilling raw material, sawmilling products, quantity and value yield.