Dose density

The kiln density describes the average gross density of dry wood , i.e. at 0% wood moisture :

${\displaystyle \rho _{\text{darr}}={\frac {m_{\text{trocken}}}{V_{\text{trocken}}}}}$

The average density because the gross density fluctuates between the individual growth zones (annual rings) and individual areas in the wood (e.g. pressure wood , tension wood). It also varies not only between the species, but also with the growing conditions and the proportion of early and late wood .

The distinction between softwood and hardwood is based on this value, which originally comes from customs:

• Hardwood : The highest Darrdichte has lignum vitae with an average of 1.2 g / cm³ (= 1200 kg / m³). ${\displaystyle \rho _{\text{darr}}>0,55\,\mathrm {g/cm^{3}} (=550\,\mathrm {kg/m^{3}} ).}$
• Softwood : . Balsa wood has the lowest kiln density with an average bulk density of 0.12 to 0.3 g / cm³ (= 120–300 kg / m³). ${\displaystyle \rho _{\text{darr}}<0,55\mathrm {g/cm^{3}} }$

Hardwood and softwood are therefore not to be equated with hardwood and softwood, as is often assumed.

Selected densities at a glance

Tree species	Density [g / cm 3 ] at 12% water content (air dry )	Bulk density [g / cm 3 ]	Daring density [g / cm 3 ]
Balsa			0.13	very easy
Black poplar			0.41	light
Silver fir			0.41
Spruce	~ 0.47	0.33-0.75	0.43	moderately easy
Douglas fir			0.47
jaw	0.52	0.33-0.89	0.49
larch	0.60	0.44-0.85	0.55
Oak	0.70	0.43-0.96	0.65	moderately difficult
beech	0.73	0.54-0.91	0.68
Hornbeam			0.79	heavy
Bongossi			1.04	very difficult
Pockwood			1.23

Attention: There is a risk of confusion between the terms raw and true density . The latter indicates the density of the pure, void-free cell wall. The true density of all types of wood is relatively constant at approx. 1.5 g / cm³.

Different terms of density using the example of pine: Concept of density Value [g / cm 3 ] True density (average for all woods) (for cellulose 1.6 g / cm 3 ; for lignin 1.4 g / cm 3 ) 1.53 Bulk density 0.52 Dose density 0.49 Spatial density 0.43

See also

• Kiln
• Density (wood)

Web links

• Density of different woods

Individual evidence

1. ↑ Softwood furniture. In: Sunchairs GmbH & Co. KG, 04229 Leipzig, massivum.de. 2020, accessed on May 13, 2020 . 
2. ↑ Darrdichte. In: Heinze GmbH, 10707 Berlin, baunetz.de. 2020, accessed on May 13, 2020 . 
3. ↑ ^{a b} Construction chemistry and building materials: wood. In: Univ.-Prof. Dr.-Ing. K.-Ch. Thienel, Institute for Construction Materials, Faculty of Civil Engineering and Environmental Sciences, University of the Federal Armed Forces, Munich. 2016, accessed May 13, 2020 .