Picea abies

'Picea abies'' (L.) Karst. -- Norway spruce'''

group: 	SOFTWOODS

Macroscopic structure of wood

heartwood/sapwood: 	sapwood (light-coloured heartwood)

description: 	yellowish white to light brown

rings: 	distinct boundary between rings; gradual transition from early wood to late wood in ring

resin canals: 	slightly distinguishable, visible in R and T

rays: 	invisible

texture: 	flatsawn (T), radial figure (R); lustrous and slightly decorative wood

Microscopic structure of wood

brief overview: 	RC; ray HetC, medium high

ring: 	gradual transition from early wood to late wood tracheids in ring	X

bordered pits on tracheids: 	usually one in a row (sometime paired)	R

tracheid thickenings: 	absent	R, T

resin canals: 	small, predominantly solitary	X, T

epithelial cells: 	thick-walled epithelial cell, smaller (8–12)	X, T

rays: 	heterocellular	R

width of rays	uniseriate and fusiform	T, (X)

height of rays: 	medium high to high, 10–15 (25)	T

cross field pitting: 	piceoid (2–4–6)	R

ray tracheid: 	one or more rows along the upper and lower margins of the ray, smooth-walled ray tracheid	R

axial parenchyma: 	absent or rare	X, (R, T)

other: 	prismatic crystals in ray cells

Wood properties

density: 	light

ρ 0: 	420 kg/m3

ρ 12-15: 	450 kg/m3

ρ green: 	kg/m3

shrinkage: 	medium

- volumetric (βV): 	12,3 %

- radial (βR): 	4 %

- tangential (βT): 	8 %

ultimate strength in compression ||: 	50 MPa

ultimate strength in bending: 	78 MPa

ultimate strength in tension ||: 	90 MPa hardness: 	soft

Janka's hardness: 	26 MPa

technological properties: 	no problem with drying, working, finishing, uneasy chemical preservation of heartwood

resistance: 	rated as slightly or nonresistant to decay

Wood utilization

very important wood not only in Europe with wide utilization; timber, mine timber, veneers, plywood, batten boards, particle board (chipboard, MDF/HDF -- medium/high density fibreboards, OSB – oriented strand boards), inside and outside building constructions, roof, windows, doors, stairs, inside and outside joinery facings, bridges, furniture, toys, chemical and paper industry, wood wool, fuel wood; slow-growing material is preffered for sounding boards of musical instruments because of its high resonant qualities (for this purposes wood has to be defectless with ring width 1–4 mm with portion of late wood ranging from 5–20 %

References