Effect of Heartwood and Sapwood Ratio on Adhesion Strength of Finished Wood Species

Table 1

Roughness and adhesions strength test results.

Species and density		Roughness value () (µm)				Adhesion strength (N/mm^2)
		Spruce	Fir	Alder	Beech	Spruce	Fir	Alder	Beech
Heartwood; Spruce (0.425 g/cm^3); Fir (0.49 g/cm^3); Alder (0.52 g/cm^3); Beech (0.69 g/cm^3)	Planing	45.50 (6.91)	41.78 (3.60)	51.49 (7.25)	48.30 (3.32)	1.95 (0.21)	1.92 (0.26)	1.98 (0.19)	2.12 (0.26)
	80	43.20 (5.40)	39.22 (6.01)	42.36 (4.21)	42.57 (7.02)	2.06 (0.26)	2.05 (0.22)	2.42 (0.36)	2.62 (0.22)
	180	25.78 (3.73)	29.99 (4.60)	31.32 (3.38)	31.05 (8.24)	1.97 (0.17)	2.01 (0.19)	2.36 (0.33)	2.56 (0.27)
Sapwood; Spruce (0.420 g/cm^3); Fir (0.48 g/cm^3); Alder (0.52 g/cm^3); Beech (0.67 g/cm^3)	Planing	42.20 (3.92)	42.54 (4.39)	53.37 (4.87)	50.82 (3.82)	1.97 (0.30)	1.88 (0.32)	2.13 (0.35)	2.40 (0.33)
	80	36.98 (3.98)	37.00 (7.42)	37.66 (5.62)	35.10 (6.14)	2.06 (0.40)	2.06 (0.32)	2.15 (0.28)	2.42 (0.19)
	180	27.53 (8.61)	32.10 (6.68)	33.69 (3.40)	29.85 (3.38)	1.92 (0.25)	1.91 (0.29)	1.92 (0.12)	2.36 (0.25)

Numbers in parentheses are standard deviation values.