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

Table 3

Duncan test results of the samples.

Strength properties	Factors	LS mean	Homogenous groups
Surface roughness	Wood species
	Spruce	38.334	b
	Fir	35.646	a
	Alder	41.652	c
	Beech	39.621	d
	Grit size
	Planing	47.005	c
	80	39.265	b
	180	30.170	a
	Wood
	Heartwood	39.386	a
	Sapwood	38.242	a
Adhesion strength	Wood species
	Spruce	1.99	a
	Fir	1.98	a
	Alder	2.16	b
	Beech	2.42	c
	Grit size
	Planing	2.05	a
	80	2.23	c
	180	2.13	b
	Wood
	Heartwood	2.17	a
	Sapwood	2.10	a

Different letter denote a statistically significant difference.