Radial- and tangential clearance angles of sawing teeth: Effect on cutting forces in wood

• Optimizing the cutting tool geometries can reduce waste while increasing timber yield. The indus-try is moving towards thin-kerf rip sawing of timber, and therefore, side cutting and the geometryof the side faces of cutting teeth become more important. Six cutting teeth with varying sideradial- (0, 2, 4, 6 degrees) and tangential clearance angles (2, 4, 6 degrees) were tested by cutting intothe heartwood and sapwood of frozen and non-frozen Norway spruce (Picea abies (L.) Karst.) andScots pine (Pinus sylvestris L.). Single cutting tooth tests were conducted, and the main and nor-mal cutting forces were measured. The main cutting forces were higher for Scots pine due to itshigher density. Frozen sapwood also resulted in higher cutting forces. The normal cutting force offrozen sapwood stood out as it was highly negative (i.e. self-feeding) compared to frozen heartwood,non-frozen heartwood and non-frozen sapwood. An increase in the radial- and tangential clearanceangles, and therefore more room for elastic spring-back, can lead to up to 40% lower main cuttingforces. Higher radial- and tangential clearance angles resulted in less-negative normal forces (i.e. lessself-feeding) for frozen sapwood but remained relatively unchanged for the other wood conditions.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Annan maskinteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Other Mechanical Engineering (hsv//eng)

Nyckelord

Bandsaw

heartwood

sapwood

sawing

frozen

Träteknik

Wood Science and Engineering

Publikations- och innehållstyp

vet (ämneskategori)

ovr (ämneskategori)