Valmet Durable Knife System ensures consistent high chip quality

Valmet Durable Knife System includes Valmet's patented chipper knife usable in almost all disc chippers. The custom-made sharp and strong knife ensures continuous high chip quality and longer change intervals for the knives, which improve the productivity of the chipper.

Sharp knives ensure high chip quality

The sharpness and durability of Valmet Durable Knife System are based on a special heat treatment for the knife material and also on the finishing of the knife edge, both of which help to make a sharper and stronger knife. This means that sharp knife edge also stays sharp longer, resulting in the constant and steady production of high quality chips.

Strong knives improve productivity

Experience indicates that knife change frequency of a softwood chipper with 12 knives is 6,000-8,000 tons and that of a softwood chipper with 15 knives, 8,000-10,000 tons. Tests prove that the lifetime of the knife compared with a traditional knife is about double. When dry and hard eucalyptus wood was chipped in Finland, tests proved that 2,721 tons could be chipped with a 12-DuraKnife chipper. This exceeds the normal knife change frequency of 1,000 tons by a significant amount. This allows longer knife change intervals, reduces downtime and results in improved productivity.

Representative customer experience - a pulp mill

This mill has two chippers with Valmet Durable Knife System chipper knives. They have chipped continuously for three days and nights and the knives remained sharp all the time. Their production record is 15,000 tons softwood without knife change. The fines amount is moderately stable. Chip quality has been good. When the knife dulls it does not have a tendency to bend at the knife tip meaning good pulling of the chipper. Toughness of the knife has been significantly improved. The new knife remains intact even though sometimes they are not chipping only wood. During the last 12 months of production the knives have proven to be of good quality under all circumstances.

For more information on improving your chip quality and woodyard productivity, contact your Valmet representative.