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Cradle type multi-stem delimber

Dahlin, Bo (1991). Cradle type multi-stem delimber. Uppsala: UNSPECIFIED, Sveriges lantbruksuniversitet. Studia forestalia Suecica ; 185

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Multi-stem delimbing devices may rationalise processing of small-sized trees. Different types of delimbing device are reviewed. Some basic features of cradle delimbing were studied experimentally for Scots pine (Pinus sylvesiris L.) and Norway spruce (Picea abies (L.) Karst.) separately. As standard for delimbing quality, the proportion of branches cut shorter than a specified value is proposed. Acceptable delimbing quality was defined in the study as 75 per cent of the branches cut shorter than 25 mm. Efficiency was measured as the time required to achieve the defined delimbing quality. Loss of stemwood mas measured simultaneousy with delimbing efficiency. The delimbing process followed an S-shaped function. When a bunch of trees first enters the cradle, little delimbing takes place. A period of fairly rapid delimbing follows, succeeded by a period of decreasing efficiency in the final stages. Active delimbing devices, with a momentum of their own. are more efficient than passive devices. The delimbing devices must have sharp edges for efficient delimbing of Norway spruce. Rotors were the most efficient of several delimbing devices tested. The design of the cradle itself, especially the inclination of the longsides, was shown to be important in improving dclimbing efficency. The optimum speed of the conveyor rotating the bunch within the cradle was found to be ca l.5 m.s -1

Authors/Creators:Dahlin, Bo
Title:Cradle type multi-stem delimber
Series Name/Journal:Studia forestalia Suecica
Year of publishing :1991
Number of Pages:31
Place of Publication:Uppsala
Publisher:Sveriges lantbruksuniversitet
ISBN for printed version:91-576-4493-4
Publication Type:Report
Full Text Status:Public
Agris subject categories.:K Forestry > K01 Forestry - General aspects
K Forestry > K11 Forest engineering
Subjects:Obsolete subject words > FORESTRY, AGRICULTURAL SCIENCES and LANDSCAPE PLANNING > Plant production > Forestry
Obsolete subject words > FORESTRY, AGRICULTURAL SCIENCES and LANDSCAPE PLANNING > Area technology > Forest engineering
(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Forest Science
Keywords:delimbing, multi-stem, processing, machine, Pinus sylvestris, Picea abies
Permanent URL:
ID Code:4066
Faculty:S - Faculty of Forest Sciences
Deposited By: Skogsbiblioteket Umeå
Deposited On:08 Mar 2010 00:00
Metadata Last Modified:16 Dec 2015 12:54

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