The impact of mechanical log surface damage on chip size uniformity during debranching and debarking<i>Eucalyptus</i>pulpwood logs using a single-grip harvester

Merwe, Jaco-Pierre van der; Ackerman, Pierre; Pulkki, Reino; Längin, Dirk

doi:10.2989/20702620.2016.1152532

Cited by 6 publications

(5 citation statements)

References 25 publications

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“…Similar findings were observed in previous studies (Bassler 1987;Uhmeier and Persson 1997;Araki 2002;True 2006;Watson and Stevenson 2007;Niedźwiecki 2011;Cáceres et al 2016b;van der Merwe et al 2016avan der Merwe et al , 2016b.…”

Section: Discussionsupporting

confidence: 91%

“…However, the production of favourable-sized chips during chipping was most strongly impacted by wood MC, even more so than feed-roller-induced log surface damage (van der Merwe et al 2016a(van der Merwe et al , 2016b. Logs dried for two weeks produced significantly more accepts and less undersized chips across respective debarking treatments and log classes.…”

Section: Discussionmentioning

confidence: 99%

“…Previous studies have found that feed roller type, tree size and species have a significant impact on the log surface, when debranching stems (Connel 2003;Brunberg et al 2006;Gerasimov and Seliverstov 2010;Sveningsson 2011;Nuutinen et al 2010;Karaszewski et al 2015;van der Merwe et al 2016b). However, no research was found regarding the impact of feed-roller-induced log surface damage and log drying period on potential pulp yield value recovery.…”

Section: Log Surface Damagementioning

confidence: 99%

“…Chatter is caused when the harvester head feed rollers cutting knives cut into (penetrate) the log surface. Van der Merwe et al (2016b) investigated the impact of log surface damage on chip uniformity when debranching and debarking eucalypt pulpwood logs, using a single grip harvester. It was found that log surface damage induced by harvester head feed rollers indeed had a negative impact on chip uniformity due to the increased production of pins and fines.…”

Section: Log Surface Damagementioning

confidence: 99%

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The impact of log surface damage caused by harvesterEucalyptusdebarking on pulp value recovery

Merwe

Pulkki

Ackerman

et al. 2017

Southern Forests: a Journal of Forest Science

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Mechanised harvesting operations are growing in popularity in South Africa, as motor-manual and manual harvesting operations pose significant health and safety risks to workers. Potential damage inflicted by singlegrip harvester feed rollers and delimbing knives on the log surface during debranching and debarking of eucalypts may affect chip size distributions during chip production. Chip size is important as it influences pulp quality and recovery in the kraft pulping process. The study investigated the influence of two mechanised debarking treatments in eucalypts (three feed roller passes and five feed roller passes along the stem surface) with feed-roller-induced log surface damage on pulp value recovery. The two mechanised treatments were compared against chips produced from manually debarked logs with no surface damage. In addition, the effect of two log drying periods (one week and two weeks) and three log classes (base, middle and top logs) on chip quality were also analysed. An economic evaluation was conducted to quantify potential recoverable pulp value losses associated with debarking treatments and log drying periods. Logs subject to manual debarking produced significantly less undesired sized chips than both three-pass and five-pass mechanically debarked logs and therefore had significantly greater pulp value recovery. Mechanically debarked logs had a projected pulp value recovery of R62, R86 and R123 less per bone dry tonne of chips produced from base, middle and top logs, respectively, when compared with manually debarked logs with no log surface damage after a one-week log drying period. Mechanically debarked logs also had a projected pulp value recovery of R77, R40 and R59 less per bone dry tonne of chips produced from base, middle and top logs, respectively, when compared with manually debarked logs with no log surface damage after a two-week log drying period. Logs dried for two weeks also produced significantly less under-sized chips than chips produced from one-week-dried logs and therefore had greater pulp value recovery. However, two-week-dried logs produced wood chips with significantly more over-thick chips than logs dried for one week. The volume of undesirable-sized chips produced during chipping increased with decreasing log size.

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Section: Discussionsupporting

confidence: 91%

Section: Discussionmentioning

confidence: 99%

Section: Log Surface Damagementioning

confidence: 99%

Section: Log Surface Damagementioning

confidence: 99%

See 2 more Smart Citations

The impact of log surface damage caused by harvesterEucalyptusdebarking on pulp value recovery

Merwe

Pulkki

Ackerman

et al. 2017

Southern Forests: a Journal of Forest Science

Self Cite

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show abstract

“…Previous studies have investigated the impact of moisture content (MC) on chip size distribution. Van Der Merwe et al (2016), investigated the influence of two pulp log drying periods (1 and 2 weeks) on moisture content and chip size distribution when chipping eucalyptus pulp logs. As result, it was observed that moisture content was lower for chips produced from logs dried for 2 weeks than chips produced from logs dried for 1 week.…”

Section: Introductionmentioning

confidence: 99%

Influence of storage time and log length on the distribution of wood chip size

Silveira

Durigan

Monteiro

et al. 2023

BioRes

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Chip size distribution is important in kraft pulping, as it affects chemical use, quality, and yield in pulp production. Pinus taeda logs with two storage periods (0 and 2 weeks) and two log lengths (2.4 and 7.0 m) were processed with a disc chipper. Logs stored for two weeks produced chips with 7% less moisture than logs with no storage period. The storage period significantly influenced the quantities of overthick, accept, pin, and fines classes. Logs stored for two weeks produced 1.7% more overthick, 3.8% more pin, and 1.1% fines than logs with no stocking period. Consequently, the amount of accept produced was 6.2% higher for chips from processing freshly harvested logs. Log length influenced the produced quantities of oversize, overthick, and accept. Logs with a length of 2.4 m produced chips with 1.4% more oversize, 2.5% more overthick, and 4.6% less accept, compared to 7.0 m logs. Thus, it was concluded that Pinus taeda logs with shorter storage periods and longer lengths generate more chips in the “accept” class.

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Extent and severity of damages caused to spruce roundwood by harvesting heads in standard versus debarking configurations

2019

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The impact of mechanical log surface damage on chip size uniformity during debranching and debarkingEucalyptuspulpwood logs using a single-grip harvester

Cited by 6 publications

References 25 publications

The impact of log surface damage caused by harvesterEucalyptusdebarking on pulp value recovery

The impact of log surface damage caused by harvesterEucalyptusdebarking on pulp value recovery

Influence of storage time and log length on the distribution of wood chip size

Extent and severity of damages caused to spruce roundwood by harvesting heads in standard versus debarking configurations

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