Produktionsskillnader och virkesskador med olika typer av matarvalsar
Earlier investigations showed that damages on timber from feeding rolls could be within the lower classes of damage according to VMRs classes. Knowledge about differences in productivity between kind types and aggressive types of feeding rolls is necessary because it should influence the question ab...
| Autor principal: | |
|---|---|
| Formato: | Otro |
| Lenguaje: | sueco sueco |
| Publicado: |
2006
|
| Materias: | |
| Acceso en línea: | https://stud.epsilon.slu.se/11943/ |
| _version_ | 1855571970459959296 |
|---|---|
| author | Dahl, Daniel |
| author_browse | Dahl, Daniel |
| author_facet | Dahl, Daniel |
| author_sort | Dahl, Daniel |
| collection | Epsilon Archive for Student Projects |
| description | Earlier investigations showed that damages on timber from feeding rolls could be within the lower classes of damage according to VMRs classes. Knowledge about differences in productivity between kind types and aggressive types of feeding rolls is necessary because it should influence the question about damages on timber caused by different feeding rolls.
In this study the production and timber damage in a harvesting head were evaluated at three levels of pressure (8, 10 and 14 MPa) on the feeding rolls, and with three different types of rolls. One type, the rubber cushioned steel plate roller had 10 mm studs and rubber damping, one "middle" type made of solid steel with 14 mm studs, and one aggressive type, also made of solid steel with 18 mm studs.
No significant general difference in productivity between the three types could be found, but the pressure on the feeding rolls influenced clearly the productivity.
The depth of the damages lied within the lower classes according to VMR. The two steel wheels gave at all pressure levels a deeper damage than type one. There was no difference in the depth of the damages between the tested pressure levels for the two steel wheel types whereas for the kind type there was a difference.
None of the feeding roll types showed a bark abrasion that would be classified as "extensive" according to VMR. The lower pressure (8 MPa) caused a little more bark abrasion for the steel rolls. The kind type caused even at 10 and 14 MPa a little more bark abrasion than the both steel rolls. |
| format | Otro |
| id | RepoSLU11943 |
| institution | Swedish University of Agricultural Sciences |
| language | Swedish swe |
| publishDate | 2006 |
| publishDateSort | 2006 |
| record_format | eprints |
| spelling | RepoSLU119432017-11-15T11:48:11Z https://stud.epsilon.slu.se/11943/ Produktionsskillnader och virkesskador med olika typer av matarvalsar Dahl, Daniel Dept. of Forest Resource Management Forestry production Earlier investigations showed that damages on timber from feeding rolls could be within the lower classes of damage according to VMRs classes. Knowledge about differences in productivity between kind types and aggressive types of feeding rolls is necessary because it should influence the question about damages on timber caused by different feeding rolls. In this study the production and timber damage in a harvesting head were evaluated at three levels of pressure (8, 10 and 14 MPa) on the feeding rolls, and with three different types of rolls. One type, the rubber cushioned steel plate roller had 10 mm studs and rubber damping, one "middle" type made of solid steel with 14 mm studs, and one aggressive type, also made of solid steel with 18 mm studs. No significant general difference in productivity between the three types could be found, but the pressure on the feeding rolls influenced clearly the productivity. The depth of the damages lied within the lower classes according to VMR. The two steel wheels gave at all pressure levels a deeper damage than type one. There was no difference in the depth of the damages between the tested pressure levels for the two steel wheel types whereas for the kind type there was a difference. None of the feeding roll types showed a bark abrasion that would be classified as "extensive" according to VMR. The lower pressure (8 MPa) caused a little more bark abrasion for the steel rolls. The kind type caused even at 10 and 14 MPa a little more bark abrasion than the both steel rolls. Tidigare undersökningar visade att dubbskador från dagens stålvalsar ligger inom de lägre skadeklasserna enligt VMRs klassning. Kunskap om produktionsskillnader mellan aggressiva och skonsamma matarvalsar saknas dock eftersom det kan spela en betydande roll i dubbskadefrågan. I studien utvärderades produktion, dubbskadedjup och barkfläkning vid tre olika valstryck (80, 110 och 140 bar), för tre typer av matarvalsar till Ponsses H73 aggregat. Den första valstypen, ”klappervalsen” var den skonsammaste med 10 mm dubbar och gummidämpning, den andra valstypen var en stålvals med rak utformning och 14 mm dubbar, den tredje, aggressiva typen var en stålvals med 18 mm dubbar samt en konisk utformning. Totalt avverkades och mättes 135 träd. Ingen statistisk skillnad i produktion mellan valstyperna kunde hittas. Trycket på valsarna hade däremot betydelse för produktionen. Skadedjupen för valsarna låg inom de lägre skadeklasserna enligt VMRs inmätningskrav. Stålvalsarna visade vid samtliga valstryck en något djupare dubbskada än klappervalsen. Mellan valstrycken skiljde dubbskadedjupet väldigt lite för stålvalsarna, men för klappervalsen hade trycket betydelse för dubbskadedjupet. Ingen av valstyperna orsakade sådan barkfläkning att det vid en inmätning skulle klassas som ”omfattande”. Vid 80 bars valstryck noterades dock en något större barkfläkningsgrad för stålvalsarna. Klappervalsen gav även vid 110 och 140 bars tryck en något större barkfläkning än stålvalsarna. Vid 80 bar noterades några slirskador för samtliga valsar. 2006-12-21 Other NonPeerReviewed application/pdf sv https://stud.epsilon.slu.se/11943/1/dahl_d_171115.pdf Dahl, Daniel, 2006. Produktionsskillnader och virkesskador med olika typer av matarvalsar. UNSPECIFIED, Umeå. Umeå: (S) > Dept. of Forest Resource Management <https://stud.epsilon.slu.se/view/divisions/OID-260.html> urn:nbn:se:slu:epsilon-s-8835 swe |
| spellingShingle | Dept. of Forest Resource Management Forestry production Dahl, Daniel Produktionsskillnader och virkesskador med olika typer av matarvalsar |
| title | Produktionsskillnader och virkesskador med olika typer av matarvalsar |
| title_full | Produktionsskillnader och virkesskador med olika typer av matarvalsar |
| title_fullStr | Produktionsskillnader och virkesskador med olika typer av matarvalsar |
| title_full_unstemmed | Produktionsskillnader och virkesskador med olika typer av matarvalsar |
| title_short | Produktionsskillnader och virkesskador med olika typer av matarvalsar |
| title_sort | produktionsskillnader och virkesskador med olika typer av matarvalsar |
| topic | Dept. of Forest Resource Management Forestry production |
| url | https://stud.epsilon.slu.se/11943/ https://stud.epsilon.slu.se/11943/ |