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The impact of log storage time, log size and steaming time on the veneer quality of Pinus elliottii & Pinus taeda
Thesis (MScFor)--Stellenbosch University, 2024.
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867613760437354496 |
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| access_status_str | Open Access |
| author | Madiope, Molatelo Sechaba |
| author2 | Meincken, Martina |
| author_browse | Madiope, Molatelo Sechaba Meincken, Martina |
| author_facet | Meincken, Martina Madiope, Molatelo Sechaba |
| author_sort | Madiope, Molatelo Sechaba |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MScFor)--Stellenbosch University, 2024. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/131812 |
| institution | Stellenbosch University (South Africa) |
| last_indexed | 2026-06-10T12:41:15.521Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/131812 The impact of log storage time, log size and steaming time on the veneer quality of Pinus elliottii & Pinus taeda Madiope, Molatelo Sechaba Meincken, Martina Van der Merwe, Jaco-Pierre Stellenbosch University. Faculty of AgriSciences. Dept. of Forest and Wood Science. Plywood -- Breeding -- South Africa Pine -- Quality -- South Africa Pine -- Genetics Fusarium circinatum Wood -- Storage Veneer production -- Management Plywood -- Effect of temperature on Plywood -- Moisture UCTD Thesis (MScFor)--Stellenbosch University, 2024. ENGLISH ABSTRACT: Plywood producers in South Africa historically used P. patula for veneer production. More recently, however, it became impossible to plant P. patula at lower altitudes, because of the fungal pathogen Fusarium circinatum, which causes high mortality soon after planting. Hybrids between P. patula and P. tecunumanii are now planted in these areas, and until they come into commercial production, P. elliottii and P. taeda are used as alternatives. There are increasing volumes of these two species that need to be optimized for veneer production in the coming years, while waiting for the hybrids to reach rotation age. The main question is whether the wood from different species can be processed under similar conditions as P. patula, or if species-specific processing production protocols are required. This study investigates how log storage time, steaming time and log size (diameter class) impact the veneer quality of P. elliottii and P. taeda. Twelve different treatments, varying the three factors (log storage time, steaming time and log size) were compared within and between species. The resultant veneer from each treatment was analysed to see how the three factors impact wet recovery, peeler waste components, dryer throughput and quality recovery. The study revealed significant differences in wet recovery between the two pine species, primarily due to their taper properties, with larger logs demonstrating better wet recovery for both species. Extended log storage negatively impacted wet recovery as blue stains were often mistaken for wane, resulting in unnecessary rounding up of logs. Logs subjected to longer storage times resulted in lower veneer grades after drying compared to those processed four weeks after felling. Steaming improved peeling performance, enhancing veneer quality despite not directly affecting wet recovery. Increasing steaming time from 8 hours to 12 hours did not have a clear impact on wet recovery, but it significantly improved the quality of the recovered veneer after drying for both species in both fresh and older logs. Larger logs generally achieved better veneer grades due to less knots, while logs stored for longer periods experienced more downgrades caused by blue stain and splitting, likely due to moisture loss. AFRIKAANSE OPSOMMING: Laaghoutprodusente in Suid-Afrika het histories P. patula vir fineerproduksie gebruik. Meer onlangs het dit egter onmoontlik geword om P. patula op laer hoogtes te plant, as gevolg van die swampatogeen Fusarium circinatum, wat ‘n hoë mortaliteitsyfer veroorsaak, kort na aanplanting. Basters tussen P. patula en P. tecunumanii word nou in hierdie gebiede geplant. Totdat hulle in kommersiële produksie kom, word P. elliottii en P. taeda as ‘n alternatief gebruik. Toenemende volumes van hierdie twee spesies moet geoptimaliseer word vir fineerproduksie, terwyl die baster spesies nog nie produksieouderdom bereik het nie. Die hoofvraag is of die hout van verskillende spesies onder soortgelyke toestande as P. patula verwerk kan word, en of spesiespesifieke verwerkingsproduksieprotokolle vereis word. Hierdie studie ondersoek hoe stoortyd, stoomtyd en stompgrootte (deursneeklas) die fineerkwaliteit van P. elliottii en P. taeda beïnvloed. Twaalf verskillende behandelinge, wat die drie faktore (houtstoortyd, stoomtyd en stompgrootte) wissel, is binne en tussen spesies vergelyk. Die gevolglike fineer van elke behandeling is ontleed om te sien hoe die drie faktore, naamlik nat volume behoud, skillerafvalkomponente, droërdeurset en kwaliteitbehoud beïnvloed. Die studie het beduidende verskille in nat volume behoud tussen die twee dennespesies aan die lig gebring, hoofsaaklik as gevolg van hul tapse eienskappe, met groter stompe wat beter nat volume behoud vir beide spesies toon. Verlengde stompberging het nat volume behoud negatief beïnvloed, aangesien blou vlekke dikwels verwar is met afneem, wat gelei het tot onnodige afronding van stompe. Stompe wat aan langer bergtye onderwerp is, het gelei tot laer fineergrade na droging in vergelyking met dié wat vier weke na afkap verwerk is. Stoombehandeling het afskilverrigting en fineerkwaliteit verbeter, dit nie nat volume behoud direk beïnvloed het nie nie. Stoombehandeling verlenging van 8 tot 12 ure het nie ‘n beduidende impak gehad op nat volume behoud nie, maar dit het die kwaliteit van die fineer, na droog, vir beide spesies, in beide vars asook ouers stompe verbeter. Groter stompe het oor die algemeen beter fineergrade behaal as gevolg van minder knope, terwyl stompe wat vir langer tydperke gestoor is, meer afgraderings ervaar het as gevolg van blou vlek en skeuring, waarskynlik as gevolg van vogverlies. Masters 2025-03-31T06:23:28Z 2025-03-31T06:23:28Z 2024-12 Thesis https://scholar.sun.ac.za/handle/10019.1/131812 Stellenbosch University 53 pages : illustrations (some color) application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Plywood -- Breeding -- South Africa Pine -- Quality -- South Africa Pine -- Genetics Fusarium circinatum Wood -- Storage Veneer production -- Management Plywood -- Effect of temperature on Plywood -- Moisture UCTD Madiope, Molatelo Sechaba The impact of log storage time, log size and steaming time on the veneer quality of Pinus elliottii & Pinus taeda |
| title | The impact of log storage time, log size and steaming time on the veneer quality of Pinus elliottii & Pinus taeda |
| title_full | The impact of log storage time, log size and steaming time on the veneer quality of Pinus elliottii & Pinus taeda |
| title_fullStr | The impact of log storage time, log size and steaming time on the veneer quality of Pinus elliottii & Pinus taeda |
| title_full_unstemmed | The impact of log storage time, log size and steaming time on the veneer quality of Pinus elliottii & Pinus taeda |
| title_short | The impact of log storage time, log size and steaming time on the veneer quality of Pinus elliottii & Pinus taeda |
| title_sort | impact of log storage time log size and steaming time on the veneer quality of pinus elliottii pinus taeda |
| topic | Plywood -- Breeding -- South Africa Pine -- Quality -- South Africa Pine -- Genetics Fusarium circinatum Wood -- Storage Veneer production -- Management Plywood -- Effect of temperature on Plywood -- Moisture UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/131812 |
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