Influence of combined hydro-thermal treatments on selected properties of Turkey oak (Quercus cerris L.) wood

Todaro, Luigi; Zanuttini, Roberto; Scopa, Antonio; Moretti, Nicola

doi:10.1007/s00226-011-0430-2

Cited by 24 publications

(22 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A recent paper examined EMC in Turkey oak (Todaro et al 2012), however the outcome of this and other studies were not congruent with our results. In fact, Burgos & Rolleri (2012) observed increased shrinkage in heat-treated Douglas fir wood, with decreased extractives, although the result might be comparable, as Douglas fir sapwood contains fewer extractives than heartwood.…”

Section: Fig 2 -Mechanical Properties Of Treated (T) and Untreated (contrasting

confidence: 99%

Physical and mechanical characteristics of poor-quality wood after heat treatment

Romagnoli¹,

Cavalli²,

Pernarella³

et al. 2015

iForest

View full text Add to dashboard Cite

© iForest -Biogeosciences and Forestry IntroductionHigh-temperature heat treatment is considered a suitable method to improve wood characteristics. It reduces toxic chemical applications normally required to increase wood durability (Kandem et al. 2002, Welzbacher & Rapper 2007, Mohareb et al. 2010 and enhance dimensional stability, reducing the hygroscopic behavior of the material (Kortelainen et al. 2006). High-temperature treatment can be viewed as a type of wood modification, due to the possibility of controlling color changes (Bekhta & Niemz 2003, Johanson & Moren 2006, Esteves et al. 2007a, 2008 and mechanical performance (Bekhta & Niemz 2003, Welzbacher et al. 2007, Bal 2014. The process results in a new material in terms of durability, woodwater relationships and some mechanical properties, which exhibits performance dependent on the specific high-temperature treatment conditions (Militz 2002, 2008, but the wood product does not present any environmental hazards in its disposal (Hillis 2006). The final product typically has the disadvantage of reduced mass and mechanical performance, although some difference in degree of change has been observed between softwoods and hardwoods depending on the treatment method (Kocaefe et al. 2010, Li et al. 2011.Therefore, the overall extent of modification and the final result of the process is quite variable. In this study, we assessed heat treatment effects on Corsican pine and Douglas fir wood properties obtained from a conifer reforestation site in Italy, with particular consideration of different sapwood and heartwood behavior. This timber is considered poor quality and is currently used as biomass for energy or packaging. Materials and methods Study area Forty Douglas fir (Pseudotsuga menziesii)and 40 Corsican Pine (Pinus nigra ssp. laricio) trees were sampled in an artificial mixed stand in Poggio Nibbio near Viterbo, Central Italy (latitude 42° 22′ N, longitude 12° 10′ W). Trees were arranged in rows with a cross-distance of 4 m; the stand was thinned to promote tree regeneration and introduction of indigenous hardwoods. The harvested wood is generally of poor quality due to the fact that the trees have grown quite fast, and not straight, producing large rings that contain a high proportion of earlywood. The sapwood is also quite large, particularly in Corsican pine.From each of the eighty trees sampled, single boards 6 cm thick, 80 cm long, and 7 cm in width were produced and subsequently crosscut to obtain two half-boards of approximately 40 cm in length. From these two half boards, we obtained twin specimens measuring 2 × 2 cm in the transverse radial and tangential directions, and 40 cm longitudinally. The wood samples were largely juvenile, approximately 10 years in cambial age, and evidence of reaction wood was not observed in any samples analyzed. For each of the 2 × 2 × 40 cm sample pairs, one sample was heat treated, and the second sample was left untreated. Subsequently, two blocks measuring 2 × 2 × 3 cm in size were cut from the end of each sample to...

show abstract

Section: Fig 2 -Mechanical Properties Of Treated (T) and Untreated (contrasting

confidence: 99%

Physical and mechanical characteristics of poor-quality wood after heat treatment

Romagnoli¹,

Cavalli²,

Pernarella³

et al. 2015

iForest

View full text Add to dashboard Cite

show abstract

“…For the following determinations, 6 g was taken from each of the 24 samples (12 from sapwood and 12 from heartwood), extracted and ground with a small rotary blade machine. Additional experimental information is described in Todaro et al (2012).…”

Section: Heat Treatmentmentioning

confidence: 99%

Effect of Combined Steam and Heat Treatments on Extractives and Lignin in Sapwood and Heartwood of Turkey Oak (Quercus cerris L.) Wood

et al. 2013

Self Cite

View full text Add to dashboard Cite

Combined treatment with steam and heat was imposed on green Turkey oak (Quercus cerris L.) wood, both for sapwood and heartwood. Steaming was carried out in an autoclave at 100, 120, or 130 °C, and then a portion of the samples was heated in an oven for 2 h at 120 or 180 °C. Extraction with ethanol provided the greatest extractive contents in sapwood, and the extractive quantity decreased as the heating temperature was increased to 180 °C. In contrast, extraction with dichloromethane provided the greatest extractive content in heartwood, and no sizeable differences were found among the various treatments. Lignin amounts increased with rising treatment temperatures combined with steaming at 100 and 120 °C until the greatest value of 31.1% lignin content was reached. However, the lignin content decreased as the steaming temperatures rose to 130 °C. In all the combined treatments, the lignin content was greater in heartwood than in sapwood. Moreover, both steaming and heating applied individually produced no significant effect on lignin content.

show abstract

“…Thus, in our study, the positive effect of steaming on moisture content reduction was weakly depicted (Tab. 2), compared with other similar studies (Todaro et al 2012a(Todaro et al , 2012b. …”

mentioning

confidence: 47%

“…However, the samples in our study were not steamed under wet conditions. On the contrary, we previously reported about significant variations in moisture content at 120 °C both for steaming and heating when wet wood was used (Todaro et al 2012b). These facts confirmed the hypothesis that the steaming process assumes a greater importance under wet conditions as compared with dry conditions.…”

mentioning

confidence: 86%

“…It has been hypothesized that during the absorption of water, the radial ray cells may act as a longitudinal barrier to the movement of wood (Todaro et al 2012b). Reiterer et al (2002) also confirmed that the volume fraction of ray cells affects wood mechanical properties in the radial direction, while has negligible effect in the tangential direction.…”

Section: Swellingmentioning

confidence: 99%

See 1 more Smart Citation

Behavior of pubescent oak (Quercus pubescens Willd.) wood to different thermal treatments

Todaro¹,

Rita²,

Negro³

et al. 2015

iForest

View full text Add to dashboard Cite

© iForest -Biogeosciences and Forestry IntroductionPubescent or Downy oak (Quercus pubescens Willd.) is a deciduous species characterized by high morphological variability (Schwarz 1993) and a widespread distribution range, from western to eastern Europe (Jalas & Suominen 1976). Pubescent oak covers with monospecific stands 876 000 and 850 000 ha in France and Italy, respectively (IGN 2013, INFC 2007). In other Mediterranean countries, e.g., Slovenia, Croatia, Montenegro, and Albania, the growing stock of mixed or pure stands of this species is rather limited, according to the national forest inventories. In general, the wood of pubescent oak is scarcely considered as industrial lumber and is mainly used as firewood. In the past, it was largely employed for rail crossbeams, while nowadays it is occasionally used for carpentry, boat-building, or packaging. It is well known that through adequate modification processes, its wood properties may be improved, creating a new and environmental-friendly material (Hill 2006).Thermal treatment of wood is applied since the beginning of the last century, when several studies demonstrated the reduced equilibrium moisture content and consequently reduced dimensional shrinkage of wood exposed to a high temperature (Kollman 1936, Stamm et al. 1946, Kollman & Schneider 1963. Lately, a great interest in thermal processing of wood had been rising, and several types of thermal treatments have been developed. Most studies aimed at analyzing the variation in the different treatment phases of several wood parameters, such as moisture content, dimensional stability, durability, mass loss, color changes, mechanical properties, and chemical modifications (Esteves & Pereira 2009).Nowadays, the industrial and scientific interest in thermally treated wood is undergoing a "new age", promoted by the growing demand for environmental-friendly construction products. Although the scientific literature is rich of studies describing the improved technological properties of several species, scant information is available on the wood of pubescent oak. In general, based on its wood properties, the choice of the most suitable thermal treatment for pubescent oak is often troublesome.Pubescent oak wood veining is macroscopically indistinguishable from other oak species. In fact, there are no significant differences in its strength properties as compared with other deciduous oak species, though pubescent oak wood is heavier with a large shrinkage, and consequently very prone to cracking (Giordano 1981). In addition, the presence of reaction wood, as well as cross grain or internal tensions, can cause serious warping, such as bowing, crooking, or twisting, and cross breaks develop in the areas of major shrinkage (Giordano 1994). Also, pubescent oak wood shows remarkable chromatic differences between sapwood and heartwood, being the latter usually darker. Furthermore, its high level of extractives, along with other features such as tylosis, make this wood less permeable and more difficult to be treated with ...

show abstract

Influence of combined hydro-thermal treatments on selected properties of Turkey oak (Quercus cerris L.) wood

Cited by 24 publications

References 17 publications

Physical and mechanical characteristics of poor-quality wood after heat treatment

Physical and mechanical characteristics of poor-quality wood after heat treatment

Effect of Combined Steam and Heat Treatments on Extractives and Lignin in Sapwood and Heartwood of Turkey Oak (Quercus cerris L.) Wood

Behavior of pubescent oak (Quercus pubescens Willd.) wood to different thermal treatments

Contact Info

Product

Resources

About