Maderas. Ciencia y tecnología

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List of Papers (Total 192)

Fijación química del preservante CCA-C en la madera de Pinus elliottii Parte 1: Influencia de la temperatura y de la humedad relativa

The water-borne preservatives are often used to increase the durability of wood-tion in civil constructions including the CCA (chromated copper arsenate) is the one with better properties. To prevent leaching when the wood preservative is in service must be submitted to a treatment setting such that the preservatives and wood components react to form stable chemical products...

Influence of veneer quality on beech LVL mechanical properties

The quality of peeled veneers is generally quoted considering 3 main criteria: surface roughness, thickness variations and lathe checking. This last criterion impacts on mechanical properties of by-products. It is well known that lathe checking occurrence can be reduced applying a good hygrothermal treatment of the round-wood before peeling coupled with optimised setting of...

Condensed tannin reactivity inhibition by internal rearrangements: Detection by CP-MAS 13C NMR

Tannin extracts were prepared from barks of maritime pine (Pinus maritimus), aleppo pine (Pinus halepensis), Norway spruce (Picea abies) and from a mixture of barks of different pine species (Pinus spp., namely 20% black pine (Pinus thunbergii)+ 30% Scots pine (Pinus sylvestris) + 20% maritime pine (Pinus maritimus) + 10% Aleppo Pine (Pinus halepensis) + 5% Douglas fir...

Why Simulate a Sample of Recycled Wood?

Wood products follow the same cycle as other materials: manufacture, use and disposal. For certain applications, chemical additives are added to wood to increase its durability against biological and physical attack. At the end of life, waste wood is chipped or crushed before being recovered as raw material for new products or as fuel for energy. In recycled wood, there is the...

Tratamiento químico de acetilación en madera de Pinus radiata

When woody cell wall is saturated with acetic anhydride, the free hydroxyl groups present on cellulosic structures are replaced. Thus, the capillary spaces are filled with acetyl groups and this replacement avoids further reactions with water or enzymatic degradation provoked by rot fungi. So, the death of different fungi is produced by the lack of food. It has been observed too...

The potential use of organosilane water soluble nanomaterials as water vapor diffusion retarders for wood

The retarding effect of organosilane water soluble nanomaterials (nano-zycosil and nano-zycofil) on water vapor diffusion through poplar wood (P.nigra) was evaluated in comparison with that of clear coatings (sealer and nitrocellulose lacquer and polyester lacquer) using cup and sorption methods. Two drying methods were applied to dry the nanomaterials -coated substrates: oven...

Influence of uron resins on the performance of UF resins as adhesives for plywood

Uron resin, a kind of urea-formaldehyde (UF) resin containing much more uron structure, were prepared. Several modified UF resins were obtained from mixing uron resins with normal UF resins as well as synthesizing UF resin with uron resin as raw material. This work demonstrated that the introducing of the uron structure reduced free formaldehyde content of UF resin and...

Preparation and characterization of nanofibrillated Cellulose/Poly (Vinyl Alcohol) composite films

Poly (vinyl alcohol) based composite films with different loadings of cellulose nanofibrils were prepared using a solvent casting method and their tensile, optical and wettability properties were tested. The morphology of both neat poly (vinyl alcohol) and nanocomposites was explored by using a field emission scanning electron microscope technique. Results indicated that the...

Wood under fresh water: Effect on the chemical properties and on decay resistance

This study aimed to evaluate the effect of waterlogging on the chemical properties and on decay resistance of two fast-growing eucalypt species. Samples of spotted gum and rose gum wood were placed underwater and taken out at different times: after 4, 8 and 12 months. Chemical properties were performed via wet chemical quantification (Tappi standards), monomeric sugars by HPLC...

Efecto del solvente y de la relación masa/solvente, sobre la extracción de compuestos fenólicos y la capacidad antioxidante de extractos de corteza de Pinus durangensis y Quercus sideroxyla

Bark from timber species might be a promising target of therapeutical interest due to its content of bioactive, phenolic compounds. However, the extraction efficiency of these metabolites depends on the type of solvent chosen and the process variables analyzed. Traditional medicine only uses ethanol and water mixtures for therapeutical purposes. Therefore, in this study...

Shape and cell wall slenderness effects on the stiffness of wood cell aggregates in the transverse plane

The present study investigates a homogenization method in the framework of finite element method to determine the effective stiffness properties of wood cell aggregates in the transverse plane. For this purpose, square and regular hexagonal representative volume elements are chosen to mimic the wood cells. Thereafter, simulation experiments are conducted to understand how...

CO2 adsorption on agricultural biomass combustion ashes

Carbon capture and storage has become an alternative means of confronting global warming. Further research and development into adequate and low-cost materials is required for CO2 adsorption technologies. Samples of fly ash, bottom ash and their respective pellets, produced from wheat bran combustion, were characterized and tested to assess their capacity for CO2 adsorption at...

Natural durability of Cedrus atlantica wood related to the bioactivity of its essential oil against wood decaying fungi

The Atlas cedar, Cedrus atlantica is a resinous species of Pinaceae originated from North Africa and well known for its noble timber. This work was conducted to assess the natural durability of its wood, to study the chemical composition of essential oil extracted from its sawdust wood and to test the bioactivity of this essential oil against four wood decaying fungi...

Planificación agregada en la cosecha forestal: Un modelo de programacion matemática y solucion

In this study, we propose and solve a mix Integer Programming model for the tactical planning in forest harvesting. The following elements we considered the replacement of products, the stand differentiation places of bucking. The instances used have: 60 stands, 25 stockyards, 10 customers, 8 planning periods and 20 bucking rules, with up to 260000 variables, 48000 integers and...

Effect of styrene maleic anhydride on physical and mechanical properties of recycled polystyrene wood flour composites

In this work, the influence of three types of styrene maleic anhydride (SMA) oligomers on the adhesion of polystyrene wood plastic composites (WPC) was investigated. The composites were processed on a twin-screw co-rotating extruder below 200°C using 20 wt% of wood flour. The styrene maleic anhydride with different content of maleic anhydride groups, 30%, 25% and 20% (w/w) and...

Enhancing dimensional stability of oriented strand composites within biorefinery

The objective of this study was to investigate the effects of hot water extraction process on the dimensional stability of oriented strand composites. Aspen wood strands were extracted using various severity factor levels. Phenol formaldehyde and polymethylene diphenyl diisocyanate resins were used for production of the oriented strandboard panels. Six panel groups were produced...

Propiedades de tableros aglomerados de partículas fabricados con madera de Eucalyptus urophylla

This is an exploratory study on the feasibility of using Eucalyptus urophylla wood for the production of particleboards. Therefore, the aims were to determine their physical and mechanical properties and to evaluate the results with German Standards Institute (DIN) and Industrial Standards Commission Venezuelan (COVENIN). For boards with a real density of 731 kg/m3, the average...

The influence of raw material growth region, anatomical structure and chemical composition of wood on the quality properties of particleboards

In the present study, the impact of raw material grown region on the physical, mechanical, surface properties and formaldehyde emission of the particleboard was investigated. Ailanthus altissima wood grown in Trabzon had longer fiber length and thicker fiber and trachea cell wall than those of the wood grown in Artvin. The highest amounts of lignin, ash, condensed tannin and...

Determination of decay resistance against Pleurotus ostreatus and Coniophora puteana fungus of heat-treated scotch pine, oak and beech wood species

The objective of this study, to investigate decay resistance against Pleurotus ostreatus and Coniophora puteana fungus of heat-treated (ThermoWood method) Scotch pine, oak and beech wood species. Scotch pine (Pinus sylvestris), oak (Quercus petreae) and beech (Fagus orientalis) wood species were heat treated at 190°C for 2 h, 212°C for 1 h and 2 h by the ThermoWood® method...

Larvicidal activities of some bark and wood extracts against wood-damaging insects

This study investigates the larvicidal activities of plant extracts and tannins against wood-damaging insects. Scots pine (Pinus sylvestris), beech (Fagus orientalis), and poplar wood (Populus tremula) were subjected to larvae of Spondylis buprestoides (Coleoptera: Cerambycidae) by impregnating them with mimosa (Acacia mollissima), quebracho (Schinopsis lorentzii) and redpine...

Clasificación mecánica de tablas de pinos resinosos cultivados en el nordeste de Argentina

The present paper reports the results of an investigation regarding the analysis of models for machine strength grading boards of resinous pine cultivated in the northeast of Argentina. An empirical research project with one sample containing 233 boards in structural sizes subjected to static bending and one sample enclosing 100 boards subjected to tension was carried out...

Effects of heat treatment on the adhesion strength, pendulum hardness, surface roughness, color and glossiness of Scots pine laminated parquet with two different types of UV varnish application

The objective of this study was to investigate the surface properties of a UV-system applied on laminated parquet made with untreated and heat treated wood (ThermoWood). In this study, wood specimens prepared from Scots pine (Pinus sylvestris) wood were heat treated according to ThermoWood method at 190ºC for 2 hours and at 212ºC for 1 and 2 hours adhesion strength, pendulum...

Effect of the anatomical structure, wood properties and machining conditions on surface roughness of wood

The main aim is to test the influence of anatomical structure (grain direction and elements size), wood hardness and machining conditions on wood surface roughness. 180 samples defect-free were obtained from beech, oak and pine and processed with different machining methods (planning, sanding with 60 grit or sanding with 180 grit). Roughness, hardness, and anatomical structure...

A newly-developed model for predicting cutting power during wood sawing with circular saw blades

In the classical approach, cutting forces and cutting power in sawing processes of orthotropic materials such as wood are generally calculated on the basis of the specific cutting resistance kc (cutting force per unit area of cut). For every type of sawing kinematics (frame saws, band saws and circular sawing machines) different empirical values of specific cutting resistance kc...

Modeling and simulation of an industrial indirect solar dryer for Iroko wood (Chlorophora excelsa) in a tropical environment

This paper presents a modeling of an instrumental indirect solar wood dryer less expensive functioning in a Cameroonian climate applied to the climate of Yaoundé. The dryer is easy to build and electric energy is only used for the fan. Applications are done on Iroko wood (Chlorophora excelsa), a tropical wood 50mm thick most utilized in Africa. A satisfactory agreement between...