Key message: An efficient use of thermal treatment of wood requires a depth understanding of the chemical modifications induced. This is a prerequisite to avoid problems of process control, and to provide high quality treated wood with accurately assessed properties to the market. Properties and structural anatomy of thermally modified woods are slightly different than un-processed woods from a same wood species. So it is necessary to create or adapt new analytical methods to control their quality.Context: Heat treatment as a wood modification process is based on chemical degradation of wood polymer by heat transfer. It improves mainly the resistance of wood to decay and provides dimensional stability. These improvements, which come at the expense of a weakening of mechanical properties, have been extensively studied. Since a decade, researches focused mainly on the understanding of wood thermal degradation, on modelling, on quality prediction and quality control.Aims: We aimed at reviewing the recent advances about (i) the analytical methods used to control thermal treatment; (ii) the effects on wood decay resistance and (iii) the advantages and drawbacks of a potential industrial use of wood heating.Methods: We carried out a literature review of the main industrial methods used to evaluate the conferred wood properties, by thermal treatment. We used papers and reports published between 1970 and 2015, identified in the web of science data base..Results: Approximately 100 papers mostly published after 2000 were retrieved. They concentrated on: (i) wood mass loss due to thermal degradation determination, (ii) spectroscopic analyses of wood properties, (iii) colour measurements, (iv) chemical composition, (v) non-destructive mechanical assessments and (vi) use of industrial data.Conclusions: One of most interesting property of heat-treated wood remains its decay resistance. Durability test with modified wood in laboratory are expensive and time-consuming. This review displays data from different analytical methods, such as spectroscopy, thermogravimetry, chemical analyses or mechanical tests that have the potential to be valuable indicators to assess the durability of heat treated wood at industrial scale. However, each method has its limits and drawbacks, such as the required investment for the equipment, reliability and accuracy of the results and ease of use at industrial scale.

Boron compounds are used as wood preservatives as they are both fungicide and insecticide, relatively inexpensive and environmentally acceptable. Nevertheless, in the field of wood protection, borates are only used for indoor non-exposed applications or in association with other biocides, due to their main disadvantage of being readily leachable from treated wood. To overcome this problem, boric acid was fixed into wood with condensed tannins and hexamine through a non-formaldehyde emission polymer network. Treated mixtures were tested with different proportions of mimosa tannins and hexamine, with and without co-added boric acid. The treated beech samples were leached and tested according to European Standard EN 113 against Pycnoporus sanguineus in tropical conditions. The systems had minimal boron depletion and good fungal decay efficacy, meeting the efficacy requirements of EN 113. Thus, these associations could be envisaged to treat timber with insufficient natural durability for above ground outdoor use, and for a long service-life of the wooden commodities.

Key Message: This article presents the enhancement in boron fixation as well as the improved biological resistance against fungi and termites for wood samples treated with tannin-caprolactam and tannin-PEG formulations. Context: Although the recently developed tannin-boron wood preservatives have shown high biological protection, they presented also average resistance against weathering. The tannin-caprolactam formulations have shown improved weathering resistances and dimensional stability. Aims: For this reason, more detailed biological tests were performed to evaluate the influence of the caprolactam and PEG on the biological resistance. Methods: In this paper, the boron leaching of the tannin-caprolactam and tannin-PEG impregnated Scots pine specimens was observed and the biocidal effect against fungi (Antrodia spp. and Coniophora puteana) and insects (Reticulitermes flavipes and Hylotrupes bajulus) were determined according to the guidelines of EN 113, EN 117, and EN 47. Results: The advanced formulations containing PEG have shown interesting resistance against fungal decay, but very low penetration and weak resistance against larvae while the tannin-caprolactam preservatives have shown overall improved biological performances and higher boron fixations. Conclusion: The biocidal activity of the caprolactam-added formulations was overall enhanced and therefore these formulations are confirmed to be an interesting alternative for the wood preservation in outdoor environment.

The use of agricultural residues in biocomposite production has gained increasing attention, driven by several benefits. Converting agricultural by-products into bio-based materials within a circular economy represents a sust... | Find, read and cite all the research you need on Tech Science Press

No desenvolvimento de painéis, deve-se dar destaque a ensaios que remetam à aplicabilidade final do produto, como os ensaios de durabilidade ao ataque de fungos e cupins. Nesse contexto, painéis confeccionados com diferentes percentuais de partículas de bagaço de cana-de-açúcar (Saccharum sp.) e fibras de eucalipto (Eucalyptus grandis), aglutinados com duas dosagens de resina ureia formol (13% e 16%), foram submetidos à avaliação de resistência biológica (bioensaios) ao ataque de cupins e fungos, ensaio fundamental na definição de uso e aplicação do produto final. Foram utilizados cupins da espécie Reticulitermes santonensis, rhinotermitidade, e fungos da espécie Pleurotus ostreatus, basidiomiceto de podridão-branca, de acordo com procedimentos da normatização AFNOR. De modo geral, os novos painéis confeccionados apresentaram-se não resistentes aos bioensaios realizados e houve similaridade na dinâmica de ataque e perda de massa entre as diferentes dosagens de resina praticadas, remetendo à necessidade da aplicação de revestimento protetor na superfície dos painéis ou adição de produtos fungicidas e cupinicidas.

In the context of the European Tempus project “Quality in Higher Agricultural Education in the Mediterranean (QESAMED)”, Analysis and Characterization Center of Cadi Ayyad University has committed to implement a quality approach according to the ISO/IEC 17025 standard. The first objective was to accredit the testing carried out in the microbiology laboratory in response to strong demand from the food industry in the Marrakesh region. The process began with an initial assessment of the center activities to identify the main gaps from ISO/IEC 17025. The range of laboratory and standard testing to be accredited were determined and an appropriate action plan was established. After that, a staff training was programmed to improve their skills in relation to this standard and metrology concepts. Implementation of the metrology function is one of the key steps for the deployment of the continuous improvement process. This function guarantees the traceability of measurements and the reliability of microbiological testing results. Several actions have been carried out, including: (i) identification of critical quantities and associated metrological requirements, (ii) checking of the metrological consistency of equipment through the calculation of the capability coefficient. The management of equipment requires several steps, from receipt of the equipment to its decommissioning or reform: (i) identification of the equipment, (ii) creation of equipment files, (iii) performance of calibration, verification, and maintenance operations. Ultimately, the definition of a strategy ensuring metrological traceability will optimize management costs by taking into account the structural constraints linked to the organization of metrology on a national scale.