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    Scritto da
    Non Autenticato
    il 2018-02-16 03:43:14.0 alle 2018-02-16 03:43:14.0
    legno resistente come l'acciaio
    l'Università del Maryland hanno sviluppato un sistema per rendere il legno più resistente dell’acciaio. In futuro il legno “densificato” potrebbe sostituire le leghe metalliche nella costruzione di edifici e automobili
    https://www.wired.it/scienza/ecologia/2018/02/08/l...
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      Scritto da
      dada216
      il 2018-02-16 09:17:57.0 alle 2018-02-16 09:17:57.0
      Trollate totali: 6369
      Re: legno resistente come l'acciaio
      https://www.nature.com/articles/nature25476

      Here we report a simple and effective strategy to transform bulk natural wood directly into a high-performance structural material with a more than tenfold increase in strength, toughness and ballistic resistance and with greater dimensional stability. Our two-step process involves the partial removal of lignin and hemicellulose from the natural wood via a boiling process in an aqueous mixture of NaOH and Na2SO3 followed by hot-pressing, leading to the total collapse of cell walls and the complete densification of the natural wood with highly aligned cellulose nanofibres. This strategy is shown to be universally effective for various species of wood. Our processed wood has a specific strength higher than that of most structural metals and alloys, making it a low-cost, high-performance, lightweight alternative.

      Sorpresa
      a leggerla cosi' sembra una stramegasuperfigata.

      cmq:

      Pre-treatment with steam, heat, ammonia or cold rolling followed by densification has led to the enhanced mechanical performance of natural wood. However, the existing methods result in incomplete densification and lack dimensional stability, particularly in response to humid environments, and wood treated in these ways can expand and weaken.

      ma intendono l'MDF e i compensati vari?

      in effetti mi era stato spiegato come in certi casi il compensato regge di piu' di una trave
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        Scritto da
        Non Autenticato
        il 2018-02-16 11:11:42.0 alle 2018-02-16 11:11:42.0
        Re: legno resistente come l'acciaio
        Scritto da: dada216
        > https://www.nature.com/articles/nature25476
        >
        > Here we report a simple and effective strategy to transform bulk natural wood directly into a high-performance structural material with a more than tenfold increase in strength, toughness and ballistic resistance and with greater dimensional stability. Our two-step process involves the partial removal of lignin and hemicellulose from the natural wood via a boiling process in an aqueous mixture of NaOH and Na2SO3 followed by hot-pressing, leading to the total collapse of cell walls and the complete densification of the natural wood with highly aligned cellulose nanofibres. This strategy is shown to be universally effective for various species of wood. Our processed wood has a specific strength higher than that of most structural metals and alloys, making it a low-cost, high-performance, lightweight alternative.
        >
        > Sorpresa
        > a leggerla cosi' sembra una stramegasuperfigata.
        >
        > cmq:
        >
        > Pre-treatment with steam, heat, ammonia or cold rolling followed by densification has led to the enhanced mechanical performance of natural wood. However, the existing methods result in incomplete densification and lack dimensional stability, particularly in response to humid environments, and wood treated in these ways can expand and weaken.
        >
        > ma intendono l'MDF e i compensati vari?
        >
        > in effetti mi era stato spiegato come in certi casi il compensato regge di piu' di una trave
        Chissà cosa ne pensano le termiti.
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