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    Biological performance of zinc borate-incorporated particleboard: Effects of leaching on efficacy
    (Elsevier Sci Ltd, 2014) Taşçıoğlu, Cihat; Umemura, Kenji; Yoshimura, Tsuyoshi; Tsunoda, Kunio
    The decay and termite resistance and effects of a robust leaching process on the efficacy of zinc borate-incorporated particleboard were examined. Particleboards (300 x 300 x 15 mm) prepared from particles of mixed wood species generated from demolished construction materials were incorporated with zinc borate at target retentions of 0%, 1%, 1.5% and 2% of the particle weight. An in-line treatment method was utilized to introduce the powdered chemical during the blending stage. ICP analysis indicated that the amount of zinc borate was not lost during manufacturing. Standard static bending tests demonstrated that there was no significant loss in mechanical properties. The decay and termite tests indicated that the efficacy of zinc borate at a higher retention was enough to suppress the biological activity, even after application of a robust leaching process. (C) 2013 Elsevier Ltd. All rights reserved.
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    Mold and Larvae Resistance of Wood-Based Composites Incorporating Sodium Fluoride
    (North Carolina State Univ Dept Wood & Paper Sci, 2020) Tascioglu, Cihat; Umemura, Kenji; Kusuma, Sukma; Kose, Coskun; Yalcin, Mesut; Akcay, Caglar; Yoshimura, Tsuyoshi
    The efficacy of particleboards manufactured with sodium fluoride against mold fungi and Hylotrupes bajulus (L.) larvae was tested. Laboratory-size particleboards were manufactured from untreated wood particles with inclusion of fine sodium fluoride (NaF) at the 1, 1.5, and 3% levels relative to total particle weight. Sodium fluoride was introduced as powder during the manufacturing process just before blending resin with wood particles. The laboratory mold test indicated that even the lowest level of retention of NaF with or without leaching significantly reduced mold growth on particleboard surfaces when compared to the untreated control specimens. The increased retention of NaF from 1% to 3% further suppressed mold growth towards lowest levels even on leached specimens. The laboratory Hylotrupes bajulus larvae tests revealed that the particleboard environment with or without NaF is not appropriate for larvacidial activity. While the tested biocide, NaF, tested positive against mold growth on particleboard surfaces, no effect was determined relative to larval deaths.
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    Potential utilization of sodium fluoride (NaF) as a biocide in particleboard production
    (Springer Japan Kk, 2017) Taşçıoğlu, Cihat; Umemura, Kenji; Kusuma, Sukma S.; Yoshimura, Tsuyoshi
    The feasibility of sodium fluoride (NaF) incorporation as a biocide in the manufacture of particleboard was examined. Laboratory-scale particleboards prepared from untreated wood particles were incorporated with NaF powder at target retentions of 1, 1.5 and 3% of the total particle weight. An in-line treatment method was used to introduce the biocide during the blending stage just before adhesive application. Standard static bending and water resistance (water absorption and thickness swelling) tests indicated that embedding of the powder biocide up to the 3% level did not cause any detrimental effects on mechanical and physical properties. The laboratory decay and termite resistance tests showed that even the lower retention levels of 1 and 1.5% NaF were enough to suppress fungal and termite activity and significantly reduce the mass loss and consumption rate values of the specimens when compared to the untreated controls. Spectrophotometric analysis of leachate waters and the mass losses of the leached specimens revealed the tendency of the NaF to be depleted from the composite specimens. Therefore, the tested biocide was found to be appropriate for interior or protected above-ground outdoor exposure conditions.
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    Seventh-year durability evaluation of zinc borate incorporated wood-plastic composites and particleboard
    (Elsevier Sci Ltd, 2018) Taşçıoğlu, Cihat; Umemura, Kenji; Yoshimura, Tsuyoshi
    Several formulations of wood-plastic composites and a particleboard were fabricated with combining zinc borate biocide at different retention levels during the manufacturing process. The treated specimens were exposed to a field test under protected above ground conditions for 7 years in southern Japan. During biannual inspections, the specimens were visually inspected and graded for decay and Formosan subterranean termite damage. While zinc borate retention levels tested were able to protect the particleboards from decay activity for 7 years, their efficacy was lower against termite attack. The retention levels tested up to 2% (w/w) helped to reduce termite damage noticeably but failed from full protection (e.g. rating 10) indicating higher zinc borate loadings are required in particleboards if they will be utilized in southern Japan climatic conditions. Wood-plastic composites were also more durable against fungal damage during the 7 years exposure period but this condition seems changed last 18 months since some lower decay ratings were recorded even for zinc borate embedded formulations. While termite destruction diminished significantly with zinc borate integrated formulations, higher retentions might be recommended as threshold for full protection in wood-polypropylene composites.