Searching for biological feedstock material: 3D printing of wood particles from house borer and drywood termite frass

Frass (fine powdery refuse or fragile perforated wood produced by the activity of boring insects) of larvae of the European house borer (EHB) and of drywood termites was tested as a natural and novel feedstock for 3D-printing of wood-based materials. Small particles produced by the drywood termite Incisitermes marginipennis and the EHB Hylotrupes bajulus during feeding in construction timber, were used. Frass is a powdery material of particularly consistent quality that is essentially biologically processed wood mixed with debris of wood and faeces. The filigree-like particles flow easily permitting the build-up of wood-based structures in a layer wise fashion using the Binder Jetting printing process. The quality of powders produced by different insect species was compared along with the processing steps and properties of the printed parts. Drywood termite frass with a Hausner Ratio HR = 1.1 with ρBulk = 0.67 g/cm3 and ρTap = 0.74 g/cm3 was perfectly suited to deposition of uniformly packed layers in 3D printing. We suggest that a variety of naturally available feedstocks could be used in environmentally responsible approaches to scientific material sciences/additive manufacturing.

Determination of decay, larvae resistance, water uptake, color, and hardness properties of wood impregnated with honeybee wax

The aim of the study was to determine the effect of honeybee wax impregnation on the antifungal, larvicidal, water uptake, color, and mechanical properties of wood. Wood samples (poplar, Scots pine, beech, and lime) were impregnated with melted honeybee wax under vacuum. The wax-impregnated samples were exposed to the wood-decay fungi Trametes versicolor and Neolentinus lepideus for 8 weeks. The larvicidal effect of the beeswax was tested against European old house borer (Hylotrupes bajulus L.). Water uptake, color measurements, and surface hardness were also tested. According to the obtained findings, a 34.6% mass loss was seen in the poplar control wood, and only 3.9% mass loss was found in the 100% beeswax-impregnated samples. The results showed that H. bajulus larvae could digest honeybee wax with wood when beeswax surface treatment was applied. Additionally, an average of 30% larvae mortality rate was achieved on beeswax-treated wood surfaces, compared to a 2.5% rate on the controls. However, when wood was deeply treated with beeswax, larval mortality reached 100%. In the water uptake test, beeswax-treated samples showed water repellent efficiency. The lowest water uptake (24.2%) was obtained in poplar wood treated with 100% beeswax, compared to 92.6% in the poplar control in 96 h immersion time. With the beeswax treatment, a* and b* color values increased, while the L* values decreased.

Decay, insect, and termite resistance of wood modified with epoxidized vegetable oils

Samples of Scots pine sapwood were treated with epoxidized linseed and soybean oils to improve decay, insect and termite resistance of wood. Non-epoxidized (raw) linseed and soybean oils were included as reference treatment in the study. In the epoxidation process, hydrogen peroxide was used to open double bounds, and acetic acid was added as a catalyst. Two retention levels, Ret A (80–140 kg m−3) and Ret B (170–270 kg m−3), two impregnation methods (full cell and empty cell) and emulsion technique were used. Samples treated with epoxidized oils had significantly lower mass losses than untreated samples while epoxidized oils showed higher mass losses than unepoxidized oils for Coniophora puteana and Trametes versicolor according to EN 113 for decay test. By adding boron, fungicidal properties were introduced to the treatment. All the vegetable oils showed 100% the mortality rate against larvae of Hylotrupes bajulus according to EN 47. Moreover, leached wood samples treated with oils also showed 100% larvae mortality. Additionally, termite testing based on EN 117 revealed 100% Reticulitermes lucifugus mortality for all leached oil treated samples.

Searching for biological feedstock material: 3D printing of wood particles from house borer and drywood termite frass

Frass (fine powdery refuse or fragile perforated wood produced by the activity of boring insects) of larvae of the European house borer and of drywood termites was tested as a natural and novel feedstock for 3D-printing of wood-based materials. Small particles produced by the drywood termite Incisitermes marginipennis and the European house borer (EHB) Hylotrupes bajulus during feeding in construction timber, were used. Frass is a powdery material of particularly consistent quality that is essentially biologically processed wood mixed with debris of wood and faeces. The filigree-like particles flow easily permitting the build-up of wood-based structures in a layer wise fashion using the Binder Jetting printing process. The quality of powders produced by different insect species was compared along with the processing steps and properties of the printed parts. Drywood termite frass with a HR = 1.1 with ρBulk = 0.67 g.cm-3 and ρTap = 0.74 g.cm-3 was perfectly suited to deposition of uniformly packed layers in 3D printing. We suggest that a variety of naturally available feedstocks could be used in environmentally responsible approaches to scientific material sciences/additive manufacturing.