Thread: Wood as strong as steel - new science!

I'm reading the paper now. Haven't gotten to the supplemental matter but a few things pop out.

The authors report in the Methods section processing basswood, Eastern white pine, poplar, Western red cedar and 'oak' without specifying the species. They only report tensile data for the processing of basswood and oak, which one of the 90 varieties native to the USA or ~600 varieties worldwide was used for the experiments is not specified!?

The processing consists of boiling the test blocks in a solution of 2.5 M NaOH/0.4M Na₂SO₃ for 7 hours, or for variable times followed by boiling in water to 'remove the chemicals'. The mechanical properties of the processed wood go through a maximum and then decline with continued chemical bath boiling. The species used for this part of the testing are not clearly specified. No mention in the body of the paper whether or not or how they checked the concentration of 'chemicals' remaining in the test specimens.

The pressing was accomplished by uniaxial (pressed between plates normal to the long axis of the grain) compression of the test blocks at 100 ^oC for 1 day. 8 hours or 24 hours isn't specified. Hot press (i.e. continuous heating) or hot initial test block with cooling to ambient in the press isn't specified. The strength increase of the treated blocks ranges from ~6X for oak to ~12X for cedar. The fracture resistance increases about 3X for oak and 9.4X for cedar.

They also report penetration resistance using a gas gun to test. Penetration resistance increases about 8 fold for densified wood and by 10 fold for laminated densified wood.

The processed product also absorbs atmospheric humidity and swells. The authors state that this tendency is reduced or eliminated by painting.

Overall a surprisingly incomplete report. Sadly this is becoming more common in the scientific literature. I'll get the supplementary materials and report more.