Reaction Wood

[Serf Life]

Picked through an old wood sci. textbook. Comparing reaction wood to non-reaction wood:

Compression (conifer) wood: ~30% shorter tracheids, 10% less cellulose, 8-9% more lignin, generally 10-20% more dense occasionally 40%, about equal strength to normal*

Tension (hardwood/broadleaf) wood: higher celluose, 5-10% more dense, less strong compare to normal

* from another section: “Although the density of this aberrant wood can be higher than normal, it’s tension strength and bending strength are often unpredictably low. Brash failure is common among compression wooden specimens.”

 

[evo]

Very interesting on the tension wood with broadleaf being WEAKER.
What is the definition of ‘brash’

 

[pete3d]

Brash might, in a word, be defined as brittle. The wood breaks off nearly at right angles to the grain with very short fibres protruding at the break. Those who fell Ash infected with EAB will be familiar with their hinges breaking like this when felling infected trees. Woodworkers abhor brash wood as it results in weak, brittle members - table and chair legs snapping off when modestly stressed - not good news in a litigious country - so are vigilant about proactively identifying it.

 

[oceans]

Picked through an old wood sci. textbook. Comparing reaction wood to non-reaction wood:

Compression (conifer) wood: ~30% shorter tracheids, 10% less cellulose, 8-9% more lignin, generally 10-20% more dense occasionally 40%, about equal strength to normal*

Tension (hardwood/broadleaf) wood: higher celluose, 5-10% more dense, less strong compare to normal

* from another section: “Although the density of this aberrant wood can be higher than normal, it’s tension strength and bending strength are often unpredictably low. Brash failure is common among compression wooden specimens.”

Great share! Tension and compression info each in their own way. Like, 10% less of this but (close to) 10% more of that…I was pondering what those %ages might indicate when it comes to the dramatic difference in grain thickness, but I’m not seeing it.

What is the title of that book?

 

[Bart_]

You guys are making my brain hurt Reminds me of research years ago, I was gangbusters to have guy fabricate and test robotic finger touch sensors against commercial units and he showed up with a paper for me to read that had exactly the proposed work results published - but not for our sensors of course. I biased a bit more to traditional literature search first before charging off experimenting after that. Always consider those that went before.


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