Kiln Drying Wood

_______ is important in trees for photosynthesis and to transport materials throughout the plant.

• Sugar

• Nutrients

• Minerals

• Water

Answer explanation

Photosynthesis is how plants create food (sugar) that they need to get energy. They do not eat food like us, so they create their own. Water is an important ingredient in this process.

Tags

NGSS.MS-LS1-6

Moisture content is expressed as the weight of the water present in the wood ________ by the dry weight of the wood.

• divided

• multiplied

Answer explanation

The moisture content is expressed as a percentage.

True or False: Moisture content does not vary between species of tree.

• True

• False

Answer explanation

Different species of trees DO have different moisture contents. It can even vary depending on if it is hardwood or sapwood.

Free water is found in

• the cell walls.

• the pores or vessels of the wood.

• the air.

Tags

NGSS.MS-ESS2-4

Bound water is found

• trapped in the cell walls.

• in the pores and vessels of the wood.

• in the air.

Tags

NGSS.MS-ESS2-4

True or False? Free water must be lost before the bound water will begin to be released.

• True

• False

True or False? Wood will gain or lose moisture until it is in balance with the environment in which it is located.

• True

• False

Answer explanation

This is called the equilibrium moisture content. Equilibrium refers to balance.

Wood is ________ meaning it swells up when it gets wet.

• non absorbent

• hydrophobic

• hygroscopic

• hydroscopic

Answer explanation

Hydroscopic is a common misspelling. A hydroscope takes deep sea measurements.

Hydrophobic is the opposite of hygroscopic. It means it does not absorb moisture.

Wood will expand and contract as it gains and loses moisture. The wood will _______ when it gains water, ________ when it loses water.

• Contract, Expand

• Expand, Contract

Answer explanation

Contract means the molecules are getting closer. It is getting smaller in size. It is also becoming more dense.

Expand means the molecules are spreading further out. It is getting bigger in size.

True or False: Where the board is cut from on the log has no effect on the expansion and contraction of the lumber.

• True

• False

Answer explanation

This is false because if the board is cut perpendicular to the growth rings the expansion will be different then other cuts. The change in shape can lead to different types of warping of the lumber.