Topic 4.2B

Question 1

Natural timber

Answer 1

Natural composite material comprising cellulose fibres in a lignin matrix

Question 1

Lignin

Answer 1

Class of complex organic polymers that form important structural materials

Question 2

Absorbed moisture

Answer 2

Moisture contained in the cell walls of timber

Question 3

Free moisture

Answer 3

Moisture contained within the cell cavities and intercellular spaces

Question 4

Equilibrium Moisture Content

Answer 4

When the moisture content of wood is same as the local environment’s.

Question 5

Seasoning

Answer 5

Commercial drying of timber to reduce the moisture content in the wood.

Question 6

Warping

Answer 6

Distortion in wood caused by uneven drying (bending/twisting)

Question 7

Bowing

Answer 7

Warping along the length of the face of the wood

Question 8

Cupping

Answer 8

Warping across the width of the face of the wood

Question 9

Twisting

Answer 9

Warping where the 2 ends do not lie on the same plane

Question 10

Knots

Answer 10

Imperfections in timber

Question 11

Hardwood

Answer 11

Wood from deciduous/broadleaved trees

Question 12

Softwood

Answer 12

Wood from coniferous (evergreen) trees

Question 13

2 other terms for man-made timber

Answer 13

Engineered board/composite wood

Question 14

Plywood

Answer 14

Layers of veneers glued together perpendicularly.

Question 15

Particle board

Answer 15

Different sizes of wood chips joined with glue and pressed.

Question 16

MDF

Answer 16

Strands of fibre mixed with resin and pressed into sheets.

Question 17

Lamination

Answer 17

Covering the surface with a thin sheet of another material for protection, preservation or aesthetic reasons.

Question 18

Creosote

Answer 18

A material that penetrates the timber fibres, protecting the integrity of the wood from attack from borer, wood lice and fungal attack