Chapter 15 - Natural & Manufactured Timbers

What is the definition of a 'physical property' in the context of materials?

The characteristics of a material, such as its appearance and features.

What is another term for a material's 'working property'?

Mechanical properties.

How is a 'working property' of a material defined?

The way in which a material responds to an external force or certain environment.

What does the term 'naturally occurring' mean when describing a material?

It comes from nature and is not made or altered by humans.

A material that is produced by humans, often using machinery, is described as ___________.

manufactured

What does the term 'synthetic' mean in relation to materials?

It is made through chemical processes.

What are the three main categories timbers can be classified into?

Hardwoods, softwoods, and manufactured boards.

Which type of timber comes from evergreen trees that have needles and do not lose them?

Softwood.

Which type of timber comes from deciduous trees whose leaves change colour and fall off in the winter?

Hardwood.

What type of grain structure do softwoods typically have due to their quick growth?

A loose grain.

What type of grain structure do hardwoods typically have due to their slow growth?

A close grain.

Why are softwoods generally cheaper than hardwoods?

They grow more quickly.

Why are hardwoods considered to give a better finish than softwoods?

They grow slowly and therefore have a close grain structure.

Softwoods are considered a ___________ material because as a tree is chopped down, many more can be planted.

sustainable

What is the typical timeframe for a tree to reach full maturity before it can be used for timber?

Between 25 and 100 years.

Both softwoods and hardwoods are classified as _________ occurring materials.

naturally

What are two key working properties of pine?

It is lightweight and easy to work with.

What are common products made from pine?

Roof joists and floorboards.

What property of cedar makes it resistant to water and fungal growth?

It contains natural oils.

Due to its weather resistance, what is cedar commonly used for?

Fences and sheds.

What is a key working property of oak?

It is durable.

What is an attractive physical property of finished oak?

It has an attractive grain.

What type of product is oak typically used for?

High-end furniture.

Which hardwood is known for being extremely lightweight and soft?

Balsa.

What is a primary use for balsa wood due to its properties?

Model making.

Manufactured boards are typically made from a combination of both and

softwoods and hardwoods

How is Medium-density fibreboard (MDF) produced?

Wood dust and fibres are mixed with glue and pressed into a flat sheet.

What is a key advantage of MDF compared to natural softwoods and hardwoods?

It is more affordable.

What are common applications for MDF?

The building and furniture trade, particularly for kitchens and flat-pack furniture.

How is plywood constructed to give it strength?

A tree trunk is sliced into thin layers (veneers) which are stuck together with the grains at alternating directions.

Plywood is often used for building and furniture that requires what specific property?

Strength.

Which hardwood has a pale colour and narrow grain, and is known for being flexible and good for steam bending?

Ash.

What is a common application for Ash wood?

Sports equipment.

Which hardwood is identified by its slight pink tint and close grain?

Beech.

What are the key working properties of Beech?

It is tough, durable, and smooth to finish.

Which hardwood is characterised by its dark-reddish colour and very close grain?

Mahogany.

What are the working properties of Mahogany that make it suitable for high-quality furniture?

It cuts and polishes easily, giving a fine finish.

Despite being a hardwood, Balsa has a ________ ____ __________ grain due to its fast growth.

pale and wide-spaced

Which softwood has a pale colour with a contrasting darker, knotty grain?

Larch.

What property of larch makes it suitable for exterior building and flooring?

Its high sap content gives it good water resistance.

Which softwood is described as pale cream with an even grain and takes stain colour well?

Spruce.

What are typical uses for Spruce?

Construction and furniture.

What are manufactured boards usually made from?

Timber waste and adhesive.

What is a 'veneer' in the context of manufactured boards?

A thin decorative covering of fine wood applied to a coarser wood or other material.

What is a significant drawback of MDF when used in certain environments?

It absorbs moisture, so it is not suitable for outdoor use.

How is chipboard made?

It is made from compacted wood chips, often laminated with a variety of coverings.

What is a key working property disadvantage of chipboard?

It is strong but very absorbent to water.

What are common uses for chipboard?

Veneered worktops and flooring.

Plywood is constructed with an ____ number of layers of veneer.

odd

At what angle are the layers of veneer in plywood glued together for strength?

90 degree angles.