DT Chapter 5

What is the definition of paper?

A thin sheet made from wood pulp that is below 170gsm.

What is gsm used for?

To classify the weights of paper and card.

What is the definition of a micron?

One-thousandth of a millimetre.

What is the definition of card?

A thicker version of paper, around 180 to 300gsm.

What is the definition of cardboard?

A thicker version of card, from around 300 microns upward.

What is the definition of a hardwood?

Wood from a deciduous tree; contains a dense grain.

What is the definition of softwood?

Wood from an evergreen tree; contains a further-apart grain.

What is the definition of a manufactured board?

Sheets of timber made by gluing wood fibres or wood layers together.

What are examples of manufactured boards?

Blockboard, Chipboard, MDF, and Plywood.

What are common paper weights used by designers?

80gsm, 90gsm, 100gsm, 120gsm, 130gsm, 150gsm, and 170gsm.

What are examples of paper types?

Bleed proof, Cartridge, Copier, Layout, and Sugar paper.

How is corrugated cardboard made?

Two layers of card with a fluted sheet in between.

Corrugated cardboard is available in thicknesses ranging from…

…3000 microns upwards.

Characteristics of corrugated cardboard?

Strong but lightweight, absorbs knocks (fluted construction), heat-insulating, and difficult to bend across flutes.

Characteristics of cardboard?

Relatively inexpensive; easy to cut, fold, and print on.

What are the benefits of double wall corrugated card?

It is twice as thick as normal corrugated card, giving extra strength and damage resistance.

What is the definition of mounting board?

A rigid card (around 1400 microns) with a smooth surface.

Characteristics of mounting board?

Usually black or white; used for picture framing and architectural modelling.

What are laminated layers?

Various materials in sheet form (like paper and card) used together in layers.

What are examples of laminated layers?

Corriflute, Foam board, and Styrofoam.

What is the definition of foam board?

Polystyrene foam sandwiched between two pieces of thin card or paper.

Characteristics of foam board?

Usually 5000 microns, lightweight but rigid, smooth surface, and easy to cut.

Applications of foam board?

Modelling and point-of-sale displays.

What is the definition of styrofoam?

Expanded polystyrene foam with a structure of uniformly small, closed cells.

Characteristics of styrofoam?

Strong, lightweight, water-resistant, good heat insulation, and easy to shape

Applications of styrofoam?

Wall insulation (boats

What is the definition of corriflute?

An extruded corrugated plastic sheet made from high-impact polypropylene resin.

Characteristics of corriflute?

Waterproof, rigid, lightweight, available in many colours, but difficult to fold along flutes.

Applications of corriflute?

Outside signs (e.g., estate agents), point-of-sale displays, and modelling.

What is the definition of hardboard?

A thin, stiff sheet made of compressed sawdust and wood pulp bound with resin under heat

Metal is made by…

…extracting metal ores from rocks in the Earth's crust by mining.

What is the most abundant ore in the Earth?

Aluminium (Bauxite is the ore).

What are the two main types of metal?

Ferrous (contains iron) and Non-ferrous (no iron).

What are characteristics of ferrous metals?

They contain iron and will corrode quickly unless treated with a coating like paint, oil, or wax.

What are characteristics of non-ferrous metals?

Resistant to corrosion and significantly better electrical conductors than ferrous metals.

What are examples of metal shapes and sizes?

Angle, Box section, Channel, Flat bar, Hexagon, Round bar, RSJs, Square bar, T-Section, and Tube.

What does RSJ stand for?

Rolled Steel Joist.

What are examples of ferrous metals?

Carbon steel, Cast iron, Mild steel, Stainless steel, and Wrought iron.

What are examples of non-ferrous metals?

Aluminium, Copper, and Tin.

What are examples of alloys?

Brass, Bronze, Lead

How can polymers occur?

They can occur naturally or be manufactured.

What are examples of naturally occurring polymers?

Hair, Silk, and Wool.

Manufactured polymers are commonly referred to as…

…plastics.

Manufactured plastics are derived from…

…petroleum oil.

What are the two families of polymers?

Thermoforming and Thermosetting.

What is the definition of polymer memory?

The ability of a thermopolymer to return to its original state after reheating.

What is the definition of thermoforming polymers?

Polymers that can be heated and moulded into shape multiple times.

What is the definition of thermosetting polymers?

Polymers that can only be heated and moulded once.

When thermoforming polymers are reheated, they…

…undergo polymer memory.

What happens when thermosetting polymers are heated?

They undergo a chemical change to become hard; they cannot be remoulded or recycled.

List the thermopolymers

PET, HDPE, PVC, LDPE, PP, PS, and "Other".

Fibres are…

…tiny hair-like structures that are spun (twisted) together to make yarns.

What is the definition of a natural fibre?

Fibres found in plants and animals.

What is the definition of a synthetic fibre?

Man-made, mostly non-biodegradable, and generally not sustainable.

Why are synthetic fibres engineered?

To give them a range of useful properties.

Where do synthetic fibres come from?

Coal, minerals, and petrochemicals (like oil).

Why are fibres mixed or blended together?

To improve the aesthetics, cost, function, or quality of the final fabric.

How are fibres mixed?

Yarns of different fibres are added together after the yarns are spun.

How are fibres blended?

Fibres are blown together before they are spun into yarns.

Woven fabrics are produced on…

…manual or automatic looms.

A woven fabric consists of…

…warp and weft yarns.

Non-woven fabrics lack…

…the strength of woven or knitted fabrics.

What are the two types of non-woven fabrics?

Bonded and felted.

How are bonded fabrics manufactured?

Fusing fibres together using pressure and adhesive or heat.

What are characteristics of bonded fabrics?

They lose strength and structure once wet; usually only suitable for one use.

Applications of bonded fabrics?

Disposable textiles, e.g., tea bags, surgical masks, and dressings.

How are felted fabrics manufactured?

Matting, condensing, and pressing fibres together using heat, moisture, and pressure.

The most commonly used fibres for felt are…

…acrylic and wool.

Applications of felted fabrics?

Decorative purposes (appliqué), snooker table surfaces, and insulation.

Knitted fabrics are made up of…

…rows of interlocking loops, also known as stitches.

The most commonly used knits are…

…weft and warp knits.

What is the definition of a modern material?

A material continually being developed through the invention of new or improved processes.

List examples of modern materials

Lenticular plastic sheet, Flexiply, Teflon, and Polymorph.

What is the definition of a conductive polymer?

Polymers that can conduct electricity.

What is the definition of a smart material?

A material whose physical properties change in response to a stimulus (like heat or light).

List examples of smart materials

Shape-memory alloy (SMA), Photochromic pigments, and Thermochromic pigments.

List examples of composite materials

Carbon-fibre, GRP (Glass Reinforced Plastic), and Kevlar.

What are laminates?

Materials made up of layers; they are examples of composites.

What is the definition of a technical textile?

A textile engineered for its performance properties, not its aesthetics.

List examples of technical textiles

Fastskin, Kevlar, and Nomex.

Water has a density of…

…1g

What is the definition of a material's strength?

The ability to withstand forces that try to bend or break it.

What is the definition of a material's hardness?

How resistant it is to pressure from cutting, scratching, or wear.

What is the definition of a material's durability?

The ability of a material to withstand wear, pressure, or damage over time.

What is the definition of a material's strength-to-weight ratio?

A measure of a material's strength compared to its weight.

What is the definition of a material's stiffness?

Its rigidity; the ability to resist being deformed when a force is applied.

What is the definition of a material's elasticity?

Its ability to return to its original shape after being bent or flexed.

What is the definition of a material's impact resistance?

Its ability to withstand a force or shock applied over a short period of time.

What is the definition of a material's plasticity?

Its ability to permanently change shape when a force is applied.

What is the definition of a material's ductility and malleability?

How easily it can be deformed or bent out of shape without snapping or breaking.

What is the definition of a material's brittleness?

How easily it will snap or break when bent or impacted.

What is the definition of corrosive resistance?

Resistance to degradation from elements such as oxygen, moisture, and chemicals.

What is the definition of a material's water resistance?

Its ability to resist the ingress of water.

What is the definition of a material's absorbency?

Its ability to absorb moisture.

What is the definition of a material's flammability?

Its ability to burn or ignite, causing fire.

What is the definition of a material's electrical conductivity?

How easy it is for electricity to flow through a material.

What is the definition of a material's thermal conductivity?

How easy it is for heat to be transferred through a material.

What is the definition of a material's magnetic properties?

The ability to emit forces that attract or repel other materials.

What is virgin material?

Material being used for the very first time (not recycled).

What is a biopolymer?

A polymer derived from a renewable or natural resource.