Materials Theory. Objectives Paper and Board – the working characteristics of paper, board and...

Materials

Theory

Objectives• Paper and Board

– the working characteristics of paper, board and other graphic materials – the units by which the thickness of paper and board are measured – paper sizes A0 to A6 and their relationship to each other – the properties and uses of different types of new, recycled and re-

useable paper and board – how paper-based boards can be laminated to other materials and the

composite adjusted to create different properties for specific purposes.• Plastics

– how plastics have different properties and can be used in different ways

– thermoplastic plastic and thermoset plastic– the types and use of thermoplastics.

AQA GCSE Design and Technology: graphic products

Material propertiesMaterial properties are the characteristics of a material.

• Flexibility – a flexible material will be able to be bent and moved at room temperature.• Rigidity – rigidity is the opposite of flexibility. A rigid material is difficult to work at room

temperature.• Ductility – a ductile material will be easy to form and change shape. • Elasticity – elasticity is the ability of a material to return to its original shape when the

applied load has been removed. • Conductivity – conductive materials allow heat or electricity to flow through them. It is

usual to specify which conductivity is being talked about, either thermal or electrical. • Transparent – the material is see-through This can include semi transparent. (An

opaque material does not let light pass through it.)• Water resistance• Strength to weight ratio

Paper and Board

Theory

Paper Sizes

Thicknesses of Paper• Expressed in grams per square meter (g/m²)

– This is the weight of one square metre of the paper.

• 80 g/m² is paper• Card starts at around 120 g/m²

Paper and Board


Laminating, coating and sizing

There are many ways to change the properties of paper and card, but the three main ways are:

• Laminating: gluing together layers (plies) of card or paper.

• Sizing: the paper or card is sealed by a chemical agent to improve its ability to accept ink.The sizing can affect the whiteness (brightness) of the material surface.

Thicknesses of Board• Board (sometimes called card or cardboard)

thickness is measured in microns: one micron is one thousandth of one millimetre.– Card we use is 230 microns (for printing) or 600

microns (for laser cutting)– Board game board is 2mm thick board (2000

microns)

Paper and Board


Coatings on card

• Plastic coating: used for water resistance. • Aluminium foil: for food products to give a

bacterial barrier against possible contamination.

• Note: adding coatings can make the material more difficult to recycle.

Other Materials

• Acetate– plastic sheet with a smooth surface, easy to cut or bend

• Foam board– It consists of three layers — an inner layer of polystyrene clad with

outer facing of either a white clay coated paper or brown Kraft paper.– very strong, lightweight and easily cut material used for the

mounting of photographic prints or as backing in picture framing• Corriflute (Corrugated plastic sheet)

– Waterproof, has good strength– Made ffrom HIPs

• Expanded polystyrene (Styrofoam)– Blue foam used for modelling

Task• Produce 1 A3 sheet for paper and board• Stick a piece of each type of material on a

page.• Next to each material include:

– Name– Thickness (if relevant)– Properties (Key features – e.g. cost, flexibility,

finish, rigidity, strength, quality, weight, environmental and sustainable issues)

– Possible uses

Example

• H.I.P.s– 1mm thick, but comes in other thicknesses– Comes in sheets for vacuum forming or can

be melted for injection moulding– Used in packaging such as yogurt pots,

counters for board games and…– Processes: vacuum forming and injection

moulding

To help, use the Focus on RM software (materials) for possible uses, and properties, processes and possible finishes

Task• Stick a piece of each type

of material on an A3 page.

• Next to each material include:– Name– Thickness (if relevant)– Properties (Key features

– e.g. flexibility, finish, rigidity, strength, quality, weight, environmental and sustainable issues)

– Possible uses

• Tracing paper• 600 micron card• 230 micron card,• Corrugated board• Foam board• 80 GSM paper• Corriflute• Grid paper• Acetate• Expanded polystyrene (Styrofoam)• Others?

Plastics

Theory


Material propertiesMaterial properties are the characteristics of a material. Using the technical

language when describing material properties adds to the QWC mark of your design project.

• Flexibility – a flexible material will be able to be bent and moved at room temperature.• Rigidity – rigidity is the opposite of flexibility. A rigid material is difficult to work at room

temperature.• Ductility – a ductile material will be easy to form and change shape. • Elasticity – elasticity is the ability of a material to return to its original shape when the

applied load has been removed. • Conductivity – conductive materials allow heat or electricity to flow through them. It is

usual to specify which conductivity is being talked about, either thermal or electrical. • Transparent – the material is see-through This can include semi transparent. (An

opaque material does not let light pass through it.)• Strength to weight ratio


Thermoplastics

There are two types of thermoplastics:

• Thermoplastic plastic – this can be formed and moulded when heated.

• Thermoset plastic – these plastics cannot be reformed, even when heated.


Common thermoplastics and their uses

• Thermoplastics are used regularly in graphic products.

• The chemicals that make up the plastic are often used as their names.

• These can be very long, so usually they are abbreviated; for example, acrylonitrile butadiene styrene is shortened to ABS.

• Sometimes the manufacturer’s name is used; perspex, manufactured by ICI, is polymethyl methacrolate, also known as acrylic.


Low density polythene

• Abbreviated name: LDPE• Used for toys, plastic sacks, outdoor furniture,

shower curtains.• Can be extruded, injection moulded, vacuum

formed, rotational moulded.


High density polythene

• Abbreviated name: HDPE• Used for buckets, bowls, milk crates, detergent

bottles• Can be extruded, injection moulded, vacuum

formed, rotational moulded.


Polyvinylchloride

• Abbreviated name: PVC• Used for pipes, gutters, flooring, window

frames, shower curtains.• Can be extruded, injection moulded, vacuum

formed, rotational moulded. • Recycling symbol number 3.


Polymethyl methacrylate

• Abbreviated name: acrylic• Used for signs, aircraft canopies, baths, light

diffusers, contact lenses.• Can be extruded, injection moulded, vacuum

formed.


High impact polystyrene

• Abbreviated name: HIPS• Used for vending cups, models, food

packaging, fridge liners.• Can be extruded, injection moulded, vacuum

formed.• Recycling symbol number 6.


Acrylonitrile butadiene styrene

• Abbreviated name: ABS• Used for kettles, hairdryers, casing of many

small products.• Can be extruded, injection moulded, vacuum

formed.


Polymide

• Abbreviated Name: Nylon• Used for gears, bearings, combs, toothbrush

bristles.• Can be extruded and injection moulded.


Polyethylene terephthalate

• Abbreviated name: PET• Used for carbonated drink bottles and

microwavable packaging.• Can be extruded, injection moulded, vacuum



Polystyrene

• Abbreviated name: PS• Used for CD cases, yoghurt pots, plastic table

wear.• Can be extruded, injection moulded, vacuum



Polypropylene

• Abbreviated name: PP• Used for cutting boards, crisp packets, bottle

caps, car bumpers, yoghurt pots.• Can be extruded, injection moulded, extruded,

rotational moulding.• Recycling symbol number 5.


Polycarbonate

• Abbreviated name: PC• Used for riot shields, security windows,

compact discs, lenses.• Can be extruded, injection moulded,

extruded.• Can be vacuum formed but must be dried in

an oven first.• Recycling symbol number 5.

Plastics

Resin identification codes

Task• Stick a piece of each type of

material on an A3 page.• Next to each material include:

– Name– Type of plastic– Properties (Key features – e.g.

flexibility, finish, rigidity, strength, quality, weight, environmental and sustainable issues)

– Possible uses– Possible processes that can be

used with each material– What form does it come in

(sheets etc)

• H.I.P.s• Acrylic• PVC• Polypropyl

ene (PP)• PET• HDPE• Others?

Plastics

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