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 properties Material 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

Paper

AQA GCSE Design and Technology : graphic products 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

Board

AQA GCSE Design and Technology : graphic products 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

AQA GCSE Design and Technology : graphic products Material properties Material 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

AQA GCSE Design and Technology : graphic products 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.

AQA GCSE Design and Technology : graphic products 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.

AQA GCSE Design and Technology : graphic products Low density polythene Abbreviated name: LDPE Used for toys, plastic sacks, outdoor furniture, shower curtains. Can be extruded, injection moulded, vacuum formed, rotational moulded.

AQA GCSE Design and Technology : graphic products High density polythene Abbreviated name: HDPE Used for buckets, bowls, milk crates, detergent bottles Can be extruded, injection moulded, vacuum formed, rotational moulded.

AQA GCSE Design and Technology : graphic products 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.

AQA GCSE Design and Technology : graphic products Polymethyl methacrylate Abbreviated name: acrylic Used for signs, aircraft canopies, baths, light diffusers, contact lenses. Can be extruded, injection moulded, vacuum formed.

AQA GCSE Design and Technology : graphic products 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.

AQA GCSE Design and Technology : graphic products Acrylonitrile butadiene styrene Abbreviated name: ABS Used for kettles, hairdryers, casing of many small products. Can be extruded, injection moulded, vacuum formed.

AQA GCSE Design and Technology : graphic products Polymide Abbreviated Name: Nylon Used for gears, bearings, combs, toothbrush bristles. Can be extruded and injection moulded.

AQA GCSE Design and Technology : graphic products Polyethylene terephthalate Abbreviated name: PET Used for carbonated drink bottles and microwavable packaging. Can be extruded, injection moulded, vacuum formed. Recycling symbol number 1.

AQA GCSE Design and Technology : graphic products Polystyrene Abbreviated name: PS Used for CD cases, yoghurt pots, plastic table wear. Can be extruded, injection moulded, vacuum formed. Recycling symbol number 6.

AQA GCSE Design and Technology : graphic products 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.

AQA GCSE Design and Technology : graphic products 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