Materials

Question 1

describe tension force and example products

Answer 1

• when an object is stretched/pulled apart in opposite directions
• springs in a trampoline have high tensile strength - they resist being permanently stretched and return to their original length to throw you back into air
• suspension bridges use springs to support weight of the bridge

Question 2

describe compressive force and example products

Answer 2

• when an object is squashed due to compressive forces directed at one another
• occurs when a material supports weight above it eg. chair legs+ bridge supports

Question 3

describe shear force and example products

Answer 3

• causes parts of an object to slide past one another
• scissors/industrial cutting machines use shear force to cut materials

Question 4

describe torsion force and example products

Answer 4

• when an object is twisted
• propeller shafts resist torsion - allows them to transfer rotary motion without breaking/twisting
• wringing water out of cotton towels

Question 5

describe the primary processing of paper

Answer 5

• trees are cut down and taken by lorry to a paper mill
• the bark is stripped off
• the wood is cut into smaller pieces by a chipper
• the bits of wood go through chemical or mechanical pulping
• the pulp is washed and bleached to desired colour
• the pulp is pressed flat between rollers, dried, and cut to size

Question 6

describe the sizes of paper and how they relate to each other

Answer 6

• sizes start of A0 and half in size/area each time
• e.g. A4 is half the size of A3

Question 7

describe the properties and use of cartridge paper

Answer 7

• high quality & has a textured surface
• good for sketching with different drawing materials (pencils, crayons, inks)

Question 8

describe the properties and use of layout paper

Answer 8

• thin+ translucent
• good for general design work/ sketching ideas

Question 9

describe the properties and use of tracing paper

Answer 9

• semi-transparent
• used to copy images

Question 10

describe the properties and use of grid paper

Answer 10

• has a square grid/ isometric pattern printed on it
• grid - orthographic+ scale drawings
• isometric - isometric drawings

Question 11

describe the properties and use of bleed-proof paper

Answer 11

• used when drawing with felt-tips/ marker pens
• ink does not bleed (spread out)

Question 12

describe the properties and use of foil-lined board/ tetrapak

Answer 12

• board with an aluminium foil lining
• used for food packaging - foil keeps flavours in and air+moisture out

Question 13

describe the properties and use of foam core board

Answer 13

• expanded polystyrene foam is sandwiched between two thin layers of card - increases strength+ rigidity by lamination
• stiff+ lightweight, outer card layers can be scored
• used for making models, mounting posters

Question 14

describe the properties and use of duplex board

Answer 14

• one side is solid white board - visible side, smooth for printing, high quality
• one side is cardboard
• used for food packaging
• outside appears high-quality
• cheaper as one side is cardboard

Question 15

describe the properties and use of corrugated card

Answer 15

• made of a fluted inner core sandwiched between two outer layers/liners
• the flutes add strength/rigidity by lamination - used for secondary packaging to protect products during transit
• air held in fluted layer provides insulation+ cushioning
• outer liners can be printed on
• is flexible/can be bent without breaking but is rigid enough to keep its shape
• negative - stronger materials are bulkier so could increase transport costs
• used for food packaging (pizza boxes), delivery boxes

Question 16

describe the properties and use of ink jet card

Answer 16

• used for ink jet printing - ink does not bleed so the printed image is sharply defined+ high quality

Question 17

describe the properties and use of solid white board

Answer 17

• high quality, bleached surface ideal for printing
• used for luxury primary packaging (packaging for individual items)

Question 18

describe properties+ examples of thermoforming plastics

Answer 18

• don’t resist heat - easily formed into diff shapes by heating/melting/remoulding
• recyclable - are ground down/melted +reused
• acrylic (PMMA) - hard/stiff/shiny, weather resistant, used for helmet visors/baths/signs
• also PVC/ HDPE

Question 19

describe properties+ examples of thermosetting plastics

Answer 19

• resist heat/fire - used for electrical fittings/pan handles
• undergo a chemical change when heated then moulded - become permanently hard/rigid
• non-recyclable - cannot be melted+reshaped
• polyester resin (PR) - hard/stiff, cheap, electrical insulator, waterproof so used in shower stalls/garden furniture, added to glass fibres to form glass-reinforced plastic
• also epoxy resin/ urea formaldehyde

Question 20

describe the properties of softwoods

Answer 20

• grow in cold climates
• fast growing - therefore cheap+ readily available
• leaves are like needles+ have cones
• leaves are evergreen

Question 21

state examples of softwoods (3)

Answer 21

• PINE - strong, contains lots of knots so harder to work with, used for telegraph poles/fences/cheap furniture
• LARCH - hard/tough/durable, resistant to rot so good for decking/fences
• SPRUCE - hard, high strength to weight ratio, contains lots of knots, used fir crates/ship masts

Question 22

describe the properties of hardwoods

Answer 22

• grow in warm climates
• slow growing - therefore rarer+ expensive
• broad/flat leaves
• deciduous - lose their leaves in autumn
• most have a tighter grain - dense/hard (except balsa)

Question 23

state examples of hardwoods (5)

Answer 23

• OAK - tough/durable/strong, attractive grain, good finish, corrodes steel screws/fittings, used for flooring/furniture
• MAHOGANY - durable, easy to work with, expensive, used for good-quality furniture
• BEECH - hard, can be bent using steam, used for chairs/toys
• BALSA - low density/soft so easy to cut/shape, used for modelling
• ASH - tough, attractive, shock-absorbent, used for tool handles/sports equipment

Question 24

state examples of manufactured boards (3)

Answer 24

• MDF
• plywood
• chipboard

Question 25

state the stock forms that paper+board come in (3)

Answer 25

sheet roll ply - refers to no. paper layers

Question 26

state what units papers and boards are measured in

Answer 26

paper: gsm (grams per square metre) board: gsm, thickness measured in microns

Question 27

describe how paper is modified to increase rigidity

Answer 27

folded/bent - lamination

Question 28

describe smart materials +examples

Answer 28

* react to changes in their environment (stress, light, temp) * thermochromic/photochromic pigment, shape memory alloy

Question 29

describe modern materials +examples

Answer 29

* developed recently as a result of new technology * graphene, titanium, LCD, nanomaterials, carbon fibre, glass-reinforced plastic GRP, metal foam

Question 30

describe composite materials +2 examples (GRP/CRP)

Answer 30

substance made from 2+ different materials bonded together * **glass reinforced plastic**: glass fibres coated in thermosetting resin, stronger+tougher, heat-resistant, easy to mould (boats/ surf boards) * **carbonfibre reinforced plastic**: carbon fibres coated in thermosetting resin, lighter, stronger+tougher than GRP but more expensive (helmets/ sports equipment/ laptops)