SA.6 Materials & Working Properties Flashcards
Physical properties
Of any material can be measured in their natural state
Phys: density
The mass per unit volume of any material
Phys: Fusibility
Ability of a material to be converted from solid to liquid by heat & combined w another mat
Working properties
Describes how a material respons when manipulated or worked
Working: ductility
Ability opto be stretched or drawn apart w/o breaking
Working: elasticity
Ability to return to og shape after stretching or compression
Working: hardness
Ability to withstand impact, wear, abrasion & indentation
Working: malleability
Ability to be bent & shaped w/o cracking
Working: strength
Ability to withstand forces sa pressure, compression, tension
Working: toughness
Ability to absorb shock w/o fracturing
What is paper measured in
Weight in grams per square metre (GSM)
Paper: Layout
Medium opacity sheet w a smooth finish
Uses: sketch & design work
Paper: Tracing
Off white, low opacity sheet
Uses: copying overlays, tracing drawings
Paper: Catridge
Thick white paper w textured surface
Uses: sketching watercolours, ink drawings
Paper: Bleed proof
Thick, coated paper that prevents inks or marker pens bleeding
Uses: high quality illustrations w vibrant colours
Paper: Grid
White paper w a printed grid of squares. Isometric lines or other patterns
Uses: scale drawings, scientific diagrams
What is card & board measure in
Microns
Card & board: Corrugated card
2 layers of lightweight card containing a fluted layer for strength
Uses: packaging for protection, insulation
Card & boards: Foil-lined
Card coated w aluminium foil in one side. Foil retains heat keeping contents warm, moist
Uses: takeaway containers
Card & board: Duplex
2 layers of card bonded tg, often w a white external layer
Uses: food, drink containers
Card & board: Foam core
An inner foam core w a paper face. Rigid, stiff
Uses: model making
Card & board: Ink jet
Treated card w smooth finish & bleed proof surfaces
Uses: printing photographs
Card & boards: Solid white
High quality card, white smooth finish on both sides
Uses: cards, book covers
Hardwood
From deciduous trees
Usually broad-leafed variety that drops leaves in winter
Slow growing
Tighter grains (visible pores, thinner firbre content, dense grain) makes harder to work w
Ash
HARDWOOD
Flexible, tough, shock res
Pale brown
Uses: sports equip
Beech
HARDWOOD
Fine finish, tough, durable
Beige w pink hue
Uses: children’s toys, furniture
Mahogany
HARDWOOD
Easily worked, durable, finishes well
Reddish brown
Uses: high end furniture, veneers
Oak
HARDWOOD
Tough, hard, durable
Light brown
Uses: flooring, furniture
Softwood
From coniferous trees
Bears needles & has cones
Loose grain strucutre (no visible pores, thicker fibre content, wide grain pattern) easier to work w
Fast growing
Pine
SOFTWOOD
Lightweight, easy to work w
Palye yellowish brown
Uses: interior construction
Spruce
SOFTWOOD
Easy to work w, high stiffness to weight ratio
Creamy white
Uses: musical instruments
Larch
SOFTWOOD
Durable, tough, water res. Resistant to extremes of climate. Its natural oil content makes water res so suitable for decking, fencing
Pale reddish brown
Uses: exterior, flooring
MT: Chipboard
Wood chips of varying sizes mixed w resin, pressed. Good compressive strength, not water res unless treated. Good value but chipping on edges & corners
Uses: flooring, worktops
MT: Medium density fibreboard (MDF)
Waste hardwood & softwood is broken down into fibres & combined w resin. Pressed into sheets that are dense, rigid & stable, smooth easy to finish surface. Very absorbent so not good in high humidity
Uses: kitchen units
MT: Plywood
Thin layers or veneers glued tg, very stable in all directions due to alternate layering at 90dc, w outside layers running in the same direction
Uses: shelving
Adv of choosing manufactured timbers over natural timber
Manufactured boards available in large board sizes, reducing no. of joints
Can be laminated to apply wide range of finishes
No grain, so easy to work w
Disadv of choosing manufactured boards over natural timber
Manufactured boards are dense making very heavy in large sheets
Edges are difficult to finish due to no natural end grain
Ferrous metals
Contain iron ferrite & have high tensile strength & durability
Magnetic
Vulnerable to rust w/o finish
Stainless steel protected from rust by presence of chromium
Low carbon/mild steel
FERROUS
Tough & ductile, rusts easily if not finished
Uses: car bodies, pipelines
Cast iron
FERROUS
Hard but brittle. Resists deformatjin & rust
Uses: kitchen pans, manhole covers
High carbon steel/tool steel
FERROUS
Hard but brittle, hard wearing, resists abrasion. Chromium may be added to add strength/resist distortion
Uses: tools as hard & abrasion, pressure res
Non-ferrous metals
Group of pure metals, do not contain iron
Non-magnetic so used for wiring & electronics
Higher res to rust but can corrode or oxidise
Aluminium
NON-FERROUS
Lighweight, ductile, res to corrosion
Uses: bike frames, drink cans
Zinc
NON-FERROUS
Brittle, yet malleable, high corrosion res
Uses: used to galvanise steel
Copper
NON-FERROUS
Ductile, malleable. Good electrical conductor
Uses: electrical cables
Alloys
Mixture of at least one pure metal and another element
Imrpoves working properties or aesthetics
Harder than pure metals bc contain atoms of diff sizes, distorting arrangement of the atoms, making jarder for layers to slide over eachother
Stainless steel
ALLOY
Low carbon + chromium
Hard, ductile, rust res. Chromium layer protects steel from corrosion.
Uses: cutlery due to being poor conductor of heat & hygienic
Brass
ALLOY
Copper + zinc
Malleable, corrosion res
Uses: musicsl instruments
Adv of alloy over pure metal
Alloys harder than pure due to (cant slide over)
Alloys better corrosion res than pure
Easily manipulated into diff forms
Natural occuring plastics
Amber
Rubber
Thermoforming polymers
Using heat to form thermoplastics
More flexible than thermosets & easy to shape, when heated
Polymer chains quite loosely entangled w few cross links. Allows chains to slide over easily when heated (formed into complex shapes multiple times)
Thermoforming molecules
O-O-O-O-O
O-O-O-O-O
Polypropylene (PP)
THERMOFORMING
Flexible, tough, lightweight
Uses: kitchens
Acrylic (PMMA)
THERMOFORMING
Tough but brittle when thin. Easily scratched
Uses: car lights
High density polyethylene (HDPE)
THERMOFORMING
Lightweight, chemical res
Uses: milk bottles
High impact polystyrene (HIPS)
THERMOFORMING
Flexigle, impact res, lighweight, used for vaccum forming
Uses: yoghurt pots
Polythylene terephthalate (PET)
THERMOFORMING
Blow moulded, chemical res, recyclable
Uses: drink bottle
Polyvinyl chloride (PVC)
THERMOFORMING
Flexible, tough, res to chemicals
Uses: raincoats, pipes
Thermosetting polymer
involves using chemical reactions to form plastic, that are very heat resistant and cannot be reformed by heat.
Hard, brittle, good insulation & chemical res
Thermosetting molecules
O-O-O-O-O
\ \ \ \ \
O-O-O-O-O
Polyester resin (PR)
THERMOSETTING
Good eletrical insulator, hard, touch when mixed w glass
Uses: boats
Epoxy resin (ER)
THERMOSETTING
Good strength:weight ratio, good electrical insulator, heat res
Uses: circuit boards
Urea Formaldehyde (UF)
THERMOSETTING
High tensile strength, heat res, electrical insulator, easily injection moulded
Uses: electrical casings
Melamine Formaldehyde (MF)
THERMOSETTING
Lightweight, hard but brittle
Uses: kitchenware
What are textiles derived from
Natural & synthetic materials
Textile: natural fibres
Made from plant or animal based fibres, renewable
Textile: synthetic fibres
Made from chemically produced polymers
Textile: blended fibres
Combine 2 or more types of fibres to produce fabric w useful properties
Cotton
NATURAL FIBRE
sourced: cotton plant
Soft, strong, absorbent, washes & takes dyes well
Uses: clothing, towel
Silk
NATURAL FIBRES
sourced: silkworm cocoon
Soft, fine, lightweight, natural shine due to its triangular structure
Uses: luxury clothing
Wool
NATURAL FIBRES
sourced: sheep, goats, rabbits
Warm, crease res, absorbent
Uses: rugs, blankets
Polyamide (Nylon)
SYNTHETIC FIBRE
Strong & hard wearing, resist creasing
Uses: parachutes
Elastine (Lycra)
SYNTHETIC FIBRE
Smooth, strong, stretchy, retains shape
Uses: swimwear
Polyester
SYNTHETIC FIBRE
Tough, hard wearing, non-absorbent
Uses: fleece, backpack
Polycotton
BLENDED FIBRE
Durable, stronger than pure cotton
Uses: bed sheets
Woven cloth
Made up of 2 sets of yarns which are threaded at 90degrees to each other
Plain weave
WOVEN CLOTH
Strong, retains shape, even surface on both sides
Uses: tablecloths
Non-woven fabric
Made directly from fibres w/o being spun into yarns
Bonded fabric
NON-WOVEN FABRIC
Lacks strength, no grain so can be cut in any direction w/o fraying
Uses: cloths, teabags
Knitted fabrics
Interlocking yarn loops tg to produce a fabric.
Uses: jumpers, socks
Weft knitting
KNITTED FABRIC
Made by hand or machine using a single yarn that forms interlocking loops across width of the fabric
Can lose its shape
Warp knitting
KNITTED FABRIC
Made by machine, forms interlocking vertical loops
Holds shape better
