4) Raw Materials to Final Production

Physical properties

tend to be characteristics of materials that can be identifies as non-destructive

mass (kg)

is the amount of matter that a body has

weight (newtons)

is the gravitational force applied on a body and is non constant

volume

the area of a 3d shape

density

the mass per unit volume of a material

electrical resistivity

measures a materials ability to conduct electricity

thermal conductivity

measures how much something expands under heat

hardness

measures a materials ability to resist scratching or penetration

tensile strength

the ability of a material to withstand pulling forces

compressive strength

the ability of a material to withstand being compressed

toughness

the ability of a material to absorb energy and plastically deform without force

stiffness

is the ability of an eastic body to deflect an applied force

plasticity

the ability of a material to permanently change shape

stress

is the force per unit are of material (stress=force/area)

strain

is the extension per unit length (strain=extension/stretch length)

youngs modulus

measures the stiffness of an elastic body

piezo electricity

is the electric charge generated by a material as it’s experiencing mechanical strength

electro-rheostatic

smart materials whose structure are significantly altered by external electric fields

magneto-rheostatic

a material or fluid that becomes thicker or more solid when a magnetic field is applied, and returns to normal when the field is removed.

shape memory

the ability of a material to return back to its pre-deformed shape.

photo chromicity

when a material changes color under light exposure

thermochromism

the property of a substace to change color due to temp. change

thermoelectricity

generates voltage from temp. differences

metals

a rock ore containing metallic compounds with a high enough concentration to make it economic to extract

grain

an architectural structure that influences the properties of a metal

a grain size can be

controlled and solidified/modified by the rate at which a metal cools or heats up

alloy

a micture of elements containing a metal

alloy advantages

harder and more useful

work hardening

to increase the hardness of a metal by working them cold (normalising) or hot (annealing).

annealing

is aheat treatment that alters the physical and chemical properties of a material to increase ductility, decrease hardness, thus making it more workable

quench hardening

heating and rapidly cooling a material to strengthen and harden

tempering

heating and cooling in air, performed after hardening to reduce excess hardness and add toughness

creep

the gradual extension of a material under constant force, and becomes more pronounced at high temps.

ferrous alloys

composed mainly of ferite or iron, they are magnetic

mild steel (ferrous)

screws, general engineering, train rails

stainless steel (ferrous)

cutlery, surgical instruments, pots

cast iron (ferrous)

cookware, machine parts

tool steel (ferrous)

chisels, handsaw blade, hand tools

high speed steel (ferrous)

drills, saw blades

non ferrous pure metals

contain no iron

alluminum (non-ferrous)

kitchen foil, soda cans, window frames

copper (non-ferrous)

cables, printed circuits, pipes, roofs, gutters

tin (non-ferrous)

accessories, tin cans

zinc (non-ferrous)

die casting, batteries

brass (alloy)

instruments, plumbing

alluminum (alloy)

wheels, bikes, engines

titanium (alloy)

implants, paint, aerospace

platinum (alloy)

electronics, jewels

gold (alloy)

electronics, jewels

timber

renewable and is a major building material

wood grain

is the longtitudinal arragement of wood fibres

wood defects

bow, crook, kink, cup, twist

coniferous trees (softwood)

are evergreen, needle leaved,, cone bearing trees grwon in temperate regions

pine (softwood)

cheap quality diy furniture

spruce (softwood)

general indoor work

european redwood (softwood)

general woodwork and furniture

parana pine (softwood)

brown furniture

yelow cedar (softwood)

furniture and boat building

deciduous trees (hardwood)

grow in temperate tropical regions

beech (hardwood)

furniture, toys (can be bent and laminated)

teak (hardwood)

outdoor furniture and boat building

oak (hardwood)

high quality furniture, floor boards, construction

mahogony (hardwood)

expensive furniture, luxury interior panels

man made timber

involves gluing wood layers and fibres

man made timber examples

• plywood

• paper phenolic laminates

• medium density fibrewood (MDF)

• oriented strand board (OSB)

• chip/particle board

treating and finishing wood is necessary to…

• prevention of insects

• protection from dry rot

• weather

• aesthetics

timber treatments include

wood or stain preservers, CCA or creosote

timber finishers include

varnish, estapol, oils, wax

glass

hard, brittle, transparent (anorphous solid) made by apidly cooling sand, lime and soda. (very unreactive)

glass is

non-porous (doesnt let air or liquid through) and can be made incredibly smooth for easiy sanitation and sterilisation

colored glass

is made using metallic oxides

laminated glass

is made using two thin sheets of glass with a plastic sheet glued between them

how does laminated glass work

under pressure, the glass fractures but the plastic absrobs energy and remains fragment

toughened (tempered glass)

is heat treated: the outside is held in compression and inside in tension (achieved by heat and cooling)

when toughened (tempered glass) shatters

breaks into smaller pieces not sharp shards

soda lime glass

is cheap and has poor thermal shock resistance, meaning it easily shatters (used for bottles, windows and lightbulbs)

thermal schock resistant glass (pyrex)

is a stronger version of soda lime glass as it contains silicon, boron, sodium and alluminum

glass fibres

are very long strands of glass combined with polymer resin

optical fibres

are flexible made using drawing glass- silica.

natural plastics

are naturally occuring materials that can be molded (shellac, wax, amber, rubber)

semi synthetic platics

are a mixture of naturally occuring plastics and another substance such as; cellulose acetate or vulcanised rubber.

bakelite (first synthetic plastic) - phenol formaldehyde

used for electronic goods as it was cheap, easy to manufacture and high quality

synthetic polymers

are derived from breaking down carbon based materials

synethtic polymers list

• neoprone

• nylon

• polystyrene

• PVC (poly vinyl chloride)

• polyacrylonitrile (acrylic)

• PVB (poly vynil butyral)

• PE (Polyethylene)

• PET (polyethylene terephthalate)

thermoplastics

can be heated and reformed as their polymer chains do not cross-link, allowing them to move freely (linear chain molecules)

PP (Polyproplene)

is cheap, versatile, stiff, chemically resistant and has polymer resin; cheap furniture, caps, buckets, pipes

PE (Polyethylene)

is very common and changes properties based on density but is usually transparent, waterproof, flexible, cheap and low melting point; bottles

PS (Polystyren)

is a solid but can be formed, hard, cheap, low melting point; foam packaging

HIPS (High Impact Polystyrene)

is versatile and cheap; aesthetic packaging

ABS (Acrylonitrile butadiene styrene)

is heat resistant and has good stiffness, has dimensional stability, also cheap; engineering plastic, construction caps

PET (Polyethylene Terephthalate)

is most common as its cheap and impact resistant; food containers, bottles, packaging

PVC (Poly vynil chloride)

has hardness but flexibility when soft, good insulation; pipes, cables, flooring, medical packaging

thermosett plastics

retain strnegth and shape (even when hot), thus they cant be molten after their first shape has been set

• (linear chain molecules with strong primary-bond cross links)

PU (Polyuerethane)

can be flexible and hard, likewise have good tensile and compressive strength; glue, paint, varnish, wheels

Urea Formaldehyde

has light tensile strnegth and surface hardness; textiles, insulation, outlets

Melamine resin

is a solid that is stain/scratch resistant with a high melting point; wood adhesvie, kitchen utensils, and nursery/camping utensils

epoxy resin

is tough with electricity and chemical resistance and can be used on metal; coating, airplanes, pipes, adhesives

what factors does plastic recycling depend on;

economic, logistical and technical

bio plastics

are derived from renewable sources including vegetable fats and oils or starch and microbie.

some bio plastics and not bio degradable because

the chemical structure of some natural resources can’t be broken down