What are the physical properties
-electrical conduction and insulation
-thermal conduction and insulation
-optical properties
-density
-fusibility
-magnetism
-degradation resistance
What are the mechanical properties a material may have
-compressive strength
-tensile strength
-shear strength
-torsional strength
-toughness (how much energy can be absorbed before fracture)
-plasticity
-ductility (being drawn out without plastic deform.)
-malleability (easily changed into a new shape
-elasticity
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What are the physical properties
-electrical conduction and insulation
-thermal conduction and insulation
-optical properties
-density
-fusibility
-magnetism
-degradation resistance
What are the mechanical properties a material may have
-compressive strength
-tensile strength
-shear strength
-torsional strength
-toughness (how much energy can be absorbed before fracture)
-plasticity
-ductility (being drawn out without plastic deform.)
-malleability (easily changed into a new shape
-elasticity
What are the categories for classification of metal
Ferrous
Non-ferrous
Alloy
What are the categories for classification of wood
Hardwood (deciduous)
Softwood (carnivorous)
Manufactured
What are the categories for classification of polymers
Thermoplastic
Thermosetting plastic
Elastomer (deformable at room temp)
What are the other classifications of materials
Smart material (changes with environment)
Modern material (made using modern materials)
Composite (2 or more materials)
How would you test for tensile strength
A high tensile strength material will resist stretching or pulling therefore it should be suspended and masses hung from it
How do you test for toughness
Hit a sample of the material with a hammer of a dot punch
How do you test for malleability and ductility
Band the test piece to 90 degrees if it cracks on the outside it is a lack of ductility if it cracks on the inside it is a lack of malleability
What are the 2 main ways to dry wood
Air drying (leaving wood in a dry space)
Kiln drying (wood is placed in a warm, moist and ventilated are until dry)
What effect does drying/seasoning wood have
Gives greater immunity to decay and rot increasing strength and stability and makes wood less corrosive to metals
Name some hardwoods
oak, mahogany, beech, balsa, ash
Name some softwoods
pine, larch, spruce, cedar
Name some manufactured boards.
MDF, plywood, chipboard
What forms do woods usually come in
Wood usually come in stock forms that are rough sawn but can also be planes square edge or plained all round however this usually takes about 3mm off the dimensions
Where do metals come from?
ores in the ground are smelted down to separate them from slag until a near pure metal is reached
Name some non ferrous metals and their properties
Aluminium- light
Copper- good thermal and electrical conductor and corrosion resistance
Silver and gold- malleable and ductile
Titanium- light and hard
Tin- ductile, malleable and low melting point
Name some ferrous metals and their properties
Low carbon steel- ductile, high tensile strength malleable, NOT corrosion resist.
Medium carbon steel- harder than low carbon but less ductile
Cast Iron- hard outer shell but brittle inside
Name some ferrous alloys and their properties
Stainless steel- Tough, Hard, corrosion resistance
High speed steel- hard tough and resistant to frictional heat
Die Steel (tool)- hard and tough
Name some non ferrous alloys and their properties
Copper- tough and corrosion resistance
Brass- corrosion resistance, good thermal and electrical conductor
What are the stock forms of metal
Sheet
Bar
Plate
Tube
Structural
How are polymers made
Polymers are distilled from crude oil by fractional distillation and cracking
Name some thermoplastics
LDPE
HDPE
PP
HIPS
PMMA
Nylon
UPVC
PVC
What are the properties and examples of LDPE
Tough, highly chemical resistant, and can be translucent not very rigid e.g. General packaging
What are the properties and examples of HDPE
Tough, weatherproof, chemical resistant can be translucent e.g. Jerry can
What are the properties and examples of PP
Fatigue and chemical resistant e.g. rope
What are the properties and examples of HIPS
Hard, rigid, tough e.g. yoghurt pot
What are the properties and examples of PMMA
Tough corrosion resistant and chemical resistance e.g. baths
What are the properties and examples of Nylon
Tough, corrosion resistant, low frict. coefficient, thermal resistance e.g. clothing
What are the properties and examples of UPVC
Rigid, Tough, hard, weather resistant, fire retardant e.g. window frames
What are the properties and examples of PVC
Tough, Flexible, weather resistance, chemical resistance e.g. hose pipe
Name some thermosets
Urea Formaldehyde
MF
Polyester resin
Epoxy resin
What are the properties of UF
Hard, heat resistant, electrical insulator, brittle e.g. electrical fittings
What are the properties of UF
Hard, Opaque, tough, chemical resistant e.g.laminated
What are the properties of polyester resin
Rigid, heat/chemical resistant e.g. GRP and boat hulls
Name the properties of epoxy resin
Rigid, clear, hard, tough, chemical resistant e.g. castings and surface coatings
Name some elastomers and their uses
Natural rubber- insulation
Butadiene rubber- tyres
Neoprene- wetsuits
Silicone- bakeware
Name some Biopolymers and their uses
Corn starch polymer- packaging
Potatopak- single use food items
Biobatch- packaging films
PLA- single use bottles
PHA- medical packaging
Lactide- slow release medicine
Glycolide- food film
What are the types of biodegradable polymers
Oxy-degradable
Photo-degradable
Hydro-degradable
Name some forming processes for papers and boards
Die cutting
Bending
Laser cutting
Name some forming processes for polymers
Vacuum forming
Line bending
Thermoforming
Calendaring
Lamination
Injection moulding
Blow moulding
Rotational moulding (mould rotated)
Extrusion moulding
Compression moulding
Name some forming processes of metals
Turning
Line bending
Press forming
Cupping
Drop forging (hydraulic ram)
Wrought iron forging (traditional)
Punch bending
Rolling
Name some redistribution processes of metal
Sand casting
Die casting (gravity/ pressure in metal moulding)
Investment (lost wax) casting
Low,temperature pewter casting
Describe the different types of welding
MIG welding- welds thin gauge metal using electrode and electric arc)
TIG welding- welds non ferrous metals and is like MIG welding except a separate filler rod is used instead of electrode welding
Oxyacetylene welding- welds low carbon steel when arc welding is not available O2 gas mix heats to 3500 degrees melting filler rod
Brazing (heavy soldering)- like OA but at 850 degrees
Name some metal addition processes
Pop riveting
Self tapping screws
Machine screws
Nut and bolt
State the metal wasting processes
Milling
Turning
Flame cutting
Plasma cutting (Uses ionising conductive gas)
Laser cutting
Punching and stamping
Name some fabrication processes of wood (joints)
Butt
Dowel
Mitre (45)
Dovetail
Mortise and tenon
Half lap
Housing
Name some addition processes of wood
Knock down fittings (flat pack)
Modesty blocks (polymers guiding screws)
Barrel nut and bolts (creates thread the other side of hole)
Cam lock connector (turns and locks screw like door chain)
Wood screws
Name some wasting and forming processes of wood
Turning
Routing
Milling
Laminating (ply)
Steam bending
Name some wood adhesives
PVA
Contact adhesive
Uv hardening adhesive
Solving cement (tensol 12 compound) can also join PVC and ABS
Describe the features of one off production
-created an individual product
-uses more skilled labour
-has a large manufacture time
-uses direct client consultation
-created a high quality individual production
Describe the features of batch production
-Jigs and fixtures used alongside CNC
-more accurate and faster than one off
-shorter production time than one off
-cheaper cost per unit than one off
Describe the features of mass production
-uses divisions of labour
-used line production
-very quick production time
-much cheaper per unit
What does quick response manufacture do
-greatly reduces the time between prototyping and production (concept to completion)
-meets client need quickly
-this can be done by reducing component arrival time ect...
What is a unit production system and where is it used
Overhead lines reducing transport time between labour stations, often used in textiles
What is vertical in house production
Where supply chains for a company ore owned by that company allowing for greater control and flexibility
How do we improve accuracy in design and manufacture
-CAD/CAM
-CNC
-six sigma (kaizen)
-JIT (making to order not stockpiling) requiring a good supply chain
What do most JIT systems rely on
EPOS, barcodes and RFID
What can a company do to make its production of a complex product more efficient and cheaper
Buy in standardised components and sub assembled parts
This can also be done by using a flexible manufacturing system (modular cell production)
State the specification criteria for fitness for purpose
Cost
Dimensions
Life span (Planned obsolescence)
Maintenance
Testing
Environmental impact
Safety
Ergonomics
Anthropometrics (95th 5th percentile)
Production
Performance (inclusive design)
Materials
Empathetic design (mirroring usage scenarios)
User centred design
By what methods can a product be developed
Concept modelling
Block modelling
Working prototypes
Rapid prototyping
Name the advantages of CAD/CAM
Easy to display ideas to client
Easy to collaborate
High accuracy
Speeds up the development process
Works together
State disadvantages of CAD/CAM
Expensive setup cost
Software has to be updated
Not very fast for quick sketches
How can CAD be used in product development
Can can be used for rapid prototyping and can be realistically rendered making it presentable to the client, these models can also be altered easily to keep up with development
for material and component behaviour- CFD and FEA can be used to test if a product may work before physical prototyping
Name some CAM processes
Laser cutting
Cnc routing
Milling
Turning
plotter cutting (mechanically cutting graphics)
3D printing
How can CAD CAM systems be used for automation and stock control
Computer systems can be used to control stocks and sales using EPOS data (capturing when consumers buy goods), JIT and a MPS can be used to control production rate
EPOS can be backed up by RFID and materials can be transported to stations by AGVs
State the 6 R's
Reduce
Repair
Reuse
Rethink
Refuse
Recycle
What is a primary carbon footprint
Measures direct emissions of CO2 from the burning of fossil fuels, including transport and domestic energy consumption
What is a secondary carbon footprint
measures indirect CO2 from the products we use
What can you do to reduce carbon footprint
Reduce product miles and use sustainable packaging (e.g. keepcup recyclable plastic cup) and materials
What three words describe a linear economy
Make
Take
Dispose
Describe a circular economy
Continues the cycle of use and recycling
preserving and optimising natural capital, optimising resource yield and fostering system effectiveness
Why is it important to maintain a circular economy
Works against a linear economy
Drives greater resource productivity
Reduces finite resource use
Reduces pollution
Drives a more competitive economy
Reduces overall environmental impact
what is the BSI and how is it represented on a product?
BSI (British Standards Organisation) represented by the kite-mark is a national organisation formed to ensure a net following of standard procedures when performing a widen range of materials, there are currently over 30,000 regulations including BS EN 62115 (electrical safety in toys)
What forms the ISO
Over 150 national bodies such as BSI
How is recycling aided in polymers
Codes on products describe a material and its recyclability in a form of categorisation
What is RoHS
This a directive aimed at preventing hazardous substances from entering the production process in order to prevent damage to human health and the environment.
What is the battery directive
An amendment of WEEE ensuring safe disposal of batteries
What is WEEE directive?
This is a mandatory European directive that covers the end of life of electric and electronic equipment.
What is the FSC Certification?
Ensures lumber comes from sustainable logging, this means that the wood was not from a clear cut or old growth forest
What is EC and eco labelling
Ensures/shows electrical efficiency and environmental impact of running an electrical product. EC labelling is recognised throughout Europe
What is the EU Energy star program?
This is was developed from an agreement between the EU and US to standardise how IT equipment was labelled to show the energy used
define material enhancement
The modification of a material to improve its properties relative to its final use/ function
Name the additives for polymers and what they do
-Lubricants- decrease the viscosity of the polymer making it easier to work with
-Thermal Antioxidants- prevent discolouration due to heat
-Fire Retardants (chlorine/bromine)- reduce chance of combustion
-Plasticisers- Make polymer more flexible
-Biobatch- Photo, Oxy and Hydrodegradable compounds added to reduce lifespan
-Antistatic- reduce build up of static by using a thin layer of moisture from the environment
-Antioxidants- reduce environmental degradation
-Fillers- reduce volume of polymer needed, mineral fillers also increase thermal conductivity
-Pigments- Give colour
-UV stabilisers- prevent polymers undergoing photolysis and altering colour and making product more brittle
-Biodegradable Antioxidants- Make product easier to break down
what are the disadvantages of natural wood
. Highly combustable
. Susceptible to Fungal/Insect attack and Rot
. Structural properties decrease when wet
. Anisotropic- different properties in different directions (grain)
What can be added to natural wood to better its properties
-Copper based preservatives can be injected, this is a naturally occurring Fungicide.
-Modified naturally occurring Polysaccharides can be added to increase hardness
-Pigments can be added to give colour.
-Resins May also be added to create manufactured boards
State the Manufactured boards/timbers and their enhanced properties due to the addition of UF resin
.MDF, Plywood, Chipboard, SCL (structural composite), LVL (laminated veneer)
-UF may also have additives promoting fire retardancy
-Boards May be clad with veneer to improve qualities
Describe how the Cold working of metal can lead to problems and how this can be corrected
Cold working can deform metal structure promoting easiness, lack of ductility. This can be fixed by Annealing
Describe the Annealing process in metal
Metal is heated ti above critical temperature and slowly cooled allowing the metal structure to form more bonds and become less ductile and brittle.
What is case hardening and how this done
Case hardening is the process of hardening the surface of steel with less than 4% carbon content this is a 2 stage process.
-Carburising- Metal is placed in ceramic box packed with carbon and heated to 930/950 degrees allowing carbon to diffuse in.
-Quenching- this is then cooled to 760 degrees and dipped in cold water
Describe the Hardening process and where is can be used. What process usually follows this to decrease hardness
Hardening is the process of heating medium/high carbon steel changing the crystalline structure and then quenching in cold water to improve hardness. Tempering may be used to make the metal a bit less hard where metal is heated to below critical temperature and left to slowly cool.
what are the different types of finishing process for papers and boards
. Lamination
-encapsulation (PET and EVA)
-Film Lamination (PP and Adhesive)
-Liquid Lamination (roller or spray
.Embossing and Debossing
.Foil Blocking
.Varnishing, UV Varnishing and Spot varnishing
what are the 4 types of printing processes that can be applied to papers and boards
.screen printing (like press printing)
.Digital Printing (like laser printing)
.Flexographic printing
.Offset Lithographic printing
Describe the Flexographic printing process including advantages and disadvantages
.4 Colour (magenta, cyan, black, yellow) system
.must be very precise to prevent blurry image so registration system is printed outside the printing area which can later be scanned
.cheap because uses water based UV curing inks
.uses flexible printing plates wrapped around rotating cylinders on web press
.Only efficient fir mass printing because of hight setup and running cost. Low maintenance and uses cheap ink.
Describe the offset Lithographic printing process
.Works on principle that oil and water don't mix so printing area is Oleophilic and non printing area is hydrophillic
1) printing substrate either sheet fed or web rolled into machinery
2)Printing plates are produced by a computer to plate process (CTP) via laser etching. these are attached to machine and dampened my a roller
3) ink applied to printing plate this rotates onto a blanket roller which becomes coated in ink, this is then rolled on to the substrate which is being fed in
.This gives a consistent high quality finish and produces long lasting printer plates however is expensive to set up and run
What are the methods of polymer finishing
.Adding pigment during moulding
.Acrylic spay paints (become water resistant after drying)
.Over-moulding (usually TPE Elastomer)
-this can be doe using two injection moulds or twin show moulding where mould rotates to reveal another shape
what are the methods of metal finishing with description
.Cellulose/ Acrylic paints (key and prime first)
.Electroplating (place in electrolyte solution and let charge attract metals out of solution)
.Dip coating (hot metal dipped in polymer moulding in fluoridation bath with air being blown thought it. this also works with metal being run under stream of other molten metal
.Powder coating (Statically (-) charged object attracts + charged thermoset polymer resin)
.baking
.Varnishing
.Sealants (polymer based)
.Anodising (similar to electroplating but sulphuric acid leaves built up oxidised layer on aluminium Anode
.Cathodic protection (next card)
Explain, including the two methods Cathodic Protection
-All metals have a natural voltage (proportional to reactivity)
-In the presence of water a current is induced in-between 2 metals creating an electrochemical cell.
-More active metals will oxidise (anode) and corrode to protect less reactive cathodes.
-This can be used via Impressed current or sacrificial anodes
.Impressed current:
-material to be protected is connected to pawer supply
-current flows through any liquid from inert electrode (anode) to material being protected causing the electrode to corrode
.Sacrificial Anodes:
more reactive metal is physically attached to less reactive metal and anode corrodes
Name the methods/types of wood finish
.Polyurethane/acrylic varnish (gives polymer properties)
.Stains
.Water based paint
.Varnishes
.Teak oil
.Danish oil
.Yacht Varnish
.pressure treating
.Wax
.colour washing
What should employers do to ensure Health and Safety in the workplace
-Ensure the workplace is safe and risk free
-Ensure Welfare facilities such as first aid are In place
-Ensure dangerous substances are stored and used safely
-Ensure Machinery is safe to use and well Maintained
-Ensure Training, Information and Supervision are provided where necessary
-Ensure Adequate safety signage is in place