Processes Flashcards
What is inejction moulding used for
Creating 3D complex shapes out of thermo plastics
Give a step by step o finejction moulding
Granuels fed into a hopper, which drops them into a screw
Screw is rotated by a motor, pushing the granuels across a heated section
Liquified granels forced into the mould
Mould is cooled and removed by steel ejector pins
Materials used in IM
PS
Polythene
Nylon
PP
ABS
Advantages of injection moulding
Detailed
High volume
Efficient
No finishing needed
Give sone disadvantages of IM
High inital costs
Expensive moulds
Step by step of blow moulding
Granuels fed into a hopper
Heated granuels are injection moulded, into a tube like form
Tueb (pre form) is placed in mould
Air is forced into the tube which expands in the mould
The mould si cooled then remoevd
What materials are used for blow moulding
HDPE
LDPE
PP
PVS
PET
Pros of BM
Rapid method
Suitable for all kind of production scales
Many types of plastic cna be sued
Less expensive then IM
Cons of BM
Limited to hollow parts
Moulds can be expensive
Difficult to produce compelx and pointed shapes
Step by step of rotationla moulding
Moulds loaded with presice amount of thermo palstic powder
Mould is clamped shut
Mould roatetd and heated
Mould cooled and remove
Materials for rotational moulding
Polyethelyne
PP
PVC
Nylon
Polycarbonate
Pros of RM
No seems or joins needed
Ideal for rigid, tough shapes
No waste
Surface textures easiluy applied
Cheaper moulds than IM and BM
Cons of BM
Only hollow shapes produced
Simpel shapes
Plastic needs alot of work doing to it before it can be used
Thermoforming step by step
A plastic sheet is held securley between two halves of a mould
Plastic is heated
Mould halves close togehter adn a vaccum is applied to the lower half
Upper mould is where the details at
Materials used in thermoforming
ABS
PS
Acrylic
Polycarbonate
Pros of Thermoformign
Low cost
Good to add deatil
COns of thermo formign
Deep moulds cn result in stretched products
Limited to simple designs
Trimmin required
Step by step of vaccum forming
Sheet of plastic heated
Mould is pushed up against plastic sheet
Vaccum is turned on and sheet moulds aroud mould
Sheet sets
Materials in VF
ABS
PS
Acylic
Polycarbonate
Pros of VF
Available to schools
Simple easy to use
Low costs
Suiatble for one off lareg scale production
Cons of VF
Trimmin reqired
Moulds have no vertical sides, draft angles needed
Can only have udnercuts with special moulds
Step by step of plastic extrusion
Granuels fed to a hopper
Motor turns a thread which pushes them alon g a heater
Heated plastic forced through a die
Extruded product cut to desrie length
Advantages of PE
Best way to keep a constient profile
Only requuires simple dies
Cons of PE
Not suitabel for one off production
Parts need to be cut to shape and assembled
Step by step of calendaring
Pre mixed thermo plastics fed into rollers
ROllers are heated
Plastic isforced through the gap roller to determien thickneess
FInal roller chills the material
Materials used in calendaring
PE
PVC
ABS
MDPE
Celluos accetate
Advantages of calendaring
Long continuous rolls without joints
Lareg quantiites
Can be combined with printing etc
Disadvantages of calendaring
Only for large scale
Step by step of comrpression moulding
Compressed plastic powder placed between two halves of a mould
Mould is heated
Mould is closed and the powder fits desired shape
Materials used in CM
thermo plastics
Ceramcis
Adv of CM
Ideal for thermosetting plastics
Long prodcution runs
Low set up and mould costs
Little waste
Good
for solid parts
Cons of CM
limited to simple parts
Dip moulding step by steop
Mould is dipped into a bath of molten plastic
Nould is removed
Mould si cooled
End product is removed
Materials used in dip moulding
PVC
Polyurethanes
Latex
Elastomers
Silicolnes
Adv of dip moulding
Cost effective
Prototypes and formers produced quick
No split lines
Suitable for large production
Cons of dip moulding
Limited to simple shapes
Plasma cutting step by step
Doen on a CNC
Materials used in plasma cuttign
Stainless steel
Alluminuim
Any conducitive metal
Pros of PC
Economical
Smooth cuts
Large range of materials cut
Cons of PC
High energy use
High amount of waste
Certain thickness needed
Laser cutting
Fine beam of light used by a CNC
Materials used in laser cutting
Alot
Advantages of laser cuttign
Can engrave and cut
High compelx shapes made
Sutiable for batch prod
Clean edged cuts
Lots of materials
Low mainetence
Cons of LC
Can leave burn marks on woods etc
Energy intesive
Slwo when working on thicker materials
High material waste
Only certain thickness can be used
3D printing step by step
Plastic filleament fed into a motor which extrudes material into desired shape, layer by laeyr
Materials used in 3D printing
Thermoplastics
Metals
Plasters
Pros of 3D printign
Any shape
Easy to improvce designs
Rapid
Cons of 3D printign
Ethical issues
Anythign xan be made
Press formign step by step
Sheets held into hydralich press and held together
Punch of press forces the sheet to take shape of die
Materials used in press formign
Steel
Copper
Brass
Aluminium
Adv of PF
Make 2D sheets into 3D
Carried out in room temp
Seamless parts made froma sheet of metak
Cons of PF
High tooling costs
Very high levels of stress needed
Sandcasting step by step
Pattern made
Each part of the patter is placed on a base board
Half a mould box placed over
Sand isi packed around
Pattern remove from mould half
Otehr half fitted with locating pins
Moletn metal fed through a tube type bit
Moudl broken once set
Materials used in SC
Copper alloys
Zinc
Aluminium
Tin
Adv of SC
Low cost
Easy to oeprate
High detailed parts
flexibel levels of production
Cons of SC
Laboru intensive
Unit cost high when one off
Lots of finishing
Die casting step by step
Molten metal poured into a chamber
Injection pin forces the metal into a cavity at high pressure
Pressure is maintained until metal solidfies
Injector pins push compoenent out of die
Adv of DC
Suitable for materials with low melt points
Complex shapes
High detail
Good surfaces finish
Small thin parts made
Fast
Cons of DC
Expensive
Not guarenteed struct sstrength
Trimming needed
Materials used in DC
Aluminium
Zinc
Sintering step by step
Materials crushed into powder
Powder compacted into a die , which gives final shape
Compacted shape is heated and powder form
Materials used in sintering
Variety of glass, metals , plastics and ceramics
Pros of sintering
Good surface finish
No wasted materials
Complex shapes
Alllows use of wasted material
Cons of sinetring
Not suited for thin walls
Several stages
shrinkage
Drop forging step by step
Meta l thing between two halves
High force pushes and drops down top half
Metal fills the cavity between two halfves
Materials used in DF
Ferrous metals
Titanium
COpper
Alluminium
Pros of DF
Makes stronger peices
Soem metals can be forged cold
Cons of DF
Expesnive
Dangerous
Wood lamionating step by step
Adhesive applied to face of cenner
Each venner is stakced ontop of each other
Venner clamped in a die
Adheisve dries
Pros of WL
Accomadates a raneg of thcikensss
Creates strong lightweight parts
Can eb combined wirth other materials
Cons of WL
Many steps
Restricted to bends in one directoon
Materials used in WL
Wood veneers
Birch is the most common
Steam bending step by step
Wood placed in steam box
Box fed steam from PVC pipe
Steam penetrates the grain and wood
Wood softens
Once softened wood is place around a former to desired shape
Pros of Steam Bending
Aesthetic appeal
Done with simple eqip
Can produce parts with good strenth to weight ratios
Any shapes
Cons of SB
Only high qualty hard wods should he use
Not good for prescion
Bending radius depends on wood used
Materials used in SB
Hard woods
Beech
Oak
ELm
Ash
Willow
Mapl e
Die cutting step by steop
Sharp edges of cutting die brought to thin sheet material
Material cut and creased and perfreated in one stpe
Materials used in die cutting
Paper
All sorts of card
PVC
PET
PP
Adv of die cutting
low set up cost
effective for batches
easil ycombiend with priniting
many shapes cut in one action
quick for large batchs
Cons of die cutting
3D products need to be assembled by hand
Brazing step by step
Metal cleaner
Flux is brushed along the joint
Pressurisied gas and air fed into anozel
Nozel is heated with flame so its hot
Brazing rod is pushd aganst the joint and the rod will metl along the joint
Materials used in brazing
Copper
Mild steel
Adv of brazing
low costs
suitable for all types of production
little time needed
strong bond
clean joints
compelx and intricate joints made
can be rejoined if it goes wrong
cons of brazing
high degrees of cleanlieness
joint colour different from metal
not as strong as welded joints
TIG step by step
arc of electricity jumps from tungsten metal electrode to metal surface
heat binds the edges
electrode coated in a flux to prevent rusting
materials used in TIG
Carbons teel
Staineless steel
aLUMIUNIUM
Pros of TIG
Safer than brazing
High quality welds
No tooling costs
Cons of tig
High set up time
Nto user friendly
Ezpensive
Skill needed to do it
what is fdm
fused deposition moulding, where layers are built of polymer to create parts
what is sla
stereolithogrpahy, which sues uv lasers to soldify layers of photopolymer
what us mjm
multi jet modelling, which gievs a very high quality finish
what si sls
selective lser sinetrimg, whcih uses alsers to fuse powdered metals into soldi models
