Homework

Injection moulding

Injection moulding consists of small plastic granuals getting melted down until it is runny enough to be pushed into the mould and fill the complete shape. when the plastic is cooled the mould opens up releasing the moilded shape and this can be completed over and over and get the exact product over and over again.

Purpose of a jig/mould

 

the purpose of a jig/mould is to increase efficiancy and imppove safty of the working area and create more accurate products ate the end of it. 

plastic/polymers

themoplastic:

no links between polymer chains. they can get re shaped over and over again also they are recyclable

thermosetting:

can not be changed after being moulded once so they are hard to recycle


Summary of plastics

good thermal and electrical insulators

good straight against weight ratio

doesnt decompose

low melting point

available in wide range of coulers and transparancy

two main catagories thermoplastic and thermosetting


Ways to improve properties of plastics

Fillers: fillers are used to bulk up plastics to make them stronger for lower cost.

Flame retardents: used to reduce the risk of combustion

Anti static agents: reduces the effect of static charges

Plasticisers: makes material less brittle and improves the flow properties

Stableisers: reduce the effect the ultra violet light has uppon the object


Close loop production



Types of thermoplastics

ABS -  Acrylonitrile butadiene styrine
CA - Cellulose acetate
NYLON - Polyamide
PMMA - Acrylic
PP - Polypropalene
HIPS - High impact polystyrene
PS - Polystyrene
LDPE - Low density polyethylene
HDPE - High density polyethylene
UPVC - Polyvynal chloride
PVC - Unplasticated flexible polyvynal chloride
PET - Polyetheylene terepheluate
PC - Polycarbinate

Types of thermosetting plastics

Epoxy resins: surface coating, adheasives
Malamine formaldahide: table ware, decorative laminates
Polyester resins: castings
Urea fomaldahide: electical fittings, adheasives

Miniture chair project

assignment 1 - I should never had purchased

Apple Iphone headphones


A few months ago I purchased a set of apple headphones as I am a keen listener of all types of music however I should have never bought these because they are terribly designed and I believe do not fit the purpose they were designed for. Although these are a very iconic piece of technology in the current time although to become this iconic the design has some bad aspects.


For starters the ear pieces I believe are the incorrect shape to fit any type of ear I should have listened to my friends who they did not fit as well. In addition the sound quality of these headphones is terrible and although they are not the most expensive headphones on the market I would expect them to be reasonably good. Furthermore the cable that is used is very prone to tangling and can cause a lot of distress when trying to listen to music and to top of this terrible product the build quality of these headphone are dreadful and broke within a month of me having them, one ear piece broke off and the wire due to a lot of knotting split and broke.


All in all  I believe that apple needs to rethink the design of their product and possibly create a new one.