Moulding of plastics

INJECTION MOULDING

Injection moulding uses small granules that are poured into a hopper. They are then carried by an Archimedes screw, through heating pads into a split mould.



COMPRESSION MOULDING

Compression moulding also uses heat in its process however in this process two shapes are pushed together with the mould inside of it and forms a specific shape.



ROTATIONAL MOULDING

The process of rotation uses centrifugal froce to push molten plastic powder to ther outside of a chosen shape. these shapes are hollow and are usually products such as childrens toys.

Plastics

There are two types of palstics and they are Thermosetting plastics and Thermoplastics.

                                                                                                                                               Polymers: summary of plastics:

Good electrical and thermal insulators
Good strength to weight ratio
Generally good resistance to atmospheric and chemical erosion
Low melting point
Lightweight
Available in a wide range of colours and transparacy

Thermoplastics:

ABS-Acrylonitrile butadiene styrene
CA-Cellulose acetate
Nylon- Nylon
PMMA-Para-Methoxymethamphetamine
PP-Polypropylene
HIPS-High impact polystyrene
PS-Polystyrene
LDPE-Low density polystyrene
HDPE-High density polystyrene
uVPC-Polyvynil chloride
PVC-unplasticized flexible, polyvynil chloride
PET-Polyethylene terephthalate
PC-Polycarbonate

Thermosetting plastics:

Epoxy resins: Surface coatings, adhesives

Melamine formaldehyde: Tableware, laminte surfaces

Polyester Resins: Castings used in GRP

Urea Formaldehyde: Electrical fittings, adhesives

The tragedy that was the playstation 3

A few years ago i had purchased the latest product from the well known company "Sony" it was 320 pounds sterling and it was the playstation 3. At first glance the product looked sleek in design and very attractive, it was black and had a unique curved shape to it. When i first set up the product it worked very well however after a few months went by the product started to become slow and i started to see a few flaws.

I didn’t really take any notice of these flaws and continued using the product but after a year or so I was using the product and it started to make some unusual sounds and suddenly cut out. After trying to manually fix the problem and failed i contacted Sony and explained what the problem was and they proceeded to tell me that it was no problem with the manufacturing of the product it must have been something that "I" the user had done and that i could purchase a brand new playstation 3 for the low price of 120 pounds but i rejected the offer, so i researched the problem online, going through various blogs and i saw a repetitive theory that when the product was being made the manufacturers had failed to properly connect the circuit board to the mains, so when the user has played the product for a certain amount of time the circuit boards solder melts and the board disconnects itself, making the playstation un-playable and this is called "The yellow light of death" . This is why I should have never purchased the Playstation 3 and I advise any reviewers of this blog not to either.