PET PLASTIC BLOW MOULDING

NOR SUHAILA NOR SAIDINUR NADIAH AJMANSITI AMINAH JENISSITI KHADIJAH ABD RAHMANSITI NORAINI KAWAEED

WHAT IS PET? Known as Polyethylene terephthalate (PET) molecule consists of repeating units white but bluish resin made from terephthalic acid and

ethylene glycol through poly-condensation. very important raw material used in man-made fibers. a kind of polyester material for fiber, injection molded

parts, as well as blow-molded bottles and jars. (PET) is used to make beverage, food and

other liquid containers, synthetic fibers, as well as for some other thermoforming applications.

PROPERTIES AND CHARACTERISTIC Properties:- consists of carbon, hydrogen and oxygen.- most valuable of the recyclable plastics. - reusable as fibre filling for clothing, pallet

strapping and moulding, carpeting, as well as in the manufacture of PET containers.

Characteristics: Light weight Shatter resistance Economic cost High clarity Resealability Recyclability

WHAT IS PET BLOW MOULDING? Blow moulding is a manufacturing process by

which hollow plastic parts are formed out of thermoplastic.

A process of inflating a hot, hollow, thermoplastic preform or parison inside a closed mold so its shape conforms to that of the mold cavity.

The third largest plastic processing technique behind injection molding and extrusion molding.

Blow molding has the advantage that molded parts can be manufactured economically in unlimited quantities with little or practically no finishing operations.

The plastics normally used in this process are; polythene, PVC and polypropylene.

TYPES OF BLOW MOULDING

There are three types of PET Blow Moulding Process:

Extrusion Blow Molding Injection Blow Molding Stretch Blow Molding

But the best known for producing PET bottles is:STRETCH BLOW MOULDING

STRETCH BLOW MOULDING

Stretch blow molding is best known for producing PET bottles commonly used for water, juice and a variety of other products.

Stretch blow molding is divided into two different categories:

Single-stage Two-stage

SINGLE STAGE STRECTH BLOW MOULDING

Uses the extruder to inject parison into a preform mold where the plastic is rapidly cooled to form the preform.

The preform is then reheated and placed in the bottle mold. Then softened parison stretches to about twice its original

length. Compressed air is then blown into the stretched parison to

expand to the bottles mold. Once the bottle is cooled the mold is opened and the

finished bottle is emptied from the mold cavity. This technique is most effective in specialty applications,

such as wide mouthed jars, where very high production rates are not a requirement.

TWO STAGE STRECTH BLOW MOULDING

Same as single-stage, except the preforms are already made.

The two-stage process uses preforms that have already been made and cooled.

The machinery involved injection molds a preform, which is then transferred within the machine to another station where it is blown and then ejected from the machine.

  Stretch blow molding: (1) injection molding of the parison; (2) stretching; and (3) blowing.

FINAL PRODUCT