3D Printing and Manufacturing

Mold Designing/ Fabrication

‘Moulding’ is referring to a method of manufacturing by shaping liquid, or pliable raw material, using a rigid frame called a mould or a matrix. This mould may be made using a pattern or model of the final object.

There is a difference between moulds depending on the application required; it could be to shape a plastic, or cut a steel plate. Moulds are generally made to reduce on cost and time factor on a volume based production.

Steel Punch Mould

Steel punch mould

Punching is a metal forming process that uses a punch press to force a tool, called a punch, through the work-piece to create a hole via shearing.

The punch often passes through the work into a die.

A scrap slug from the hole is deposited into the die in the process. Depending on the type of material being punched this slug may be recycled and reused or discarded.

Punching is often considered the cheapest method for creating holes in sheet metal if you are facing medium to high production volumes

Injection Moulds

Injection moulds

Injection moulding is a manufacturing process for producing parts by injecting the raw material into a mould.

Injection moulding can be performed with a host of raw materials, including metals, glasses, elastomers, confections, and most commonly thermoplastic and thermosetting polymers.

Material for the part is fed into a heated barrel, mixed, and forced into a mould cavity, where it cools and hardens to the shape of the cavity

Blow Mould

Blow Mould

Blow moulding is a manufacturing process through which hollow plastic parts are formed.

In general, there are three main types of blow moulding:

a) Extrusion blow moulding

b) Injection blow moulding

c) Injection stretch blow moulding

The blow moulding process begins by melting down the plastic and forming it into a ‘parison’ or in the case of injection and injection stretch blow moulding (ISB) a preform.

Extrusion Blow Moulding

Extrusion Blow Moulding

The parison is a tube-like piece of plastic with a hole in one end through which compressed air can pass.

The parison is then clamped into a mould and air is blown into it. The air pressure then pushes the plastic out to match the mould. Once the plastic has cooled and hardened the mould opens up and the part is ejected. A very good example of this is the PET bottle

Injection Stretch Blow Moulding

Injection Stretch Blow Moulding

Basically it is the beginning of the process, before the bottle is blown. In Extrusion Blow Moulding, plastic is melted and extruded, or pushed, through the opening into continuous tube. Molds come up and close on either side of the tube and air is blown in the mold.

For Injection Blow Moulding, the plastic is melted and then injected into an already closed set of molds shaped like a test tube with a neck finish. The plastic is cooled enough to open and sent to another set of molds in the shape you require, and air is blown in to push the plastic into the shape you require.

Once the plastic has cooled and hardened the mould opens up and the part is ejected.