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in injection moulding by between 30 and 60% depending on the mould and machine
used.
l Power requirement is provided by the direct electrical drive eliminating hydraulic
system & thus need for the cooling of hydraulic oils
Hybrid Machines
l Uses both servomotors and hydraulic pumps
l Common con?guration is using the hydraulic pump for clamping and the
servomotors for the screw movements.
l Hybrid machines are generally lower in cost than the all-electric machines,
however, they are not as energy efficient nor as quiet.
Injection moulding Process:
Advantage Disadvantage
Low costs with high production output rates High initial setup costs
High precision and accuracy Tooling is expensive
Close tolerances on small intricate parts is possible Tooling requires more time
Raw Materials: Injection moulding process provides the largest choice of materials
available for processing. Materials with MFIs of about 5 to 100 or so are available.
Commonly used polymers are Polyethylene's: LLDPE, LDPE, HDPE, Acrylic, ABS,
Polypropylene, Nylons, PVC, Polycarbonates, PEEK, Acetals, TPU and many others
Applications of Rotational Moulding: Automobile components like dash board,
under hood components, handles, Household containers, crates, bins, ice cream
cups, trays , glasses, electrical and electronics, computer and machine parts,
appliances housings and parts, toys, cell phones, copier machine, medical devices,
syringes, defence, aircraft and marine applications and many others.
TYPES OF INJECTION MOULDING:
Insert Moulding:
Insert moulding is a process by which an object or insert, is placed into the mould
cavity between cycles and the plastic is injected around the insert, so that the insert
becomes a part of the final moulded product. The materials used as inserts include
a variety of metallic inserts, cloth, retaining rings, and film. For insert moulding
products a Vertical Clamping Injection Moulding Machine wherein the mould
opens and close vertically is used to facilitate the placing of insert in the mould
cavity. E.g. knife handles, screw drivers, appliance cabinet.
Foam Moulding Process:
The Structural Foam Process is a low pressure injection moulding process where an
inert gas is introduced into melted polymer for the purpose of reducing density and
hence weight of the finished product. Structural foam moulded products have cellular
cores surrounded by rigid, integral skins. Foaming agent (N2, CO2 or CBA) is

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