Injection Moulding Machine

Introduction

A normal Injection moulding machine Consists of 4 Units, namely

1. Hydraulic Unit
2. Clamping Unit
3. Injection Unit
4. Control Unit

 Hydraulic Unit

This unit is responsible for movements of the machine, like the injection movement, machine movement, Pallets movement etc. As it name suggests it works on Hydraulic Mechanisms.The hydraulic system on the injection moulding machine provides the power to open and close the mould, build and hold the clamping tonnage, turn the reciprocating screw, drive the reciprocating screw, and energise ejector pins and moving mould cores. A number of hydraulic components are required to provide this power, which include pumps, valves, hydraulic motors, hydraulic fittings, hydraulic tubing, and hydraulic reservoirs.

Clamping Unit

The clamping system opens and closes the mould, supports and carries the constituent parts of the mould, and generates sufficient force to prevent the mould from opening. Clamping force can be generated by a mechanical (toggle) lock, hydraulic lock, or a combination of the two basic types.

Injection Unit

The injection system consists of a hopper, a reciprocating screw and barrel assembly, and an injection nozzle. This system confines and transports the plastic as it progresses through the feeding, compressing, degassing, melting, injection, and packing stages.

Control Unit

Now-a-days, Injection Moulding machines have PLC (Programmable Logic Controllers), NC(Numeric Controllers), and CNC's.

Purging

When we are changing the colour of plastic we are using to make a component, we need to first clean the injection and make sure that two colours do not mix with each other without our conscience. This Process is known as Purging.

We need to use a Purging Compound with high Viscosity to clean the barrel. 

Machine Specification

Injection or Short Capacity

The Maximum weight of molten material that can be pushed out by the accumulator is called as Short Capacity.

Plasticising Capacity

The maximum Amount of plastic which can be molten in a unit Time. It influences the cycle time greatly.

Injection Rate or Injection Velocity

The performance of an injection unit is expressed as injection rate.

Mould Clamping Unit

The mould clamping unit is a unit in charge of installing the mould in the injection M\c opening and closing. It is is necessary to clamp the mould so that it does not open under the high pressure applied by the molten plastic.

Maximum Day Light

As far as the mould thickness that can be accommodated between the machine platoon is conserved a distinction is made between open or maximum Light and closed day light is the distance between those platoons when the machine clamping mechanism is fully extended.