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PRINCIPLE for SETTING OF INJECTION SPEED, PRESSURE AND POSITION

POSITION

SPEED

PRESSURE

FILLING PHASE

Also known as Speed phase.

Select end of 1st step and start of 2nd step.

Set SPEED 1

Try to set high.

Only one pressure setting is required during FILLING PHASE.

Pressure Setting should be more than actual filling pressure. as relief valve should not be actuated. If it is actuated, then speed control will be lost.

Filling pressure depends on resistance to move the melt. It depends on flow ratio and viscosity of melt.

Also known as Speed phase.

There may be no. of steps available on machine.

Select end of 2nd step and start of 3rd step

Set SPEED 2

Lower speed for crossing narrow passage / gate

Steps are position controlled.

Select end of 3rd step and start of SWITCH OVER POINT. This point is at around 80-95% of the injection stroke.

Set SPEED 3

Reduce to lower sink mark / increase to shift weld line.

PRESSURE PHASE-

Holding phase.

There may be no. of steps available on machine.

Timer controls the Holding pressure steps if available on machine.

Holding pressure time for step 1 is set on a timer,

Set SPEED low value say up to 35% not more.

This can be one step of speed for different Holding steps.

Speed set is low, as there is less or no space to move the melt.

Holding pressure 1 set just enough to fill cavity without overpacking.

Steps are timers controlled.

Holding pressure time for step 2 is set on a timer,

Holding pressure 2 set just enough to fill cavity without overpacking.

Holding pressure time for step 3 is set on a timer,

Holding pressure 3 set just enough to fill cavity without overpacking.

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