1st filling ( Injection phase )

During 1st filling ( Injection phase ) , is it right practice to turn off both holding pressure and holding time ? :confused:

When first setting up the filling phase I do trun off the pack/hold pressures and leave the times there so the maching cycle time is consistant. I also start with the initial injection pressure set very high so the process will not be pressure limited. On some critical jobs I record the weight and take a picture of the part with the holding pressures turned off (95% filled). I don't do viscosity studies that often. When I have the fill phase set I set the injection pressure a couple of hundred psi (machine pressure) above what is used to fill at the speeds I have indicated. Then add the holding pressures after doing a gate freeze. I mostly do the gate freeze graphs for larger parts.

I leave a time in the press, normally using a similar part's numbers for hold time, until I finish. Then I do the gate freeze. Nowperfrom the viscosity study since it has been saving me lots of time and scrap, first; then the gate freeze. I also try to run my hold pressure at about 60% of peak injection; another one of those time and scrap savers.

Set the minimum value of the second stage pressure. [ some machine the minimum value was available ]
Set the holding time with the consideration of gate size, melt and mold temperature by right.

To minimize the screw bounce back at the transfer position time.

The answer to the original question is yes. Turn off hold time and pressure. Some machine slope/ramp 1st stage hold pressure so if there is any time on the clock it will use that time to ramp down from pressure at transfer to 0.

GBYA
Aahz

Correct Aahz, One must study the controller to understand this.
Suhas