Older Injection Molding Machine conversion to a PLC?

[baldone]

How do you do that? By the time a foreign object is detected it is too late to stop before the mold closes.

We could do this on presses but by the time we detected the foreign material the press is closed and the press doesn't stop instantly.

The mold will be shut but you do not allow the hydraulics to build tonnage unless close position is achieved.

Most IMMs will open back up and alarm if closed position is not achieved within a certain amount of time.

I spent 20+ years in the plastics industry rebuilding Injection, Blow Molding, and Thermoforming equipment.

Most of our control upgrades on older machines did not involve proportional hydraulic systems so you can get by with less PLC horsepower.

Depending on the machine we used everything from PLC2s, PLC5s, SLCs, and did quite a few Barber Coleman retrofits.

We kind of got out of rebuilding when IMM prices got so low it just was not cost effective unless it was either large tonnage or specialty.

 

[osmanmomin]

http://www.youtube.com/watch?v=XSh6xbIRUc4

http://www.youtube.com/watch?v=jPBnSqaPiSg

http://www.youtube.com/watch?v=RBC2vCKqJH8

http://www.youtube.com/watch?v=rmNAb2NKqVY

 

[iant]

The mold will be shut but you do not allow the hydraulics to build tonnage unless close position is achieved.

Most IMMs will open back up and alarm if closed position is not achieved within a certain amount of time.

I spent 20+ years in the plastics industry rebuilding Injection, Blow Molding, and Thermoforming equipment.

Most of our control upgrades on older machines did not involve proportional hydraulic systems so you can get by with less PLC horsepower.

Depending on the machine we used everything from PLC2s, PLC5s, SLCs, and did quite a few Barber Coleman retrofits.

We kind of got out of rebuilding when IMM prices got so low it just was not cost effective unless it was either large tonnage or specialty.

I do not Know what the everyone elses requirements are.
in 2009 the Aus. Std.s were changed.
Now they require any modification to a Hydraulic press, (or Hydraulic whatever) to include Monitored Valving.
(Cat3/4 risk profile - I think that is SIL.3)

Note: (Setup conditions apply)
Mechanical Press stopping time (500 ton)
200mS @ 90deg. = about 75 mm distance from stop
250mS @ 90deg. = about 200 mm Distance from stop

 

[iant]

@osmanmomin
The videos are great
this is good a Die protection system.
My point is - the guard is closed - so no problems.
when we refer to "safety" - we are usually talking about the guarding
very rarely do we call a system like this a safety device.
As I said before. the movement of the mold is not permitted with the guard open.