Toshiba part quality monitoring question

[Ten Fingers]

Hi all,

I have told a molder I work with to start using process alarms on my parts. They have set up monitor alarms with max rejects=3 without a problem. I want them to use an injection timer alarm with the max set at 1.2 seconds (actual inj time is around .95 seconds) to prevent over-packing on a stuck part or plugged gate. When I have checked, this alarm has been turned off. They say that when the press is restarted following an alarm they have to turn this alarm off or the press needs to be restarted several times until the inj time is below the 1.2 seconds due to continued alarming.

Is there a way to have the alarm function, but not be active during the first couple rejected parts when the press is started up? Controllers are V30 and V50.

Thanks!

... and yes, I think it is scary that they were not using the monitors in the first place. Sadly, it is not my decision on where parts are molded.

[rickbatey]

What about peak injection pressure monitoring? I'd think that would trend up faster than the injection time. I know on an Engel you can set multiple switch over parameters like 6 mm of screw stroke plus say Max injection psi of 180B as well as a peak pressure of 165B after half the injection stroke.
On an Engel this is handled through the start up shot counter plus you can set a separate switch over stroke and a percentage of hold pressure during the start up shots. My time on Toschiba's doesn't ring a bell with that functionality on the press.
Rick.

[brentb]

I can't find that feature on the V30 where the initial shots are discounted, but there are so many features. we monitor fill time and many other parameters and do get alarms at first, but discipline is always needed.

Our later Sodicks and Engle presses can be set to reject and ignore a set number of startup shots

A good non-pressure limited (SM) process should always keep fill time very close to set, I mean a few hundredths of a second.

KOM

brent

[brentb]

What Rick said got me thinking. PI1 is set on the Toshiba inject screen. It is maximum allowed inject (fill)pressure. Many (lazy?) Molders set and or leave this at maximum. So the press can go to system max if transfer point is not reached.
Establish a "good" process and set PI1 just above the pressure needed to fill the part. between 10% and 20% is more tan enough. This is your reserve pressure to maintain fill velocity.
If this is done and the Molder forgets to configure or turn on alarms, you are still safe. This is basic SM Molding.
All these "labor saving" features on the newer presses can lead to brain atrophy and the death of common sense!

KOM

brent

[Ten Fingers]

Thanks all, sounds like there is no easy way to get what I want to happen on a Toshiba. I am used to having a start up reject counter to ignore the first couple shots. A little saddened to hear Toshiba's don't have that available.

[Wittmann_Molder]

It might be worth trying to call Toshiba and see if it's an option. Our newer (V50) machines didn't have an eject forward delay timer on them for some reason. All of our older machines have them and we use them for faster take-out with the robots. So I called Toshiba up and asked why the newer ones didn't have the option and they told me they just weren't "unlocked". A few easy steps in the "back pages" and the icon popped up on the screen.

But as was stated above, a tight peak pressure limit and a little bit of discipline with the techs may negate the need for the start-up shots.

Best of luck.

[rickbatey]

One thing I forgot to ask: Are they using any automation? If so a counter could be set up in the robot to reject those start up parts and any shots made out of tolerance. If it's a sprue picker or very basic robot then you're still sunk.
Rick

[Brisli]

It has been a couple years since I've worked on a Toshiba, but if I recall correctly the timer for injection covers both fill and pack or hold what ever they call it, right? if the alarm can be set to just monitor the fill stage that is good but will not prevent over packing due to a stuck gate. if your actual fill time is .95 seconds, that is the time to fill all cavities, if you have a stuck part or gate the alarm will go off to late resulting in over packing. as Brent mentioned above you need to monitor fill pressure until just before transfer, and alarm then.

[brentb]

Maybe it does, call Toshiba 847 593 1616