Product collection improvement

[martijnjanssen]

Hello

For my internship i'm responsible for the product collection improvement. The problem is that alot of the small products get lost, my coördinator was telling me about something that get full forclosure around the mold, you click it on the tie bars, then it would go down over the open mold. When the products eject they will be trapped and can only go downards.I was looking for examples how other companies do this.

Was thinking of something like this that would click on the tie bars
126

Thanks in advance



Best regards
Martijn Janssen

[brentb]

Contact: MAC which is Molding Automation Concepts or: Harvard Factory Automation -


and

KOM

brent

[martijnjanssen]

thanks for your reply Brentb, those companies were really usefull.. If you know more of these, feel free to share

Martijn Janssen

[joeprocess]

Martijn,
I have found the curtains and chutes as shown in this picture not all that effective for very small parts that are very light. As you can see there is still a lot of areas for parts to go. We built an EOAT that looks almost exactly as what you have drawn up. We included a gripper to grab the sprue for depositing it into a grinder. This EOAT enters the molding area and butts up right to the core side P/L so that when the parts eject they have no where to go but down.127

[martijnjanssen]

Joe,
You're right, the curtains don't work too well on parts that are very small but I think an EOAT would make the production time alot longer, and also is more expensive then what I had in mind.
I've been designing what I was talking about before129 this would go down when the mold would open 128, then the product will ecject and go down in a chute that leads to a conveyor.

But since i'm using a hydraulic cylinder and not a robot, can I still teach the machine not to close when the cylinder is down?

[joeprocess]

Sure, that is pretty easy. All that is needed is a mold close inhibit switch affixed to the top of the cylinder. You will also need to figure out how to control when to enter the mold area so as not to run into the top of the mold. I'm guessing you know that already though. Additionally, you will want to figure out a safety circuit that prevents actuation of the cylinder when the door is open. This can be done with a set of relays if you are trying to keep cost down.

[Suhas]

Joe Thumbs up !

[martijnjanssen]

Has anyone looked into making a air curtain with airknives for this problem?
Is it plausible, or am I waisting my time researching this?

[rickbatey]

Typically with air it will take a couple seconds for the air flow to be created and flowing like you need it. Now I've seen vacuum attached to tubes that are tied to a small catch bin. A device similar to yours is driven into the mold by the opening stroke ( you could drive yours mechanically) and the vacuum is always on. The parts are sucked into the tube/hose and off to the catch pan. This was done to allow separation of multi-cavity molds. That way only the bad parts were tossed into the grinder. If I was you, I'd use air versus hydraulics. If you blow a hose or the cylinder leaks, clean up is nothing and it shouldn't make you scrap any parts. Plus I figure you can use a valve block and hoses large enough for speed to not be an issue. Plus you can use a spring return cylinder to reduce air loss in plant letting the mold close on you containment piece. You will need to stop ejection until extended as well as not allowing mold close until back up. You could run them as a core function which makes tying into the press easy and allows easy clamp and ejector control until end positions are met.
Rick

[martijnjanssen]

Rick you've given me a few good things to think about. Thanks for the input.

[joeprocess]

Another device we built for small parts that fall straight down is a flexible, funnel-shaped guide skirt that necks down to a 3" opening. At the bottom of the opening a venturi tube is attached. The outgoing side is attached to a hose that feeds a baffle box. The unit is triggered with a mold open signal.

[martijnjanssen]

Thanks Joe, that is a interesting idea.
What was the distance between your guide skirt and the bottom side of the mold? Also, to be sure I understand 100%, could you add some pictures?

Regards,
Martijn

[joeprocess]

The skirt/funnel is hung on platen bolts directly underneath the mold and is removable.132133131

[martijnjanssen]

How did it do? If I only used this, no curtains or anything. Would it suffice?

[joeprocess]

It works well if the parts fall straight down, if the parts launch sideways or up than we run the job with the EOAT attached to the sprue picker robot as mentioned way up in the forum. We have a couple jobs that are sub-gated on the core side of the mold and when the sub-gate flexes out of the steel it flicks some of the parts sending them flying. I'm sure that there is some mold tooling solution for this, like delayed ejection, but being a 5X8 MUD it becomes more challenging. So we went with the diverter EOAT.

[JayDub]

I have used accordian-type curtains that attached right to the side of the mold. That helped with a part that wanted to bounce around before it fell down. I can't recall where we got them though. For a very tiny part that tended to float like a snowflake, we had to use EOAT with vacuum and air blast to put the parts where we wanted them.