best way to install inserts on plastic parts

[Krypton1]

Hi. I am currently looking for alternate ways to install some brass inserts nuts into some molded products that we are to start producing.
These molded products are currently being molded along with inserts. I would like to try to install them right after being molded. I have been talking with a vendor who's actually building some insert installer machines. He told me the following:
"I understand the customer’s comments and had envisioned this “strip feed” process would be that easy. In reality it hasn’t. The vast majority of the molders we work with found it was not cost effective to purchase and have operators for both an insert placement machine and an insertion machine. While the system we developed worked wonderfully – after about six months of use the customer decided to go back to manually loading parts.

Not only is the insert more expensive (due to loading on plastic strip), the tended to have issues with operators skill levels and the fact they were manually loading inserts anyway after failing to load properly with the equipment. Occasionally when they ran out of stock of insert on strip they used bulk parts – with few employee issues.

I’m not opposed to this type of development; the cost for insert loading only could approach $10,000 to $15,000 and would like to be sure all the issues are addressed. Additionally – the insert cost also increases due us having to load on strip". What do you think?

 

[patprimmer]

I am not quite clear about your question despite your commendable efforts to include all relevant information.

I understand you are loading the inserts into the mould and over moulding to form the plastic part.

I understand you have an automatic loader system that works mostly, but has some reliability issues.

When you revert to a fully manual system you get a satisfactory outcome re quality and cost when compared to the automatic system.

You are now considering adding the inserts after moulding.

If all this is so, I would expect ultrasonic or vibration welding to be the method. Hot staking might also be possible

Is your question about which alternate methods, or details of mentioned methods.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Krypton1]

We are not molding any of those products yet, these are being molded by an outside vendor for another of our branches. We are to start molding those, yet I just know that the outside vendor is currently manually loading into the molds. my question is: If we are to start molding those parts, what's the best way to install them: manually loading into molds before molding or an after molding operation? most of these parts have around 5 inserts to be installed, so if an after molding installer device is to be used then it would have to be very complex as we'd have to install that qty of inserts. What do you think?

 

[patprimmer]

It is usually a case by case situation.

I would be searching for equipment manufacturers to get quotes on systems, ang trying to get real costs for the various done to date options from the other branches.

I would try to determine if the automatic loading system used by other branches was flawed in concept or just in detail. If in detail, can it be easily corrected, or can the concept be changed, ie to say use robots to place the inserts instead of plastic strip.

Would a vertical press be of advantage. If so is one likely to be available.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.