Positive Control of Non Conforming Material at Machines

[Jane27]

My company manufactures metal parts for automotive and aerospace. The parts are about the size of a hockey puck. Currently operators place bad parts into red plastic scrap bins. They are supposed to paint each bad part with red dykem, but this doesn't always happen. As the result of this it is not uncommon for a bad part gets mixed in with good parts. I would like to implement locked scrap containers that only allow the operator to place the part in. I have seen one company that did this using Hazmat containers. They drilled 5 x 5 holes in the lid, and stenciled SCRAP on the bins. The problem I have with this, is that I don't like the fact that you can't see what is being rejected. I am wondering if any one has seen other types of containers/ baskets/ cages being used to contain scrap at the machine. A PVC coated cage sounds interesting, because fallout would be visible (good indicator as to how job is running). Can't find a product that is designed for this purpose. Would appreciate any suggestions. Thanks

 

[Golfman25]

You really need to find out why the parts are getting mixed. My guess would be it is due to a brain cramp in which the operator puts the part in the wrong bin -- been there and done it. IF that is the case, then locked bins would not really prevent the mixing. If the mixing is after the parts are in bins, then a locked container would certainly help prevent mixing. Any chance you can stop making "scrap" in the first place?

 

[Joy]

My company manufactures metal parts for automotive and aerospace. The parts are about the size of a hockey puck. Currently operators place bad parts into red plastic scrap bins. They are supposed to paint each bad part with red dykem, but this doesn't always happen. As the result of this it is not uncommon for a bad part gets mixed in with good parts. I would like to implement locked scrap containers that only allow the operator to place the part in. I have seen one company that did this using Hazmat containers. They drilled 5 x 5 holes in the lid, and stenciled SCRAP on the bins. The problem I have with this, is that I don't like the fact that you can't see what is being rejected. I am wondering if any one has seen other types of containers/ baskets/ cages being used to contain scrap at the machine. A PVC coated cage sounds interesting, because fallout would be visible (good indicator as to how job is running). Can't find a product that is designed for this purpose. Would appreciate any suggestions. Thanks

I thought to suggest you a glass container with a metal lid and provision of locking

Try thick metal wire mesh container with metal lid with locking system.Select the mesh size as per your product size.So,you see from out side but the parts don't come out.

 

[silentrunning]

I'm not sure what your processes are, but we manufacture springs and the machine sorts and records the long, good and short springs. We then weigh count the scrap springs to match the machine counter. This prevents operators from "sweetening" their scrap ratio by dumping some bad parts in with the good. If your machines automatically sort the product, you could try something similiar. If not I would go for a full blown Corrective Action and find the Root Cause. Having bad parts get to a customer can be disasterous.

 

[sitapaty]

Your original method of placing NC parts in a red box is perfectly allright.What you are facing is crisis of indescipline among your work force.Take your work force to a class room and motivate them to segregate NC parts in a dedicated box.
There is no substitute for decipline.
-SITAPATY

 

[Big Jim]

In automotive, this is known as "error proofing". A common method is to have a container that the operator cannot retrieve parts from, similar to a mail box. Only those authorized have keys to the box, such as quality engineers or quality managers.

In aerospace there is the very stringent requirement that once something has been dispositioned as scrap, it need to be permanently marked or positively controlled until it is rendered unusable. Painting it red does not qualify as it is not permanent. It is common to destroy a key feature, such as with a saw, hammer, or grinder.

It is critical, in either case, that you completely prevent any of this bad (or even questionable) material out of the supply chain. You have to do it, or you are not permitted in the game.

 

[sitapaty]

Permanent deforming a rejected part is done after the final decision by the empowered salvage committee.Till then a foolproof segregation method has to be followed.We con't distroy the component at the spot of production.
SITAPATY

 

[bbarbee]

I had a system when I was in automotive where the scrap bins were attached to locking reject chutes attached to the machine frame. When a bad part was detected, the work station would release it and unlock the reject chute. A red light would activate at the station. The operator would confirm the reject on the machine, then put the part in the chute. When the part crossed a thru-beam into the bin, the door to the chute would lock again and the machine would operate.

It's a shame we have to go to these lengths to make people put stuff in the right bins, but there you go. This system, while complicated, worked very well. The team lead was allowed to get bad parts from the bin to take them to the rework loop, but regular operators didn't have access to remove parts.

 

[Jane27]

I thought to suggest you a glass container with a metal lid and provision of locking

Try thick metal wire mesh container with metal lid with locking system.Select the mesh size as per your product size.So,you see from out side but the parts don't come out.

Yes, actually have just gotten quotes for red PVC coated cage tops that fit like shoe box lids onton our existing scrap containers. The lids are locked onto the scrap bins and have slots that only alow parts to be placed in. Just have not quite thought thru how operators will (or wont) identify what the cause of reject was/ when scrap will be collected/ etc. Thanks for your comments.