The Inherited Tool / Job part 1

We all have them, the new job to you but the one that the other guy lost, gave up or in some cases happily gave up to the low bidder. Need we say more, what was someone else’s headache, lost leader or maybe best tool is now in your possession. No run sheet, no real data or maybe a set up sheet for the machine.

Where to start? Basically this is a new mold for you so maybe you want to run a mold sampling and process optimization. If you have the previous machine setup card great, but understand these are typically machine setting. If in fact you have mold settings such as fill time, plastic pressure you are pretty much home free.

So we dial in the mold and produce the parts that look good to everyone, in fact the customer has never seen his parts look this good, only one problem they are too big. So what do we do??  The molders dance! We cut down the cooling time or pressure and process the parts to size. Everyone is happy and you get the okay to make the first run and away you go. At the end of the run the costing comes back and it is not good. You make cycle time but the reject rate was 20% or maybe only 10%  and we made no monies.

What happened? When in fact it was found that parts were too big we may have wanted to measure steel and part to see what our shrinkage was. Are we shrinking to specification? We realize the tool made good parts but do we really know all the history behind the job? .
The above is real, been there done that as have many of you. The data is in the details, of running the process optimization and or first article steps. Basically setting the job up to use scientific molding and generating the information. There are further steps to be taken and hopefully a process to follow.

The list following are steps, tips and or ideas to follow with any new tool to you.
1- inspect the mold.
2- Inspect parts from previous molder or trial shop
3- Calculate out the press to use
4- Know what material is to be use
5- What was it quoted at cycle time wise…
6- Anything special to know,, inserts, secondary, packaging
7- Hang the tool and test, dry cycle first.
8- Measure the parts
9- Communicate concerns and data back to appropriate people.
10- Run the job.

Though the above list is general, over the next few tips we well explore the details.

Thanks much for the time.

Steven L Silvey
Silveys’ Plastic Consulting
peipai@aol.com
360-882-3183