The Inherited Tool / Job part 3

In the previous articles we have covered a general overview and the inspection of the mold. Let us now continue on our inspection process.

The parts, hopefully you have some from the previous molder or trial shop for your review.
1- How do they look, cosmetically, color, glass filler if glass filled. Make your notes as to how they appear to you. Were these acceptable to the customer?
2- If a family mold or multi cavity, do you have parts on the runner? Does it appear they all ran at the same time?  Everyone has been there when you first shoot the new tool (to you) and find that they had block off a cavity or two to get production out. Viewing the runner and inspecting the gate may give a heads up. Do you note any joints in the runner?
3- If the parts are colored, do you have a chip to match or have they given you a part and said to match this? Is this critical match or non critical? What range do you have and within their color spectrum what place is this part in their range? It is very easy to have been given something that is at the plus end of the range and you go for a +/- range on this and fall out of favor due to being on the plus side.
4- Do you note any markings on the part, say an ejector pin or inside the part? This may be an indication that the previous molder may have inherited the tool. This marking lets people identify products they made.
5- Do you have a part that the customer has marked up to tell you where they have issues with and or critical dimensions?

These are only a few for the part but are a starting point for questions and comments from you and your team. If you do not receive any parts than review your first molded parts with customer and their quality folks to establish all the boundaries.

The calculation of what press to use is usually established by where the job will fit or what press is open at the time. Basically this is a first guess, and after placing and test shooting via a scientific method you will have a better understanding of where to run the tool. If in fact you have the data that it ran in a 500 ton 12 ounce press than that’s a good start. If you can get other information out of the customer it might be:
1- Size and tonnage of press
2- Do they happen to have a set up sheet?
3- Make of press and possibly vintage, than you can back track and possibly figure out the intensification ratio and speeds this press is capable of.
4-  If no information is forth coming than:
a. Calculate out projected area
b. Estimate clamp tonnage based on projected area and of course mold size
c. Using material supplier data should help here. Stay in midpoint of what they recommend.
d. Know the stroke of ejectors, and opening stroke for mold
e. Shot size.
Again just a starting point to the questions, use it as a start for your list or check sheet of things to review.

Thanks for the time, to be continued.
 

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