Injecton molding standards

[nemanja]

Hi all,

There is one problem that i have, and that is explaining quality of molded products to people (quality control :confused:) who dont realy know nothing about molding itselff. It happens that in one shift product is good, and in other same product with same cosmetics is not. It makes stoppages in production and it realy confuses operators on mac.hine. Now is more "personal feeling" and mood of people who need to confirm production quality
You simply cant explain that in some applications we need high pressure for good part but that we have pressure limit for some other reasons, so we cant have 100% good part.
Is it any standard that we can use that describes problems as "good", "aceptable" and "defect" beside IPC standard that we use now?
In IPC is explained some problems in overmolding but not all.

BR,
Nemanja.

[rickbatey]

The definition of a GOOD part is simple: One that the customer will pay for and has acceptable appearance that fits the mating part/car. A customer wants a $9.00 part but is only willing to pay about .35 cent for it!! If you leave it up to how a person feels, you’ll go out of business far too soon. Get a part signed off by the customer and keep it in a bag so it doesn’t fade, get dirty, or covered in fingerprints. This doesn’t mean you can’t and shouldn’t try to improve the part every run. But at least you should make a profit on the parts.
Rick

[nemanja]

Main point in 90% of my products is that they are water-proof, and if there is any sign that is visible. Customers will accept as long as those two conditions are meet. On the other side we trying to be best as we can, but we working with tools that price is around 2000$, and they are often not so great (bad wenting, flow of material, small or big gate etc.). We constantly improving tools but in meanwhile production must run. And there is problem with ignorant people. You kill yourself trying to make best part possible with tools that you have, and someone form quality department say just "I dont like it" and make headache for me. Thats why i need some general standard if there is any, if not ill try to make one on level of company.
Also we approval from customer takes from 3 weeks till 6 months and is not always possible to get it with export 2 times per week.

N.

[brentb]

Main point in 90% of my products is that they are water-proof, and if there is any sign that is visible. Customers will accept as long as those two conditions are meet. On the other side we trying to be best as we can, but we working with tools that price is around 2000$, and they are often not so great (bad wenting, flow of material, small or big gate etc.). We constantly improving tools but in meanwhile production must run. And there is problem with ignorant people. You kill yourself trying to make best part possible with tools that you have, and someone form quality department say just "I dont like it" and make headache for me. Thats why i need some general standard if there is any, if not ill try to make one on level of company.
Also we approval from customer takes from 3 weeks till 6 months and is not always possible to get it with export 2 times per week.

N.

Age old "Molder's Dilemma"! This is one thing fought all over the world, and is common across all cultures!

I can only say:KOM

KOM
brent

[chrisprocess]

If you do some type of up-front mold validation or process validation before you ship parts, you could communicate these quality issues with your team before hand and determine "acceptable" levels of defects. Measurable defects could be similar for every mold, or specific to certain molds. But yeah I hear you when working with older tools those quality issues can easily escalate. However there's really no point in taking the quality guys on, at the end of the day they make the calls!

Could always get yourself a quality manager that isn't strict

[brentb]

If you do some type of up-front mold validation or process validation before you ship parts, you could communicate these quality issues with your team before hand and determine "acceptable" levels of defects. Measurable defects could be similar for every mold, or specific to certain molds. But yeah I hear you when working with older tools those quality issues can easily escalate. However there's really no point in taking the quality guys on, at the end of the day they make the calls!

Could always get yourself a quality manager that isn't strict

Or a QA Manager that is visually impaired? (Can I say that?)

KOM

brent

[chrisprocess]

Once worked with a company that wanted to improve quality so the brilliant quality manager had a "passing thought" and decided from this-day-forth all molds would hit a 1.67 Ppk capability, which is extremely difficult to hit with tight tolerances and sub-par equipment. He didn't have any type of action plan or anything.. Eventually all it did was open up drawing specifications on existing and new drawings so customer effectively was getting a lower quality part. But hey we hit the 1.67 Ppk. He probably got his bonus for the year :rolleyes:

[nemanja]

Answers to this problems, make my day.:cool:
As i see now, only solution is to make catalog with all criteria, pictures and description of problems and what is acceptable and what is not, signed by QA manager.
I already started to work on something like that but it takes long time to finish, especially when we have over 100 different products, and all the time new problems.
But once when is done i will be able to see the day when i wont get 10 pictures of problems, while im out of company on fishing trip. :D
Thanks for replays.