:) Hi guys!
Anyone out there who has samples of FMEA PLAN regarding Plastic Injection.......tnx .....more power to all! :) :agree1:

You are wanting a Process FMEA example, correct?

Yes sir that is correct, but specifically that is patterned after plastic injection.......thank you very much.

Yes sir that is correct, but specifically that is patterned after plastic injection.......thank you very much.

There are some samples here: :agree1:
Generic Molding FMEA - Can some one provide me with an example? (http://elsmar.com/Forums/showthread.php?t=10948)

FMEA - plastic molding - Not sure how to start (http://elsmar.com/Forums/showthread.php?t=16074)

much aprreciation for the directions sir_knight :bigwave:

I have just started working in plastics. I am looking for suggstions in education myself in this porcess. Such as correlation on measurements done when the part come out of the mold vs an hour or day later. Also, color standards.
Can anyone point me to a few good books or web sites or share their experiences in controlling and measuring molded parts?

http://www.plastics.com/forums/viewtopic.php?t=23940
http://www.immnet.com/
http://www.pma-magazine.com/issues/
http://www.catalog.com.hk/tatming/quality/content.html
http://www.ferris.edu/htmls/academics/course.offerings/hillm/MYWEB7/Injection%20Molding/IMM%20cycle%20animation.htm
http://www.dynisco.com/
http://www.bykgardner.com/index.php?content=englisch/home.php&service=englisch/service.php
http://se.konicaminolta.us/

Just a few for start. On each site you will find additional links. Good luck.
György

Wow, plastics is really something. I am wondering if anyone can share their best practices in regard to visual boards. They have boards with defects and boards for color They're all over the place but it is doubtfull to me that the
boards are makign an impact on training or improving rejects. Then there is storing them all and controllign them.

Any ideas?

1day38,

here is a sample of visual board that we used

They have boards with defects and boards for color They're all over the place but it is doubtfull to me that the
boards are makign an impact on training or improving rejects.

This is a tough call without knowing more about the culture. It could be that while there's no apparent usefulness, they serve as a sort of security blanket. It's usually not a good idea to evaluate color at the machine; different lighting sources can have a profound affect on color perception. There's a phenomenon called metamerism (http://en.wikipedia.org/wiki/Metamerism_%28color%29) that will cause wildly different results when viewing samples under different light sources. It's best to use a controlled light source and objective measurement and make sure that your evaluation method jibes with your customers'. You can see some examples here (http://www.gretagmacbeth.com/index/communities/reliabledigitalworkflow/ca-digital-workflow-plastics.htm).

As for the sample boards, if you can look at reject data before and after the boards were in place you might be able to form an objective opinion as to their utility. Another option would be to selectively remove some boards and see if there's any adverse effect. You might also want to talk to operators and get their feelings; there might be usefulness that you're not seeing.

Both posting are educating me. I can see where the description, cause and picture can be benefical. They mostly use samples but they are somewhat an organization problem and often outdated.
Do you have any more you can send me such as flash, cracking, etc?

I am looking for anyone who may have encountered a plastic part design where the inside diameter is called off and shows a 4 degree draft angle inside. The wall thickness is .025 thick. The part measurment history has been to measure 90 degrees opposite the gate. The tolerance is a total of .015 and they been measuring with a caliper but no one can repeat their reading and they are always unsure of what they are measuring.
I beleive I should contact the customer and ask if the measurment takes the draft into account and must be at the entire length of the cap of .300. Also why woudl they only measure opposite the gate?
I woudl rather see a mating part being used in this case. Has anyoen this type of situation.
LInda

If the drawing shows the diametrical specification at the large end of the hole, the mearuement is to be taken at the "minus draft" end of the hole. The 4 degrees of draft are then applied - making the hole smaller at the "plus draft" end of the hole. Typically that dimension needs to be calculated based on the length of the hole and your shrink rate.

If the specification is at the small end of the hole, the reverse applies.

As far as a "mating part" to check for functionality, you would need to know that it is at the MMC of that component. You could also build your own "gage" if you knew the dimensions of the mating part.

IMHO - A caliper is not a very good means of checking a hole.

anybody got a good picture explaining + Draft and - DFT ON HOLES AND STUDS??

anybody got a good picture explaining + Draft and - DFT ON HOLES AND STUDS??

Hello kmbgrove,

Welcome to The Cove Forums! :bigwave: :bigwave:

We love to help, but can you be a little bit more specific?

What product?
What material?
What process? (molding?)
What does DFT mean?
Please be aware that this is an international forum. Some terms and acronyms may not always be understood by Fellow Covers from other parts of the world.

Stijloor.

Plastic parts, I mean plus draft and minus draft on holes ( I.D ) and studs ( O.D )...i just get confused sometimes...a picture would help....thanks

Plastic parts, I mean plus draft and minus draft on holes ( I.D ) and studs ( O.D )...i just get confused sometimes...a picture would help....thanks

Could this help?


Handbook of Molded Part Shrinkage and Warpage (http://books.google.com/books?id=0J3DkSwR3qIC&pg=PA117&lpg=PA117&dq=draft+angles+on+holes+and+pins&source=web&ots=7jqngSVPr8&sig=XxkZjrpDv17C0GMpAftllBUIA3c#PPA123,M1).
Basic Plastic Component Design Considerations (http://www.mech.uwa.edu.au/unit/MECH4403/Plastic%20Design%20Guideline.pdf).

There are injection molding process experts here at The Cove Forums. I am sure you'll hear from them.

Stijloor.