What does your factory do to avoid contamination?

[jake1]

Hello everyone, I am currently doing a contamination study at our injection molding factory, and one of my tasks is to figure out what the industry standards/practices are in this regard. There seems to be very little information available on this topic online (mostly just people selling you stuff) so I was hoping you guys could help me out. We are not a clean room factory, just trying to make improvements so you don't get nylon in your PP and clog up the nozzle and stuff like that.

My main questions are regarding materials contamination avoidance practices. Does your factory use special covers on all barrels/gaylord or do you just crack the original lid? What grinder/dryer cleaning policies and practices do you have? Do you train and have a well laid out procedure to purge machines? Do you pay for purging material or just use resin? Any information or advice would be helpful, thanks in advance!

[brentb]

We do everything you mentioned, and:
Use vacuum cleaners instead of compressed air to clean
Clean grinders in enclosed room (with filtered ventilation) newer units are easy to disassemble and clean.
We use DynaPurge purging compound Grades M, E2 and P and use a standard procedure based on the purge compound maker and our collaboration
Closed, marked and wheeled resin bins
Traceability and ID on resin and regrind

Keep On Molding!

brent

[Suhas]

Also educate your operators - all black runners are not made out of the same material.
Suhas

[stewartbf]

Hi,

We use virgin material only. Eliminates most problems.
We have a well documented process that uses pictures as visual aids as much as possible.
tests for those who are molding.
no purging compound needed resin only.
document any and everything make it a procedure put in MPI

Stew

[jake1]

Thanks for the great feedback! Another interesting procedure I found was "flushing a grinder" as described here: http://bernardray0.tripod.com/id26.htm (tip number 21). This is the only mention I of granulator flushing I can find on the internet, so I was wondering if any of you practice this or have heard of this before.
Thanks,
Jake