melt flow analysis

Anybody can help me to explain the difference betwen Melt Flow Rate & Melt Flow Analysis????

Doing a Burnout test will show you if your process/screw is breaking up your glass.

Get your hands on a ceramic oven. Burnoff part slowly at 1200deg for about 8-12 hours. The part should look just like before you put it in except you've burned away the plastic and are left with the glass. If one side of the part looks fine and the other side the glass has collapsed it means your beating the glass up and should look at your process/mold/screw, etc.......

This is the test material suppliers would do for you.

Well first look up the ASTM standard for MFI/MFR testing: D1238. I have a couple a home so if you need I can scan and email.

First off your variation is seen by the fibers laying across one another over the die. There is no such "GE test" that melt's the glass away called Kayness.

KAYENESS: Is bascially the same idea as your plastometer. But it gives you shear rate at a particular temperature. Also the weight on top is mechanically pushed down purging the material through a die giving you the resistance against the load cell. This is a great test to run with highly filled Mat'ls.

Tips b/c I use to run these tests sometimes 100x/day:

-Make sure to dry your samples in a vacuum oven.

-With GF PC use the highest weight(5kg if I remember)

-Make sure to thoroughly clean out barrel with swabbs, then use wire pippet, then swabbs again. It's clean when your die bounces on the bottom of the barrel.

-Melt Flow Index= When you do x amount of cuts, weight and take average. Used mainly for Polyethylene.

-Melt flow rate=The machine does all the work and references time and distance travelled.

-Go grab that ASTM test method or Ask your resin salesman to hook you up with some Kayeness data.

Hope this helps

>I have some parts that are
>brittle, cracking, and breaking around
>a hole formed by a
>core pin. I have been
>asked to perform a MFI
>test on the material but
>have so far been unable
>to get any repeatable test
>results. I think it's more
>to do with my testing
>methods and abilities than anything
>else. I'm new to this
>test and am trying to
>just follow the instructions in
>the manual. (Dynisco) The material
>in question is a glass
>filled polycarb. I have ran
>tests before with ABS and
>straight unfilled PC and PC/ABS

>blends and the results were
>seemingly ok. At least they
>were consistent in the results
>I was getting. Will the
>glass in this resin cause
>difficulty when trying to run
>this MFI test with this
>type of plastometer? Would I
>be better off sending parts
>to the manufacturer and having
>them test them properly on
>some other sort of machine?
>Any thoughts?

We just went through this - any glass filler will cause you problems. The variation increases as the % increases 10% -30%. You could get through this by just molding he base resin with no glass and evaluate melt flow for dedragation. There is also another test "kayness (sp)". This is a method of disolving the glass before testing. I have only seen this offered from a GE testing lab.

Good luck

Yes, glass fill will give widely varying results. Had to tell our QA man this the other day.

Send the parts to your resin makers, they have sophisticated testing equipment.

brent