Dear Mr Liang,
Further to our discussion, you will be receiving a new masterbatch sample
made with 25% LIFE AI-00-1A sample shortly. This new material has a
refractive index of 1.51, which is about the same as normal PP resin. So it
should yield the best transparency in clarified PP resin. However, we are
having some difficulties to produce good transparent plaques in clarified
Borough PP RG468MO resin.
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(Left) Clarified PP RG468MO with 0.5% LIFE AI-00-1A (Right)
Clarified PP RG468MO only - Control sample
I think there are a couple of factors that could have contributed to the
haziness, so please take the following factors into account when evaluating
the samples.
Sample #1 25% LIFE AI-00-1A Suggested use rate is 1.2%
Sample #2 25% LIFE AI-00-1A with FDA approved toner Suggested
use rate is 1.2%
Masterbatch use rate. Our recommended usage is 1.2% (= 0.3% active),
but you use only 0.2% active in your current products. So, you may
consider lower the usage if greater transparency is required.
Container wall thickness. Your container will become milky white if
container wall is thicker.
Selection of clarified PP. Help test our products in different grades of
your clarified PP as there could be "unknown reaction / oxidation" with
catalyst residue, nucleating agent or other minor ingredient in PP.
Injection molding process conditions. "Care must be taken in processing
clarified random copolymer PP resins because if too high of a melt
temperature is used, the clarifier degrades, and haze values go up.
Parts molded from clarified resins may have a slight, cherry-like odor,
but a very strong smell near the molding machine can be a sign of
clarifier degradation." In any event, it seems that lowering processing
temperatures might help the clarifiers survive and do their job.
For translucent or opaque PP parts, please consider the following garde as
it will be a lot more cost effective.
16287-Z1-400 nShield AMIC Natural PP Lot: S-10705-A-141103
Usage 2.0% ( 1.0 kg) Additive Ingredient: 25% LIFE CD/I-00-1A
Give me call when you receive the samples so that we can walk through the
test protocol again. Thank you!
Kind regards,
Stanley
(See attached file: Borouge PP RG468MO CN.PDF)