In most cases today masterbatch (MB) comprises a concentrate of
colorants, fillers, additives or other ingredients for cleanly and
easily attaining specific characteristics needed for the end
application. Since many of the ingredients are originally in powder or
liquid form, they would otherwise be difficult to handle or require
considerable processing outlay. This applies for example to nanoparticle
incorporation in a safe environment, or combining several additives to
attain a specific characteristics profile. After compounding the
ingredients into masterbatches with a system for masterbatch
compounding, metering and processing the resultant granulate is much
easier for end users. Standard processing masterbatch compounding
machinery can often be used instead of complex compounding systems.master batch formula
The
name “masterbatch” is said to have originated in the times when the
“Master” was responsible for mixing specific batch formulations
containing particularly valuable and costly additives. This is exactly
how masterbatch production is classified today: precisely metered
mixtures are compounded through compounding machinery with plastics or
substrates into batches suitable for further processing. The master’s
responsibility of former times is now taken by the masterbatch plant
operator’s specialists.
There are basically three masterbatch compounding methods:
In
many cases the Premix process is used. All the formulation components
are first premixed in the solid phase, often including polymers in
powder form. The premixtures are then volumetrically dispensed to a BUSS
Co-Kneader for compounding.
In the split-feed process, polymer is
fed to the BUSS Co-Kneader melting zone while additives are dispensed
downstream, at several points if so required.
The colour matching
method, with separate feed of the primary colours, enables rapid hue
adjustments for high-quality applications, and efficient colour
changing.
Thanks to multiple feed points, the BUSS Kneader’s specific
capabilities for masterbatch compounding really come to the fore in the
following applications. Due to the operating principle of the BUSS
Kneader’s compounding system, the enormous number of mixing cycles at
moderate and uniform shear rates enables unsurpassed mixing efficiency
with minimal polymer matrix content. As a side effect of the moderate
shear rates, wear and tear is significantly lower than with other kinds
of screw extruders. The modular design of the entire BUSS Co-Kneader
line makes it easily adaptable to all requirements. Together with the
widely based BUSS processing expertise, the BUSS Kneader within the
compounding system for masterbatch is first choice for compounding
filler masterbatches.