The properties listed are determined according to following test conditions.
ADVANTAGES OF PLASTIC FLUSH FOR MASTERBATCHES –
Among the pigments, high performance polycyclic pigments like phthalocyanines, quinacridones etc. are hard to disperse. Their dispersion hardness is high. The pigments for plastics need to be finer. As they become finer, the dispersion related problems increase.
The result is agglomeration, difficulty to achieve high pigment loading, lower colour strength, high energy input to achieve dispersion, necessity to use costly dispersion machinery, lower productivity and need strict control on process parameters.
This has severe effects in coloration of thin films and fine denier fibre production.
The films have specks, on continuity and may tear off. The film with such defects can not be used in many applications. In fibre production, the agglomerated particles cause frequent choke up of spinnerates. This results in loss of productivity, more downtime and inferior quality of fibres. The properties of fibres are affected by oversized particles.
With the best of pigment powders the particle size achieved after dispersion could be 5 – 10 mµ.using best dispersion machineries. Thus, pigment powders have limitations to achieve fine dispersion, lower pigment loading is another limitation.
Flushing is an established technique of transferring the pigment from aqueous phase into the polymer of application. This began in ink industry wherein this is a standard technique.
Since the pigment is transferred from presscake stage into polymer, the particle size is maintained between 2 – 5 mµ The agglomeration and hardening during conventional drying is avoided. The pigment primary particles are coated with polyethylene wax which prevents the pigment from reagglomeration. Since the pigment is already fully dispersed in wax which is compatible with the polymer, final masterbatch with any pigment level ( below that of flush) is possible using even low shear dispersion machines.
The result is agglomerate free, high color strength stable dispersion which needs much less energy input.
The productivity increases. Handling of pigment powders result in dusty atmosphere. Flushes are easier to handle and they can be metered into machine in a better manner than powders, maintaining clean environment.
There is another advantage of maintaining lesser inventory of colours. Using selected primary flushes, a wide range of shades can be manufactured in a faster way.
They are made from plastic grade pigment press cake manufactured in our modern plant. AArbor offers 50% pigment content in high grade polyethylene wax. The wax allows the flush to be used in Polyolefines and PVC. with which it is compatible.
The flushes are controlled for various quality parameters listed earlier.
Compatibility :
AArbor flushes are compatible with Low Density Polypropylene, High Density Polypropylene, PP (film, fibre, sheeting, containers, injection moulding).
AArbor flushes can also be used for coloration of rigid & flexible PVC (film, sheet, moulding etc.)