Color masterbatch market is rapidly increasing in size and potential. This leads to some difficulties in finding the most suitable color masterbatch for each specific desire. But how to know the masterbatch you are using is good or bad? Read this article to find the basic criteria that need to be followed in evaluating the colored plastic compound.
Dispersion of color masterbatch is very important in manufacturing
Regarding to different types of colorant for plastic, there are 2 outstanding names: pigments and dyes. Dyes are known as the soluble colorant whereas pigments are not dissolvable in the medium. The pigments we use daily to create color masterbatch exist as aggregates and agglomerates of particles instead of individual particles. If these agglomerates are broken up into the precise size of requirement, it could be said that the masterbatch has good color dispersion.
Natural transparency of base resin can be preserved in color masterbatch
Transparency of color masterbatch is a special effect that nearly every manufacturer can offer to enrich the diversity of their product catalogue. Master batch with transparent appearance not only provides good looking to the final products but also allows the color compound to be used widely in various applications. This appearance is surprisingly quite easy to be achieved since the primary base resin, especially those with polyolefin base, is naturally transparent. However, this transparency is easily affected by additives, fillers and color components added into the plastic mixture during production. Obviously we can not cut down the amount of fillers and additives added into color plastic beads as they provide extra stiffness, enhance rigidity, thermal resistance and tensile strength, so controlling quality and properties of these additives is extremely crucial.
Opacity is another aspect in appraising color masterbatch
Contradictory to the transparency, opacity is considered as another crucial element in evaluating quality and properties of a color masterbatch. In some places, opacity of the master batch is called as hiding power. In particular, organic pigment that does not contain heavy metal is likely weaker in providing opacity, color performance and dispersion as good as the inorganic pigment with heavy metal elements. Differences in the opacity and lightfastness between organic and inorganic pigments (both contain heavy metal) are also noticed and reported.
Pigments in color masterbatch should follow CONEG legislation
Colorant for plastic used in masterbatch is encouraged to be under the control of CONEG model toxics legislation which aiming to reduce the sum concentration of all 4 heavy metals including lead, mercury, cadmium and hexavalent chromium. The total consumption of all mentioned metal must be less than 100 ppm (parts per million). In general, color plastic beads with heavy metal are recommended for utilizing in applications exposed constantly to harsh conditions and required long durability.
Lightfastness need to be seriously controlled in color masterbatch manufacturing
Lightfastness is defined as fading resistance of the color masterbatch. This is one of the most important indexes that need to be well considered when choosing colorant for plastic. The values of lightfastness is measured according to a standard Blue Scale rating system consisting of 8 levels in which 8 represents the highest resistance to fading. Quality of the used pigment in masterbatch manufacturing has a huge impact to the lightfastness of that masterbatch. Besides the pigment’s quality, the exposure condition during lifetime of the product also determines this factor and leads to the reduction in product’s life expectancies.
High lightfastness partly ensure that durability of the finished applications requires this feature, especially outdoor goods such as fiber optic cable conduit, industrial containers, external furniture, safety fences, etc. However, in consumer packaging productions, lightfastness of the color masterbatches is generally not a concern.
Color masterbatch also needs to be highly stable and contains good heat resistance
There are several factors affect durability and thermal resistance of the master batch, such as the lightfastness and dispersion of pigments which are mentioned above, the molecular structure and chemical properties of pigment particles. There is not the absolute good or bad when you evaluate the color masterbatch. The point is whether it is compatible with other ingredients. Therefore, it’s importance to check chemical properties of all components involving in the masterbatch.