Mixing and making process of masterbatches in India

Masterbatches is a product in which additives or pigments are dispersed in a carrier material. This carrier material is same as the main plastic, in which this carrier material will be let down in either granule or pill form. The carrier material can be low density polypropylene, polyethylene, EVA, low molecular weight, an alkyd resin, polymer specific material or polystyrene. The let down ratio of the carrier material can vary depending on the type of additives and pigments quantity required in the final product. The ratio can be below 1 % for some types of additives, UV and color tints to above 50 % in case of flame retardants. Generally for most color products the 1- 3 % is the normal range. To obtain a particular color or additive strength the ratio can be changed.  

 

The most important first step, when masterbatches are made, is  the additive ratio or color formulation. Then all the ingredients are mixed in such a way that they produce homogeneous product. These ingredients are also weighed or may be pre-mixed if necessary. The melting stage must have exact pre-determined temperature, so that the final mixing is homogeneous. The low or high temperatures can give lead to poor shearing and pigment dispersion. To control the rate at which this pre-mix is fed to the extruder, a screw fed system, matched with extruder’s output, must be used.

Using high melt index resin and compounding it with pigments and additives is the efficient way of dispersing.  This high melt resin is compatible with the end use product. The equipment used for mixing should provide high degree of shear with suitable mixing temperature. The mixing is best, when the level of viscosity of the polymer used is quite high. The highest point is the point beyond flux. If mixing is done beyond this threshold, the temperature will rise and viscosity will come down.  The pigment and additives must be properly dispersed .For large production, the internal mixer Banbury is used,

The final masterbatch must be in consistent form and there should be no oversize or presence of any extra matter in the granule form. Today most competent producers use color computers to give all the required information. Color Masterbatches Manufacturer in India  is using the database of more colors and shades to give precise matching with spectrophotometer. The products are made with strict safety and regulatory measures. From the health point of view also care is taken to ensure that the final use of products have no adverse on the users in food packaging products, cosmetics and toys.  More and more manufacturers are customizing the products and color selection. Black Masterbatches Manufacturer in India is using special carbon black to give the quality of UV protection, and resistance to shocks to the products. The final product can withstand heat also.