Rotor Dispersers and Colloid Mills for Paints and Varnish Production

Rotor Dispersers and Colloid Mills for Paints and Varnish Production

After centuries of hard and time consuming grinding of natural mineral and organic pigments, mixing them with vegetable oils, lime milk, chicken egg yolk, turpentine and other types of binders, paint manufacturers have finally developed high performance production lines that are capable of producing tons of paints continuously without interuption.

Paints have become complex multicomponent mixtures, consisting  of fillers, pigments, solvents, surface active agents, film-forming substances and other reagents.

Paint production is a very complicated technological process.  The first stage consists in producing a pigment paste by dispersing a powder-like filler in a liquid base.  Then comes color matching with the help of the main pigment which is followed by adding the necessary amount of solvent to obtain a paint with the necessary color and viscosity or thickness.

In this chain of technological processes, dispersion of solid fractions in a liquid base is deemed to be the main process that largely determines the quality of the final product.  In the proper order, the quality of dispersion depends on technological characteristics of the equipment used in the paint making process.  The type of the disperser used is determined by the viscosity of the suspension being processed.  Originally, burr and ball mills or roller machines were used as dispersers.  Then they were replaced with pearl mills, friction rollers and screw type mixers.

Since the volumes of paint production increased, the production engineers started to pay special attention to dispersers and colloid mills.  The specialists know that decorative, protective and optical properties of paint materials depend on the  degree of paint dispersion.

Powder bases and pigments, produced by the chemical industry, consist of  separate crystals and their joints.  Given that the size of crystal joints are much bigger than that of a solid fraction,  it is one of the main technological processes during paint production that is considered to be a destruction of crystal joints or disaggregation.  Rotor dispersers and colloid mills are used to solve such tasks.

Influenced by  high-frequency load and cavitation impacts, colloid mills and dispersers not only destroy solid particles, but they also intensify  the moistening of their surfaces, and force out adsorbed gasses and water thereby stabilizing the created suspension.

It should be noted that at a certain stage of dispersion secondary agents are formed that reduce the final degree of dispersion.  The stability of a disperse system however, may be disturbed by other reasons such as excessive dispersion that lacks surface-active substances or dispersion of the pigment with a moisture content.

To avoid this, production engineers are required to create the proper technological modes.

If it  is necessary to additionally reduce the size of the pigment particles,  this process is performed in a colloid mill.  GlobeCore has developed the CLM dispersers-homogenizers to grind down and blend the components of paint.  Equipment, produced by  GlobeCore, ensures a fine grinding of solids and thorough blending of components.

обновлено: September 15, 2015 автором: globecore