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Silica For Matting Agent
Silica for Matting Agent Dispersion is the process of deagglomerating, wetting,evenly distributing and stabilizing pigment particles. Aswith all pigments and fillers, silica matting agents tend to agglomerate during storage and shipment. Due to strong attraction and compaction forces, the...Chat Now
Silica for Matting Agent
Dispersion is the process of deagglomerating, wetting,evenly distributing and stabilizing pigment particles. Aswith all pigments and fillers, silica matting agents tend to agglomerate during storage and shipment. Due to strong attraction and compaction forces, the individualparticles tend to form the smallest external surfacecausing agglomeration.Sufficient shear for dispersion can be achieved by the use of high speed stirring equipment e.g. a dissolver, and such equipment is to be recommended in all cases. Care should be taken to avoid temperatures above 50° C when using wax treated products .To obtain good dispersion results, it is necessary that the liquid rotates in the container with a laminar flow. The right type of flow is achieved when the mill-base forms a vortex and the central portion of the blade is barely visible. This is called the doughnut effect.Under these conditions and using a tip speed of the blade(= peripheral speed) of 5 – 6 m/sec.,matting agents with our silica will be de-agglomerated and fully dispersed within 10 –15 minutes.Relatively high shear forces are developed during the dispersion process as a result of the rotational speed and the geometry/size of the dissolver blade. The relative dimensions of the dissolver blade, the container and the filling height, as well as the optimum viscosity of the mill-
base are of decisive importance for an effective dispersion.The peripheral speed of the blade depends on the rotation speed and the size of the blade and can be calculated using the following equation:
π • d • u = peripheral speed (m/sec)
π = 3.14
d = diameter of the blade in cm
u = rotation speed per minute (rpm)
The danger of destroying the matting agent particles through excessive shear forces during dispersion, called“overgrind“, is generally not a problem for these stable
micronized silica gels. Care must be taken when a milling process is used to incorporate the matting agent. Under excessive shear conditions overgrind can occur resulting in a loss of matting efficiency and an increase of viscosity.
Example: Rotation speed = 3000 rpm, Blade diameter = 4 cm
3.14 • 4 • 3000 = 6.28 m/sec peripheral speed
The state of dispersion (= fineness of grind) according to EN 21524 can be measured by using a grind gauge, e.g.a Hegman gauge. For every JK silica product there is a typical achievable Hegman value depending on the particle size distribution.
Our matting agents are easily dispersible and can be incorporated directly into the finished coatings
system at any stage of the manufacturing process. This enables the postcorrection of gloss in the ready-made paint system.
Loss on drying (2Hrs,105℃)加热减量
Ignition loss 1000℃
DBP absorption value
pH value (10%aqueous suspension) pH值
SiO2 (Dry Basis)
BET specific surface area
Soluble salt (Na2SO4)
Average particle size 平均粒径
45µm sieve residue
This batch of product is qualified
Jinsha Precipitated Silica Manufacturing Co., Ltd. is one of the brilliant silica for matting agent manufacturers and suppliers in China, welcome to buy silica for matting agent made in Shaxian Sanming in China from our factory.