industry
Manufacture of paints, varnishes and similar coatings, printing inks and emulsions
product
Environmental medium viscosity (200-300 microns), the density of water-based paint is 1.4gr/cm3. The product is pre-mixed, but not dispersed.
new challenge
Improve the dispersion process and obtain a dispersed product with a lower fineness (fineness is about 2-3 microns);
Manufactures a high quality product with improved tinting strength comparable to that produced by major suppliers of artist pigments.
The customer's factory was equipped with about 25 outdated open three-roll machines. After 7 hours of milling, the resulting particle size was 15-20 microns. These Grinders require a lot of storage space and a long installation and maintenance time.
solution
1. Pre-disperse with "Dispermat AE3" disperser
1.4kg of pre-mixed product is placed in a 2L jacketed Water Bath cup with cooling water, using a 40mm dispersion disc, Dispermat AE3 is dispersed at a line speed of 17m/s.
Dispersion effect: After 30 minutes of predispersion, the agglomerates were dispersed to 90 microns.
2. Fine grinding with a "TML 1" basket mill
When it comes time for the grinding process, the shaft of the disperser is replaced with the grinding system TML 1 and 40 ml of zirconium beads with a size of 1.2 - -1.7 mmø are added. In order to improve the recyclability of the product, a heavy-duty dispersing disc with a larger diameter of 80mmø can be installed. Maintain a constant temperature of 33°C throughout the milling process (the maximum acceptable temperature is 60°C). The required grinding effect is that when the total time of grinding is 60 minutes with a linear speed of 11.7m/s (4000rpm/min), the particle size is 2-3 microns, and there are also some particles of 5-6 microns.
Figure 1: Before dispersion: Particle size is 200-300 microns |
Figure 2: Dispersion after 30 minutes: Partial particle size is 90-100 microns |
Figure 3: After 30 minutes of fine grinding: 2-3 microns (some 10 microns) |
Figure 4: Fine grinding after 60 minutes: 2-3 microns |
equipment
Dispersion process: Dispermat AE3 (power 11KW) disperser Grinding process: basket mill TML1
Practical achievements
The customer's workshop has been equipped with two TORUSMILL SK 500 basket mills, which is actually a further improvement on the above experimental results. The introduction of the SK500 reduced production time from 7 hours to 15 minutes. The quality of the product has improved and the handling and maintenance of the product has become easier and faster
