Current Situation and Development of Basket Grinder

Summary:

This paper discusses the reasons for the emergence of basket mills, the current application status, and the development of basket mills with different structures at home and abroad. The working principle, function and characteristics of a new type of basket mill integrating dispersing and grinding (first dispersing and then grinding) are introduced emphatically. The development prospect of the basket mill equipment is prospected.

Keywords: Basket Mill; Dispersion and Grinding; First Dispersion-Grinding; Coating Production Equipment

The process of paint production is to mix the solid particles of pigments and fillers into the liquid paint to form a uniform and fine suspension dispersion. The primary particles of pigments and fillers are very small, with a particle size of about 0.01-2 μm. Since the primary particles of raw materials are often bonded to each other to form aggregates (secondary particles) during processing and storage, their particle size may increase to 100 μm or more, so it is necessary to de-aggregate the aggregates and disperse them stably and evenly in the paint during the manufacture of the paint.

In the production process of coatings, the selected grinding and dispersing equipment has a great influence on the dispersion state of pigments in coatings, good pigment properties (coloring power, hiding power, weather resistance, etc.), and the resulting coatings and coatings. Performance plays a very important role. Therefore, how to improve the dispersion effect in the production of coatings, develop and adopt effective dispersion equipment, and select good raw materials and good formulas have become one of the important issues in the production of coatings.

The following four steps are usually used in the coating production process:

①Pre-dispersion: This process is mainly based on mixing and plays a certain role in dispersion;

At present, the most used pre-dispersion equipment is high-speed disperser; this process is a preparatory process for fine grinding.

②Grinding and dispersing equipment: the main equipment for coating production. At present, there are many types, common vertical sand mill, horizontal sand mill, three-roll mill and so on. The basket mill described in this article is the grinding and dispersing equipment in the production of coatings.

③ Adjust the paint.

④ filter packaging.

At present, the basket mill is more and more widely used in the grinding fields of coatings, inks and other varieties and colors.

Some people think that because the basket mill can be used for batching, grinding and dispersing with cylinders, there is no delivery pump and pipeline, and it is easy to clean, so it is especially suitable for small batches and multi-variety production. This is a misunderstanding of the scope of use of the basket Grinder.

"Immersion Grinding Machine—Simple and Effective" (authored by American HOCKM-EYER Company) published in the 9th issue of PCI Magazine (Paint & Coatings Industry) in 2003 stated in the article: "...they think that the 'immersion type' grinding machine ( Basket Mill) for small batches, low viscosity, and easy-to-grind products. In our opinion, they do not understand immersion grinding technology, or are misleading you. …Because of their efficiency, immersion basket mills The machine can be called <Satisfactory Grinder Design>".

Judging from the use practice of the basket mill, as long as the design is reasonable, the powerful circulation makes the basket mill suitable for high-viscosity and large-volume materials, and the fineness and efficiency of grinding are also satisfactory.

The German VMA company has applied the basket mill to the dispersion grinding of the 3 t reactor (2004). Domestic enterprises have also successfully applied the basket mill to the dispersing and grinding of the 3t reactor in the 10000t/a paint automatic production line, and it has been used well in practice. However, if the 3 t reactor uses a traditional horizontal sand mill for dispersion and grinding, a 75kW high-speed disperser and an 80-90L horizontal sand mill are required, and the slurry dispersed by the high-speed disperser needs to be subjected to horizontal sand mill The closed grinding chamber of the machine (the volume of the horizontal sand mill above 80 L is already very large) is used for circular grinding, and its efficiency is much lower than that of the basket sand mill, and the fineness and particle size distribution are not as good as those of the basket in the kettle. Grinder grinding effect.