English  |
ACM
TOPSUN
8474
| Quantity: | |
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The fine grinding process follows the hot melt compounding. After leaving the extruder die, cooling and squeezing between the chill rolls, additional cooling on the cooling band to a brittle, easily breakable continuous strip and flaking by a kibble unit, the material is usually collected in movable containers and transported to the grinding system –Air Classification Mill.
Powder coating is formulated in a way that the glass transition temperature of the system is at least 40 °C to ensure storage stability of the coating. If the grinding of the material is performed at room temperature by appropriate removal of the heat developed during the grinding process, the material is subjected to the mechanical forces action below its glass transition temperature. Polyester, epoxy or acrylic resins used for the manufacture of thermosetting powder coatings usually have molecular weights between 3000 and 6000. With such a molecular weight, below, their glass transition temperature, these binders are brittle materials with a low modulus which allows easy non-problematic grinding. High molecular weight thermoplastic binders, however, are extremely tough and resilient. Cryogenic grinding at low temperatures is the only method for reducing the size of the particles of the thermoplastic powder coatings.
The fine grinding process follows the hot melt compounding. After leaving the extruder die, cooling and squeezing between the chill rolls, additional cooling on the cooling band to a brittle, easily breakable continuous strip and flaking by a kibble unit, the material is usually collected in movable containers and transported to the grinding system –Air Classification Mill.
Powder coating is formulated in a way that the glass transition temperature of the system is at least 40 °C to ensure storage stability of the coating. If the grinding of the material is performed at room temperature by appropriate removal of the heat developed during the grinding process, the material is subjected to the mechanical forces action below its glass transition temperature. Polyester, epoxy or acrylic resins used for the manufacture of thermosetting powder coatings usually have molecular weights between 3000 and 6000. With such a molecular weight, below, their glass transition temperature, these binders are brittle materials with a low modulus which allows easy non-problematic grinding. High molecular weight thermoplastic binders, however, are extremely tough and resilient. Cryogenic grinding at low temperatures is the only method for reducing the size of the particles of the thermoplastic powder coatings.
