Mixing Tools Need Thermal Spray Coatings
Before we can discuss thermal spray coatings and how they are beneficial when used on mixing tools, let’s specify what we are referring to when we say “mixing tools”. The following are included in this category:
- Granulation equipment
- Stirring equipment
- General tools
- Stirrer/mixer, and any other equipment used for mixing
Thermal spray coatings can help protect these tools against corrosion and wear. Where the mixing process may be endangered by the risk of contamination, strategically selected coating materials are used. The strength of the coating is defined by several classifications:
- The expected corrosion and wear
- Element
- Spraying method
Where coating strength is concerned, 0.5 mm is the standard.
Mixing Tools
Granulation equipment, stirring equipment, stirrers/mixers, and other mixing tools are normally coated with rust free, stainless steel components with various application methods. These can consist of the following:
- Thermal spraying to specifications
- Metal spraying
- Flame spraying
Stainless steel underwater granulation equipment and stainless steel mixing equipment are two of the most common uses for protective coatings.
Coating Components
Each individual case will determine the coating component. It is also defined by the following:
- Element geometry
- Medium to be mixed
- Volume speed
All mixing equipment, including granulation equipment – depending on the piece that is being coated – uses a different method for spraying.
Typically used as coating components are NiCrBSi alloys of 60HRc to 42HRc, just as an example. For granulation equipment and mixing tools that are exposed to more extreme conditions, based on a specific type of carbide, a hard metal coating may be used. The latter coating, in addition to protecting against corrosion and wear, is polishable.
Industrial Application Mixers
Numerous industries utilize mixers at different levels. In the industrial application alone, the following mixers can be found:
- Emulsifier
- Homogenizer
- Planetary
- Blender
- Food
- Drum
- Static, and more
Also in an industrial application are paddle mixers. They are used for conditioning, blending, and mixing. These agitators deal with slurries, sludges, dry friable materials, and more.
Mixing Tool Coating
Chrome oxide with PTFE, tungsten carbide, and plasma sprayed aluminum oxide are used to create a lining that has both quick release characteristics, is abrasion resistant, and hard. It is used on any number of mixing tools including but not limited to the following:
- Augers
- Spiral pitch screws
- Finger blades
- Rectangular blades
- HV blades
- Double planetary mixers
- Blenders
- Pots
- Mixing tubs
The more extreme the environment (including weather, materials being mixed, environment, frequency of use, etc.), the more importance is assigned to the hardness and protective capabilities of the coating. It must be able to withstand even the most abusive, abrasive conditions. As an example, cement mixing tools are constantly under attack by not only corrosive materials but abrasive substances as well. One can only imagine how hard a coating would need to be to truly give this kind of equipment the protection it needs.
At A&A Coatings, we provide protective coatings for various mixing tools used in numerous industries. We have been leaders in our field for more than 70 years and show no signs of slowing down. At our plant, we concentrate on the application of cermet, hard faced, ceramic, and metal coatings. Our services are unmatched and include specialization in the additional areas of machining capabilities, lapping, and grinding. Contact us today if you would like to inquire further as to what thermal spray coatings can do for your company.
