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Owing to the Company’s technological strengths in the field of coating chemicals, FILTRA has emerged as a major source of coating chemicals for Electrical Steel over the past 2 decades.

What started as an “Import substitution” effort in the 1990’s has sailed along over these 2 decades to price and performance effective support to the Electrical Steel Manufacturers and processors in a dynamically changing environment. Globalization and technology upgradation requirements calling for innovativeness and adaptation to high line speeds, lower coating thickness, change-over to more eco-friendly coating materials, have been well addressed by our organization.

FILTRA’s products are developed in its R&D center which has dedicated equipment and personnel for coatings development and testing. This strong technological knowhow has helped FILTRA develop a strong base of products which has led to established supplies to over 90% of India’s leading Electrical Steel manufacturers and down-stream users.

With high production capacities and state of the art Quality Control, FILTRA’s coating chemicals are poised to cater to the international markets, with good performance specifications over fully processed Electrical Steel.

FILTRA possesses a wide range of coating chemicals from C-3, C-5 and C-6 classes which are suitable for various coating systems with varying line speeds. These products are also compliant with the European standards (ROHS) for coating chemicals.

AISI Classification of Coating Types:

C-3 class Coatings:

The C-3 coating will enhance punchability with improvement up to three times as compared to uncoated electrical steel., It is resistant to normal operating temperatures & is highly corrosion resistant (C3 coatings can be used as a corrosion undercoat for C6 coatings) but will not withstand stress relieving annealing (SRA). It is suitable for applications where high level of interlaminar resistance is required. C-3 coatings are suitable for small and medium sized motors as well as small transformers.

C-5 class coatings:

C-5 coatings provide excellent surface resistivity both before and after stress relief annealing (SRA ). Customer does the SRA after slitting. Presence of organic part ensures improved punch and die life during stamping operations. During annealing the organic component of the coating volatilizes but inorganic part remains to provide an adherent film with a high level of surface resistivity. Correct blend of organic and inorganic avoids yield losses and gives better performance. No significant flaking occurs at the punched edges of laminations. Used for refrigerator motors, small to large sized motors and transformers, large turbogenerators . Also useful where high temperature resistance and weldability are required. Withstands stress relief annealing and other high temperature treatment.

C-6 class Coatings:

It is suitable for high frequency applications and other power house equipments .Provides thick coatings and therefore increases surface resistivity. Inorganic fillers have been added to increase the insulating ability of the coating .Has excellent punchability & withstand high temperature “burn off” treatments used during rebuilding of motors. It provides ridge free coatings. They are most suitable for the high stacking factor as required at customer’s end. This coating exhibits low shrinkage (compressibility ) . Has excellent match of thermal coefficient of expansion with steel due to high pigment concentration. Suitable for large and medium sized motors , H2 cooled generators . C-6 coatings are ideal for magnetic cores of contractors and high frequency application because of its ability to withstand vibrations.

Filtra offers following products as per AISI Classification:

C3 Coating

C5 Coating

C6 Coating