Kapton® FWR for "Stirrer Motors" in Mining Industry


Few conditions are as severe as those encountered by South Africa’s mining industry in the production of molten steel. To ensure uniform dispersion of impurities, “stirrer motors” are used in each continuous casting line as molten steel passes through the bore. This creates extreme conditions at very high temperatures. DuPont Films customer P&H Minepro uses heatsealable Kapton® 150 FWR019 polyimide film on conductors in stirrer motors it manufactures for the mining industry.

Benefits Gained

Water resistance. Stirrer motor coils are immersed in force-circulated water to maintain coolness. The entire system must be waterproof. P&H Minepro found Kapton® 150 FWR019 is particularly well suited for use in environments where continuous water exposure is a concern.

Temperature resistance

The high water temperatures and aggressive cooling conditions of this application require insulation material that will stand up to the heat. Kapton® FWR retains its physical, chemical, electrical, and mechanical properties over a wide temperature range.

Chemical resistance

Because pure distilled water is not freely available, P&H required an insulating material with strong chemical resistance. It found Kapton® FWR ideally suited for its closed motor system.

Space savings

Conductor wires are large and rectangular and need tough insulation to meet the rigors of forming and insertion in the stirrer manufacturing process. By using Kapton® FWR, P&H Minepro found it could devote less space to insulation material, allowing more room for water flow.

Materials Chosen and Why

Kapton® FWR019 is 25 μm (1 mil) laminated to 12.4 μm (0.5 mil) Teflon® FEP fluoropolymer resin. A fiberglass coating is applied to the Kapton® to enhance adherence of the impregnating resin. P&H Minepro reports that the water resistance, performance at high temperatures, and space savings of Kapton® polyimide film are helping extend the service life of its products.




This information corresponds to our current knowledge on the subject. It is offered solely to provide possible suggestions for your own experimentations. It is not intended, however, to substitute for any testing you may need to conduct to determine for yourself the suitability of our products for your particular purposes. This  information may be subject to revision as new knowledge and experience becomes available. Since we cannot anticipate all variations in actual end-use conditions, DuPont makes no warranties and assumes no liability in connection with any use of this information. Nothing in this publication is to be considered as a license to operate under or a recommendation to infringe any patent right.


Caution: Do not use in medical applications involving permanent implantation in the human body. For other medical applications, see “DuPont Medical Caution Statement:, H-51459 or H-50102-2.