Mica tape for electric furnace

I. High-temperature Furnaces (≥800℃)

1. Synthetic Mica Tape (Preferred Option)

Recommended Model ：R-5461-S-GD (Synthetic Mica Double-Sided Fiberglass Tape)

Core Advantages ：Uses artificially synthesized fluorophlogopite paper, contains no crystal water, and withstands temperatures up to 1000℃ (Does not break down under 1000V voltage for 3 hours), far exceeding the 800℃ upper limit of mica tape. Its dielectric strength ≥40kV/mm, volume resistivity ≥10¹⁵Ω・cm, and insulation stability at high temperatures is significantly better than natural mica tape.

Application Scenarios:

Insulation layer for heating elements (such as molybdenum wire, silicon carbide rod coating) in ultra-high-temperature equipment such as industrial resistance furnaces and vacuum furnaces.

Furnace lining insulation in high-temperature kilns (used with ceramic fiber), capable of withstanding long-term baking above 1000℃.

Process Compatibility:

Multi-adhesive molding type (adhesive content 18%-25%) is suitable for making molded insulation parts (such as furnace door seals), and has high mechanical strength after curing;

Low-adhesive VPI type (adhesive content 5%-10%) is suitable for impregnation processes, and combines with high-temperature resin to form an integral insulation layer.

High Thermal Conductivity Enhancement Scheme ： If the furnace requires rapid heat dissipation, you can choose Synthetic mica tape with added boron nitride , with a thermal conductivity of 1.2W/(m・K), 30% higher than ordinary synthetic mica tape, suitable for winding heating elements in high-power furnaces.

2. Mica Roll (Overall Furnace Insulation)

Recommended Model: ST-RCMG (Mica/Synthetic Mica Roll, one side fiberglass cloth + one side ceramic cotton)

Core Advantages ：Thickness can reach 0.8mm, single-layer withstand voltage ≥15kV, temperature resistance 800-1200℃, combines rigid support and flexible fitting capabilities. The ceramic cotton side can directly contact the furnace lining refractory material, and the fiberglass cloth side is used to fix the heating element.

Application Scenarios:

Furnace body insulation layer for medium-frequency furnaces and arc furnaces, replacing traditional asbestos materials and meeting environmental protection requirements.

Coil insulation for high-temperature furnaces, capable of withstanding mechanical vibrations and thermal shocks during the casting process.

II. Medium-temperature Furnaces (300-800℃)

1. Mica Tape (Cost-effective Choice)

Recommended Model: R-5461-P-GS (Mica Single-sided Fiberglass Tape)

Core Advantages ：Temperature resistance 800℃ (does not break down under 1000V voltage for 90 minutes), the price is only 1/2 of synthetic mica tape, dielectric strength ≥35kV/mm, suitable for cost-sensitive medium-temperature scenarios.

Application Scenarios:

Heating tube insulation for household electric ceramic stoves and baking ovens, capable of withstanding long-term operation at 500℃.

Heating wire winding for industrial drying ovens, and the combination with silicone rubber sleeves can further improve moisture resistance.

2. Multi-adhesive Molded Mica Tape

Recommended Model: 5438-1 Epoxy Powder Mica Tape

Core Advantages ：Adhesive content 20%-25%, high mechanical strength after curing, temperature resistance 155℃ (F class), but can withstand 600℃ for a short time through high-temperature curing process.

Application Scenarios:

Insulation wrapping of furnace terminals, strong vibration resistance after molding.

Coil frame for small furnaces, replacing traditional laminated paperboard, reducing the risk of high-temperature deformation.

III. Special Needs Furnaces

1. High-frequency/High-voltage Furnaces

Recommended Model: WD5453-1S Polyimide Film Low-adhesive Mica Tape

Core Advantages ：Uses KAPTON CR corona-resistant film reinforcement, surface resistivity ≥10¹²Ω・cm, can suppress corona discharge under high-frequency pulses, temperature resistance 200℃, suitable for furnace transformers above 10kV.

Application Scenarios:

Resonant capacitor insulation for induction heating furnaces, reducing partial discharge (≤5pC).

Coil insulation for high-frequency quenching equipment, reducing energy loss.

2. Furnaces in High-humidity Environments

Recommended Model: R-5461-S-GFD (Synthetic Mica Fiberglass Film Three-in-one Tape)

Core Advantages ：Double-sided fiberglass cloth + polyester film structure, moisture-proof grade reaches IP67, volume resistivity still ≥10¹³Ω・cm in 95% humidity environment.

Application Scenarios:

Reaction kettle heating furnaces in the chemical industry, preventing water vapor intrusion from causing insulation failure.

Steam heating tube insulation for food processing furnaces, resistant to periodic wet heat environments.

3. Explosion-proof/Fire-resistant Furnaces

Recommended Model: R-5461-P-R Mica Fire-resistant Tape

Core Advantages ：Passed IEC60331 fire resistance test, does not break down under 750℃ flame for 90 minutes, no halogen release during combustion, meets GB/T1303.5 standard.

Application Scenarios:

Explosion-proof furnaces in the petrochemical industry, preventing short circuits from causing explosions.

Key circuit insulation for fire emergency furnaces, ensuring continuous power supply during fires.

IV. Key Parameter Comparison Table for Model Selection

V. Installation and Verification Suggestions

High Temperature Bonding Solution ：

For scenarios above 1000℃: Use high-temperature ceramic adhesive (such as boron nitride adhesive) to replace traditional epoxy resin, ensuring that the mica tape is tightly bonded to the heating element.

For medium temperature scenarios: Silicone rubber adhesive can be used, which combines elasticity and high temperature resistance (temperature resistance 250℃).

Insulation Verification ：

Use an insulation resistance tester (such as a megohmmeter) to test the insulation performance of the mica tape at high temperatures. The requirement is ≥10¹²Ω (room temperature), ≥10¹⁰Ω (high temperature).

For high-voltage furnaces, it is recommended to perform partial discharge testing (such as using a PD detector) to ensure that the discharge amount is ≤10pC.

Lifespan Prediction ：

The long-term service life of synthetic mica tape at 1000℃ is about 5000 hours, and that of muscovite tape at 800℃ is about 3000 hours. The surface temperature of the mica tape can be monitored using an infrared thermal imager. If the local temperature rise exceeds the design value by 20%, it should be replaced in time.

Example Selection ：

1000℃ Industrial Electric Furnace ：R-5461-S-GFD (Synthetic mica fiberglass film three-in-one tape, 0.16mm thickness) + high thermal conductivity boron nitride coating, total insulation layer thickness 0.5mm, withstand voltage ≥50kV, meeting the requirements of high temperature insulation and heat dissipation.

Medium Frequency Melting Furnace ：ST-RCMG mica roll (0.8mm thickness) + ceramic fiber blanket, used for furnace lining insulation, temperature resistance 1200℃, withstand voltage 20kV, resistance to mechanical impact during the casting process.

It is recommended to refer to the technical specifications of the electric furnace manufacturer (such as ABB, Isa's electric furnace design manual) and contact the mica tape manufacturer (such as Yuefeng Mica) to obtain customized solutions. For critical applications, a third-party laboratory (such as SGS) can be commissioned to conduct high-temperature aging tests to verify the long-term reliability of the mica tape.