METHERM® Microporous Insulation Panels — Ultra-Low Thermal Conductivity to 1100°C

Overview

Microporous insulation panels are rigid, high-performance thermal insulation boards based on a fumed silica (SiO₂) microporous core compounded with opacifiers — typically silicon carbide (SiC) or titanium dioxide (TiO₂) — for infrared radiation suppression at elevated temperatures, and reinforced with glass or ceramic fibres for structural integrity. The combination of engineered pore architecture, opacification, and fibre reinforcement produces an insulation material with properties that no conventional insulation can match across the range from ambient temperature to 1100°C.

The defining physical mechanism is the Knudsen effect: when the mean pore size of the silica matrix falls below the mean free path of air molecules (approximately 70 nm at atmospheric pressure), gas-phase conductive heat transfer is suppressed. The result is a thermal conductivity at 20°C of 0.020 W/(m·K) — measurably lower than still air at 0.026 W/(m·K). This is not achievable by any conventional insulation technology at atmospheric pressure. By comparison, calcium silicate boards achieve 0.10–0.16 W/(m·K) at 200°C; mineral wool at 400°C typically runs 0.10–0.14 W/(m·K). A 40 mm METHERM microporous panel can replace 150–200 mm of mineral wool at equivalent thermal resistance, with significantly higher maximum temperature capability.

The critical advantage for high-temperature industrial applications is that METHERM microporous panels maintain near-flat thermal conductivity as temperature rises. At 800°C, the best METHERM grade still achieves 0.033 W/(m·K). Conventional insulation materials degrade rapidly above 400°C — mineral wool doubles or triples in conductivity by 600°C; even calcium silicate boards at 600°C run 0.15–0.25 W/(m·K). The flat-lambda characteristic of microporous insulation is unique and is the engineering basis for the extreme thickness reductions achievable in furnace backup insulation.

The METHERM® microporous range from Henan Minmetals East covers three grades: M 1000 (standard grade, max 1000°C), M 1000 Max (enhanced mechanical strength, max 1000°C), and M 1100 (extended temperature ceiling to 1100°C). All grades are non-combustible Class A1, asbestos-free, CFC-free, and can be sawn, drilled, and shaped on site with standard tools — unlike vacuum insulation panels, which cannot be cut.

Technical Specifications

Grade Selection Guide

M 1000 is the standard-specification grade for furnace backup insulation, kiln car lining, and industrial thermal systems operating up to 1000°C. Its combination of 0.020 W/(m·K) at ambient and 0.033 W/(m·K) at 800°C makes it the baseline specification for most industrial applications where temperature does not exceed 1000°C.

M 1000 Max carries the same 1000°C temperature ceiling as M 1000 but offers enhanced flexural strength (0.13 MPa vs 0.12 MPa). The slightly higher thermal conductivity across all temperatures reflects the higher reinforcement fibre fraction. M 1000 Max is the preferred specification for applications subject to vibration, mechanical load during installation, or repeated thermal cycling where board cracking risk is a concern — for example, kiln car decks with mechanical traffic or furnace structures exposed to vibration from adjacent equipment.

M 1100 extends the maximum service temperature to 1100°C while maintaining the same thermal conductivity as M 1000 at all measured points. This is achieved through use of higher-grade ceramic fibre reinforcement or higher-purity opacifier formulation that retains IR suppression effectiveness at the higher temperature ceiling. M 1100 is specified for aluminium melting furnaces, ceramic sintering kilns, and steel industry applications where hot-face temperatures may transiently exceed 1000°C.

Applications

Industrial Furnace Backup Insulation

The primary application for METHERM microporous panels is as backup (cold-face) insulation in industrial furnaces behind hot-face castable refractories or ceramic fibre modules. In this position, the microporous board reduces heat loss through the furnace shell without adding thermal mass that would slow heat-up. A typical installation: 25–40 mm of METHERM M 1000 behind a 150 mm monolithic castable lining reduces furnace shell temperature from 120°C to below 60°C — improving both energy efficiency and operator safety.

Compared to using an equivalent R-value of conventional insulation, the extreme thinness of microporous board reduces the total furnace shell thickness, which matters in retrofit situations where available space is constrained by existing structure or where reducing furnace shell weight improves foundation loading.

Steel Industry

In continuous reheating furnaces, walking beam furnaces, and batch annealing furnaces, METHERM microporous panels serve as backup insulation in furnace walls, roof sections, and door surrounds. The flat-lambda characteristic means that heat loss through the backup layer remains controlled even during temperature excursions. Ladle cover and tundish lid insulation systems can also benefit from microporous panels where extreme service life and thin-profile are required.

Aluminium Industry

Aluminium holding furnaces, die casting furnaces, and reverberatory melting furnaces operate in the 700–900°C range. METHERM M 1000 or M 1100 backup insulation reduces heat losses from the furnace shell, improving metal temperature uniformity and reducing gas consumption. The low thermal mass of microporous boards accelerates furnace heat-up following maintenance shutdowns.

Ceramic and Glass Industries

Ceramic sintering kilns and tunnel kilns operating at 900–1100°C use M 1100 as backup insulation behind refractory bricks or ceramic fibre linings. Kiln car deck insulation using M 1100 panels reduces heat storage in the car structure, improving overall kiln thermal efficiency. Glass lehrs and decorating kilns use M 1000 for sidewall and top insulation where thin-profile insulation preserves production floor space.

Boiler and Steam Generator Backup Insulation

In utility boilers and process steam generators, the transition from thick mineral wool backup to microporous panel backup reduces outer casing temperature and heat loss without increasing total boiler shell diameter — a significant advantage in retrofit programmes.

Energy Savings Quantification

A useful benchmark: replacing 200 mm of mineral wool (λ approximately 0.10 W/(m·K) at 400°C) with 50 mm of METHERM M 1000 (λ 0.025 W/(m·K) at 400°C) achieves equivalent thermal resistance in one-quarter the thickness. In practice, a 40 mm METHERM panel with the same furnace surface temperature on the hot face will produce a lower heat flux through the shell than 200 mm of mineral wool, because the near-flat lambda characteristic of microporous insulation allows a favourable differential at high temperatures.

Packaging & Storage

METHERM microporous insulation panels are supplied as rigid flat boards. Standard board format is typically 1000 × 500 mm; standard thickness range is 15–50 mm. Custom thickness and custom cut-to-size are available for container-quantity orders. Boards are palletised and carton-packaged for ocean freight (FCL and LCL, FOB Shanghai).

Handle with gloves — the fumed silica matrix generates fine respirable dust when boards are cut or broken. Cutting on site should be performed using standard masonry or woodworking tools with dust extraction. Boards are fragile under point impact; store flat on a level pallet and avoid stacking heavy items on top of panels.

Store in dry conditions away from water and rain. No special temperature or humidity storage requirements beyond keeping boards dry. Shelf life is indefinite when stored dry.

Related Products

• METHERM® Calcium Silicate Insulation — CS 1050 and CS 650 rigid boards for industrial insulation where higher compressive strength is required
• MEGEL® Aerogel Insulation — aerogel felt blanket for flexible, irregular-geometry insulation applications
• MEVAC® VIP Panels — vacuum insulation panels for cold-side ultra-low-λ insulation
• METHERM Microporous M 1000 — standard grade, max 1000°C
• METHERM Microporous M 1000 Max — enhanced mechanical strength, max 1000°C
• METHERM Microporous M 1100 — extended temperature grade, max 1100°C
• thermaleast.com — high-temperature refractory and furnace insulation system catalogue (SEMITECH sister site)