Thermal Insulation – Overview of Classes and Application Areas

Insulation is a key topic in modern technology and industry that goes far beyond just keeping buildings warm. Whether it’s the electrical insulation of motors, thermal insulation of pipelines or the protection against extreme temperatures in industrial processes – the correct insulation is critical to the efficiency, safety and durability of systems and equipment. In electrical engineering, insulating material classes play a essential role in ensuring that electrical machines can work reliably under extreme conditions. What exactly are insulating materials, and how do they help increase the efficiency and safety of industrial processes? You will find out in the following article.

What is insulation?

The purpose of insulation is to prevent or reduce an unwanted flow of energy (electricity, heat) or substances that could otherwise lead to damage and loss of function. A distinction is made between thermal and electrical insulation. Electrical insulation refers exclusively to the flow of electrical energy, while thermal insulation refers to the transfer of heat or cold.

Thermal vs. Electrical Insulation

Thermal insulation refers to the use of materials and systems that control and minimize the heat flow between different areas. In industrial applications, such as in mechanical engineering, thermal insulation is crucial to optimizing energy efficiency, ensuring process stability and increasing operational safety. By reducing heat losses in heating and cooling systems, energy consumption can be significantly reduced. In addition, thermal insulation protects both personnel and equipment against extreme temperatures common in industrial environments.

Thermal Classes According to DIN 60085

DIN EN 60085 refers to the thermal classification of electrical insulating materials and insulating systems. It deals with electrical insulation in the context of its thermal stability. The standard establishes how insulating materials and systems used in electrical machines and equipment are classified in terms of their maximum permissible operating temperatures. The objective is to ensure that these materials work reliably under thermal stress without losing their insulating properties. The various classes of insulating materials are identified by letters or numbers, each of which corresponds to a maximum permissible operating temperature.

The following insulating material classes are differentiated as follows:

The insulating material classes F and H are common for insulating systems in electrical machines and motors. Insulating systems of this class ensure machines work reliably under the high loads and difficult conditions of industrial environments. For example, a motor designed for the insulating material class F can safely work at a maximum operating temperature of 155°C, while a class H motor can withstand temperatures up to 180°C.

Insulating substances and insulating materials

Thermal insulating materials are used in industrial applications to minimize heat losses, increase energy efficiency and make work environments safer. Thermal insulators are used in the industry in a variety of applications, including the insulation of pipelines, furnaces, and other equipment and systems that generate or handle high temperatures.

Due to their properties, some materials are particularly suitable for use as insulation. Polyurethane rubbers and foams can be used over a wide temperature range, they are generally limited to moderate temperatures up to about 80-100°C, while general rubbers have very high temperature resistance. Silicone rubber, for example, can withstand temperatures of over 250°C.

Insulation panels as insulating components

Insulation panels are components specifically developed for thermal insulation. Typical materials that consist of insulation panels are, for example, polystyrene, glass wool, extruder foam or polyurethane. Each material has special characteristics, not only related to thermal conductivity, but also to fire protection or moisture resistance.

MISUMI Insulation Panels

MISUMI offers a comprehensive range of insulation panels. These consist of laminated heat-resistant fiberglass films (for the frame) and composite materials with high heat resistance. There are different variants, such as a standard version for use as normal construction material for heating presses or spacers. In addition, there are also versions designed to withstand high or very high temperatures. These can have a high degree of heat resistance of up to 1000°C. MISUMI’s thermal insulating panels provide superior thermal insulation to help improve and ensure a safer operating environment.

Instructions for use for insulation panels

There are some special features available in insulation panels that should be considered for a successful application, such as:

• thermal insulating panels can break easily. Therefore, a washer should always be used when tightening the panel. Do not screw it in too tightly.
• As soon as the insulation panels become saturated with moisture, cracks may occur and the performance may be reduced. Therefore, they should only be stored and used in a dry environment.
• Smoke or odors may develop at very high temperatures. Although they are not harmful to your health, insulation panels should only be used in well-ventilated environments.

Thermal Insulation Characteristics

Thermal insulation can be described or quantified using different parameters. These parameters provide the foundation for making decision when selecting the appropriate insulation material for various applications. The characteristics of thermal insulation include, for example:

• Thermal conductivity: Thermal conductivity is a measure of the ability of a material to conduct heat. It is measured in watts per meter per Kelvin (W/m * K). Lower values mean better insulation.
• Thermal resistance: Thermal resistance, or also called R-value, is a measure of the resistance of a substance or a material to the flow of heat. It is indicated in square meters Kelvin per watt (m²K/W). The higher the thermal resistance, the better is the insulation.
• Heat transmission coefficient: The heat transmission coefficient, also called U value, indicates the heat flow through a component if the temperature on the outside is different than the temperature on the inside. A low heat transmission coefficient indicates that the material allows little heat to pass through and is a good insulator.
• Specific heat capacity: The specific heat capacity refers to the heat quantity required to increase the temperature of a particular mass of a material. This value is indicated in joules per kilogram and Kelvin (J/kgK). The higher the specific heat capacity, the more heat can be absorbed by the material.
• Fire behavior: The fire behavior refers to the ability of a material to withstand fire and high temperatures. It indicates whether it is flammable or emits smoke and toxins in the event of a fire.

When selecting a suitable insulating material, the specific requirements of an application must be carefully evaluated. When planning insulation applications, safety reserves must always be included in order to cope with unexpected stresses or extreme conditions. These reserves ensure that the insulating material works reliably even under unfavorable conditions and meets the system requirements. The effect of thermal expansions and the possibility of failures due to mechanical stresses should also be considered. Integrating safety reserves in the planning phase increases the robustness of the system and ensures that the insulation works efficiently and reliably.

Applications of Thermal Insulation

Thermal insulation is applied in a variety of areas. In mechanical engineering and industrial manufacturing, thermal insulation improves energy efficiency, optimizes processes, and increases the overall safety. In mechanical engineering, insulation panels improve the efficiency of heating and cooling systems by minimizing heat losses and improving temperature control.

Thermal Insulation in Injection Molding Machines

Injection molding machines are used for the production of complex plastic parts. This process requires significant quantities of energy and it involves high temperatures. By heating plastic granulate up to the melting point, the plastic can be processed in the injection molding machine. Thermal insulation is used in injection molding machines to ensure a uniform temperature distribution and to prevent the melt from cooling down on the one hand. On the other hand, the insulation should minimize heat losses, increase operating safety and reduce energy consumption.

For further information and tips on machine settings for injection molding machines, consult the Blog Plastic Injection Molding - Machine Settings.

Industrial Pipe Insulation

In industrial processes, pipes are insulated, among other things, to reduce the heat transfer of hot or cold media into the environment. This not only increases the protection of workers from potentially dangerous surface temperatures of the pipes, but also prevents condensation on the outside of refrigeration lines, which can lead to corrosion.

Insulation Panels in Metal Processing

In the metal processing industry, heating furnaces are used for heat treatment to change the mechanical properties of metals through processes such as hardening, tempering and annealing. Thermal insulation is particular important here. Insulation panels made of high-temperature resistant composite materials reduce heat loss and at the same time allowing for a more uniform distribution of the temperature in the furnace. Composite materials used in insulation panels for furnaces are specifically designed to withstand extreme temperatures. Ceramic fiber composites, for example, are known for their excellent heat resistance and low thermal conductivity.