{"id":144,"date":"2026-07-21T03:27:47","date_gmt":"2026-07-20T19:27:47","guid":{"rendered":"http:\/\/www.vissmaya.com\/blog\/?p=144"},"modified":"2026-07-21T03:27:47","modified_gmt":"2026-07-20T19:27:47","slug":"how-do-the-properties-of-thermal-insulation-materials-change-under-different-pressures-4242-328257","status":"publish","type":"post","link":"http:\/\/www.vissmaya.com\/blog\/2026\/07\/21\/how-do-the-properties-of-thermal-insulation-materials-change-under-different-pressures-4242-328257\/","title":{"rendered":"How do the properties of thermal insulation materials change under different pressures?"},"content":{"rendered":"

Hey there! I’m a supplier of thermal insulation materials, and I’ve been in this business for quite a while. One question that often pops up from our clients is how the properties of thermal insulation materials change under different pressures. So, I thought I’d share some insights on this topic. Thermal Insulation Materials<\/a><\/p>\n

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First off, let’s talk about why pressure matters. In many real – world applications, thermal insulation materials are subjected to different levels of pressure. For example, in some industrial pipelines, the insulation materials might experience high internal pressure due to the fluid flowing inside. In building construction, insulation in basements or underground structures can be under the pressure of the soil above.<\/p>\n

Thermal Conductivity<\/h3>\n

The most important property of a thermal insulation material is its thermal conductivity. Thermal conductivity is the measure of how easily heat can pass through a material. Generally, as the pressure increases, the thermal conductivity of most insulation materials changes.<\/p>\n

Let’s take fiberglass insulation as an example. Fiberglass is made up of fine glass fibers that trap air pockets. These air pockets are what make fiberglass a good insulator because air is a poor conductor of heat. When the pressure is low, the air pockets are relatively large and intact. The heat transfer mainly occurs through the air inside the pockets and the glass fibers themselves.<\/p>\n

However, when the pressure increases, the air pockets get compressed. The smaller air pockets mean that there is less space for the air to move around, and the heat transfer by convection (the movement of hot air) is reduced. But at the same time, the compression of the material can bring the glass fibers closer together, which increases the heat transfer through conduction (the direct transfer of heat through the material).<\/p>\n

In most cases, at moderate increases in pressure, the decrease in convective heat transfer is more significant than the increase in conductive heat transfer. So, the thermal conductivity of fiberglass insulation may actually decrease a bit. But if the pressure gets too high, the compaction of the material becomes so severe that the conductive heat transfer dominates, and the thermal conductivity starts to increase.<\/p>\n

Compression and Density<\/h3>\n

Pressure also affects the compression and density of thermal insulation materials. As you might expect, when a material is under pressure, it gets compressed. And when it gets compressed, its density increases.<\/p>\n

For cellular insulation materials like polyurethane foam, which has a lot of closed – cell structures, the cells are filled with gas. When pressure is applied, these cells start to deform. If the pressure is kept within a certain range, the cells can withstand the deformation without breaking. But if the pressure is too high, the cells will rupture.<\/p>\n

When the cells rupture, the gas inside escapes, and the insulation performance drops significantly. The density of the material also changes during this process. At first, as the cells are just being compressed, the density increases gradually. But after the cells rupture, the density may increase more rapidly, and the material loses its original insulating properties.<\/p>\n

Mechanical Properties<\/h3>\n

The mechanical properties of thermal insulation materials are also influenced by pressure. For instance, the strength and flexibility of the material can change.<\/p>\n

Mineral wool is a popular insulation material known for its good mechanical properties. Under normal pressure, it has a certain level of flexibility, which makes it easy to install in various shapes and spaces. But when it’s under high pressure, the fibers in the mineral wool get packed more tightly. This can make the material stiffer and less flexible.<\/p>\n

On the other hand, the strength of the material may increase to some extent. The closer – packed fibers can better resist external forces. However, if the pressure is excessive, the fibers may break, and the material will lose its structural integrity and mechanical strength.<\/p>\n

Moisture Resistance<\/h3>\n

Pressure can have an impact on the moisture resistance of thermal insulation materials. In some cases, increased pressure can force moisture into the material.<\/p>\n

Take expanded polystyrene (EPS) insulation. EPS has a relatively good moisture resistance under normal conditions because of its closed – cell structure. But when it’s under high pressure, the pressure can cause small cracks in the cell walls. These cracks allow moisture to penetrate into the material.<\/p>\n

Once moisture gets into the insulation, it not only reduces the insulation performance but can also lead to other problems like mold growth and material degradation. So, in applications where the insulation material is likely to be under pressure, it’s crucial to consider its moisture – resistance properties under pressure.<\/p>\n

Applications and Considerations<\/h3>\n

Now, let’s talk about how these pressure – related property changes matter in different applications.<\/p>\n

In the aerospace industry, insulation materials are used in spacecraft and airplanes. These materials are exposed to different pressures during flight. For example, when a spacecraft is in space, the pressure is extremely low. And during re – entry into the Earth’s atmosphere, the pressure can increase significantly. Insulation materials need to maintain their thermal and mechanical properties under these extreme pressure changes.<\/p>\n

In the oil and gas industry, pipelines are often underground or underwater, where the insulation materials experience high external pressures. The insulation must be able to resist compression and maintain its insulating performance over a long period.<\/p>\n

As a supplier of thermal insulation materials, I always recommend that our clients consider the pressure conditions in their specific applications. We have a wide range of insulation materials, and each one has different performance characteristics under pressure.<\/p>\n

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If you’re working on a project where pressure is a concern, it’s a good idea to consult with us. We can help you choose the right material based on the expected pressure levels, temperature requirements, and other factors. Whether you need insulation for a high – pressure industrial pipeline or a low – pressure building application, we’ve got you covered.<\/p>\n

Insulation Board<\/a> If you’re interested in learning more about our thermal insulation materials or have any questions about how they perform under different pressures, don’t hesitate to reach out. We’d love to have a chat with you and help you find the best solution for your project. We look forward to discussing your procurement needs and seeing how we can work together.<\/p>\n

References<\/h3>\n