Thermal insulation products also have properties such as acoustic insulation. More specifically, these properties are the dynamic stiffness and airflow resistivity.

Sound is transmitted through the air and through solids. Dynamic stiffness is related to impact sound reduction index. The test consists of determining the resonance frequency of a mass-spring system where the spring is the insulating material. The lower the dynamic stiffness value, the higher the sound reduction index of the material.

In the case of air insulation, the airflow resistivity of the material is important, kPa·s/m². This property is exhibited by fibrous materials such as mineral wool. Resistance to air flow of a material is closely related to its structure and friction of sound waves on the filaments and reduction of the intensity thereof. This avoids it passing through the material. The test subjects the material to a constant air flow, measuring the difference in pressure caused by the material.

Thermal insulation materials to test:

• Expanded polystyrene
• Mineral wool
• Polyurethane foam

La entrada Acoustic properties se publicó primero en CEISLAB.

Thermal insulation products in use can dilate because of the thermal influence or can undergo variation or alteration due to the effects of certain temperature and/or humidity conditions. To check the durability of thermal resistance to ageing and deterioration, the dimensional stability of these products must be determined under specific temperature and humidity conditions, their dimensional stability in laboratory conditions or dimensional stability under compression and temperature stress conditions for applications in which the products are subjected to pressure and temperature.

Thermal insulation materials to test:

• Expanded polystyrene
• Extruded polystyrene
• Mineral wool
• Polyurethane foam

La entrada Dimensional stability se publicó primero en CEISLAB.

Thermal insulation products must have certain mechanical properties according to the use to be made of the product. Consequently, the following mechanical properties can be determined.

• Shear behaviour for insulating products that are part of External Thermal Insulation Composite Systems (ETICS) where the product is subjected to tangential forces.
• Compression and compression creep for products subjected to loads (floors and roofs).
• Tensile strength perpendicular to faces when the product is subject to adherences stresses and when the intrinsic weight or suction caused by wind subjects the product to tensile forces.
• Bending strength  in order to guarantee good cohesion of the insulation product (EPS) when handling the product.
• Parallel strength parallel to faces to guarantee the physical integrity of the panels and to verify the stress resistance in use.
• Compressibility when the product guarantees a certain degree of elasticity, e.g. in stress applications such as floating flooring.
• Point load resistance  when the product is subjected to localised stresses.
• Resistance to freeze / thaw cycles in products that are subjected to the effects of freezing. After thermal treatment the variation of the resistance to compression is assessed.

Thermal insulation materials to test:

• Expanded polystyrene
• Extruded polystyrene
• Mineral wool

La entrada Mechanical tests se publicó primero en CEISLAB.

The cell structure of some materials confers low thermal resistance. This is the case of extruded polyurethane polystyrene. This test is based on the Boyle-Mariotte Law, consisting of determining the impenetrable volume of the sample through which the percentage of closed cells can be calculated.

Thermal insulation materials to test:

• Extruded polystyrene
• Polyurethane foam

La entrada Closed cell content se publicó primero en CEISLAB.

This is the fundamental property of thermal insulation products. The test is carried out using a Heat Flow Meter in which a test sample is subjected to a thermal difference between its sides, measuring the flow through it. Once the stationary state has been reached, the thermal resistance and conductivity of the sample can be determined.

Thermal insulation materials to test:

• Expanded polystyrene
• Extruded polystyrene
• Mineral wool
• Polyurethane
• Cellulose
• Wood wool
• Cork
• Cellular glass
• Elastomeric foam
• Phenolic foam
• Expanded perlite

La entrada Thermal conductivity and thermal resistance se publicó primero en CEISLAB.

Thermal insulation products must be non-absorbent since any small increases in moisture content will reduce their thermal resistance. Therefore, the moisture content they can absorb when work is carried out on site and when they are in place is limited. This can be checked by water absorption tests through partial and complete, short and long-term immersion, and the water diffusion absorption test.

On the other hand, water vapour can spread through thermal insulators when there is a gradient of relative humidity between both sides of the material. Likewise, such diffusion can be interrupted by using certain coatings such as Kraft paper which acts as a vapour barrier. Therefore, in applications where a condensation study is required, e.g. on vertical enclosures, the resistance to water vapour diffusion (MU, µ factor) of the material or resistance to water vapour Z of the coating needs to be determined.

Thermal insulation materials to test:

• Expanded polystyrene
• Extruded polystyrene
• Mineral wool
• Polyurethane foam

La entrada Performance against water and water vapour transmission properties. se publicó primero en CEISLAB.