Ilmajäämist

Ilmajäämist is a Finnish term that can be translated to "air remaining" or "air content." It is a concept primarily used in the context of material science and engineering, particularly when discussing the properties of porous materials or substances that are not entirely solid.

The term refers to the volume of air or voids trapped within a material's structure. This can occur naturally during the formation of certain substances, such as in foamed materials or aerogels, or it can be intentionally introduced through processes like aeration or frothing. The presence of ilmajäämist significantly influences a material's density, thermal conductivity, acoustic properties, and mechanical strength.

For instance, in insulation materials, a high percentage of ilmajäämist is desirable as trapped air is a poor conductor of heat, thus enhancing the material's insulating capabilities. Conversely, in applications where high density and rigidity are required, a low ilmajäämist is preferred. Understanding and controlling the amount of ilmajäämist is crucial for optimizing the performance of various products, ranging from construction materials and packaging to food products and medical devices. The measurement and analysis of ilmajäämist are often performed using techniques such as mercury porosimetry or gas adsorption.