diffusionshemmende

Diffusionshemmende is a Danish term referring to substances, coatings, or layers that restrict the rate at which molecules diffuse through a material. In practice, it describes diffusion barriers that reduce the transfer of moisture, gases, or other substances across a boundary. The goal is usually to protect contents, improve durability, or control condensation and climate in a system.

In building physics, diffusion barriers are used to manage water vapor diffusion through building assemblies. They are designed to be more impermeable than surrounding materials and are often placed on the warm side of insulation to minimize dew formation. Common implementations include plastic films, metal foils, and multilayer laminates. The effectiveness depends on climate, the desired diffusion resistance, and compatibility with adjacent layers. However, overly diffusion-tight layers without adequate ventilation can trap moisture and lead to mold or damage, so diffusion resistance is balanced with air leakage control and drainage.

In packaging, diffusion barriers limit the transmission of oxygen, moisture, and flavors to preserve contents and extend shelf life. Materials such as metalized polymers and aluminum foil laminates create low transmission rates for gases and water vapor.

In electronics and optics, diffusion barriers protect sensitive components by slowing the ingress of moisture or contaminants or by containing dopant diffusion in semiconductor devices. The performance of a diffusion barrier is typically described by permeability, diffusivity, and solubility, and is measured using standard tests for water vapor transmission rate (WVTR) and oxygen transmission rate (OTR).