Fólie

Fólie are thin sheets of material, usually metal or plastic, whose thickness is measured in micrometres and is typically less than 0.2 millimetres. They are produced by rolling metal to create metal foils or by extruding and casting polymers to form plastic foils, and sometimes by depositing a very thin metal layer onto a polymer film to produce a metallized or foil-coated film.

Common materials include metal foils such as aluminium, copper or tin; plastic foils made from polyethylene (PE), polypropylene (PP), or polyethylene terephthalate (PET); and laminated or composite foils in which metal or plastic layers are bonded to other films. Metallized foils are used when a barrier or reflective surface is needed without the weight of solid metal.

Fólie offer specific properties: high barrier against moisture and gases, reflectivity, electrical conductivity or shielding in some cases, and barrier properties that depend on thickness and the lamination structure. Their performance can be adjusted by lamination, coatings, or combining different materials.

Applications are widespread. In packaging, foil acts as a barrier to preserve freshness and protect contents. In construction and insulation, aluminium foil reflects heat and reduces transfer. In electronics, foil or metallized films provide shielding or are used in capacitors. Gold leaf and other metal foils serve decorative and artistic purposes.

Manufacture and recycling: foils are produced by rolling or extrusion, with thickness specified in micrometres. Aluminium foil is widely recycled; plastic foils require dedicated recycling streams and are not always accepted by curbside programs. Proper disposal depends on material and local facilities.