läpäistävä

Läpäistävä is a Finnish adjective derived from the verb läpäistä, meaning to pass through or penetrate. It describes something that can be passed through or penetrated, typically a barrier, membrane or material. In technical and scientific contexts läpäistövä is used to express permeability or penetrability for liquids, gases or signals. The term is closely related to läpäisy, the noun for penetration or permeation, and to läpäisevyys, the property of being permeable. A more widely used synonym in everyday language is läpäisevä, which conveys a similar meaning and is often preferred in descriptive text.

Grammatically läpäistävä is formed with the suffix -vä from the verb läpäistä and functions as a qualitative adjective that can modify nouns (for example kalvo, materiaali). It can be used attributively and predicatively, depending on sentence structure. In contemporary usage läpäisevä is more common, while läpäistävä emphasizes the potential or capability to be penetrated in particular contexts.

Related terms include läpäisy (permeation) and läpäisevyys (permeability). Antonyms include läpäisemätön (impermeable) or ei-läpäisevä (non-permeable). In Finnish technical language the concepts of permeability and penetrability are frequently discussed together, with läpäistövä forms appearing mainly in formal or specialized writing. See also materials science, membrane technology, and filtration terminology for broader context.