Transport of Moist Air Through Microporous Polyolefin Films

Abstract

The technological revolution and busy schedule compel human society to search for better civic amenities. This leads to the use of modern personal care goods such as disposable diapers and sanitary napkins. Presently, all of the goods use microporous polyolefin films. The high-strength microporous polyolefin films also find applications in packaging industries. The polyolefins create a liquid barrier due to their hydrophobic character, whereas the microporosity allows permeation of moist air, thereby providing comfort. The introduction of microporosity in the polyolefin film is rather an art than a science. One of the techniques of generating microporosity is by the pulling of a polyolefin at the interface of a solid inclusion. The other technique includes pulling of pure polyolefin films, which are mainly used for packaging, to create interlamellar voids or pores in the films. This review article discusses the theory of diffusion through the microporous film and the various factors of microporosity such as the addition of filler, its nature (organic or inorganic), size and quantity, film drawing temperature, stretch ratio, its direction (uniaxial and biaxial), and above all, the type of polyolefins used. The aim of this review is to introduce readers to the fascinating science and technology of breathable microporous polyolefin films.