Electrolytic capacitor paper prodn. - from esparto pulp opt. mixed with other pulp, giving good impedance, short circuit behaviour and tensile strength

摘要

The paper is produced in the form of a (thin) sheet from an esparto (Stipa tenacissima) pulp mixed with another pulp in a ratio of 9-95 wt. %, the esparto pulp having fibres of small dia. and approx. circular cross-section. The other pulp can be manilla hemp (Musa textilis), wood, flax, (Linum usitalissiumum), hemp (Cannabis sativa), 'Benares' hemp, gampi (Wikstroemia sikokiana) bast fibre, kozo (Broussonetia kazinoki) bast fibre, mitsumata (Edgeworthia papyrifera) bast fibre or bamboo pulp. Esparto grass fibres have a certain stiffness and give a finer paper than manilla hemp, with good impedance characteristics and better properties w.r.t. damage by short circuits. The other pulp improves the tensile strength. In an example, paper produced from 60% esparto pulp + 40% manilla hemp pulp (100% manilla hemp pulp), with a thickness of 51.5 (51.0) mu m and density of 0.413 (0.425) g./cm3, had a tensile strength of 2.2 (3.0) kg./15 mm. width, impedance at -40 degrees C. and 10 kHz of 10.9 (12.0) and short circuit damage of 0.3 (0.8)%.