A Cigarette filter is part of an cigarette, along with cigarette paper, capsules and adhesives. The filter could be made from cellulose acetate fibre, paper or activated charcoal (either as being a cavity filter or embedded in the cellulose acetate). Macroporous phenol-formaldehyde resins and asbestos are also used in cigarette filters The acetate and paper get a new particulate smoke phase by particle retention (filtration), and finely divided carbon modifies the gaseous phase (adsorption). Filters can reduce “tar” and nicotine smoke yields around 50%, having a greater removal rate for other classes of compounds (e.g., phenols), however are ineffective in filtering toxins including deadly carbon monoxide. Most factory-made cigarettes include a filter; people who roll their particular can buy them from your tobacconist.
Cellulose acetate is manufactured by esterifying bleached cotton or wood pulp with acetic acid. From the three cellulose hydroxy groups readily available for esterification, between two and three are esterified by managing the level of acid (level of substitution (DS) 2.35-2.55). The ester is spun into fibers and formed into bundles called filter tow. Flavors (menthol), sweeteners, softeners (triacetin), flame retardants (sodium tungstate), breakable capsules releasing flavors when needed, and additives colouring the tobacco smoke could be put into cigarette filters. 5 largest manufactures of filter tow are Hoechst-Celanese and Eastman Chemicals in the United States, Rhodia Acetow in Germany, Daicel in Japan, and Courtaulds in the United Kingdom.
Starch glues or emulsion-based adhesives are used for gluing cigarette seams. Hot-melt and emulsion-based adhesives bring filter seams. Emulsion-based adhesives can be used bonding the filters on the cigarettes.
Cellulose acetate is non-toxic, odorless, tasteless, and weakly flammable. It can be resistant to weak acids and is also largely stable to mineral and fatty oils and also petroleum. It is biodegradable as well as the raw material is a renewable natural polymer anticipated to find application for other uses down the road. Smoked cigarette butts contain 5-7 mg nicotine (about 25% from the total cigarette nicotine content), children ingesting >2 whole cigarettes, 6 cigarette butts or possibly a total of 0.5 mg/kg of nicotine ought to be admitted to a hospital. Cellulose acetate is hydrophilic and retains the water-soluble smoke constituents, ones most are irritating (acids, alkali, aldehydes, and phenols), while letting over the lipophilic aromatic compounds.
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