A Cigarette filter is an element of a cigarette, together with cigarette paper, capsules and adhesives. The filter may be created from cellulose acetate fibre, paper or activated charcoal (either as a cavity filter or embedded in to the cellulose acetate). Macroporous phenol-formaldehyde resins and asbestos are also used in cigarette filters The acetate and paper change the particulate smoke phase by particle retention (filtration), and finely divided carbon modifies the gaseous phase (adsorption). Filters is able to reduce “tar” and nicotine smoke yields around 50%, which has a greater removal rate for other classes of compounds (e.g., phenols), but are ineffective in filtering toxins like carbon monoxide. Most factory-made cigarettes are equipped with a filter; people that roll their own can buy them coming from a tobacconist.
Cellulose acetate is created by esterifying bleached cotton or wood pulp with acetic acid. With the three cellulose hydroxy groups available for esterification, between two and three are esterified by controlling the amount 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 at will, and additives colouring the tobacco smoke could possibly be combined with cigarette filters. The 5 largest manufactures of filter tow are Hoechst-Celanese and Eastman Chemicals in america, Rhodia Acetow in Germany, Daicel in Japan, and Courtaulds in england.
Starch glues or emulsion-based adhesives can be used for gluing cigarette seams. Hot-melt and emulsion-based adhesives can be used for filter seams. Emulsion-based adhesives bring bonding filters for the cigarettes.
Cellulose acetate is non-toxic, odorless, tasteless, and weakly flammable. It can be resistance against weak acids and is also largely stable to mineral and fatty oils and also petroleum. It really is biodegradable along with the raw materials are a renewable natural polymer expected to find application for other uses later on. Smoked cigarette butts contain 5-7 mg nicotine (about 25% in the total cigarette nicotine content), children ingesting >2 whole cigarettes, 6 cigarette butts or a total of 0.5 mg/kg of nicotine needs to be admitted to some hospital. Cellulose acetate is hydrophilic and retains the water-soluble smoke constituents, of which lots of people are irritating (acids, alkali, aldehydes, and phenols), while letting over the lipophilic aromatic compounds.
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