A cigarette filter, also known as a filter tip, is a component of a cigarette, along with cigarette paper, capsules and adhesives. Filters were introduced in the early 1950s.[
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Filters may be made from plastic cellulose acetate fiber, paper or activated charcoal (either as a cavity filter or embedded into the plastic cellulose acetate fibers). Macroporous phenol-formaldehyde resins and asbestos have also been used.
Filters are intended to reduce the harm caused by smoking by reducing harmful chemicals inhaled by smokers. While laboratory tests show a reduction of "tar" and nicotine in cigarette smoke, filters are ineffective at removing gases of low molecular weight, such as carbon monoxide.
Most factory-made cigarettes are equipped with a filter; those who roll their own can buy them from a tobacconist.
History
In 1925, Hungarian inventor Boris Aivaz patented the process of making a cigarette filter from crepe paper.
From 1935, Molins Machine Co Ltd
Between the 1930s and the 1950s, most cigarettes were long. The modern cigarette market includes mainly filter cigarettes that are .
Cigarettes filters were originally made of cork and used to prevent tobacco flakes from getting on the smoker's tongue. Many are still patterned to look like cork.[
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Manufacture
Cigarette filters are usually made from plastic cellulose acetate fibre,[ but sometimes also from paper or activated charcoal (either as a cavity filter or embedded into the cellulose acetate).
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Cellulose acetate is made by bleaching cotton or wood pulp with acetic acid. Of the three cellulose hydroxy groups available for esterification, between two and three are esterified by controlling the amount of acid (degree of substitution (DS) 2.35-2.55). The ester is spun into fibers and formed into bundles called filter tow. Flavors (menthol), sweeteners, Plasticizer (triacetin), (sodium tungstate), breakable capsules releasing flavors on demand, and additives colouring the tobacco smoke may be added to cigarette filters.
or emulsion-based adhesives are used for gluing cigarette seams. Hot-melt and emulsion-based adhesives are used for filter seams. Emulsion-based adhesives are used for bonding the filters to the cigarettes.
Colour change
The tobacco industry determined that the illusion of filtration was more important than filtration itself. The pH of the cellulose acetate used is modified, so that its colour becomes darker when exposed to smoke (this was invented in 1953 by Claude Teague,[ working for R. J. Reynolds Tobacco Company).]
Health risks
In the 1970s epidemiologic evidence relative to tobacco-related cancers and data for coronary heart disease indicated a reduced risk among filter smokers for these diseases.
Light cigarettes
In spite of the changes in cigarette design and manufacturing over the last fifty years, the use of filters and "light" cigarettes neither decreased the nicotine intake per cigarette, nor lowered the incidence of lung cancer (NCI, 2001; IARC 83, 2004; U.S. Surgeon General, 2004).
Waste
Cigarette butts are the most anthropogenic (man-made) litter in the world. Approximately 5.6 trillion cigarettes are smoked every year worldwide.
During the act of smoking, plastic cellulose acetate fibers and tipping paper absorb a wide range of chemicals that are present in tobacco smoke. After cigarette butts are discarded, they can leach toxins including nicotine, arsenic, polycyclic aromatic hydrocarbons and heavy metals into the environment.[ The next option is using cigarette packs with a compartment for discarded cigarette butts, implementing monetary deposits on filters, increasing the availability of cigarette receptacles, and expanding public education. Others have suggested banning the sale of filtered cigarettes altogether on the basis of their adverse environmental impact.][
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Recent research has been put into finding ways to use the filter waste in order to develop other products. One research group in South Korea have developed a one-step process that converts the cellulose acetate in discarded cigarette filters into a high-performing supercapacitor electrode material. These materials have demonstrated superior performance as compared to commercially available carbon, graphene and carbon nano tubes.
Another group of researchers has proposed adding tablets of food grade acid inside the filters. Once wet enough the tablets would release acid that accelerates degradation to around two weeks, instead of using cellulose triacetate and besides of cigarette smoke being quite acidic.
Activated charcoal filtration
Cigarette filter can incorporate an activated charcoal filtration system. Instead of acetate or cardboard filters, it consists of two ceramic caps on either sides containing activated charcoal, which reduces tar and other toxins in the smoke.
See also
