Cigarettes have four basic components:
- The tobacco rod
- The cigarette paper
- The tipping paper
- The filter
The tobacco in the rod includes tobacco lamina (the flat part of the tobacco leaf), tobacco stem (midribs of the leaf), and expanded lamina.
The cigarette paper includes paper and adhesive.
The filter is made mainly from cellulose acetate fibres, known as tow. Cellulose acetate is derived from wood pulp. The fibres are bonded together with a hardening agent, triacetin plasticizer, which helps the filter to keep its shape. The filter is wrapped in paper and sealed with a line of adhesive. Sometimes charcoal is added to filters.
The tipping paper includes paper and adhesive.
Design adjustments achieve different strengths and tastes, and can reduce smoke yields of various smoke components, as measured by a standardised machine method.
What happens when a cigarette burns?
To understand cigarette design, it helps to know how a cigarette burns. It is the combustion process – the burning of the cigarette – that produces tar. If hay were burned instead of tobacco, it would also produce a type of tar. When an item burns, it produces tiny particles mixed with gases – this is smoke. A cigarette filter traps some of these particles.
When a smoker puffs on a cigarette, whole smoke, including both fine particles and gases, is sucked through the tobacco rod and the filter. Gases pass through the filter, and some particles are trapped in it. It is this particulate matter, minus nicotine and water, that is called tar.
Smoke has over 5,000 constituents, many of them also found in the air we breathe and our food. These constituents include the emissions listed on packs, such as tar, nicotine and carbon monoxide. Water vapour is also produced by the combustion, because the burning of any organic material breaks down the chemical components and produces water.
Filter biodegradability
Our filter tips are biodegradable over a period of between a month and three years, depending on environmental conditions. Although we are researching more rapid breakdown, at present we know of no practical way of making consumer-acceptable filters that would degrade so quickly that they would not cause short-term littering problems.
British American Tobacco Malaysia believes the best way to reduce potential litter problems is for consumers to dispose of filters and cigarette packs in a responsible way.
