Biodegradable Filters

Filter Rods for Cigarettes

A wide variety of fibrous materials has been suggested as filters for cigarette smoke. Cellulose acetates tow is the most commonly used filter material. One disadvantage associated with this filter material is, however, that is slow to degrade. Whilst most of the components of a spent smoking article dissociate into their individual constituent parts and degrade within a relatively short period of time when exposed to moisture and/or mechanical abrasion, cellulose acetate filter material is slow to degrade because the cellulose acetate fibres themselves are effectively not water soluble and therefore poorly biodegradable.

For disposable products, it is desirable to use materials which are biodegradable. Biodegradable polymers disposed of in bioactive environment degrade by the enzymatic action of microorganisms such as bacteria, fungi and algae. Their polymer chains may also be cleaved by non-enzymatic processes such as chemical hydrolysis. The term “biodegradable” means that the composition degrades within one year using the standard test method for deterring aerobic biodegradation of plastic materials under controlled composting conditions.

Polylactic Acid or Polylactide, is an attractive biodegradable and biocompatible polymer. It is derived from renewable resources(eg. corn, wheat, or rice) and it is biodegradable, recyclable, and compostable. In addition, PLA exhibits excellent process ability. It can be produced to biodegradable filter materials, preferably are made from materials which can be easily processed to produce fibres, which are thermally processable and which have good mechanical and physical properties.