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Cellulose acetate is an easter formed by the action of glacial acetic acid on cellulose derived from wood pulp. The main chemical reaction is called acetylation and forms a viscous intermediate product known as cellulose triacetate. The triacetate is converted into the secondary acetate by partial hydrolysis, precipitation, washing and drying steps then convert the viscous secondary acetate into a dry flake form suitable for further processing into cigarette tow.

In general, cigarette filter tow is made by spinning a dope into a plurality of filaments, taking up the filaments, lubricating the filaments, forming a tow by bundling a plurality of the filaments, crimping the tow, drying the crimped tow, and baling the dried crimped tow.

The production of cigarette filter tow can be described in four principal steps.

STEP 1: Preparation of the spinning solution

Cellulose acetate flakes and acetone are mixed together intensively. A small amount of titanium dioxide is added as a delustering agent for the later product. To achieve a spinning solution free of particles able to block the spinnerets, the mixing is followed by an intensive filtration.

STEP 2: Spinning

After passing the spinneret of a spinning cell the acetone starts to evaporate from the spinning solution. The evolving filaments solidify and are brought together while the acetone is almost completely removed and recovered.

STEP 3: Crimping

The resulting filaments from numerous spinnerets are combined to form a cable of up to several tens of thousands of filaments. These cables are subsequently crimped in a stuffer box to obtain the typical cigarette filter tow structure.

STEP 4: Drying and processing

The fresh crimped structure is fixed by drying, and the cigarette filter tow is compressed in bale presses to form filter tow bales.