FILTER ELEMENTS SUITABLE FOR USE IN SMOKING ARTICLES AND PROCESSES FOR PRODUCING THE SAME
A filter element suitable for use in smoking articles may include: cellulose acetate fibers bonded together using polyhydroxyalkanoate (PHA) surrounding the cellulose acetate fibers, bonded together using PHA on surfaces of the cellulose acetate fibers, and/or bonded together using PHA. A process for producing the filter element suitable for use in the smoking articles may include: embedding a bundle of the cellulose acetate fibers with an aqueous suspension of the PHA to obtain a wet bundle of the cellulose acetate fibers covered by the aqueous suspension; shaping the wet bundle into a continuous elongated element; heating the elongated element to temperature greater than or equal to 140° C. and less than or equal to 180° C. to melt the PHA and to evaporate water from the elongated element; cooling the heated elongated element to obtain crystallization of the PHA; and/or cutting the elongated element into segments.
1 . A filter element suitable for use in smoking articles, the filter element comprising:
cellulose acetate fibers bonded together using polyhydroxyalkanoate (PHA) surrounding the cellulose acetate fibers.
2 . The filter element of claim 1 , wherein the PHA is a polymer containing repeating units of formula (I):
—O—CHR 1 —(CH 2 ) n —CO— (I)
where R 1 is selected from: C 1 -C 12 alkyls, C 4 -C 16 cycloalkyls, C 2 -C 12 alkenyls, optionally substituted with at least one group selected from: halogen (F, Cl, Br), —CN, —OH, —OOH, —OR, or —COOR (R═C 1 -C 4 alkyl, benzyl), and
where ‘n’ is zero or is an integer from 1 to 6.
3 . The filter element of claim 2 , wherein the PHA is selected from polyhydroxybutyrate (PHB) or poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV).
4 . The filter element of claim 1 , wherein the PHA has a weight-average molecular weight (M w ) greater than or equal to 10,000 daltons (Da) and less than or equal to 1,000,000 Da.
5 . The filter element of claim 1 , wherein the PHA is present in an amount greater than or equal to 5% by weight and less than or equal to 30% by weight with respect to a total weight of the filter element.
6 . The filter element of claim 1 , wherein the cellulose acetate fibers have diameter, expressed as denier per filament (dpf), greater than or equal to 1 and less than or equal to 15.
7 . A process for producing the filter element suitable for use in the smoking articles of claim 1 , the process comprising:
embedding a bundle of the cellulose acetate fibers with an aqueous suspension of the PHA to obtain a wet bundle of the cellulose acetate fibers covered by the aqueous suspension of the PHA;
shaping the wet bundle in a form of a continuous elongated element;
heating the continuous elongated element to temperature greater than or equal to 140° C. and less than or equal to 180° C. for time sufficient to melt the PHA and to evaporate water from the continuous elongated element;
cooling the heated continuous elongated element to obtain crystallization of the PHA; and
cutting the so-obtained continuous elongated element into segments of predetermined length.
8 . The process of claim 7 , wherein prior to the embedding, the bundle of cellulose acetate fibers has total denier greater than or equal to 20,000 denier and less than or equal to 80,000 denier.
9 . A method for quenching reactive oxygen species (ROS) in smoke produced by a smoking article, the method comprising:
providing the filter element suitable for use in smoking articles of claim 1 .
10 . The filter element of claim 2 , where ‘n’ is 0.
11 . The filter element of claim 2 , where ‘n’ is 1.
12 . The filter element of claim 2 , where ‘n’ is 2.
13 . The filter element of claim 1 , wherein the PHA is present in an amount greater than or equal to 10% by weight and less than or equal to 20% by weight with respect to a total weight of the filter element.
14 . The filter element of claim 1 , wherein the cellulose acetate fibers have diameter, expressed as denier per filament (dpf), greater than or equal to 5 and less than or equal to 10.
15 . The process of claim 7 , wherein prior to the embedding, the bundle of cellulose acetate fibers has total denier greater than or equal to 30,000 denier and less than or equal to 60,000 denier.
16 . The filter element of claim 1 , wherein the PHA comprises at least one homopolymer.
17 . The filter element of claim 1 , wherein the PHA comprises at least one copolymer.
18 . The filter element of claim 1 , wherein the PHA comprises at least one terpolymer.
19 . A filter element suitable for use in smoking articles, the filter element comprising:
cellulose acetate fibers bonded together using polyhydroxyalkanoate (PHA) on surfaces of the cellulose acetate fibers.
20 . A filter element suitable for use in smoking articles, the filter element comprising:
cellulose acetate fibers bonded together using polyhydroxyalkanoate (PHA).