US 11,918,036 B2
Biodegradable cigarette filter
Andries D. Sebastian, Clemmons, NC (US); Alan B. Norman, Clemmons, NC (US); Leigh Ann Joyce, Lewisville, NC (US); and Huamin Gan, Clemmons, NC (US)
Assigned to R.J. Reynolds Tobacco Company, Winston-Salem, NC (US)
Filed by R.J. Reynolds Tobacco Company, Winston-Salem, NC (US)
Filed on Jul. 26, 2018, as Appl. No. 16/046,392.
Application 16/046,392 is a continuation of application No. 14/737,009, filed on Jun. 11, 2015, granted, now 10,058,121.
Application 14/737,009 is a continuation of application No. 12/963,275, filed on Dec. 8, 2010, abandoned.
Application 12/963,275 is a continuation in part of application No. 12/827,618, filed on Jun. 30, 2010, abandoned.
Prior Publication US 2018/0338525 A1, Nov. 29, 2018
This patent is subject to a terminal disclaimer.
Int. Cl. A24D 3/10 (2006.01); A24D 3/06 (2006.01); A24D 3/02 (2006.01)
CPC A24D 3/068 (2013.01) [A24D 3/0237 (2013.01); A24D 3/0287 (2013.01); A24D 3/064 (2013.01); A24D 3/065 (2013.01); A24D 3/10 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A filter material configured for use as part of a smoking article, comprising:
a plurality of bi-component fibers assembled as fibrous filter tow, each fiber including a core comprising a first degradable polymer material including polylactic acid or a polyhydroxyalkanoate and a sheath comprising a second polymer material including at least one of a cellulose ester and a plasticizer;
wherein the core comprises a higher melt temperature than the sheath;
wherein the fibrous filter tow comprises particles of starch and/or particles of cellulose; and
wherein the second polymer material further comprises polylactic acid.