Cigarette paper with improved air-permeability
A cigarette paper is shown which has the following properties over at least a part of its surface: no artificial perforation, the air permeability is at least 15 CU, preferably at least 20 CU, and especially preferably at least 25 CU, and for the exponent k, measured with a measuring head with a rectangular opening of 2 mm by 15 mm, in accordance with ISO 2965:2009, which is defined by k = log Q 1 Q 2 log p 1 p 2 with Q 1 : air-flow through the paper at a pressure difference p 1 =1.00 kPa and Q 2 : air-flow through the paper at a pressure difference p 2 =0.25 kPa, the following holds k≦0.98, preferably k≦0.95, especially preferably k≦0.93, and k≧0.80, preferably k≧0.85.
1. A cigarette paper having a surface, at least a part of the surface having the following properties:
no artificial perforation
an air permeability of at least 15 CU, and
for an exponent k measured with a measuring head with a rectangular opening of 2 mm
by 15 mm in accordance with ISO 2965:2009, which is defined as:
k
=
log
Q
1
Q
2
log
p
1
p
2
where:
Q 1 represents air-flow through the paper at a pressure difference p 1 =1.00 kPa,
Q 2 represents air-flow through the paper at a pressure difference p 2 =0.25 kPa, and wherein k≦0.98 and k≧0.8,
wherein the exponent k in said part of the surface varies over a length of the surface.
2. The cigarette paper according to claim 1 , wherein said part of the surface has a first part and a second part, wherein the exponent k is less in the first part than in the second part.
3. The cigarette paper according to claim 1 , wherein registration marks are provided which are in register with said part of the surface.