Disclosure of Invention
The invention aims to provide a method for predicting the ventilation rate of cigarettes, which aims to solve the problems that the prediction of the ventilation rate of the cigarettes in the prior art is difficult to measure due to related parameters, has certain hysteresis relative to the design of the cigarettes, and avoids the blindness of the design of the cigarettes.
The invention is realized by the following technical scheme:
a method of predicting the ventilation rate of a cigarette, comprising the steps of:
1) acquiring the characteristics of raw and auxiliary materials of cigarettes and cigarette specification data;
2) judging the air permeability of the tipping paper, if the air permeability of the tipping paper is 0, firstly calculating the ventilation rate pv of the cigarette paper, and then calculating the total ventilation rate tv, wherein the calculation formula is as follows:
pv=-7.78+6.1×10-7×jt×d×l1×pd
tv=pv;
wherein jt represents the air permeability of the cigarette paper, and unit cu; d represents the diameter of the cigarette in mm; l1Indicates the length of the non-mouth cigarette in mm; pd represents the cigarette resistance, unit Pa;
if the air permeability of the tipping paper is not 0, firstly calculating the total ventilation rate tv and then calculating the ventilation rate pv of the cigarette paper, wherein the calculation formula is as follows:
tv=-18.09+1.06×fv+0.017×pd+2.6×10-4×jt×d×l1
pv=tv-fv;
wherein fv represents the ventilation rate of the cigarette filter; pd represents the cigarette suction resistance, and the unit Pa and the unit jt represent the air permeability of the cigarette paper and the unit cu; d represents the diameter of the cigarette in mm; l1Indicates the length of the non-tipped cigarette in mm.
The cigarette resistance is obtained through the following steps:
1) obtaining the suction resistance cpd of the closed cigarette, and calculating according to the following formula:
where ρ is1The density of the tobacco shreds in the cigarette is shown in unit of g/cm3(ii) a tc represents the filling value of the finished cut tobacco in cm3/g;l1Indicates the length of the non-mouth cigarette in mm; r represents the reduction proportion of the filling value of the finished cut tobacco; d represents the diameter of the cigarette in mm; lbpd represents 4 times longer filter rod pressure drop, unit Pa;
2) obtaining the ventilation rate fv of the cigarette filter, and calculating according to the following formula:
fv=(-43.9+1.55×l2-197.3×ρ2+0.53×l1+0.01×st×d)×j,
wherein l2The length of the filter stick is expressed in unit mm; rho2Expressing the density of the filter stick in g/cm3;l1Indicates the length of the non-mouth cigarette in mm; st represents the air permeability of the tipping paperC, positioning cu; j is an indicator variable, and j is 0 when the tipping paper air permeability is 0, and j is 1 when the tipping paper air permeability is not 0;
3) calculating the difference value er between the suction resistance of the cigarette in the open suction and the suction resistance of the cigarette in the closed suction according to the following formula:
wherein, 1 represents the length of the cigarette in mm; fv represents the ventilation rate of the cigarette filter; d represents the diameter of the cigarette in mm; j is an indicator variable, and j is 0 when the tipping paper air permeability is 0, and j is 1 when the tipping paper air permeability is not 0;
4) calculating the cigarette suction resistance pd according to the following formula:
pd=cpd-er。
the characteristics of the raw and auxiliary materials of the cigarette and the cigarette specification data comprise finished tobacco filling value, filter stick suction resistance, cigarette paper air permeability, tipping paper air permeability, cigarette length, cigarette circumference and filter stick length.
The finished tobacco filling value takes the cigarette brand filling value of similar tobacco group formulas and the same tobacco processing equipment as an empirical value.
The tipping paper comprises perforated tipping paper and non-perforated tipping paper.
When the tipping paper is not punched, the air permeability of the tipping paper is set to be 0, and the ventilation rate of the filter tip is set to be 0.
The invention has the beneficial effects that:
according to the technical scheme, according to the detection method and the process principle of the cigarette suction resistance and the ventilation rate, a prediction model of each index and the characteristics of the raw and auxiliary materials of the cigarette is established by combining a large number of cigarettes of different brands and different specifications, a basis is provided for reasonably designing the cigarette structure, selecting the cigarette material according to the characteristics of the raw material, controlling the release amount of tar and the like, and the predictability of product design is realized.
Meanwhile, the internal relation between the cigarette physical indexes and the original auxiliary materials is disclosed, when the cigarette physical indexes have problems in actual production, the problem reasons can be determined according to the model, the direction is indicated for quality improvement, the blindness in production is avoided, and the internal quality of the cigarettes is continuously improved.
Detailed Description
The technical solutions of the present invention are described in detail below by examples, and the following examples are only exemplary and can be used only for explaining and explaining the technical solutions of the present invention, but not construed as limiting the technical solutions of the present invention.
The technical scheme provides a method for predicting the ventilation rate of cigarettes, which comprises the following steps:
1) acquiring the characteristics of the raw and auxiliary materials of the cigarette and the specification of the cigarette, wherein the characteristics comprise finished tobacco shred filling values, filter stick suction resistance, cigarette paper air permeability, tipping paper air permeability, cigarette length, cigarette circumference, filter stick length and filter stick weight, and the finished tobacco shred filling values take similar tobacco leaf group formulas and cigarette brand filling values of the same tobacco shred processing equipment as experience values; the following assumptions were made in establishing the prediction model: the tipping paper comprises perforated tipping paper and non-perforated tipping paper; when the tipping paper is not perforated, it is considered that its air permeability is approximately 0 and the filter ventilation rate is 0.
2) Judging the air permeability of the tipping paper, if the air permeability of the tipping paper is 0, firstly calculating the ventilation rate pv of the cigarette paper, and then calculating the total ventilation rate tv, wherein the calculation formula is as follows:
pv=-7.78+6.1×10-7×jt×d×l1×pd
tv=pv;
wherein jt represents the air permeability of the cigarette paper, and unit cu; d represents the diameter of the cigarette in mm; l1Indicates the length of the non-mouth cigarette in mm; pd represents the cigarette resistance, unit Pa;
if the air permeability of the tipping paper is not 0, firstly calculating the total ventilation rate tv and then calculating the ventilation rate pv of the cigarette paper, wherein the calculation formula is as follows:
tv=-18.09+1.06×fv+0.017×pd+2.6×10-4×jt×d×l1
pv=tv-fv;
wherein fv represents the ventilation rate of the cigarette filter; pd represents the cigarette suction resistance, and the unit Pa and the unit jt represent the air permeability of the cigarette paper and the unit cu; d represents the diameter of the cigarette in mm; l1Indicating the length of a non-tipping cigaretteBit mm.
The cigarette resistance is obtained by the following steps:
1) calculating the smoking resistance cpd of the closed cigarette (the smoking resistance of the cigarette measured by the closed filter section), and the unit Pa: the cigarette cut-off is calculated according to the following formula:
in the formula, ρ1The density of the tobacco shreds in the cigarette is shown in unit of g/cm3(ii) a tc represents the filling value of the finished cut tobacco in cm3/g;l1Indicates the length of the non-mouth cigarette in mm; r represents the reduction proportion of the filling value of the finished cut tobacco; d represents the diameter of the cigarette in mm; lbpd represents 4 times longer filter rod pressure drop in Pa.
2) Calculating the ventilation rate fv of the cigarette filter: calculating the ventilation rate of the cigarette filter according to the following formula:
fv=(-43.9+1.55×l2-197.3×ρ2+0.53×l1+0.01×st×d)×j
in the formula I2The length of the filter stick is expressed in unit mm; rho2Expressing the density of the filter stick in g/cm3;l1Indicates the length of the non-mouth cigarette in mm; st represents the air permeability of the tipping paper, unit cu; j is an indicator variable, and j is 0 when the tipping paper is not perforated (air permeability is approximately 0) and 1 when the tipping paper is not 0.
3) Calculating the difference er between the suction resistance of the cigarette in the opening process and the suction resistance of the cigarette in the closing process, wherein the unit is Pa: the cigarette open-draw is measured at a base open cigarette filter segment where the cigarette is measured to be closed, so that the difference between the open-draw and closed-draw is related to the filter ventilation rate, and the filter ventilation rate is used to predict the difference:
in the formula: l represents the length of the cigarette in mm; fv represents the ventilation rate of the cigarette filter; d represents the diameter of the cigarette in mm; j is an indication variable, and j is 0 when the tipping paper is not perforated, and j is 1 when the air permeability of the tipping paper is not 0.
4) Calculating the cigarette resistance: the cigarette resistance was calculated as follows:
pd=cpd-er
in the formula: pd represents the cigarette resistance, unit Pa; cpd represents the suction resistance of the closed cigarette, and the unit Pa; and er represents the difference between the suction resistance of the cigarette when the cigarette is opened and the suction resistance of the cigarette when the cigarette is closed, and the unit is Pa.
Example 1
The design standard of part indexes and the characteristics of raw and auxiliary materials of a certain brand of cigarettes are shown in the following table 1:
TABLE 1 cigarette index design criteria and raw and auxiliary material characteristics
(1) Calculating the resistance of the cigarette to closed draw (the resistance of the cigarette measured at the closed filter section):
(2) calculating the ventilation rate of the cigarette filter: calculating the ventilation rate of the cigarette filter according to the following formula:
fv=(-43.9+1.55×l2-197.3×ρ2+0.53×l1+0.01×st×d)×j=-43.9+1.55×30-197.3×0.16+0.53×54+0.01×280×7.72=22.8%
(3) calculating the difference value between the suction resistance of the cigarette in the open state and the suction resistance of the cigarette in the closed state:
(4) calculating the cigarette resistance: the cigarette resistance was calculated as follows:
pd=cpd-er=1210.6-176.6=1034Pa。
(5) calculating the ventilation rate and the total ventilation rate of the cigarette paper:
when the air permeability of the tipping paper is not 0, the total ventilation rate is calculated firstly, and then the ventilation rate of the tipping paper is calculated, wherein the calculation formula is as follows:
tv=-18.09+1.06×fv+0.017×pd+2.6×10-4×jt×d×l1=-18.09+1.06×22.8+0.017×1034+2.6×10-4×60×7.72×54=30.2%
pv=tv-fv=30.2-22.8=7.4%。
the predicted results were compared to the actual results as shown in the following table:
TABLE 2 comparison of measured and predicted results
Index (I)
|
Measured in fact
|
Prediction
|
Relative error%
|
Suction resistance Pa
|
1044
|
1034
|
0.96
|
Total ventilation rate%
|
27.4
|
30.2
|
10.22 |
As can be seen from Table 2, the method can better predict the ventilation rate of the cigarette according to the design index of the cigarette and the specification of related raw and auxiliary materials.
Example 2
In order to further verify the prediction effect of the invention, cigarettes with different specifications and brands are selected for prediction and compared with the actual measurement result, and the result is as follows:
TABLE 3 cigarette design index and raw and auxiliary material characteristics
TABLE 4 comparison of predicted results and actual results
According to the prediction results of the physical indexes of the cigarettes of different brands and different specifications, the maximum error of the suction resistance is 84Pa, the average absolute error is 33Pa, the average relative error is 2.68%, the average relative error of the total ventilation rate is 10.66%, and the prediction results are ideal.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.