US20180360106A1

US20180360106A1 - Systems and Methods for a Smoking Product Filter

Info

Publication number: US20180360106A1
Application number: US16/010,241
Authority: US
Inventors: Bin Chen; Yi Wang; Xiaohang Lin
Original assignee: Ankang Group Ltd
Current assignee: Ankang Group Ltd
Priority date: 2017-06-16
Filing date: 2018-06-15
Publication date: 2018-12-20

Abstract

A smoking product with one or more filters, such as a cigar or cigarette. The filters may comprise micro-fibers, nano-fibers, or a combination thereof, wherein the fibers are provided by electrospinning. The filters may be disc-shaped, hemispherical-shaped, convex lens-shaped, and/or may comprise one or more folding structures. The smoking product may be a tobacco product, and may comprise a plurality of filters comprising one or more materials and one or more sizes and/or shapes, and the filters may comprise fibers of provide a size gradient from a first end of the product to the second end. In addition, the filters may further comprise one or more catalysts adapted to adsorb or filter to reduce or remove one or more materials, which may be toxic. Methods of making the filters and tobacco products are provided.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of U.S. provisional patent application Ser. No. 62/521,048, which was filed on June 16, 2017, and which is hereby incorporated herein by reference.

BACKGROUND

The present disclosure relates to the field of smoking product filtration, including cigar and cigarette filtration. In particular, it relates to the addition of one or more layers of nano filters and/or micro filters to the filter and the body of tobacco products, including but not limited to cigarettes and cigars, in the aim of effectively reducing the inhalation of toxic and hazardous substances and tar by the human body. Nano filters are composed of nanomaterials of which a single unit is sized (in at least one dimension) between 1 and 1000 nanometers, including but not limited to nanofibrous materials, carbon nanotubes, carbon nanotube membranes, and graphene oxide. Micro filters are composed of micromaterials of which a single unit is sized (in at least one dimension) between 1 and 1000 micrometers, including but not limited to meltblown nonwoven fabrics, carbon fibers, carbon fiber cloths, carbon membranes, and carbon fiber membranes. Nanomaterials and micromaterials can be interwoven or synthesized together to form a filter with mixed sizes of constituent elements. The present disclosure also relates to a method for preparing nanofibrous layers using electrospinning.
In order to minimize the impacts of smoking on human health, to protect the health of people living around the smokers and in the environment affected by smoking, and to prevent the intake of respirable particulate matters and other harmful and unhealthy substances from smoking into human body, there is increasing attention on adding filter layers to cigarettes. A variety of filtering methods and filter materials have been studied for cigarette filtration. However, conventional research and the application of filter materials to reduce the inhalation of particulate matter have not fully met the filtration requirements on the particles and harmful substances generated during cigarette smoking.
In the last century, cigarette filters have widely been used to reduce the harmfulness of smoking on human health. In the 1930s, doctors and researchers published a series of studies on the relation between smoking and lung diseases. At that time, cigarette filters began to receive attention. The purpose of a filter in a cigarette is to reduce the amount of tar and suspended particles in smoke inhaled by a smoker from burning tobacco. There is a dilemma: in order to block tar and small-sized particles, the filter has to be less porous, with high filtration efficiency, but unfortunately as a result, the filter easily becomes clogged by tar and toxic articles. If a filter is clogged, it is impossible for smokers to smoke after only a few puffs. There is an urgent need to find a solution such that fine particles can be blocked while smokers do not suffer from clogged filters.
Electrospinning is a technique that uses a polymer solution or a melt to form a jet stream under a strong electric field for spinning. In recent years, due to its ultra-fine fiber processing technology, electrospinning has received more and more attention. There are currently at least 30 kinds of polymers that can be electrospun, including natural polymers such as DNA, collagen, and silk protein, and synthetic polymers including polyoxyethylene, polyacrylonitrile, nylon, polyvinyl alcohol, polyurethane, and polyester. Compared to other methods that are expensive, time-consuming, and easy to cause pollution, electrospinning can save a lot of cost and energy.
In order to enhance the filtration of tar, nicotine, and suspended particles, various materials and structures for a cigarette filter have been proposed. PCT application WO 2004/080217 A1 discloses a method of electrically processed phenolic materials and the application of such materials to cigarettes. The method of electrical processing in WO 2004/080217 A1 is essentially the same as the electrospinning method, but the method also includes steps of drying and high-temperature carbonization after electrical processing. The method can be used for to produce nano/micro fibers and particles. Such anodized phenolic materials used in cigarettes are not safe. Also, carbonated phenolic materials are brittle and easy to be inhaled. When fine micro/nano fibers or particles are used as filler materials in the filter and placed in the filter with a small pore size, the filter layer is easily clogged with tar or particles of harmful substances.
PCT application WO 2007/048359 A1 discloses the design of mixing 5 to 10 percent nanofibers into a micron fiber filter. With the introduction of nanofibers, it increases the surface area of the material and hence its filtration capacity. The disclosure in WO 2007/048359 A1 still uses conventional acetate fibers as filter materials. This disclosure provides a small improvement on filtration effects because the amount of nanofibers is low. At the same time, due to the mixed design of using nano and micron fibers, the tar, nicotine, suspended particles are more likely to pass through the micron fibers. The nanofibers do not function well, as when fine micro/nano fibers or particles with small pore sizes are placed in the filter as filter materials, the filter layer is easily clogged with tar or particles of harmful substances.
PCT application WO 2013/164623 A1 discloses the addition of short fibers with adsorbents or adsorbed particles on the surface of the cigarette filters. The diameter and length of the short fibers are approximately 5-9 millimeters and 5-20 millimeters, respectively. Short fibers are a mixture of acetate fibers and other common polymer fibers. The size of the adsorbents or adsorbed particles, including activated carbon, on the fibers is between 0.1 and 1 millimeters. The materials used in the invention do not reach the nanoscale either in the diameter of the fiber or in the particle size. The materials are not safe.
Chinese patent CN 102423141 A discloses a method for using an electrospun acetate fiber membrane in the cigarette filter to improve the efficiency of harmful substances filtration. The solvents used are acetone and dimethyl acetamide. Solvent residues are likely contained in the electrospun membrane if the solvent evaporation is not well completed during the production process, leading to potential health risks to smokers. The patent puts the fiber membrane inside the cigarette filter tip portion. Filtration effects and respiratory resistances cannot be well controlled.
Chinese Patent CN 103625090 A discloses a method to prepare a nanofiber membrane modified paper substrate by electrospinning and its application. The nano-spun yarns are between 500 nm and 1 μm in diameter, with a narrow spinning range and larger diameter than the effective nanomaterial filtration.
Because of their excellent filtration effects, electrospinning materials have been developed as filter materials, such as masks, to improve human respiratory health. Chinese Patent CN 104740934 A discloses a stereoscopic electrospinning filter material for a mask and a preparation method thereof. The invention uses polyvinyl butyral as a substrate, and a micro/nanofiber film of 0.2 microns to 1.5 microns in size is prepared on a stereoscopic model using an electrospinning technique. The solvent used in CN 104740934 A is ethanol, which is not as safe and reliable as using a water solvent to produce nano fibers for large-scale production. The diameters of micro/nano fibers prepared in the disclosure in CN 104740934 A are in the range of 0.2 to 1.5 microns, a range that is too small, and the control of the product is not as good. The spinning solution concentration of the polymer polyvinyl butyral is 0.06 g/ml, which is too low.
Chinese Patent CN 102872654 A and CN 102920067 A disclose the use of electrospinning to produce a mask capable of filtering pollutants of 2.5 microns in size or larger. However, the polymer used and the solvents used for preparing the electrospinning solution are toxic, posing serious health risks if a complete evaporation of solvent cannot be achieved. At the same time, the filter materials prepared by these patents are not as effective for filtration of pollutants of 2.5 microns in size or larger.

SUMMARY

A first advantage of the present disclosure relates to the placement of one or more filters in a body of a tobacco product or other body for smoking to filter harmful substances caused by smoking thereby protecting human health. The advantage of adding filters to the cigarette body is that the filters can be burnt up, before they are clogged by the accumulation of tar and particles, along with the tobacco in the cigarette body.
A second advantage of the present disclosure is that the surface area of the filter(s) can be increased when specific shapes of the filters are adopted, thereby allowing the same sized filter to tolerate a higher amount of tar without clogging.
A third advantage of the present disclosure is that when multiple filter layers are deployed within one filter, their porosities and thicknesses can vary and they can be placed in either the cigarette filter and/or body section, e.g., filter layers with larger porosities can be closer to the lit end of the cigarette to capture larger contaminants and filter layers with smaller porosity can be closer to the mouth of the smoker to capture smaller contaminants. The porosity determines the sizes of the contaminants that a filter layer can capture, with less porous filters being able to block smaller particles. As a result, finer filter layers, or filter layers that are less porous will unlikely be clogged by larger contaminants, hence enhancing their capability to block more finer contaminants. Similar results can be achieved when multiple filters—but with different porosities—are placed in either the cigarette filter and/or body section.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the present disclosure will become better understood with regard to the following description, appended claims, and accompanying drawings where:

FIG. 1A is a perspective view of a cigarette containing a filter in its filter tip portion, which is cone-shaped according to a first embodiment of the present disclosure.

FIG. 1B is a perspective view of a cigarette containing a filter in its body section, which is cone-shaped according to a first embodiment of the present disclosure.

FIG. 1C is a perspective view of a cigarette containing a filter in its filter tip portion and another filter in its body section, both of which are cone-shaped according to a first embodiment of the present disclosure.

FIG. 1D is a cross-sectional view of a cone-shaped filter in FIGS. 1A, 1B, and 1C according to a first embodiment of the present disclosure.

FIG. 1E is a cross-sectional view of a cone-shaped filter in FIGS. 1A, 1B, and 1C according to a first embodiment of the present disclosure.

FIG. 2A is a perspective view of a cigarette containing three filters in its filter tip portion, which are hemisphere-shaped according to a second embodiment of the present disclosure.

FIG. 2B is a perspective view of a cigarette containing three filters in its body section, which are hemisphere-shaped according to a second embodiment of the present disclosure.

FIG. 2C is a perspective view of a cigarette containing one filter in its filter tip portion and two filters in its body section, all of which are hemisphere-shaped according to a second embodiment of the present disclosure.

FIG. 2D is a cross-sectional view of a hemisphere-shaped filter in FIGS. 2A, 2B, and 2C according to a second embodiment of the present disclosure.

FIG. 2E is a cross-sectional view of a hemisphere-shaped filter in FIGS. 2A, 2B, and 2C according to a second embodiment of the present disclosure.

FIG. 3A is a perspective view of a cigarette containing three filters in its filter tip portion, which have a folding structure according to a third embodiment of the present disclosure.

FIG. 3B is a perspective view of a cigarette containing three filters in its body section, which have a folding structure according to a third embodiment of the present disclosure.

FIG. 3C is a perspective view of a cigarette containing two filters in its filter tip portion and two filter in its body section, all of which have a folding structure according to a third embodiment of the present disclosure.

FIG. 3D is a cross-sectional view of a filter in FIGS. 3A, 3B, and 3C, which has a folding structure according to a third embodiment of the present disclosure.

FIG. 3E is a cross-sectional view of a filter in FIGS. 3A, 3B, and 3C, which has a folding structure according to a third embodiment of the present disclosure.

FIG. 4 is a perspective view of a cigarette containing a filter that is disc shaped and with different layers according to a fourth embodiment of the present disclosure.

FIG. 5A is a perspective view of a cigarette containing three filters in the body portion of the cigarette, with an unevenly distributed placement in the cigarette body.

FIG. 5B is a perspective view of a cigarette containing three filters in the body portion of the cigarette, with an evenly distributed placement in the cigarette body.

DETAILED DESCRIPTION

The present disclosure can be better understood by the following discussion of the manufacture and use of certain preferred embodiments. Like reference numerals are used to describe like parts in all figures of the drawings.
This present disclosure applies one or more filters in tobacco products including but not limited to cigarettes and cigars, especially for the filtration of toxic suspended particles, with each filter capable of containing one of more layers. Both the layers and filters can display different porosities. Preferably, the filters have a large surface area. Using nano-sized and/or micro-sized particle filtration, the filters can effectively reduce tar and other harmful impurities in smoke, or aerosol, and reduce irritation to the respiratory tracts to protect human health. Filters in the present disclosure can be made of biodegradable materials. Preferably, the selected materials are not toxic and have no side effects. Nanofibers produced by electrospinning can be used in the filters due to their cost effectiveness.
In the present disclosure, the concept of filtration includes any or a combination of various mechanical, physical, chemical, or biological operations or materials that blocks, restricts, adsorbs, traps, disintegrates, destroys, damages, or has any means of restricting certain substances from passing from one point to another, or filter. The substances filtered can be in solid, liquid or gas format.
During the combustion of tobacco leaves, a plurality of harmful gaseous components may be generated, including but not limited to at least one of carbon monoxide, ammonia, 1,3-butadiene, isoprene, acraldehyde, acrylonitrile, hydrogen cyanide, 0-toluidine, 2-naphthylamine, nitrosamine, nitrogen oxide, benzene, n-nitrosonornicotine (NNN), phenol, catechol, benzoanthracene, and benzopyrene. A large number of studies have been carried out on reducing harmful gaseous components from burning tobacco, such as applying filter tips. Such filter tips are often clogged or filled with tar after only a few puffs. According to the present disclosure, the filter(s) is directly placed in the cigarette body, and the filter(s) has a specific adsorption effect and/or is mixed with a specific catalyst, so that more harmful materials can be removed when the filter(s) is designed to possess a large surface area. Particularly, the filter(s) can be burnt out along with the combustion of the tobacco in the cigarette body. Harmful chemicals can be subject to thermal decomposition and/or catalytic decomposition under the high temperature of combustion, and thus reducing inhalation of harmful gas by human body.
When cigarettes are burned, aerosol and tar are produced. After cooling down, tar is in oily liquid form, containing a large number of harmful substances. It's important to filter and remove selectively the harmful substances, and reduce tar. As nicotine and flavor chemicals are also in the aerosol and tar, care needs to be taken to preserve flavors. General tar filtration methods using acetate fibers only are problematic because the filters quickly become clogged. In cases when fine or ultrafine fibers are employed to remove small aerosol particles, smokers often cannot even smoke after a few puffs.
The present disclosure employs two approaches to avoid the clogging problem.
First, one or more filters can be placed in a body of a tobacco product. In case there is more than one filter, the number of filters per unit distance can be set to increase gradually towards the filter tip portion (non-lit end) of the cigarette. Tar clogging can be avoided as the filter or filters close to the lit end are burned subsequently during smoking. That is, as more and more tar accumulates on the filter closer to the lit end, that filter is to be burned when smoking continues, thereby destroying the clogged filter. In another variation of the current design where multiple filters are employed, the number of filters per unit distance remains the same, but the thickness of each layer is gradually increased toward the end of the cigarette, which can also prevent the clogging of the tar while maintaining a high filtration efficiency.
Secondly, multiple layers with different porosities can be bound together to form a filter, called a multi-layer filter, to alleviate the clogging problem. A multi-layer filter effectively enlarges the surface area for filtration. In the present disclosure, one or more multi-layer filters are placed in either the cigarette body, or the tobacco section, or both. The layer(s) that is more porous or that can block only coarse or large particles can be located closer to the lit end of the cigarette, while the layer(s) that is less porous or that can block finer particles can be located closer to filter tip portion of the cigarette. With such an arrangement, larger particles will be blocked or absorbed by the layer(s) closer to the lit end. They will not clog the layer that is designed to block finer particles.
FIG. 1A is a perspective view of a cigarette 100 containing a filter 130 according to a first embodiment of the present disclosure. In the first embodiment, a filter having a substantially conical shape is embedded within the filter tip portion of the cigarette. A cigarette 100 comprises a body portion 110, tobacco 112(which may be tobacco leaves) rolled into the body portion 110), a filter tip portion 120, acetate fibers 122 that are within the filter tip portion 120, and a filter 130 that is substantially cone shaped and embedded within the acetate fiber 122 of the filter tip portion 120. A single filter 130 or multiple filters 130 can be placed within the acetate fiber 122 of the filter tip portion 120 depending on specific filtration requirements.
FIG. 1B is a perspective view of a cigarette 100 containing the same filter 130 as that in FIG. 1A, which is placed in the body, or tobacco, portion of the cigarette. This filter can be burned during smoking, thus avoiding being clogged by tars and other contaminants.
FIG. 1C is a perspective view of a cigarette 100 containing two filters 130 that are the same as that in FIG. 1A, which are placed in the filter and the body portions of the cigarette, respectively. The filter in the cigarette body can be burned during smoking, thus avoiding being clogged by tars and other contaminants.
Referring now to FIG. 1D, there are at least two layers in at least one filter, with the first layer closer to the lit end of the cigarette and the second layer closer to the filter tip portion of the cigarette. Multiple layers with different porosities or filtration capabilities can be placed or bound together to form a filter, called a multi-layer filter, in which the first layer is designed to block or adsorb or disintegrate particles with larger sizes than the second layer. For example, the filter 130 comprises of a spunlace nonwovens layer 132 and a nanofiber membrane layer 134. Bound together, these two layers form a cone-shaped two-layer filter. The spunlace layer 132 can be made of fibers with larger diameters, for example, from 2 to 20 millimeters. The nanofiber membrane layer 134 can be made from fibers with diameters from 10 to 500 nanometers. Unlike the nanofiber membrane layer 134, layer 132 is unable to block ultra-fine particles, but only larger, coarser granules. Hence layer 134 is shielded from and unlikely to be clogged by larger particles. The filter 130 can be made of materials that are non-toxic and harmless. Referring now to FIG. 1E, alternatively the filter 130 can comprise of a meltblown nonwoven fabrics layer 136 and a nanofiber membrane layer 134. The diameters of fibers or nanotubes that constitute filter 130 can be between 1 nanometers and 5 microns, which can effectively filter out toxic substances, harmful substances and solid particles produced by the combustion of the tobacco 112 of the cigarette 100. The filter 130 can be configured to reduce one or more of the gaseous components in the smoke through, for example, specific adsorption materials and/or specific catalysts that can decompose of at least one harmful gaseous component. The cone shape of the filter 130 can filter tar to a large extent by allowing tar deposits to form at the tip of the conical structure, serving both a filtration and a storage function, while air and smoke can still flow through the walls of the cone shaped filters.
FIG. 2A is a perspective view of a cigarette 200 containing three filters 140 according to a second embodiment of the present disclosure. In the second embodiment, three filters with a substantially hemispherical shape are embedded within the filter tip portion of the cigarette. The cigarette 200 comprises a body portion 110, tobacco 112, a filter tip portion 120, acetate fibers 122 that are within the filter tip portion 120, and three filters 140 that are substantially hemispherical shaped embedded within the acetate fiber 122 of the filter tip portion 120. If necessary, one single filter 140, instead of multiple ones, can be placed within the acetate fiber 122 of the filter tip portion 120.
FIG. 2B is a perspective view of a cigarette 200 containing three filters 140 that may be the same as those in FIG. 2A, but are placed in the body portion of the cigarette 200. These filters can be burned during smoking, to avoid being clogged by tars and other contaminants. If necessary, one single filter, instead of multiple filters, can be placed within the cigarette body 110 depending on specific filtration requirements.
FIG. 2C is a perspective view of a cigarette 200 containing three filters 140 that may be the same as those in FIG. 2A, but one is placed in the filter tip portion and the other two are placed in the body portion of the cigarette 200. The filters in the cigarette body can be burned during smoking, to avoid being clogged by tars and other contaminants.
Referring now to FIG. 2D, which is a cross-sectional view of the filter 140, the generally hemisphere-shaped filter 140 shown comprises a spunlace nonwovens layer 142 and a nanofiber membrane or a nanotube membrane layer 144. The spunlace layer 142 forms the inner layer of the hemisphere-shaped filter 140 while the nanofiber membrane layer 144 forms the outer layer of the hemisphere-shaped filter 140. The spunlace layer 142 may be made of fibers with larger diameters. Unlike the nanofiber membrane layer 144, layer 142 is unable to block ultra-fine particles, but only larger, coarser granules. Hence layer 144 is unlikely to be clogged by larger particles. The filters 140 can be made of non-toxic and harmless materials. Referring now to FIG. 2E, alternatively the filter 140 can be comprised of a meltblown nonwoven fabrics layer 146 and a nanofiber membrane layer 144. The diameter of fibers or nanotubes that constitute the filter 140 may be between 1 nanometers and 5 microns, which can effectively filter out toxic substances, harmful substances and solid particles produced by the combustion of the tobacco leaves 112 of the cigarette 200. The filter 140 can be configured to reduce one or more of the gaseous components in the smoke through, for example, specific adsorption materials and/or specific catalysts that can decompose of at least one harmful gaseous component.
FIG. 3A is a perspective view of a cigarette 300 containing two filters, 151 and 152, according to a third embodiment of the present disclosure. In the third embodiment, two filters with a folded structure are embedded within the filter tip portion of the cigarette. A cigarette 300 comprises a body portion 110, tobacco 112, a filter tip portion 120, acetate fibers 122 that are within the filter tip portion 120, and two filters 151 and 152 that comprise a folded structure embedded within the acetate fibers 122 of the filter tip portion 120. Alternatively, the filters in the filter tip portion 122 can be either of the same type or different types. If necessary, one single filter, instead of multiple filters, can be placed within the acetate fibers 122 of the filter tip portion 120 depending on specific filtration requirements.
FIG. 3B is a perspective view of a cigarette 300 containing three filters 150 that may be the same as those in FIG. 3A, but are placed in the body portion of the cigarette 300. These filters can be burned during smoking, to avoid being clogged by tars and other contaminants.
FIG. 3C is a perspective view of a cigarette 300 containing four filters 150 that may be the same as those in FIG. 3A, but two are placed in the filter tip portion and the other two are placed in the body portion of the cigarette 300. The filters in the cigarette body can be burned during smoking, to avoid being clogged by tars and other contaminants.
Referring now to FIGS. 3D and 3E, different filters have different filtration or adsorption capabilities, for example, the filter 151 may be made of either spunlace nonwovens or meltblown nonwoven fabrics or any other materials and structures such that filter 151 can capture larger, coarser particles. The filter 152 is made of nanofiber membranes or nanotube membranes or other materials and structures such that filter 152 is designed to block finer or ultrafine particles. With such an arrangement, filter 152 is unlikely to be clogged by larger particles. Both filters 151 and 152 can be made of non-toxic and harmless materials. The diameter of fibers or nanotubes that constitute the filters 151 and 152 is between 1 nanometers and 5 microns, which can effectively filter out toxic substances, harmful substances and solid particles produced by the combustion of the tobacco 112 of the cigarette 100.
FIG. 4 is a perspective view of a cigarette 400 containing multiple filters according to a fourth embodiment of the present disclosure. In the fourth embodiment, at least one filter having a substantially disc shape is embedded within the body portion of the cigarette and/or the filter tip portion of the cigarette. A cigarette 400 comprises a body portion 110, tobacco leaves 112 rolled into the body portion 110, a filter tip portion 120, acetate fibers 122 within the filter tip portion 120, and a filter 160 that is disc shaped embedded within the acetate fibers 122 of the filter tip portion 120. A second filter 170 that is disc shaped is placed within the body portion 110 of the cigarette 400.
The filter 160 can comprise of one or a combination of a nanofiber layer or a micro meltblown nonwoven layer, and/or other layers with different porosities. In the exemplary embodiment of FIG. 4, a first filter 160 is placed in the filter tip portion 120 and comprises of a layer 166 made of porous nonwoven fabrics, a micro meltblown nonwoven fabrics layer 164, and a nanofiber layer 162. A second filter 170 is placed in the body portion 110 and comprises of a micro meltblown nonwoven fabrics layer 174 and a nanofiber layer 172. The filter 170 in the cigarette body can be burned without affecting the combustion of the cigarette. The micro/nano filter layer is composed of nanofibers and micron fibers prepared by electrospinning and meltblown. The burning of the filter will result with non-toxic and harmless substances. The diameters of the fibers can be between 100 nanometer and 5 microns. The filter 170 can be configured to reduce one or more of the gaseous components in the smoke through, for example, specific adsorption materials and/or specific catalysts that can decompose of at least one harmful gaseous component.
FIG. 5A is a perspective view of a cigarette containing three filters in a body portion of the cigarette, with an unevenly distributed placement in the cigarette body. Filtering of the tar produced by cigarette burning is one of the most important ways to reduce the harmful substances inhaled by the human body. The general method of tar filtration using a single filter tip portion with acetate fibers attached to the end furthest from the lit-end of the cigarette tends to cause the tar to clog the filter, affecting further filtration. As described above, the present disclosure adds single-layer or multi-layer micro/nano filters in the cigarette body portion and/or the filter tip portion. Referring now to FIG. 5A, three filters 160 a, 160 b, and 160 c are placed within the cigarette 400. When the cigarette is burning, the filter 160 a closest to the lit end will be the first filter to filter the tar. It will be burned before it becomes clogged with tar. The filters 160 b and 160 c will continue to filter tar and contaminants. Filters 160 a and 160 b can be placed closer to the lit end of the cigarette because the first few initial puffs on the cigarette by a smoker are often the heaviest puffs. This arrangement allows for greater filtration when the smoker first starts to smoke the cigarette. Referring now to FIG. 5B, three filters 160 a, 160 b, and 160 c are placed within the body portion 110 of the cigarette 400. The three filters can be placed so that the amount of tobacco 112 between them is evenly distributed.
Although the filters in FIGS. 5A and 5B are disc shaped in this example, the filters can be cone shaped, hemisphere shaped, with a folding structure as described above, or of some other shapes and structures as needed. The thickness or filtration capabilities of each filter can also be adjusted.
In the present disclosure, the micro or nanofiber filter layers can be manufactured by electrospinning and/or meltblowing techniques. These techniques can be applied to the nanotube membrane and micro membrane filters, which use synthetic and natural polymers as their raw materials. Based on modern micro/nano technologies, the aforementioned filters can significantly reduce the amount of particulate matters and toxic substances inhaled.
In the embodiment shown in FIGS. 5A and 5B, the filter(s) can be used to reduce one of the gaseous components in the smoke, wherein the gaseous components that can be reduced in the smoke include at least one of carbon monoxide, ammonia, 1,3-butadiene, isoprene, acraldehyde, acrylonitrile, hydrogen cyanide, 0-toluidine, 2-naphthylamine, nitrosamine, nitrogen oxide, benzene, NNN, phenol, catechol, benzoanthracene, benzopyrene, and any combination thereof.
Preferably, a material for preparing the filters or filter layers is filled with a catalyst for decomposing, selectively, toxic matters. For example, CO generated by incomplete combustion of tobacco can be converted into CO₂by using a transition metal-manganese composite oxide catalyst or a catalyst containing CuO, MgO. For another example, hydrogen cyanide can be catalytically decomposed into non-toxic substances by using silver nitrate and nickel nitrate nanoparticles or using cobalt oxide or nickel oxide. Similarly, the level of phenol in smoke or aerosol can be reduced by using copper nitrate and cobalt nitrate. Nitrosamine can be catalytically decomposed by using one or more rare earth oxides such as lanthanum oxide, cerium oxide and praseodymium oxide.
More preferably, the catalysts included within one or more filters can be activated or remain active under high-temperatures. Catalysts can be selected from a relatively wide range, for example, having an activation temperature of between 600˜1000° C. Tobacco combustion can provide the desired high temperature for catalyst activation.
Preferably, the materials used to make the filters and filter layers can selectively adsorb certain toxic gaseous components. When such filters are placed in cigarette body and subsequently burned during smoking, some or most of the toxic matters adsorbed by the filters are subject to thermal decomposition. Selective adsorption can be combined with the catalysts mentioned earlier to better facilitate the elimination of harmful chemicals resulting from burning tobacco.
The present disclosure discloses a group of high efficiency filter materials which can be used for filtering for tobacco products, including electrospinning nanofibers, nanotubes, meltblown micrometer nonwoven fabrics, spunlace nonwoven fabrics, cellulose acetate filter layer, phenolic filter layer, synthetic polymer filter layer, activated carbon particles and the like, or combinations thereof. Electrospun nanofibers can be prepared using one or a mixture of synthetic polymers and natural polymers under normal temperature and pressure. The electrospun nanofibers can be sprayed directly onto the surface of the meltblown or spunlace nonwoven fabrics to form a composite adsorbent filter, or they can be sprayed directly to tobacco or matters in the cigarette body portion, or sprayed directly onto or mixed with acetate fibers or other materials in the cigarette filter tip portion. The materials include synthetic polylactic acid, polyvinylpyrrolidone, nylon, poly Diols, polyvinyl alcohol, chlorinated polyvinyl chloride, diacetate, polyether sulfone, and natural polymers such as chitosan, silk protein, corn gluten, and combinations thereof. They can be dissolved in water, formic acid, glacial acetic acid, ethanol, isopropyl alcohol in the concentration range of 10˜500 mg/ml,
For electrospinning, the concentration of the polymer solution can be 10 to 500 mg/ml, and the solvent can be one or a mixture of the volatile solvents. The number of syringes can be set to 1-2000 as needed, the number of electrospinning needles can be set to 1-2000 as needed. The voltage of electrospinning is the combination of positive voltage, which is in the range of 0˜200 kV, and negative voltage, which is in the range of −0˜−200 kV. The total voltage difference is 10˜400 kV, the solution moving speed of each needle is 0.1-50 ml/hr, and the distance from the spinning needle to the receiving plate is 5-200 cm. The electrospinning process can also be carried out using a wire instead of the needles.
As described above, the filters described in the present disclosure may be made by the process of electrospinning. The material(s) and the electrospinning parameters used can be selected to provide filters like those described above with the desired sizes and desired filtering characteristics. One or more catalysts can be added to the filters if desired. The filters can be located within a body of a tobacco product in the desired location during manufacturing of the tobacco product. For example, the body of the tobacco product may be considered as comprising a plurality of segments, and the body can be filled with alternating portions comprising primarily or consisting essentially of filter or tobacco. Alternatively, the body portion of a tobacco product may be filled with tobacco or one or more filters, then with one or more filters or tobacco, respectively, and so on, such that the body portion of the tobacco product comprises alternating one or more tobacco portions and one or more filter portions. In one embodiment, a filter material can be electrospun onto a tobacco product to create a mixed composition of tobacco and filter materials, with the resulting mixed composition then placed into a body portion of a tobacco product, with that body portion able to include one or more additional filters like those shown and described herein if desired.
It should be noted that a tobacco product may include a plurality of filters, each adapted to provide certain desired filtering characteristics. As noted, two or more filters having different porosities from one another can be placed in the body of the tobacco product, thereby providing a size gradient for filtering particulates. In addition, two or more filters, each having one or more catalysts thereto, wherein the catalysts may differ from filter to filter, can be located in the body of the tobacco product to thereby provide a variety of filtering or adsorption characteristics as may be desired. Moreover, two or more filters, having the same or different shapes, the same or different sizes, and/or comprising the same or different materials, may be located within the body of the tobacco product to provide the desired filtering characteristics.
Although the present disclosure has been described with reference to specific exemplary embodiments, it will be recognized that the disclosure is not limited to the embodiments described, but can be practiced with modification and alteration within the spirit and scope of the appended claims. For example, although most of the foregoing discussion refers to cigarettes and to tobacco products, it should be noted, however, that the systems and methods of the present disclosure can be used in a wider variety of products. For example, filters like those described above may be included in cigars as well as cigarettes. Similarly, filters like those described above may be included in and part of other smoking implements, such as pipes, hookahs, bongs, and the like. Moreover, it should be noted that, although the foregoing discussion has focused on tobacco products and the smoking thereof, the filters and methods described above may be used in connection with other smoking products, such as pipe tobacco, marijuana, hashish, tobacco mixed with molasses or other sweeteners or flavors, other smoking materials for hookahs, and combinations thereof. Accordingly, the specification and drawings are to be regarded in an illustrative sense rather than a restrictive sense. Unless otherwise specifically stated, the terms and expressions have been used herein as terms of description and not terms of limitation. There is no intention to use the terms or expressions to exclude any equivalent of features shown and described or portions thereof and this disclosure should be defined in accordance with the claims that follow.

Claims

What is claimed is:

1. A tobacco product comprising:

a body portion and a filter tip portion;

tobacco within the body portion;

wherein at least one filter is located within the body portion.

2. The tobacco product of claim 1, wherein the filter comprises a cone shape.

3. The tobacco product of claim 1, wherein the filter comprises a hemisphere shape.

4. The tobacco product of claim 1, wherein the filter comprises a folding structure.

5. The tobacco product of claim 1, wherein the filter comprises a disc shape.

6. The tobacco product of claim 1, wherein there are at least two layers in at least one filter, with the first layer located closer to a first end of the cigarette and the second layer located closer to the second end portion of the tobacco product.

7. The tobacco product of claim 6, wherein different layers in a filter have different filtration or adsorption characteristics.

8. The tobacco product of claim 7, wherein the first layer is configured to block, adsorb, or disintegrate particles with larger sizes than the second layer.

9. The tobacco product of claim 1, comprising at least two filters in the body portion of a cigarette, with the first filter closer to a first end of the cigarette and the second filter closer to the second end of the cigarette.

10. The tobacco product of claim 9, wherein different filters have different filtration or adsorption capabilities.

11. The tobacco product of claim 1, wherein at least one filter in the body portion is adapted to burn, or partially or completely disintegrate during combustion of the tobacco.

12. The tobacco product of claim 1, comprising a plurality of filters in the body portion and wherein the filters are evenly spaced apart from each other within the body portion.

13. The tobacco product of claim 1, comprising a plurality of filters in the body portion and wherein the filters are unevenly spaced apart from each other within the body portion.

14. The tobacco product of claim 1, wherein at least one filter is adapted to reduce at least one material from the smoke or aerosol resulting from combustion of the tobacco.

15. The tobacco product of claim 1, wherein at least one filter is configured to reduce or remove from the smoke or aerosol resulting from combustion of the tobacco at least one of the following chemicals: carbon monoxide, ammonia, 1,3-butadiene, isoprene, acraldehyde, acrylonitrile, hydrogen cyanide, 0-toluidine, 2-naphthylamine, nitrosamine, nitrogen oxide, benzene, NNN, phenol, catechol, benzoanthracene, and benzopyrene.

16. The tobacco product of claim 15, wherein at least one filter comprises one or more catalysts adapted to reduce or remove one or more materials from the smoke or aerosol resulting from combustion of the tobacco.

17. The tobacco product of claim 16, wherein the catalyst or catalysts is active or can be activated at temperatures of between 600 and 900 degrees Celsius.

18. The tobacco product of claim 1, wherein at least one filter is configured to adsorb or block tar or particles resulting from combustion of the tobacco.

19. A method of making a tobacco product, comprising:

electrospinning non-toxic fibers;

forming a filter comprising the fibers;

locating the filter within a tubular body of a tobacco product; and

locating tobacco within the remainder of the tubular body on at least one side of the filter,

wherein the fibers comprise micro-fibers, nano-fibers, or a combination thereof, and

wherein the fibers are adapted to combust when the tobacco combusts.

20. The method according to claim 19 further comprising the step of adding one or more catalysts to the filter.

21. The method according to claim 19 further comprising the step of locating a second filter within the tubular body of the tobacco product and spaced apart from the filter, wherein tobacco is located within the tubular body between the filter and the second filter.

22. The method according to claim 19 wherein the tobacco product comprises a cigarette.

23. The method according to claim 20 wherein the filter is adapted to reduce or remove at least one of carbon monoxide, ammonia, 1,3-butadiene, isoprene, acraldehyde, acrylonitrile, hydrogen cyanide, 0-toluidine, 2-naphthylamine, nitrosamine, nitrogen oxide, benzene, N-Nitrosonornicotine, phenol, catechol, benzoanthracene, and benzopyrene.

24. The method according to 21 wherein the filter and second filter comprise fibers having different porosities from one another, thereby providing a filtering size gradient from one end of the tubular body to a second end, and wherein each of the filter and the second filter comprise a catalyst that is different from one another.