CN116322382A

CN116322382A - Degradable cellulose acetate tow band comprising filler

Info

Publication number: CN116322382A
Application number: CN202180066717.4A
Authority: CN
Inventors: M·库姆斯; N·德瓦纳坦
Original assignee: Celanese International Corp
Current assignee: Celanese International Corp
Priority date: 2020-11-20
Filing date: 2021-11-19
Publication date: 2023-06-23
Also published as: CA3195674A1; WO2022109253A1; US20220160026A1; EP4247191A1; JP2023550230A; MX2023005989A; KR20230107794A

Abstract

A tow band comprising cellulose acetate and a filler is disclosed. The filler may be selected to have a degradation rate greater than the degradation rate of the cellulose acetate. The tow band may be puffed and formed into a filter rod, which may then be incorporated into a cigarette filter. The tow, tow band and filter structures described herein degrade faster than other known tow, tow band and filter structures.

Description

Degradable cellulose acetate tow band comprising filler

Priority claim

The present application claims priority from U.S. provisional application No. 63/116,613, filed 11/20 in 2020, the entire contents and disclosure of which provisional application is incorporated herein by reference.

Technical Field

The present invention relates generally to tows, tow bands and cigarette filters comprising cellulose acetate and filler. In particular, the present invention relates to the inclusion of filler in tows, tow bands and filters, wherein the filler is selected to increase the sustainability and biodegradability of the filter.

Background

Cellulose esters are widely used for many purposes, including as cellulose acetate tow in cigarette filters. Although cellulose esters (e.g., cellulose acetate) are biopolymers that are known to degrade, the rate of degradation is slower than natural cellulose. For example, cigarette filters may require up to 15 years to degrade because cellulose acetate does not degrade until enough acetyl groups are removed, allowing the microbial identification material to degrade. After smoking, the filter is often discarded in the environment and is one of the most common forms of artificial waste in the world. It is estimated that 4.5 trillion cigarette filters become waste each year. The trash remains longer than desired due to the degradation time of the cellulose acetate and the plasticizer contained in the filter. Although attempts have been made to form biodegradable filters comprising cellulose acetate, none of these attempts have been successful for a number of reasons, including undesirable changes in cigarette taste due to modification and/or additives and inadequate reduction in degradation time. Molded articles made from cellulose esters suffer from similar drawbacks.

U.S. patent No. 5,084,296, incorporated herein by reference, discloses a composition comprising cellulose acetate or other cellulose ester and anatase titanium oxide having (1) a molecular weight of not less than 30m ² Specific surface area per gram, (2) primary particle diameter of 0.001 to 0.07 μm, or (3) not less than 30m ² Specific surface area per gram and primary particle size of 0.001 to 0.07. Mu.m. To enhance photodegradation and dispersibility, the surface of the titanium oxide may be treated with a phosphate or other phosphorus compound, a polyol, an amino acid, or other substance. The use of a low substituted cellulose ester having an average substitution degree of not more than 2.15 ensures high biodegradability. The composition may further contain a plasticizer and/or an aliphatic polyester, a biodegradation accelerator (e.g., an organic acid or an ester thereof). The degradable cellulose ester compositions are highly photodegradable and moldable and thus can be used to make a variety of articles.

Us patent No. 8,397,733, incorporated herein by reference, discloses a degradable cigarette filter comprising a filter element of bulked cellulose acetate tow and plug wrap surrounding the filter element, and pellets dispersed in the tow. The pellets comprise a material suitable for catalyzing the hydrolysis of cellulose acetate tow, the material being encapsulated with an inner layer of a water-soluble or water-permeable material and an outer layer of cellulose acetate having a d.s. in the range of 2.0-2.6.

U.S. patent publication No. 2009/0151738, incorporated herein by reference, discloses a degradable cigarette filter comprising a filter element of an expanded cellulose acetate tow, plug wrap surrounding the filter element, and a coating or pill in contact with the tow. The coating and/or pellets may be composed of a material suitable for catalyzing the hydrolysis of cellulose acetate tow and a water-soluble matrix material. The material may be an acid, an acid salt, a base, and/or a bacterium suitable for producing an acid. The coating may be applied to the tow, plug wrap, or both. The pill may be placed in the filter element. When water contacts the water-soluble matrix material, materials suitable for catalyzing hydrolysis are released and catalyze hydrolysis and subsequent degradation of the cellulose acetate tow. The foregoing also applies to articles made from cellulose esters.

Thus, there is a need for controlled and sustained release of materials that facilitate degradation of cellulose esters used in cigarette filters.

Disclosure of Invention

In some aspects, the disclosure relates to a cellulose acetate tow band comprising: a) Cellulose acetate having a Degree of Substitution (DS) of greater than 1.3; and b) a filler; wherein the filler has a greater degradation rate than the cellulose acetate. In some aspects, the filler may include monosaccharides, polysaccharides, polysaccharide esters, hydrolyzed polysaccharides, oligosaccharides, or combinations thereof. In some aspects, the filler may include dextran, hydrolyzed starch, modified hydrolyzed starch, hemp, cellulose, or a combination thereof. The filler may be present from 0.1% to 99.9% by weight based on the total weight of the tow band, from 0.1% to 75% by weight based on the total weight of the tow band, from 0.1% to 50% by weight based on the total weight of the tow band, or from 0.1% to 25% by weight based on the total weight of the tow band. The filler may have a degradation rate that is at least 3% greater than the degradation rate of the cellulose acetate, at least 10% greater than the degradation rate of the cellulose acetate, or at least 15% greater than the degradation rate of the cellulose acetate. The tow band may comprise a weight ratio of the cellulose acetate to the filler of from 1:99 to 99:1, from 1:50 to 50:1, or from 1:25 to 25:1. The tow band may comprise cellulose acetate in an amount of from 0.1% to 99.9% by weight based on the total weight of the tow band. The cellulose acetate may have a degree of substitution of from 1.3 to 2.9 or from 2 to 2.9. The tow band may contain from 0.01% to 25% by weight of additives based on the total weight of the tow band.

In some embodiments, the present disclosure relates to a cigarette filter comprising: a filter element comprising bulked tow, wherein the bulked tow comprises a tow band. The tow band may comprise: a) Cellulose acetate having a Degree of Substitution (DS) of greater than 1.3; and b) a filler; wherein the filler has a greater degradation rate than the cellulose acetate. In some aspects, the filler may include monosaccharides, polysaccharides, polysaccharide esters, hydrolyzed polysaccharides, oligosaccharides, or combinations thereof. In some aspects, the filler may include dextran, hydrolyzed starch, modified hydrolyzed starch, hemp, cellulose, or a combination thereof. The filler may be present from 0.1% to 99.9% by weight based on the total weight of the tow band, from 0.1% to 75% by weight based on the total weight of the tow band, from 0.1% to 50% by weight based on the total weight of the tow band, or from 0.1% to 25% by weight based on the total weight of the tow band. The filler may have a degradation rate that is at least 3% greater than the degradation rate of the cellulose acetate, at least 10% greater than the degradation rate of the cellulose acetate, or at least 15% greater than the degradation rate of the cellulose acetate. The tow band may comprise a weight ratio of the cellulose acetate to the filler of from 1:99 to 99:1, from 1:50 to 50:1, or from 1:25 to 25:1. The tow band may comprise cellulose acetate in an amount of from 0.1% to 99.9% by weight based on the total weight of the tow band. The cellulose acetate may have a degree of substitution of from 1.3 to 2.9 or from 2 to 2.9. The tow band may contain from 0.01% to 25% by weight of additives based on the total weight of the tow band.

In some embodiments, the present disclosure relates to a method for forming a cigarette filter, the method comprising: a) Providing a cellulose acetate tow band comprising cellulose acetate and a filler; b) Puffing the tow band; and c) forming the puffed tow band into a filter rod. In some aspects, the tow band is formed by: a) Combining cellulose acetate and the filler with a solvent to form a dope; b) Solvent spinning the spinning dope to form a plurality of tow filaments; and c) combining the plurality of tow filaments to form the tow band. In some aspects, the tow band is formed by: a) Combining cellulose acetate and the filler to form a sheet; b) Combining the flakes with a solvent to form a dope; c) Solvent spinning the spinning dope to form a plurality of tow filaments; and d) combining the plurality of tow filaments to form the tow band. The tow band may comprise: a) Cellulose acetate having a Degree of Substitution (DS) of greater than 1.3; and b) a filler; wherein the filler has a greater degradation rate than the cellulose acetate. In some aspects, the filler may include monosaccharides, polysaccharides, polysaccharide esters, hydrolyzed polysaccharides, oligosaccharides, or combinations thereof. In some aspects, the filler may include dextran, hydrolyzed starch, modified hydrolyzed starch, hemp, cellulose, or a combination thereof. The filler may be present from 0.1% to 99.9% by weight based on the total weight of the tow band, from 0.1% to 75% by weight based on the total weight of the tow band, from 0.1% to 50% by weight based on the total weight of the tow band, or from 0.1% to 25% by weight based on the total weight of the tow band. The filler may have a degradation rate that is at least 3% greater than the degradation rate of the cellulose acetate, at least 10% greater than the degradation rate of the cellulose acetate, or at least 15% greater than the degradation rate of the cellulose acetate. The tow band may comprise a weight ratio of the cellulose acetate to the filler of from 1:99 to 99:1, from 1:50 to 50:1, or from 1:25 to 25:1. The tow band may comprise cellulose acetate in an amount of from 0.1% to 99.9% by weight based on the total weight of the tow band. The cellulose acetate may have a degree of substitution of from 1.3 to 2.9 or from 2 to 2.9. The tow band may contain from 0.01% to 25% by weight of additives based on the total weight of the tow band.

Detailed Description

Introduction to the invention

The present disclosure relates to the formation of tows, tow bands, and cigarette filters using a combination comprising a cellulose ester (e.g., cellulose acetate) and a filler. The cellulose ester may have a degree of substitution greater than 1.3 and the filler may be selected to have a greater degradation rate than the cellulose ester. In some aspects, the filler may be a monosaccharide, a polysaccharide, or a combination thereof. In further aspects, the filler may include dextran, hydrolyzed starch, modified hydrolyzed starch, cellulose, or a combination thereof. The filler may be present at from 0.1% to 99.9% by weight of the tow, depending on the degradation desired, filler and degradation mechanism. In some aspects, the filler is present at from 0.1% to 75% by weight of the tow, e.g., from 0.1% to 50% by weight, from 0.1% to 20% by weight, and all values therebetween. The degradation rate of the filler may be at least 3% greater than the degradation rate of the cellulose acetate, e.g., at least 5% greater, at least 7% greater, at least 10% greater, at least 15% greater, or at least 20% greater.

The present disclosure also relates to methods of forming tows, tow bands, and cigarette filters. In some aspects, the filler can be combined with a cellulose ester (e.g., cellulose acetate) to form a dope, which is then solvent spun to form a tow. Depending on the filler, the filler may be added after the formation of the dope, such as during fiber formation. Once the fibers are formed (tow), the fibers are combined to form a tow band. The tow band may then be subjected to additional processing, packaging, and ultimately formed into a filter rod for a cigarette filter.

The basic mechanism of cellulose ester degradation depends on the degree of substitution ("DS") of the cellulose ester. The DS of cellulose esters refers to the degree of substitution and can be measured by ASTM 871-96 (2010), for example for cellulose acetate. When the DS of cellulose acetate is greater than 1.3, the cellulose acetate is not degraded by naturally occurring enzymes or bacteria due to the presence of acetate moieties. To replace the acetate moiety with a hydroxyl moiety and thereby reduce DS, cellulose acetate is hydrolyzed. Hydrolysis of the acetyl moiety is also known as deacetylation. The degradable cigarette filters described herein typically have a DS of greater than 1.3 (usually in the range of 2.0 to 2.6, but up to 2.9), and thus, due to the presence of acetate moieties, are not degraded by naturally occurring enzymes or bacteria.

Without being bound by theory, it is believed that by incorporating fillers having a degradation rate greater than that of cellulose esters, degradation of tows, tow bands, and cigarette filters can be accelerated. The selection of filler is made to balance the improvement of degradation with the filtration performance. For example, the filler may be selected to have a sufficiently small domain to avoid being filtered out. Some fillers, such as starch, glucose, or dextran, as further described herein, may be used as a food source for various microorganisms. Such fillers will allow microbial growth to build directly on the tow, tow band or cigarette filter, resulting in accelerated degradation. Combinations of different fillers may be used to take advantage of the different characteristics and properties of the filter. For example, dextran may be included to improve degradation, while hemp or short continuous fibers may be included to improve other mechanical properties.

Cellulose esters

As described herein, the present disclosure relates to tows, tow bands, and cigarette filters comprising a filler and a cellulose ester (e.g., cellulose acetate). Fillers are included with the cellulose esters, preferably prior to tow formation, to increase the degradation rate of the cellulose esters. As used herein, cellulose acetate refers to cellulose diacetate, although the fillers and methods described herein can be used with other types of cellulose esters, including cellulose triacetate, cellulose propionate, cellulose acetate propionate, cellulose butyrate, cellulose acetate butyrate, cellulose propionate butyrate, cellulose nitrate, cellulose sulfate, cellulose phthalate, and combinations thereof.

Cellulose esters can be prepared by known methods, including those disclosed in U.S. patent No. 2,740,775 and U.S. publication No. 2013/0096297, the entire contents of which are incorporated herein by reference. Typically, acetylated cellulose is prepared by reacting cellulose with an acetylating agent in the presence of a suitable acidic catalyst and then de-esterifying.

The cellulose may be from a variety of materials including cotton linters, softwoods, or hardwoods. Cork is a general term typically used to refer to wood from conifer (i.e., conifer from the order Pinus koraiensis). Cork-producing trees include pine, spruce, cedar, fir, larch, douglas fir, hemlock, cypress, sequoia and yew. In contrast, the term hardwood is typically used to refer to wood from hardwood or angiosperm trees. The terms "softwood" and "hardwood" do not necessarily describe the actual hardness of wood. However, on average, the density and hardness of hardwoods is higher than softwoods, but there is a considerable variation in the actual wood hardness of both groups, and some softwood trees may actually produce harder woods than the woods from the hardwood trees. One feature that distinguishes between hardwoods and softwoods is the presence of holes or ducts in the hardwood tree, and not in the softwood tree. On a microscopic level, cork contains two types of cells, namely, wood fibers (or tracheids) in the longitudinal direction and radiation cells in the transverse direction. In cork, the moisture transport within the tree is through the cells rather than the pores of the hardwood. In some aspects, hardwood cellulose is preferred for acetylation.

Acylating agents may include both carboxylic acid anhydrides (or simply anhydrides) and carboxylic acid halides, especially carboxylic acid chlorides (or simply acid chlorides). Suitable acid chlorides may include, for example, acetyl chloride, propionyl chloride, butyryl chloride, benzoyl chloride, and similar acid chlorides. Suitable anhydrides may include, for example, acetic anhydride, propionic anhydride, butyric anhydride, benzoic anhydride and the like. Mixtures of these anhydrides or other acylating agents can also be used to introduce different acyl groups into the cellulose. In some embodiments, mixed anhydrides, such as, for example, acetic propionic anhydride, acetic butyric anhydride, and the like, may also be used for this purpose.

In most cases, the cellulose is thoroughly acetylated with an acetylating agent to produce a derivatized cellulose having a high Degree of Substitution (DS) value (e.g., from 2.4 to 3), and in some cases some additional hydroxyl substitution (e.g., sulfate). Complete acetylation of cellulose refers to an acetylation reaction that is driven toward completion so that as many hydroxyl groups as possible in cellulose undergo an acetylation reaction.

Suitable acidic catalysts for promoting the acetylation of cellulose generally contain sulfuric acid or a mixture of sulfuric acid and at least one other acid. Other acidic catalysts that do not contain sulfuric acid can be similarly used to promote the acetylation reaction. In the case of sulfuric acid, at least some of the hydroxyl groups in the cellulose may become initially functionalized to sulfate esters during the acetylation reaction. Once thoroughly acetylated, the cellulose is subjected to a controlled partial de-esterification step (typically in the presence of a de-esterifying agent), which is also referred to as a controlled partial hydrolysis step.

As used herein, deesterification refers to a chemical reaction during which one or more ester groups of the intermediate cellulose ester are cleaved from the cellulose acetate and replaced with hydroxyl groups, yielding a cellulose acetate product having a (second) DS of less than 3. As used herein, "deesterifying agent" refers to a chemical agent capable of reacting with one or more ester groups of cellulose acetate to form hydroxyl groups on an intermediate cellulose ester. Suitable deesterifying agents include low molecular weight alcohols such as methanol, ethanol, isopropanol, pentanol, R-OH (where R is a C1 to C20 alkyl group), and mixtures thereof. Water and mixtures of water and methanol may also be used as deesterifying agents. Typically, most of these sulfate esters break during controlled partial hydrolysis to reduce the amount of acetyl substitution. The reduced degree of substitution may range from 0.5 to 3.0, for example from 1.3 to 3, from 1.3 to 2.9, from 1.5 to 2.9 or from 2 to 2.6. For the purposes of this disclosure, the degree of substitution is typically from 1.3 to 2.9, as below 1.3, natural degradation may occur. The degree of substitution may be selected based on at least one organic solvent used in the binder composition. For example, when acetone is used as the organic solvent, the degree of substitution may range from 2.2 to 2.65. As used herein, "degradation" may refer to any mechanism and rate of degradation, including photochemical degradation, biological degradation, or any form of degradation. When comparing the degradation of cellulose acetate to that of filler, the comparison may be based on the same degradation mechanism in order to compare similar rates.

The number average molecular weight of the cellulose ester may range from 30,000amu to 100,000amu, for example, from 50,000amu to 80,000amu, and may have a polydispersity of from 1.5 to 2.5, for example, from 1.75 to 2.25 or from 1.8 to 2.2. All molecular weights described herein are number average molecular weights unless otherwise indicated. The molecular weight may be selected based on the desired stiffness of the final tow or filter rod. While a larger molecular weight results in increased hardness, a larger molecular weight also increases viscosity. The cellulose esters may be provided in powder or flake form.

In some aspects, blends of cellulose ester flakes or powders of different molecular weights may be used. Thus, a blend of high molecular weight cellulose esters (e.g., cellulose esters having a molecular weight greater than 60,000 amu) may be blended with low molecular weight cellulose esters (e.g., cellulose esters having a molecular weight less than 60,000 amu). The ratio of high molecular weight cellulose ester to low molecular weight cellulose ester may vary, but may generally range from 1:10 to 10:1; for example from 1:5 to 5:1 or from 1:3 to 3:1. Blends of different cellulose esters may also be used and may contain two, three, four or more different cellulose esters in different ratios. In some aspects, one cellulose ester may be present in a majority, while other cellulose esters are present in lesser amounts.

Cellulose ester fibers, tows and tow bales

There are many ways to form fibers from cellulose esters (e.g., cellulose acetate) that can be used to form the tows of the present disclosure. In some embodiments, to form fibers from cellulose esters, the dope is formed by dissolving cellulose ester flakes or powder in a solvent to form a dope solution. The dope solution is typically a highly viscous solution. The solvent of the dope solution may be selected from the group consisting of: water, acetone, methyl ethyl ketone, methylene chloride, dioxane, dimethylformamide, methanol, ethanol, glacial acetic acid, supercritical carbon dioxide, any suitable solvent capable of dissolving the above polymers, and combinations thereof. In some aspects, the solvent is acetone or a combination of acetone and up to 5wt.% water. The dope is then filtered and degassed before spinning to form fibers (known as solvent spinning). The dope may be spun in a spinning machine comprising one or more compartments, each compartment comprising a spinneret. The spinneret contains holes that affect the rate at which solvent evaporates from the fibers.

The fillers described herein may be added to the dope and are limited to having a degradation rate greater than that of the cellulose ester. The degradation rate of cellulose esters depends on the degree of substitution and the degradation environment to which the cellulose ester is exposed. Exemplary fillers include monosaccharides (e.g., glucose, sucrose, lactose, fructose, galactose, ribose, xylose, etc.), polysaccharides (e.g., polysaccharide esters, hydrolyzed polysaccharides, oligosaccharides, starches, celluloses (including alpha-cellulose, hemicellulose), hyaluronic acid, alginates, guar gum, chitin and chondroitin, modified starches, hydrolyzed starches, cannabis seed polysaccharides, etc.). As described herein, the filler may be selected such that it may be included in the spin dope, i.e. have domains small enough that it is not filtered out. This size may depend on the size of the spinneret orifice. Exemplary fillers included in the spin dope include monosaccharides, polysaccharides, polysaccharide esters, hydrolyzed polysaccharides, oligosaccharides, or combinations thereof.

The solvent may be included in the spin dope in an amount from 60% to 90% by weight, for example, from 60% to 85% by weight, from 60% to 80% by weight, from 60% to 75% by weight, from 60% to 70% by weight, from 60% to 65% by weight, from 65% to 90% by weight, from 70% to 90% by weight, from 75% to 90% by weight, from 80% to 90% by weight, or from 85% to 90% by weight. All values therebetween are also contemplated and included.

Fillers may be included in the dope in amounts sufficient to achieve the desired improvement in degradation rate of the tow, tow band or cigarette filter while balancing the desired properties of the tow, tow band or cigarette filter. For example, the filler may be present at from 0.1% to 39% by weight of the spin dope, e.g., from 0.1% to 35% by weight, from 0.1% to 30% by weight, from 0.1% to 25% by weight, from 0.1% to 20% by weight, from 0.1% to 15% by weight, from 0.1% to 10% by weight, from 0.1% to 7.5% by weight, or from 0.1% to 5% by weight. In further aspects, the lower limit of the filler may be at least 0.5% by weight, at least 0.75% by weight, at least 1% by weight, at least 2% by weight, or at least 3% by weight. All other values and ranges between the above values are also included and contemplated.

Cellulose acetate may be included in the dope in an amount sufficient to retain the desired properties of the tow, tow band or cigarette filter, for example, filtration of the cigarette filter. For example, the cellulose acetate may be present from 0.1% to 39.9% by weight of the spin dope, e.g., from 0.1% to 37.5% by weight, from 0.1% to 35% by weight, from 0.1% to 30% by weight, from 0.1% to 25% by weight, from 0.1% to 20% by weight, from 0.1% to 15% by weight, from 0.1% to 10% by weight, from 0.1% to 7.5% by weight, or from 0.1% to 5% by weight. In further aspects, the lower limit of cellulose acetate may be at least 0.5% by weight, at least 0.75% by weight, at least 1% by weight, at least 2% by weight, at least 3% by weight, at least 5% by weight, at least 10% by weight, at least 15% by weight, at least 20% by weight, at least 25% by weight, at least 30% by weight, at least 35% by weight, at least 37.5%, at least 39% by weight, or at least 39.5%. All other values and ranges between the above values are also included and contemplated.

Pigments may also be added to the dope. The spin dope may comprise, for example, from 5 to 40wt.% cellulose acetate, from 0.1 to 35% filler, and from 60 to 90wt.% solvent. Pigments, when added, may be present in from 0.1 to 5wt.%, e.g., from 0.1 to 4wt.%, from 0.1 to 3wt.%, from 0.1 to 2wt.%, from 0.5 to 5wt.%, from 0.5 to 4wt.%, from 0.5 to 3wt.%, from 0.5 to 2wt.%, from 1 to 5wt.%, from 1 to 4wt.%, from 1 to 3wt.%, or from 1 to 2 wt.%. The pigment added to the spinning dope is not particularly limited, and any conventional pigment may be used. Examples of common, suitable pigments include calcium carbonate, diatomaceous earth, magnesium oxide, zinc oxide, and barium sulfate.

Generally, the production of a tow band package may involve spinning fibers from a dope, forming a tow containing the fibers, forming a tow band from the fibers, crimping the tow band, and packaging the crimped tow band. In such production, optional steps may include, but are not limited to, heating the fiber after spinning, applying a finish or additive to the fiber and/or tow band prior to crimping, and conditioning the crimped tow band. At least the parameters of these steps are important for producing the desired package.

In some aspects, if the filler has too large a domain to be included in the spin dope, the filler may be included at a later point in the process (any of the steps described above). Specifically, fillers may be added to the cellulose acetate flake.

It should be noted that the size and shape of the bag may vary depending on the need for further processing. In some embodiments, the bag may have dimensions ranging from 30 inches (76 cm) to 60 inches (152 cm) in height, 46 inches (117 cm) to 56 inches (142 cm) in length, and 35 inches (89 cm) to 45 inches (114 cm) in width. In some embodiments, the weight of the bag may range from 900 pounds (408 kg) to 2100 pounds (953 kg). In some embodiments, the bag may have a density greater than 300kg/m3 (18.8 lb/ft 3).

Fiber

The structure of the cellulose acetate fiber used in the present disclosure is not particularly limited, and various known fiber structures may be used. For example, a tow band may utilize fibers having a wide range of denier per filament (dpf). In some embodiments, the tow band has from 1 to 30dpf, e.g., from 2 to 28dpf, from 3 to 25dpf, from 4 to 22dpf, from 5 to 30dpf, from 5 to 28dpf, from 5 to 25dpf, from 5 to 22dpf, from 10 to 30dpf, from 10 to 28dpf, from 10 to 25dpf, from 10 to 22dpf, from 15 to 30dpf, from 15 to 28dpf, from 15 to 25dpf, from 15 to 22dpf, from 20 to 30dpf, from 20 to 28dpf, from 20 to 25dpf, or from 20 to 22dpf.

Fibers for use in the present disclosure may have any suitable cross-sectional shape including, but not limited to, circular, substantially circular, fine scalloped, oval, substantially oval, polygonal, substantially polygonal, dog-bone, "Y", "X", "K", "C", multi-lobed, and any mixtures thereof. As used herein, the term "multi-lobed" refers to a cross-sectional shape having a point (not necessarily at the center of the cross-section) from which at least two blades extend (not necessarily uniformly spaced or uniformly sized).

As noted above, fibers for use in the present disclosure may be produced by any method known to those skilled in the art. As noted, in some embodiments, the fibers may be produced by spinning a dope through a spinneret. As used herein, the term "dope" refers to a solution and/or suspension of cellulose acetate from which fibers are produced. In some embodiments, the spin dope can comprise cellulose acetate, a filler, and a solvent. In some embodiments, the spin dope used in connection with the present disclosure may comprise cellulose acetate, fillers, solvents, and additives. In some embodiments, the concentration of cellulose acetate in the spin dope may range from 10 to 40wt.% (e.g., from 20 to 30wt.%, from 25 to 40wt.%, from 25 to 30 wt.%) and the concentration of solvent may be from 60 to 90wt.% (e.g., 60 to 80wt.%, 70 to 80wt.%, 80 to 90 wt.%). The fillers and additives may constitute the remainder of the dope. In some embodiments, the spin dope can be heated to a temperature ranging from 40 ℃ to 100 ℃ (e.g., from 45 ℃ to 95 ℃, from 50 ℃ to 90 ℃, from 55 ℃ to 85 ℃, from 60 ℃ to 80 ℃).

Suitable solvents may include, but are not limited to, water, acetone, methyl ethyl ketone, methylene chloride, dioxane, dimethylformamide, methanol, ethanol, glacial acetic acid, supercritical CO2, any suitable solvent capable of dissolving the above-described polymers, or any combination thereof. As a non-limiting example, the solvent for cellulose acetate may be an acetone/methanol mixture. In some embodiments, to produce very high dpf values of the present disclosure, increased solvent levels may be used compared to typical amounts of dpf values (e.g., 2 to 8 dpf). For example, in some embodiments, to produce very high dpf tows, the amount of solvent can be from 5 to 30wt.% greater when compared to the amount of solvent for typical dpf tows. In some cases, additional amounts of solvent may present challenges to the processing of the fibers.

Some embodiments of the present disclosure may relate to treating fibers to achieve surface functions on the fibers. In some embodiments, the fibers may include surface functions including, but not limited to, biodegradable sites (e.g., defective sites that increase surface area to enhance biodegradability), chemical treatments (e.g., carboxylic acid groups for subsequent functionalization), active particle binding sites (e.g., sulfide sites that bind gold particles or chelating groups for binding iron oxide particles), sulfur moieties, or any combination thereof. Those skilled in the art will appreciate the variety of methods and mechanisms for accomplishing the surface function. Some embodiments may involve dipping, spraying, ionization, functionalization, acidification, hydrolysis, exposure to plasma, exposure to ionized gas, or any combination thereof to achieve a surface function. Suitable chemicals that impart surface functionality may be any chemical or collection of chemicals that are capable of reacting with cellulose acetate, including, but not limited to, acids (e.g., sulfuric acid, nitric acid, acetic acid, hydrofluoric acid, hydrochloric acid, etc.), reducing agents (e.g., liAlH4, naBH4, H2/Pt, etc.), grignard reagents (e.g., CH3MgBr, etc.), transesterification reagents, amines (e.g., R-NH3 such as CH3NH 3), or any combination thereof. Exposure to plasma and/or ionized gases may react with the surface, create defects in the surface, or any combination thereof. The defects may increase the surface area of the fibers, which may result in higher loading and/or higher filtration efficacy in the final filtration product.

Some embodiments of the present disclosure may involve applying a finish to the fibers. Suitable finishes may include, but are not limited to, at least one of the following: oil (e.g., mineral oil or liquid petroleum derivatives), water, additives, or any combination thereof. Examples of suitable mineral oils may include, but are not limited to, colorless transparent (i.e., clear) mineral oils having a viscosity of 80-95 SUS(s) (seebot general seconds (Sabolt Universal Seconds)) measured at 38 ℃ (100°f). Examples of suitable emulsifiers may include, but are not limited to, sorbitan monolaurate, e.g

20 (available from He's company, wilmington, del.) of Wilmington, del.) poly (ethylene oxide) sorbitan monolaurate, e.g.>

20 (available from He's company, wilmington, del.). The water may be demineralized water, deionized water, or other suitable filtered and treated water. The lubricant or finish may be applied by spraying or wiping. Generally, a lubricant or finish is added to the fibers prior to forming the fibers into tows.

In some embodiments of the present disclosure, the finish may be applied as a neat finish or as a finish emulsion in water. As used herein, the term "neat finish" refers to a finish formulation that does not add excessive water. It should be noted that the finish formulation may comprise water. In some embodiments, the finish may be applied in neat form, followed by separate application of water.

In some embodiments of the present disclosure, the finish emulsion may comprise less than 98%, less than 95%, less than 92%, or less than 85% water. In some embodiments, it may be advantageous to obtain fibers with a lower weight percentage of moisture (e.g., 5% to 25% w/w of the tow band) in a subsequent step, where water is the contributor. The water content of the finish emulsion may be at least one parameter that may help achieve the weight percent moisture in the fiber. Thus, in some embodiments, the finish emulsion may comprise less than 92% water, less than 85% water, or less than 75% water.

Tow

Once the dope is formed and solvent spun, the solvent is evaporated and the dope is spun and extruded to form a plurality of extruded fibers, known as tows.

The filler may be included in the tow in an amount sufficient to achieve the desired improvement in degradation rate of the tow, tow band or cigarette filter while balancing the desired properties of the tow, tow band or cigarette filter. For example, the filler may be present from 0.1% to 99% by weight of the tow, e.g., from 0.1% to 95% by weight, from 0.1% to 90% by weight, from 0.1% to 85% by weight, from 0.1% to 80% by weight, from 0.1% to 75% by weight, from 0.1% to 70% by weight, from 0.1% to 65% by weight, from 0.1% to 60% by weight, from 0.1% to 55% by weight, from 0.1% to 50% by weight, from 0.1% to 45% by weight, from 0.1% to 40% by weight, from 0.1% to 35% by weight, from 0.1% to 30% by weight, from 0.1% to 25% by weight, from 0.1% to 20% by weight, from 0.1% to 15% by weight, from 0.1% to 10% by weight, or from 0.1% to 5% by weight. In further aspects, the lower limit of the filler may be at least 0.5% by weight, at least 0.75% by weight, at least 1% by weight, at least 2% by weight, or at least 3% by weight. All other values and ranges between the above values are also included and contemplated.

Cellulose acetate may be included in the tow in an amount sufficient to retain the desired properties of the tow, tow band, or cigarette filter, for example, filtration of the cigarette filter. For example, the cellulose acetate may be present from 0.1% to 99% by weight of the tow, e.g., from 0.1% to 95% by weight, from 0.1% to 90% by weight, from 0.1% to 85% by weight, from 0.1% to 80% by weight, from 0.1% to 75% by weight, from 0.1% to 70% by weight, from 0.1% to 65% by weight, from 0.1% to 60% by weight, from 0.1% to 55% by weight, from 0.1% to 50% by weight, from 0.1% to 45% by weight, from 0.1% to 40% by weight, from 0.1% to 35% by weight, from 0.1% to 30% by weight, from 0.1% to 25% by weight, from 0.1% to 20% by weight, from 0.1% to 15% by weight, from 0.1% to 10% by weight, or from 0.1% to 5% by weight. In further aspects, the lower limit of cellulose acetate may be at least 0.5% by weight, at least 0.75% by weight, at least 1% by weight, at least 2% by weight, at least 3% by weight, at least 5% by weight, at least 10% by weight, at least 15% by weight, at least 20% by weight, at least 25% by weight, at least 30% by weight, at least 35% by weight, at least 40% by weight, at least 45% by weight, at least 50% by weight, or greater. All other values and ranges between the above values are also included and contemplated. Furthermore, the scope of the above-included tow is also applicable to tow bands and filter rods incorporated into cigarette filters.

The weight ratio of cellulose acetate to filler in the dope, tow band, filter rod, and cigarette filter may also vary, including from 1:99 to 99:1, for example, from 1:75 to 75:1, from 1:50 to 50:1, from 1:25 to 25:1, from 1:10 to 10:1, from 1:5 to 5:1, from 1:3 to 3:1, from 1:2 to 2:1, or about 1:1. In some embodiments, the cellulose acetate is present in a greater weight ratio than the filler, e.g., at least 1.5:1, at least 2:1, at least 3:1, at least 5:1, at least 10:1, at least 15:1, at least 20:1, at least 25:5, or at least 50:1, including all ranges therebetween.

Tow, tow band, filter rod and cigarette filter may also contain additives. The additive may be present in an amount from 0.01% to 25% by weight, for example, from 0.01% to 20% by weight, from 0.1% to 15% by weight, from 0.1% to 10% by weight, or from 0.1% to 5% by weight. In further aspects, the lower limit of cellulose acetate may be at least 0.5% by weight, at least 0.75% by weight, at least 1% by weight, at least 2% by weight, at least 3% by weight, at least 5% by weight, at least 10% by weight, at least 15% by weight, at least 20% by weight, at least 25% by weight, at least 30% by weight, at least 35% by weight, at least 40% by weight, at least 45% by weight, at least 50% by weight, or greater. All other values and ranges between the above values are also included and contemplated.

Once the tow is formed, it may be combined to form a tow band comprising a plurality of tow filaments. In some embodiments, the tow band is from 10,000 to 100,000 total denier, e.g., from 15,000 to 100,000, from 20,000 to 100,000, from 25,000 to 100,000, from 30,000 to 100,000, from 10,000 to 90,000, from 15,000 to 90,000, from 20,000 to 90,000, from 25,000 to 90,000, from 30,000 to 90,000, from 10,000 to 80,000, from 15,000 to 80,000, from 20,000 to 80,000, from 25,000 to 80,000, from 30,000 to 80,000, from 10,000 to 70,000, from 15,000 to 70,000, from 20,000 to 70,000, from 25,000 to 70,000, from 30,000 to 70,000, from 25,000 to 60,000, from 60,000, or from 60,000. With respect to the upper limit, the tow band may be less than 100,000 total denier, for example, less than 90,000, less than 80,000, less than 70,000, or less than 60,000. With respect to the lower limit, the tow band may be greater than 10,000 total denier, for example, greater than 15,000, greater than 20,000, greater than 25,000, or greater than 30,000.

In some embodiments, the tow may have a breaking strength of between 3.5kg and 25kg, for example, from 3.5kg to 22.5kg, from 3.5kg to 20kg, from 3.5kg to 17.5kg, from 3.5kg to 15kg, from 4kg to 25kg, from 4kg to 22.5kg, from 4kg to 20kg, from 4kg to 17.5kg, from 4kg to 15kg, from 4.5kg to 25kg, from 4.5kg to 22.5kg, from 4.5kg to 20kg, from 4.5kg to 17.5kg, from 4.5kg to 15kg, from 5kg to 25kg, from 5kg to 22.5kg, from 5kg to 20kg, from 5kg to 17.5kg, or from 5kg to 15kg. As an upper limit, the tow may have a breaking strength of less than 25kg, for example, less than 22.5kg, less than 20kg, less than 17.5kg, or less than 15kg. For the lower limit, the tow may have a breaking strength of greater than 3.5kg, for example, greater than 4kg, greater than 4.5kg, or greater than 5kg.

In some embodiments of the present disclosure, the tow band may comprise more than one type of fiber. In some embodiments, more than one type of fiber may vary based on dpf, cross-sectional shape, composition, treatment prior to forming the tow band, or any combination thereof. Examples of suitable additional fibers may include, but are not limited to, carbon fibers, activated carbon fibers, natural fibers, synthetic fibers, or any combination thereof. Further examples include some cellulose acetate tows that contain filler and some cellulose acetate tows that do not contain filler. The weight ratio of tows containing filler to tows not containing filler may range from 1:99 to 99:1, for example, from 1:75 to 75:1, from 1:50 to 50:1, from 1:25 to 25:1, from 1:10 to 10:1, from 1:5 to 5:1, from 1:3 to 3:1, from 1:2 to 2:1, or about 1:1. In some embodiments, the cellulose acetate is present in a greater weight ratio than the filler, e.g., at least 1.5:1, at least 2:1, at least 3:1, at least 5:1, at least 10:1, at least 15:1, at least 20:1, at least 25:5, or at least 50:1, including all ranges therebetween. It is also contemplated that different types of fillers may be included in different tows, which are ultimately combined to form a tow band. For example, some tow filaments may comprise monosaccharides, while other tow filaments may comprise different fillers, such as polysaccharides or starches. In addition, the tow may contain fillers integral to the tow, for example, added to the flakes, powder or dope, as well as fillers added later in the manufacturing process, such as cellulose or certain starches.

Some embodiments of the present disclosure may include crimping the tow band to form a crimped tow band. Crimping the tow band may involve the use of any suitable crimping technique known to those skilled in the art. These techniques may include a variety of devices including, but not limited to, stuffer boxes or gears. Non-limiting examples of crimping devices and their operating mechanisms can be found in U.S. patent nos. 7,610,852 and 7,585,441, the entire contents and disclosures of which are incorporated herein by reference. Suitable stuffer box crimpers may have a smooth crimper nip roller, a threaded or grooved crimper nip roller, a textured crimper nip roller, an upper flap, a lower flap, or any combination thereof.

The crimped configuration may play a role in the processability of the final package. Examples of crimping configurations may include, but are not limited to, lateral, vertical, some degree between lateral and vertical, random, or any combination thereof. As used herein, the term "transverse" when describing a crimp orientation refers to crimping or fiber bending in the plane of the tow band. As used herein, the term "perpendicular" when describing a crimp orientation refers to a crimp that protrudes out of and is perpendicular to the plane of the tow band. It should be noted that the terms transverse and perpendicular refer to the general overall coiled orientation and may have a deviation of +/-30 degrees from the configuration.

In some embodiments of the present disclosure, a crimped tow band may include fibers having a first crimped configuration and fibers having a second crimped configuration.

In some embodiments of the present disclosure, a crimped tow band may include fibers having at least a vertical crimp configuration near the edges and fibers having at least a lateral crimp configuration near the center. In some embodiments, the crimped tow band may include fibers having a vertical crimp configuration near the edges and fibers having a transverse crimp configuration near the center.

The crimped configuration may be important for the processability of the final package in subsequent processing steps, e.g., a transverse crimped configuration may provide better fiber adhesion than a vertical crimped configuration unless additional steps are taken to improve adhesion. Methods for crimping a tow band having a substantially transverse crimped configuration are disclosed, for example, in U.S. publication No. 2013/015452 and U.S. publication No. 2015/0128964, each of which is incorporated herein in its entirety.

In some embodiments of the present disclosure, the fibers may adhere to each other to provide better processability of the final package. While the adhesion additive may be used in conjunction with any crimping configuration, it may be advantageous to use the adhesion additive with a vertical crimping configuration. In some embodiments, adhesion may involve adhesion additives on and/or in the fibers. Examples of such adhesion additives may include, but are not limited to, adhesives, binders, resins, tackifiers, or any combination thereof. It should be noted that any of the additives described herein or other additives capable of adhering two fibers together may be used and may include, but are not limited to, active particles, active compounds, ionic resins, zeolites, nanoparticles, ceramic particles, softeners, plasticizers, pigments, dyes, flavors, fragrances, controlled release vesicles, surface modifiers, lubricants, emulsifiers, vitamins, peroxides, biocides, fungicides, antimicrobial agents, antistatic agents, flame retardants, defoamers, degradants, conductivity modifiers, stabilizers, or any combination thereof. Some embodiments of the present disclosure may involve adding binder additives to the fibers (in, on, or both) by: the binder additive is incorporated into the spin dope, the binder additive is incorporated into the finish, the binder additive is applied to the fibers (before, after, and/or during formation of the tow band), the binder additive is applied to the tow band (before, after, and/or during crimping), or any combination thereof.

The binder additive may be included in and/or on the fibers in a concentration sufficient to adhere the fibers together at multiple points of contact to provide better processability of the final package. The concentration of the adhesive additive to be used may depend on the type of adhesive additive and the adhesive strength provided by the adhesive additive. In some embodiments, the concentration of the adhesive additive may range from a lower limit of 0.01%, 0.05%, 0.1%, or 0.25% to an upper limit of 5%, 2.5%, 1%, or 0.5% (by weight of the tow band in the final package). It should be noted that the concentration in the tow band in the final package may be higher, for example 25% or less, for additives used for more than adhesion.

Further, some embodiments of the present disclosure may involve heating the fibers before, after, and/or during crimping. While the heating may be used in conjunction with any crimping configuration, it may be advantageous to use the heating with a vertical crimping configuration. The heating may involve exposing the fibers of the tow band to steam, an atomizing compound (e.g., a plasticizer), a liquid, a heating fluid, a direct heat source, an indirect heat source, an irradiation source that causes additives (e.g., nanoparticles) in the fibers to generate heat, or any combination thereof.

Some embodiments of the present disclosure may include conditioning a crimped tow band. Conditioning may be used to achieve a crimped tow band having a residual acetone content of 0.5% or less w/w of the crimped tow band. Conditioning may be used to achieve a crimped tow band having a residual water content of 8% or less w/w of the crimped tow band. Conditioning may involve exposing the fibers of the crimped tow band to steam, an atomizing compound (e.g., a plasticizer), a liquid, a heating fluid, a direct heat source, an indirect heat source, an irradiation source that causes the additives (e.g., nanoparticles) in the fibers to generate heat, or any combination thereof.

UCE is the amount of work required to decurl the fiber. As reported below, UCE is sampled prior to packaging (i.e., after drying and prior to packaging). As used herein, UCE is measured as follows: using a pre-heated (20 minutes prior to conventional calibration) Instron (Instron) tensile tester (model 1130, crosshead gear-gear numbers R1940-1 and R940-2, instron series IX-6 version data acquisition and analysis software, instron 50Kg maximum capacity load cell, instron top roll assembly, 1 "x 4" x 1/8 "thick high grade Buna-N70 shore a durometer rubber clamp face), a pre-conditioned tow sample of about 76cm length (pre-conditioned 24 hours at 22 ℃ ± 2 ℃ and 60% ± 2% relative humidity) was wrapped around the center of the top roll and evenly distributed, pre-stretched by gently pulling to 100g ± 2g (according to the reading display), and each end of the sample was clamped in a lower clamp (at the highest available pressure, but not exceeding the manufacturer's recommended value) to achieve a 50cm gauge length (length measured from the top of the rubber clamp) and then tested at a crosshead break rate of 30 cm. This test was repeated until three acceptable tests were obtained and the average of three data points for these tests was reported. The energy (E) limit is between 0.220kg and 10.0 kg. The displacement (D) has a preset point of 10.0 kg. UCE is calculated by the following formula: UCE (gcm/cm) = (e×1000)/((d×2) +500). The breaking strength can be calculated using the same test and the following equation bs=l, where L is the load at maximum load (kg). In certain embodiments of the present disclosure, the UCE value (in gcm/cm) may range from 190 to 400, such as 200 to 300, such as 290. In certain embodiments of the present disclosure, the breaking strength may range between 3.5kg and 25kg, for example 4kg to 20kg, 4.5kg to 15kg, or 5kg to 12kg.

Cigarette filter tip

Degradable cigarette filters typically include a filter element (or plug) made from a plug of bulked cellulose acetate tow containing a filler and plug wrap surrounding the filter element. The cellulose acetate tow may be delivered as a package to the filter producer. The tow is then opened or "puffed" in a rod making apparatus to form a filter rod and a final cigarette filter. Various characteristics of cigarette filters are desirable, including robustness, pressure drop variability, openability, fly ash (fly) and decurling energy. The filler materials described herein, as well as the amounts used, may be selected to balance these properties with the degradability of the cigarette filter.

Examples

Example 1: a cellulose acetate tow band, the tow band comprising: a) Cellulose acetate having a Degree of Substitution (DS) of greater than 1.3; and b) a filler; wherein the filler has a greater degradation rate than the cellulose acetate.

Example 2: the tow band of embodiment 1, wherein the filler comprises a monosaccharide, polysaccharide ester, hydrolyzed polysaccharide, oligosaccharide, or a combination thereof.

Example 3: the tow band according to embodiment 1 or 2, wherein the filler comprises dextran, hydrolyzed starch, modified hydrolyzed starch, hemp, cellulose, or a combination thereof.

Example 4: the tow band according to any one of embodiments 1-3, wherein the filler is present at from 0.1% to 99.9% by weight based on the total weight of the tow band.

Example 5: the tow band according to any one of embodiments 1-4, wherein the filler is present at from 0.1% to 75% by weight based on the total weight of the tow band.

Example 6: the tow band according to any one of embodiments 1-5, wherein the filler is present at from 0.1% to 50% by weight based on the total weight of the tow band.

Example 7: the tow band according to any one of embodiments 1-6, wherein the filler is present at from 0.1% to 25% by weight based on the total weight of the tow band.

Example 8: the tow band according to any one of embodiments 1-7, wherein the filler has a degradation rate at least 3% greater than the degradation rate of the cellulose acetate.

Example 9: the tow band according to any one of embodiments 1-8, wherein the filler has a degradation rate at least 10% greater than the degradation rate of the cellulose acetate.

Example 10: the tow band according to any one of embodiments 1-9, wherein the filler has a degradation rate at least 15% greater than the degradation rate of the cellulose acetate.

Example 11: the tow band according to any one of embodiments 1-10, wherein the tow band comprises a weight ratio of the cellulose acetate to the filler of from 1:99 to 99:1.

Example 12: the tow band according to any one of embodiments 1-11, wherein the tow band comprises a weight ratio of the cellulose acetate to the filler of from 1:50 to 50:1.

Example 13: the tow band according to any one of embodiments 1-12, wherein the tow band comprises a weight ratio of the cellulose acetate to the filler of from 1:25 to 25:1.

Example 14: the tow band according to any one of embodiments 1-13, wherein the tow band comprises cellulose acetate in an amount of from 0.1% to 99.9% by weight based on the total weight of the tow band.

Example 15: the tow band according to any one of embodiments 1-14, wherein the cellulose acetate has a degree of substitution of from 2 to 2.9.

Example 16: the tow band according to any one of embodiments 1-15, wherein the tow band comprises from 0.01% to 25% by weight of additives based on the total weight of the tow band.

Example 17: a cigarette filter, comprising: a filter element comprising an expanded tow, wherein the expanded tow comprises a tow band according to any one of embodiments 1-16.

Example 18: a method for forming a cigarette filter according to embodiment 17, the method comprising a) providing the cellulose acetate tow band; b) Puffing the tow band; and c) forming the puffed tow band into a filter rod.

Example 19: the method of embodiment 18, wherein the tow band is formed by: a) Combining cellulose acetate and the filler with a solvent to form a dope; b) Solvent spinning the spinning dope to form a plurality of tow filaments; and c) combining the plurality of tow filaments to form the tow band.

Example 20: the method of embodiment 18, wherein the tow band is formed by: a) Combining cellulose acetate and the filler to form a sheet; b) Combining the flakes with a solvent to form a dope; c) Solvent spinning the spinning dope to form a plurality of tow filaments; and d) combining the plurality of tow filaments to form the tow band.

Although the present invention has been described in detail, modifications within the spirit and scope of the invention will be apparent to those of skill in the art. It should be understood that aspects of the invention, as well as portions of the various embodiments and features described above and/or in the appended claims, may be combined or interchanged both in whole or in part. In the foregoing description of the various embodiments, those embodiments referring to another embodiment may be combined with other embodiments as appropriate, as will be appreciated by those of ordinary skill in the art. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention.

Claims

1. A cellulose acetate tow band, the tow band comprising:

a) Cellulose acetate having a Degree of Substitution (DS) of greater than 1.3; and

b) A filler; wherein the filler has a greater degradation rate than the cellulose acetate.

2. The tow band according to claim 1, wherein the filler comprises a monosaccharide, polysaccharide ester, hydrolyzed polysaccharide, oligosaccharide, or a combination thereof.

3. The tow band according to claim 1 or 2, wherein the filler comprises dextran, hydrolyzed starch, modified hydrolyzed starch, hemp, cellulose, or a combination thereof.

4. A tow band according to any one of claims 1-3, wherein the filler is present from 0.1% to 99.9% by weight, from 0.1% to 75% by weight, from 0.1% to 50% by weight, or from 0.1% to 25% by weight, based on the total weight of the tow band.

5. The tow band according to any one of claims 1-4, wherein the degradation rate of the filler is at least 3% greater than the degradation rate of the cellulose acetate.

6. The tow band according to any one of claims 1-5, wherein the filler has a degradation rate that is at least 10% greater than or at least 15% greater than the degradation rate of the cellulose acetate.

7. The tow band according to any one of claims 1-6, wherein the tow band comprises a weight ratio of the cellulose acetate to the filler of from 1:99 to 99:1, from 1:50 to 50:1, or from 1:25 to 25:1.

8. The tow band according to any one of claims 1-7, wherein the tow band comprises cellulose acetate in an amount of from 0.1% to 99.9% by weight based on the total weight of the tow band.

9. The tow band according to any one of claims 1-8, wherein the cellulose acetate has a degree of substitution of from 1.3 to 2.9 or from 2 to 2.9.

10. The tow band according to any one of claims 1-9, wherein the tow band comprises from 0.01% to 25% by weight of additives based on the total weight of the tow band.

11. A cigarette filter, comprising:

a filter element comprising a bulked tow, wherein the bulked tow comprises a tow band according to any one of claims 1-10.

12. A method for forming a cigarette filter according to claim 11, the method comprising

a) Providing the cellulose acetate tow band;

b) Puffing the tow band; and

c) The puffed tow band is formed into a filter rod.

13. The method of claim 12, wherein the tow band is formed by:

a) Combining cellulose acetate and the filler with a solvent to form a dope;

b) Solvent spinning the spinning dope to form a plurality of tow filaments; and

c) The plurality of tow filaments are combined to form the tow band.

14. The method of claim 12, wherein the tow band is formed by:

a) Combining cellulose acetate and the filler to form a sheet;

b) Combining the flakes with a solvent to form a dope;

c) Solvent spinning the spinning dope to form a plurality of tow filaments; and

d) The plurality of tow filaments are combined to form the tow band.