Filter comprising paper substrate modified with natural starch

Abstract

The present invention relates to a filter comprising a paper substrate modified with natural starch.

Description

Technical Field

[0001] The present invention provides a filter comprising a paper substrate modified with natural starch. The filter can be used as a filter for smoking products or electronic cigarette products. Background Art

[0002] Filters for smoking or electronic cigarette articles have a right cylindrical shape and typically include an outer wrapper of plug wrapping paper and a substrate positioned within the outer wrapper. The substrate allows filters for smoking or electronic cigarette articles to prevent users from inhaling tobacco particles while retaining harmful particulate matter, such as tar, contained in smoke or aerosol.

[0003] Conventional filters comprise cellulose acetate fibers. These conventional filters are also known as cellulose acetate filters. However, cellulose acetate filters degrade very slowly, negatively impacting the environment. In reality, the filters are not consumed during the puffing of cigarettes / electronic cigarettes and are often found in the environment. Therefore, cellulose acetate filters have a significant impact on the environment.

[0004] To limit the environmental impact of cellulose acetate filters, it has been proposed to replace cellulose acetate fibers with paper substrates produced through wet-laid or hydroentangled processes. Because paper substrates are biodegradable, filters containing paper substrates degrade rapidly. However, compared to cellulose acetate filters, filters containing paper substrates have a lower hardness. Consequently, due to their lower hardness, filters containing paper substrates can collapse during use. Consequently, the user experience provided by filters containing paper substrates is less satisfactory than that provided by cellulose acetate filters.

[0005] Technical issues

[0006] Therefore, there is a need for a paper substrate that can be used to manufacture filters that have satisfactory mechanical properties and thus provide a satisfactory user experience.

[0007] The inventors are therefore to be commended for having discovered that this need can be met by modifying paper substrates with native starch.

[0008] Overview

[0009] A filter is proposed, comprising a paper substrate, the paper substrate comprising:

[0010] -base network, and

[0011] - natural starch,

[0012] The native starch is present in an amount of 1.2% to 3.8% by weight of the base web, particularly 1.3% to 2.0% by weight of the base web, more particularly 1.35% to 1.5% by weight of the base web.

[0013] Compared to standard paper filters, the filter of the present invention has very satisfactory mechanical properties. In particular, it has a higher hardness and is therefore more resistant to collapse than filters comprising a standard paper substrate.

[0014] Without wishing to be bound by any theory, the inventors believe that the mechanical properties of the filter of the present invention are due to the natural starch. In fact, the natural starch makes the density of the paper substrate higher than the density of a standard paper substrate. Therefore, at the same pressure drop, the density of the filter of the present invention is higher than the density of a filter including a standard paper substrate.

[0015] Furthermore, the inventors have noticed that when the starch content is higher than 3.8% by weight of the base web, filters cannot be manufactured. In fact, substrates containing more than 3.8% by weight of the base web cannot be rolled without being shredded, thus affecting the manufacture of filters.

[0016] Furthermore, the filter of the present invention, due to its composition, degrades rapidly in the environment compared to cellulose acetate filters. This is particularly advantageous because the environmental impact of the filter of the present invention is lower than that of cellulose acetate filters.

[0017] According to another aspect, a method is proposed for producing a filter for a smoking article or electronic smoking article as defined above, comprising the following steps:

[0018] a) producing a base web by a wet-laid process or a wet-laid hydroentanglement process, in particular a wet-laid process;

[0019] b) applying native starch to a base web to produce a paper substrate;

[0020] c) forming a rod from the paper substrate produced in step b);

[0021] d) wrapping the stick-shaped object with a plug-wrapped paper sheet;

[0022] e) depositing lines of adhesive at the joints of the plugwrap sheets to obtain a rod of filter material;

[0023] f) Cutting the rod of filter material to produce the filter. DETAILED DESCRIPTION

[0024] A filter is proposed, comprising a paper substrate, the paper substrate comprising:

[0025] -base network, and

[0026] - natural starch,

[0027] The native starch is present in an amount of 1.2% to 3.8% by weight of the base web, particularly 1.3% to 2.0% by weight of the base web, more particularly 1.35% to 1.5% by weight of the base web.

[0028] As used herein, the term "base web" refers to a fibrous sheet.

[0029] Base webs are typically used to manufacture filters for smoking or electronic cigarette products. Those skilled in the art will appreciate how to obtain a base web having desired properties to produce a paper substrate having desired properties. Furthermore, the base web can be obtained through a wet-laid or hydroentangled process, particularly a wet-laid process. Therefore, the paper substrate of the filter of the present invention can also be obtained through a wet-laid or hydroentangled process, particularly a wet-laid process.

[0030] Typically, the base web may comprise more than 50 wt. % wood fibers, in particular 100 wt. % wood fibers.

[0031] The wood fibers may be hardwood pulp, bleached hardwood pulp, softwood pulp, bleached softwood pulp, softwood fluff pulp, lyocell fibers (cellulose fibers ground and dissolved in N-methylmorpholine N-oxide monohydrate in order to obtain fibers with variable cross-section shapes (arc-shaped, elliptical, cross-shaped, circular, lamellar cross-sections), which have a calibrated length and mass per unit length, which can be selected by those skilled in the art according to their needs), viscose fibers (fibers obtained by dissolving cellulose by modifying the hydroxyl groups of cellulose with carbon disulfide (CS2) and then precipitating the cellulose in the presence of sulfuric acid (H2SO4), in order to obtain fibers with variable cross-section shapes (arc-shaped, elliptical, cross-shaped, circular, lamellar cross-sections), which have a calibrated length and mass per unit length, which can be selected by those skilled in the art according to their needs) or mixtures thereof, in particular bleached softwood pulp, softwood pulp, softwood fluff pulp, lyocell fibers, viscose fibers or mixtures thereof, more in particular softwood pulp, softwood fluff pulp or mixtures thereof.

[0032] The base web may further comprise natural fibers, such as leaf fibers, fruit fibers, seed fibers, bast fibers, stem fibers, reed fibers or mixtures thereof, in particular leaf fibers, seed fibers, bast fibers or mixtures thereof, more in particular bast fibers.

[0033] For the purposes of this application, "bast fibers" refer to plant fibers contained in the phloem of a plant.

[0034] The bast fibers may be abaca fibers, hemp fibers, Indian hemp fibers, jute fibers, kenaf fibers, kudzu fibers, coin vine fibers, flax fibers, okra fibers, nettle fibers, papyrus fibers, ramie fibers, sisal fibers, esparto fibers or mixtures thereof, in particular hemp fibers, flax fibers, sisal fibers or combinations thereof, more in particular flax fibers, sisal fibers or mixtures thereof.

[0035] For the purposes of this application, "seed fiber" refers to fiber obtained from the seeds of a plant. The seed fiber can be cotton fiber, kapok fiber, loofah fiber, milkweed fiber, or a mixture thereof.

[0036] As used herein, the term "native starch" refers to starch of plant origin.

[0037] Natural starch can be natural starch from cereals, tubers, roots, legumes and fruits. Starch sources can include corn, peas, potatoes, bananas, barley, wheat, rice, sago, amaranth, cassava, arrowroot, canna, sorghum, oats, cassaya, amioca and waxy or high amylose varieties thereof.

[0038] Natural starch can also be modified starch or a mixture of natural starch and modified starch. The term "modified starch" is used herein to refer to natural starch modified using any modification method known in the art, including physically modified starch, chemically modified starch, conversion products derived from any starch, pregelatinized starch and mixtures thereof.

[0039] Physically modified starches can be shear-modified starches or heat-inhibited starches.

[0040] Chemically modified starches may be cross-linked, acetylated, and organically esterified, hydroxyethylated, and hydroxypropylated, phosphated, and inorganically esterified, cationic, anionic, nonionic, amphoteric, and zwitterionic, as well as succinate and substituted succinate derivatives thereof.

[0041] Conversion products derived from any starch can be fluid or thin boiling starches prepared by oxidation, enzymatic conversion, acid hydrolysis, thermal or acid gelatinization, and thermal and / or shear products can also be used in this application.

[0042] Hydroxyethyl starch and oxidized waxy potato starch are examples of modified starches.

[0043] The native starch can be applied to the base web by various wetting or impregnation processes (discussed in detail below). Thus, the native starch can form a layer on one or more surfaces of the base web, can partially penetrate the base web, can completely penetrate the base web, or a combination of these, particularly a combination of these.

[0044] The terms "impregnation" and "drenching" have their commonly known meanings in the art and are synonymous and used interchangeably to refer to applying the native starch to the base web so that the native starch forms a layer on one or more surfaces of the base web, partially penetrates the base web, completely penetrates the base web, or a combination of these, in particular a combination of these.

[0045] The paper substrate may further include additives commonly used in filters for smoking or electronic smoking articles.

[0046] The density of the paper substrate may be, for example, higher than 431 mg / cm 3 , especially 431mg / cm 3 Up to 600mg / cm 3 , more particularly 433 mg / cm 3 Up to 500mg / cm 3 , even more particularly 435 mg / cm 3 Up to 465mg / cm 3 .

[0047] The density within these values is higher than the density of paper substrates used in standard paper filters, which is approximately 429 mg / cm 3 Advantageously, filters of the present invention comprising a paper substrate having a density within these values have improved mechanical properties, particularly hardness and collapse resistance, compared to filters using standard paper substrates. The inventors believe that the improved hardness of the filter is due to the higher density of the paper, which results in a higher density of the filter.

[0048] The density of a paper substrate is calculated by dividing the basis weight of the paper substrate by its thickness.

[0049] Standard ISO 536:2012 can be used to determine the basis weight of paper substrates. Prior to measurement, the paper substrate can be conditioned at 23°C and 50% humidity for at least 30 minutes.

[0050] Standard ISO 534:2011 can be used to determine the thickness of paper substrates. The measurement is performed on a single layer. Before the measurement, the paper substrate is conditioned at 23°C and 50% humidity for at least 30 minutes.

[0051] One skilled in the art will know how to adjust the basis weight and thickness of the paper substrate to achieve the desired density.

[0052] For example, the basis weight of a paper substrate may be 10 g.m -2 to 60g.m -2 , especially 20g.m -2 Up to 50g.m -2 , more particularly 26g.m -2 Up to 40g.m -2 .

[0053] The thickness of the paper substrate may be 30 μm to 250 μm, specifically 37 μm to 150 μm, more specifically 40 μm to 100 μm.

[0054] The air permeability of the paper substrate may be 350 Coresta units (CU) to 35,000 CU, specifically 1,000 CU to 10,000 CU, and more specifically 2,000 CU to 3,000 CU.

[0055] The air permeability of a paper substrate can be determined by ISO 2965: 2009. Prior to measurement, the paper substrate can be conditioned at 23°C and 50% humidity for at least 30 minutes.

[0056] In some cases, the paper substrate may have a density of 435 mg / cm 3 Up to 465mg / cm 3 Density, 26g.m -2 Up to 40g.m -2 The natural starch may be hydroxyethyl starch or oxidized waxy potato starch.

[0057] The paper substrate of the filter of the present invention can be shaped; in particular, it can be curled, embossed, pleated, compressed, or a combination of these. This shaping can modify the properties of the paper substrate and, in turn, the properties of the filter of the present invention. For example, by curling, the density of the paper substrate can be altered, thereby increasing or decreasing the pressure drop of the filter of the present invention without increasing the weight of the filter.

[0058] The filter of the present invention may be a filter for a smoking article or an electronic smoking article.

[0059] For the purposes of this application, a "smoking article" refers to an article comprising tobacco and / or any other plant material intended to be smoked. For example, a smoking article may be a machine-made cigarette, a hand-rolled cigarette, or a homemade cigarette.

[0060] Typically, filters for smoking articles are of right cylindrical shape and comprise an outer wrapper of plugging paper for smoking articles, particularly cigarettes, and a paper substrate as defined above within the outer wrapper.

[0061] For the purposes of this application, an "electronic smoking article" is an article comprising tobacco and / or any other plant material intended to be vaped electronically, which is intended to be inserted into a device that heats the tobacco and / or plant material without burning it, and is capable of delivering an aerosol to a user. For example, an electronic smoking article may be a tobacco stick.

[0062] Typically, the filter for electronic smoking articles is in the shape of a right cylinder and comprises an outer wrapper of plugging paper for electronic smoking articles, particularly tobacco rods, and a paper substrate as defined above located within the outer wrapper.

[0063] The filter of the present invention can have a 135 mg / cm 3 Up to 350mg / cm 3 , especially 200mg / cm 3 Up to 280mg / cm 3 , more particularly 220 mg / cm 3 Up to 265mg / cm 3 density.

[0064] Typically, the density of a filter is measured after the filter is manufactured by dividing the mass of the filter by its volume. For a right cylindrical filter, the volume of the filter (V 过滤器 ) is calculated by the following formula: V 过滤器 =π*L*r 2 , where r represents the radius of the filter and L represents the length of the filter.

[0065] The density of the filter of the present invention is higher than that of a standard paper filter. Without wishing to be bound by any theory, the inventors believe that the mechanical properties of the filter of the present invention, in particular its hardness and resistance to collapse, are primarily due to the high density of the filter of the present invention.

[0066] The filter of the present invention may include:

[0067] - outer wrappers of plug wrapping paper for filters of smoking or electronic smoking articles, and

[0068] - A paper substrate within said outer cover.

[0069] The filter of the present invention may be in the shape of a right cylinder.

[0070] According to another aspect, the present invention also relates to a smoking article comprising a filter as defined above.

[0071] According to another aspect, the present invention also relates to an electronic smoking article comprising a filter as defined above.

[0072] The present invention also relates to a method for producing a filter as defined above for a smoking article or an electronic smoking article, comprising the following steps:

[0073] a) producing a base web by a wet-laid process or a wet-laid hydroentangled process, in particular a wet-laid process;

[0074] b) applying native starch to a base web to produce a paper substrate;

[0075] c) forming a rod from the paper substrate produced in step b);

[0076] d) wrapping the stick-shaped object with a plug-wrapped paper sheet;

[0077] e) depositing lines of adhesive at the junctions of the plugwrap sheets to obtain a plug of filter material; and

[0078] f) Cutting the rod of filter material to produce the filter.

[0079] The paper substrate, base web and native starch are as defined above.

[0080] Wet-laid web forming and wet-laid hydroentanglement are conventional processes well known to those skilled in the art. Those skilled in the art know how to adjust the parameters of these processes to produce a base web in step a).

[0081] In step b), the native starch is applied to the substrate by various wetting or impregnation processes (discussed in detail below). Thus, the native starch may form a layer on one or more surfaces of the substrate, may partially penetrate into the substrate, may fully penetrate into the substrate, or a combination of these, in particular a combination of these.

[0082] The application of step b) can be carried out by size press, film sizing, saturator, dip coating, roller coating, knife coating, flexographic printing, spraying or a combination thereof, in particular by film sizing, spraying, size press or a combination thereof, more in particular by size press.

[0083] The methods for applying these native starches are well known to those skilled in the art. Therefore, those skilled in the art know how to adjust the parameters of these methods to produce a paper substrate.

[0084] The base web produced in step a), the paper substrate produced in step b), or both may be shaped.

[0085] Thus, the method may comprise, between steps a) and b), a step of shaping the base web by crimping, embossing, folding, compressing or a combination of these methods. The inventors believe that applying native starch after crimping can reduce the amount of upright fibers generated during the crimping process.

[0086] Alternatively, or in addition, the method may include a step between step b) and step c) of shaping the paper substrate by curling, embossing, folding, compressing, or a combination of these methods. The inventors believe that applying native starch before curling can bind the fibers together, thereby limiting the formation of upright fibers during the curling process.

[0087] Steps c) to e) are well known to those skilled in the art. Those skilled in the art know how to adjust the parameters of these processes to produce the filter of the present invention.

[0088] Example

[0089] Example 1: Paper substrate production

[0090] The base web is produced by a wet-laid process using bleached softwood fibers. The base web is cut into 2 different parts.

[0091] One part was impregnated with oxidized starch by film sizing.

[0092] Another part was impregnated with hydroxyethyl starch by means of a size press.

[0093] The properties of the base web and these different paper substrates are shown in Table 1 below, Examples 1.1 and 1.2.

[0094] Table 1

[0095]

[0096] Example 2: Filter Manufacturing

[0097] Using 23.5g / m 2 The non-porous plug wrapping paper of Examples 1.1 and 1.2 was used as an outer cover, and the base web or substrate of Examples 1.1 and 1.2 were crimped by a standard method for making filters to produce filters for smoking articles.

[0098] The performance of these three filters was compared to Marlboro Red France TM The performance of commercial cellulose acetate filters for cigarettes was compared.

[0099] The hardness of the filter was measured using a standard method using a Filtrona DHT200 device. The results were expressed as % of the crushed diameter of the filter relative to the initial diameter.

[0100] The characteristics of the filters are shown in Table 2 below.

[0101] [Table 2] shows that the filter according to the present invention has:

[0102] -Higher hardness than traditional paper filters, and

[0103] -Hardness of the same order of magnitude as or greater than that of commercial cellulose acetate filters.

[0104] Table 2

[0105]

[0106] Comparative Example

[0107] The base mesh was prepared as in Example 1. The base mesh was cut into two different parts:

[0108] One section was impregnated with 4% hydroxyethyl starch based on the weight of the base web through a size press.

[0109] Another portion was impregnated with 8% hydroxyethyl starch based on the weight of the base web through a size press.

[0110] During the process of crimping the two parts, the two parts broke apart, making it impossible to manufacture the filter.

[0111] This comparative example therefore demonstrates that when the amount of starch is higher than 3.8% by weight of the base web, it is not possible to produce a filter.

Claims

1. A filter comprising a paper substrate, the paper substrate comprising: -base network, and - natural starch, wherein the native starch is present in an amount of 1.2% to 3.8% by weight of the base web.

2. The filter of claim 1, wherein the starch is hydroxyethyl starch, oxidized waxy potato starch, or a mixture thereof.

3. The filter according to claim 1 or 2, wherein the paper substrate has a viscosity higher than 431 mg / cm 3 density.

4. The filter according to any one of claims 1 to 3, wherein the paper substrate has a thickness of 10 g.m - 2 to 60g.m - 2 basis weight.

5. The filter according to any one of claims 1 to 4, wherein the paper substrate is obtainable by a wet-laid process or a wet-hydroentangled process.

6. The filter according to any one of claims 1 to 5, which is used in a smoking article or an electronic smoking article.

7. A smoking article comprising a filter as defined in claim 6.

8. An electronic smoking article comprising the filter defined in claim 6.

9. A method for producing a filter for a smoking article or an electronic smoking article as defined in claim 6, comprising the steps of: a) producing a base web by a wet-laid web process or a wet-laid hydroentanglement process; b) applying native starch to the base web to produce a paper substrate; c) forming a rod from the paper substrate produced in step b); d) wrapping the stick-shaped object with a plug-wrap paper sheet; e) depositing lines of adhesive at the junctions of the plug wrap sheets to obtain a rod of filter material; f) Cutting the rod of filter material to produce the filter.

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