US20240180237A1

US20240180237A1 - Fiber cell structure expansion process

Info

Publication number: US20240180237A1
Application number: US18/521,993
Authority: US
Inventors: Luis Antonio SANCHES; Tadas Lukas LISAUSKAS
Original assignee: GREENBUTTS LLC
Current assignee: GREENBUTTS LLC
Priority date: 2022-12-06
Filing date: 2023-11-28
Publication date: 2024-06-06
Also published as: WO2024123567A1

Abstract

A method for expanding cigarette filter fiber cell structure, comprises providing a cigarette filter fiber, adding a liquid to the cigarette filter fiber to form a cigarette filter fiber and liquid solution; and expanding total fiber volume and cell cavities in the cigarette filter fiber by performing an expansion process on the filter fiber and liquid solution.

Description

BACKGROUND

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Patent Application No. 63/430,441, filed Dec. 6, 2022, which is incorporated by reference herein, under 35 USC 119.

1. Field of the Invention

The present invention relates generally to cigarettes and is particularly concerned with a more environmentally friendly cigarette filters to reduce the problems of discarded cigarette filters in adding to environmental pollution or litter.

2. Related Art

A typical cigarette includes a filter at one end which has a core or body which filters the smoke generated from burning tobacco and a paper wrapper having one or more wrapper layers surrounding the filter body. The filter core or body is commonly made from synthetic filaments (cellulose acetate) forming a fibrous filter material and added plasticizer (triacetin). After a user smokes the cigarette, the plastic filter (single-use plastic) or cigarette butt is typically discarded. Such filters are often discarded in outdoor areas such as beaches, parks, and the like. The materials making up the filter core and plasticizer, single-use plastic, biodegrade only very slowly over lengthy periods of time (10 to 15 years) and significantly add to the problems of unsightly environmental litter and pollution.
U.S. Pat. No. 10,076,135, which is incorporated herein, discloses a filter substrate that addresses the biggest littered item on planet Earth, caused by cellulose acetate with the plasticizer (triacetin) utilized in the manufacturing of the cigarette filter rods. Due to the biodegradability, water dispersibility and compostability properties, including its filtration capability and sensorial attributes of the filter substrate, it is a viable replacement for the single-use plastic (SUP) cellulose acetate which is almost exclusively utilized by the tobacco industry for filtration globally.
The filter substrate is composed of four main fibers: Abaca, Tencel, Cotton Flock and Hemp. Each of the fibers has a particular role in the substrate, which depends on its fiber size, strength, cellular construction, chemical composition, flexibility, commercial availability and also, cost. Each fiber is also added to the substrate, according to its formulation, in a particular ratio where each of the fibers can perform within its ideal role, giving the filter substrate a competitive advantage and superior filterability, biodegradability, mechanical strength, chemical and sensorial performance when compared to paper substrates and even cellulose acetate.

SUMMARY

To further improve the filter substrate properties including mechanical strength, filtration capability for both vapor and particulate phases, bio-credentials (biodegradability, water dispersibility, compostability, among others), sensorial neutrality and processability, an aspect of the disclosure involves a process (the “fiber cell structure expansion process”) to expand cell structure of one or more of the filter substrate fiber(s) (and/or other fiber(s) comprising soaking the fiber(s) with liquid carbon dioxide (“CO2”) under higher pressure, quick freezing the fiber and CO2 solution by decompression, and heat expanding the quick-frozen fiber(s) in a high temperature, high humidity dryer. An alternative fiber cell structure expansion process that may be used is based on steam application. Both processes further comprise reconditioning the fiber(s) to room temperature and bringing back the fiber(s) to typical moisture for repack, and utilizing the expanded fiber(s) in a downstream process to be mixed with other expanded and non-expanded fibers in a slur blending and mixing process.
Once the individual fibers are expanded through the fiber cell structure expansion process, the filter substrate will then be manufactured with a specific range of fibers, meeting desired filtration performance both in vapor and particulate phases. The final mix and ratio of fibers will be tailored to deliver the desire smoke chemistry, sensorial performance and meet any specific regulation.
The filter substrate has been tested in other industries outside of tobacco with great success (oil filtration, air, HVAC, dust masks, medical equipment, etc.). Accordingly, the fiber cell structure expansion process is not only applicable to the filter substrate fiber(s) in the manufacture of environmentally friendly cigarette filters, but is applicable to a wide range of industrial and personal applications where the use of plastics is the industry standard.
Another aspect of the disclosure involves a method for expanding cigarette filter fiber cell structure, comprises providing a cigarette filter fiber; adding a liquid to the cigarette filter fiber to form a cigarette filter fiber and liquid solution; and expanding total fiber volume and cell cavities in the cigarette filter fiber by performing an expansion process on the filter fiber and liquid solution. The same method of filter fiber cell structure expansion is not limited to cigarette filtration application only. The enhancement of fiber filtration capability, preserving its natural core structural biological form, opens the possibility to solve a multitude of industrial applications facing biodegradability and sustainability challenges.
One or more implementations of the above aspect of the disclosure involves one or more of the following: adding a liquid to the cigarette filter fiber includes soaking the cigarette filter fiber with liquid CO2 under pressure; the expansion process to expand total fiber volume and cell cavities includes quick freezing the cigarette filter fiber and CO2 solution by decompression, and heat expanding the quick-frozen cigarette filter fiber in a dryer; reconditioning the cigarette filter fiber to room temperature and increasing moisture in the cigarette filter fiber for repack; utilizing the expanded cigarette filter fiber in a downstream process to be mixed with at least one of expanded cigarette filter fiber and non-expanded cigarette filter fiber in a slur blending and mixing process; adding a liquid to the cigarette filter fiber includes providing a duct having an inlet, an outlet, and a flow path; introducing a steam flow into the inlet of the duct; introducing moist cigarette filter fiber into the duct downstream from the steam inlet; entraining the cigarette filter fiber in the steam flow; the expansion process to expand total fiber volume and cell cavities includes conveying the steam and entrained cigarette filter fiber along the flow path and toward the outlet of the duct whereby the steam penetrates deeply into the cigarette filter fiber and increases filling capacity of the cigarette filter fiber; collecting the steam and expanded cigarette filter fiber from the outlet of the duct; separating the steam from the expanded cigarette filter fiber by a heat treatment process; reconditioning the cigarette filter fiber to room temperature and increasing moisture in the cigarette filter fiber for repack; utilizing the expanded cigarette filter fiber in a downstream process to be mixed with at least one of expanded cigarette filter fiber and non-expanded cigarette filter fiber in a slur blending and mixing process; the cigarette filter fiber is at least one of Abaca, Tencel, Cotton Flock and Hemp; and/or utilizing the expanded cigarette filter fiber in a downstream process to be mixed with at least one of expanded cigarette filter fiber and non-expanded cigarette filter fiber including at least one of Abaca, Tencel, Cotton Flock and Hemp in a slur blending and mixing process.
Other features and advantages of the present disclosure will become more readily apparent to those of ordinary skill in the art after reviewing the following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The details of the present invention, both as to its structure and operation, may be gleaned in part by study of the accompanying drawings, in which like reference numerals refer to like parts, and in which:

FIG. 1 is a flow chart of an exemplary fiber cell structure expansion process.

FIG. 2 is a flow chart of a more-detailed exemplary fiber cell structure expansion process.

FIG. 3 is a table illustrating test results from a fiber cell structure expansion process performed on hemp fibers and cotton fibers by a process similar to the fiber cell structure expansion process of FIG. 2 .

FIG. 4 is a flow chart of an alternative exemplary fiber cell structure expansion process.

DETAILED DESCRIPTION

With reference to FIG. 1 , certain embodiments as disclosed herein provide for a fiber cell structure expansion process referred to herein as the fiber cell structure expansion process 50, which improve the filter substrate properties including mechanical strength, filtration capability for both vapor and particulate phases, bio-credentials (biodegradability, water dispersibility, compostability, among others), sensorial neutrality and processability. While the fiber cell structure expansion process 50 will generally be described in conjunction with the fiber cell structure expansion of the four main filter substrate fibers of Abaca, Tencel, Cotton Flock and Hemp, the fiber cell structure expansion process 50 is applicable to fiber cell structure expansion of other fibers in a wide range of industrial and personal applications where the use of plastics is the industry standard.
After reading this description it will become apparent to one skilled in the art how to implement the invention in various alternative embodiments and alternative applications. However, although various embodiments of the present invention will be described herein, it is understood that these embodiments are presented by way of example only, and not limitation.
The fiber cell structure expansion process (or method for expanding cigarette filter fiber cell structure to produce fiber(s) of expanded cell structure) 50 generally comprises, a step 60, providing a cigarette filter fiber, at step 70, adding a liquid to the cigarette filter fiber to form a cigarette filter fiber and liquid solution; and, at step 80, expanding total fiber volume and cell cavities in the cigarette filter fiber by performing an expansion process on the filter fiber and liquid solution. The same method of filter fiber cell structure expansion is not limited to cigarette filtration application only. The enhancement of fiber filtration capability, preserving its natural core structural biological form, opens the possibility to solve a multitude of industrial applications facing biodegradability and sustainability challenges.
With reference to FIG. 2 , a more-detailed exemplary fiber cell structure expansion process 100 comprises, at step 110, soaking the fiber(s) with liquid carbon dioxide (“CO2”) under higher pressure. The inner fiber cell impregnation, with the liquid carbon dioxide, is effectively achieved through controlled high pressure and exposure time, allowing every single cell to be fully soaked and saturated. A closed-loop system ensures a maximized recovery of the carbon dioxide in its liquid and gaseous form for later and continuous reuse in a cyclical process. At step 120, the fiber cell structure expansion process 100 includes quick freezing the fiber and CO2 solution by decompression, and, at step 130, heat expanding the quick-frozen fiber(s) in a high temperature, high humidity dryer. The carbon dioxide trapped into the fiber cell structure in its solid state is then quickly heated through a controlled hot air producing the desired fiber cell structure expansion as the carbon monoxide escapes from the micropores of the fiber due to high inner cell pressure. Each fiber will have, and is able to achieve, different ratios of expansion depending on its natural cell construction, fiber length, surface porosity, and controlled process parameters; the combination of these factors will deliver the intended expansion and, consequently, the enhanced enlargement of the cell surface area and filtration capability. The greater the impregnation of the fiber cell structure with liquid carbon dioxide that gets entrapped, and later converted into solid carbon dioxide, the higher will be the expansion rate. Expansion ratios can be achieved from 10% up to 200% of its original size. At step 140, after the expansion, the fiber(s) are then reconditioned to room temperature and brought back to typical moisture for repack. At step 150, after repack, the expanded fiber(s) are utilized in a downstream process to be mixed with other expanded and/or non-expanded fiber(s) in a slur blending and mixing process.
FIG. 3 is a table illustrating test results from a fiber cell structure expansion process performed on hemp fibers of hemp flock and cotton fibers of cotton flock by a process similar to the fiber cell structure expansion process of FIG. 2 . During the test process, separate batches of loose hemp fibers and loose cotton fibers were placed in a transparent pressure vessel, and a weight applied to achieve consistent compression. The height of the compressed fiber volume was measured before expansion. The transparent pressure vessel was then filled with dry ice on top. The vessel was then pressurized while the dry ice melted. The pressure was stabilized at approximately 30 bars in about 5-15 minutes. The fibers were left to soak in the liquid CO2 for about 5-8 minutes and then the pressure was released. The fibers were then immediately placed in an oven that was heated to 140° C. and exposed to the heat for up to 8 minutes. After cooling, the height of the compressed fiber volume was measured after the expansion, and the percentage expansion rate was calculated.
With reference to FIG. 4 , an alternative fiber cell structure expansion process 200 produces fiber(s) of expanded cell structure by entrainment of a moist fiber(s) in a flowing stream of steam. The method does not involve any appreciable impregnation of the moist fiber(s) with volatile expansion agents or compounds, such as CO₂. Rather, the process only requires a mixture of steam and fiber(s) in order to appropriately process that fiber(s). The process 200 involves, at step 210, providing a duct having an inlet and an outlet, the duct having an appropriate shape, and preferably defining an arcuate flow path; at step 220, introducing a steam flow into the inlet of the duct and, and at step 230, introducing moist fiber(s) into the duct downstream from the steam inlet. The moistened fiber(s) most preferably is/are substantially free of impregnated CO2 or other impregnated volatile organic or inorganic compounds. The steam flow entering the duct has a sufficient temperature to cause expansion of the fiber(s), as well as a sufficient flow rate and velocity to convey the fiber(s) through the duct. The process 200 comprises, at step 240, entraining the fiber(s) is/are in the steam flow, and, at step 250, conveying the steam and entrained fiber(s) along the appropriate flow path defined by the overall shape of the duct, and toward the outlet region of the duct. As the fiber(s) travel(s) through the duct, the steam can penetrate deeply into the fiber structure and allowing internal stresses, such as folds and compactions within that fiber(s), to relax. As such, the filling capacity of the fiber(s) is/are increased. The process 200 comprises, at step 260, collecting the steam and expanded fiber(s) from the outlet of the duct, and, at step 270, separating the steam from the expanded fiber(s) by a heat treatment process that will rapidly remove the saturated cell impregnation and therefore maintain the expansion stress caused by the deep steam. As a result, the process steps provide for fiber(s) of increased filling capacity. Expansion ratios can be achieved from 10% to 25% of its original size. At step 280, after the expansion, the fiber(s) are then reconditioned to room temperature and brought back to typical moisture for repack. At step 290, after repack, the expanded fiber(s) are utilized in a downstream process to be mixed with other expanded and/or non-expanded fiber(s) in a slur blending and mixing process.
The steam fiber cell structure expansion process 200 (compared to the CO2 fiber cell structure expansion process 100) is less efficient from expansion value, but is much less complex, is carried out in a less hazard manner and it is very cost effective when compared to CO₂. Nitrogen or any other volatile compounds.
Additional aspects and/or advantages related to the fiber cell structure expansion processes 100, 200, especially with respect to the filter substrate fibers of Abaca, Tencel, Cotton Flock, and/or Hemp, are described below.

Fiber Cell Expansion and Structural Modification

Plant fibers have a cell structure that is naturally complex. As such, it follows a predictable pattern depending on its biological family, age and growing environment (soil and climate).
Knowing and understanding deeply, each of the fibers utilized by the filter substrate, allowed the exploration of how the expansion process would alter and permanently modify its cell structure without compromising its resistance to traction, flexibility and malleability.

Filtration Enhancement

The expanded cells are aimed to create additional surface cavities and deformities which will function as gas and solid (vapor and particulate phase of the aerosol) entrapments and obstacles for air flow, reducing air speed and creating customized turbulence, essential to enhance filtration efficiency and effectiveness.

Sensorial Improvement

The reduction of fiber material mass due to the increase of available fiber cell surface area and fiber tissue enhancement will provide an additional design feature to optimize the filtration characteristic and therefore reduce sensorial off-notes while improving the more neutral fiber flavor and/or taste attributes.

Filter Rod Filling Power—Hardness

The expanded fibers, individually and/or collectively, will enhance the energy that the fibers produce when they are compacted. Its flexibility and malleability produce a “spring effect” inside the filter rod increasing the hardness of the filter segment.

Cost Reduction

The expanded cell structure also allows the reduction of material utilization without compromising air filtration capability and draw effort once the substrate is converted into filter rods. Therefore, it represents an important design feature for cost reduction.

Catalyst of Bio-Properties

Another benefit of the expanded natural fibers is related to the substrate degradability and compostability properties. The optimized utilization of each expanded fiber would allow the reduction of total material mass and the opening of the cell structure of the filter with cavities and deformation would promote enhanced bio activity catalyzing the total biodegradation time.

Customized Filtration Capability

The expansion process could target one fiber only, a subset of fibers, or all of the fibers in different ratios and formulation proportions. The possibility to expand the fiber structure cell separately and in combination with other fibers, expanded or not, enables the latitude and freedom to design substrates that will meet targeted filtration chemicals and tailored aerosol substances according to clients' preferences, applications and/or regulation.
Once the fibers are expanded individually or in groups of fibers, they will be added to the final formulation in different ratios and proportions according to client and product/industry purposes.
The expansion of all the fibers simultaneously would target cost reduction primarily without offering any customized filtration characteristic.

CO2 Impregnation, CO2 circulation and CO2 recovery process

Due to specific fiber cell structure characteristics some or all the process parameters may be separately and specifically assessed and set (temperature, pressure, vacuum, residual time, among others), with each fiber having a specific set of process parameters.

No-Woven, Wet Laid Substrate Process

There are an extensive list of possible substrate recipes, alternatives, and possible combinations of ratios and mixes of expanded and non-expanded fibers to optimize and delivered all the innovative benefits listed above.
Expanded and non-expanded fibers may be raw-materials utilized during the slur blending and mixing process.

The Filter Substrate

The filter substrate described herein may include one or more of the features described in U.S. Pat. No. 10, 076,135, which is incorporated herein, and one or more of the following features.
An improved biodegradable cigarette filter tow and an improved biodegradable cigarette filter material includes the filter substrate.
According to one embodiment, a biodegradable cigarette filter tow is made from a mixture of two or more natural fibers or pulps or man-made fibers derived from natural sources, selected from the group consisting of hemp fiber, flax fiber, wood fiber pulp, abaca fiber or abaca pulp, sisal fiber or sisal pulp, and cotton fiber or cotton flock. In one example, the filter mixture also contains a man-made fiber derived from a natural resource such as wood pulp, for example regenerated cellulose fiber such as Tencel® brand cellulosic fiber, viscose, or Lyocell®. In one embodiment, the cigarette filter mixture contains three natural fibers or pulps.
In one embodiment, the biodegradable cigarette filter tow contains abaca or sisal pulp along with at least one other natural fiber material. According to one aspect, the abaca or sisal is in the form of pulp or short cut fiber. In one embodiment, the biodegradable cigarette filter tow contains wood pulp in place of abaca or sisal fiber or pulp, or in addition to abaca or sisal fiber or pulp. In one aspect, the biodegradable cigarette filter tow is made from a non-woven, fibrous sheet of abaca or sisal pulp or fiber, hemp or abaca filler, cotton flock, and regenerated cellulose fiber, and may also contain a natural binder such as cationic starch.
In one aspect, the biodegradable filter tow comprises:

- 20-60% by weight of abaca or sisal pulp or fiber or wood pulp, or 20-60% by weight of combinations of two or more of wood pulp, abaca pulp or fiber, and sisal pulp or fiber;
- 5-25% by weight of hemp or flax short cut fibers or filler;
- 10-35% by weight of cotton flock;
- 5-40% by weight of regenerated cellulose fiber.

In one embodiment, the mixture also includes a natural binder or a binder manufactured from natural renewable sources. The binder may be derived from biopolymers or bio-based polymers, such as starch, a water soluble biodegradable polymer material such as carboxymethyl cellulose. The binder is water soluble to create a solution, or water dispersible to create binder dispersion/emulsion in water. Binder solution/dispersion/emulsion viscosity is adjusted to comply with the application process. Solid binder content applied on the fibrous web varies in range 2%-30% of dry weight. In another embodiment, no binder is used, and the filter is manufactured using a wet laid and hydroentanglement process.
In one embodiment, the natural binder is selected from the group consisting of natural latex, vegetable gums, biopolymer or bio-based binders, such as starch based binders, cationic starch binder and binders made from renewable sources such as Carboxymethyl cellulose (CMC).
In one embodiment, an intimate blend of two or more natural fibers is used to form a nonwoven sheet for manufacturing of a cigarette filter element. The fiber blend also contains fiber from a regenerated natural polymer, preferably cellulose. A natural binder (adhesive) or binder derived from a natural source is applied to the nonwoven sheet. The binder may be applied such that it coats all of the constituent fiber surfaces, or may be applied in specific locations on the sheet. The optimum fiber morphology, fiber composition, binder content and nonwoven sheet parameters such as areal density, volume density, air permeability and mechanical properties can be altered to obtain different performance of a cigarette filter with respect to smoking parameters, such as pressure drop and retention properties. These depend on the particular product requirements. The binder provides nonwoven material with the strength for converting process. The water soluble binder allows for disintegration in dry state, and promotes quick dispersibility in high moisture (humidity) and wet state.
According to another aspect, a nonwoven sheet for use in manufacture of a biodegradable cigarette filter comprises a mixture of:

- 0-50% by weight of hemp fiber, hemp short cut fiber, or hemp filler;
- 0-50% by weight of flax fiber, flax short cut fiber, or flax filler;
- 0-95% by weight of abaca fiber or abaca pulp;
- 0-95% by weight of sisal fibers or sisal pulp;
- 0-50% by weight of wood pulp;
- 0-50% by weight of cotton fibers or cotton flock;
- 0-50% by weight of regenerated cellulose fibers; and
- 0-30% by weight of a natural binder or a binder manufactured from natural renewable sources.

In one embodiment, a biodegradable cigarette filter tow comprises a natural binder; 30%-40% by weight of regenerated cellulose fiber based on the total weight of fibrous material in the filter tow; and at least three natural fibrous materials, the natural fibrous materials comprising: 5-25% by weight of hemp fiber or filler based on the total weight of fibrous material in the filter tow; 20-50% by weight of abaca pulp or fiber based on the total weight of fibrous material in the filter tow; and 10-30% by weight of cotton flock based on the total weight of fibrous material in the filter tow.
One or more implementations of the embodiment described immediately above includes one or more of the following: the hemp is short cut fiber; the natural binder is cationic starch; the abaca is abaca pulp; the natural binder is selected from the group consisting of natural latex, vegetable gum, starch based binder, cationic starch binder, carboxymethyl cellulose, and other biopolymer and bio based polymers; the filter tow comprises no more than 20% by weight hemp filler based on the total weight of fibrous material in the filter tow; the filter tow comprises 30 to 45% by weight abaca based on the total weight of fibrous material in the filter tow; the filter tow comprises 15 to 30% cotton flock based on the total weight of fibrous material in the filter tow; the hemp has a mean fiber length in the range from 1 mm to 3.5 mm; the hemp has a fiber diameter that is no greater than 50 μm; the cotton flock has a cotton fiber length that is no greater than 1500 μm; the cotton fiber length is in the range of 250-1000 μm; the cotton flock has a cotton fiber thickness that is in the range from 10-50 μm; the regenerated cellulose fibers have a fiber length in the range from 2 to 6 mm; the fibrous materials are formed into a fibrous web having an open bulky structure with a volume density of no greater than 200 kg·m⁻³; the at least three natural fibrous materials are formed into a fibrous web having an areal density in the range from 25 g·m⁻²to 65 g·m⁻².
In one embodiment, a biodegradable cigarette filter material consists of a natural binder; 30-40% by weight of regenerated cellulose fiber based on the total weight of fibrous material in the filter material; and at least three natural fibrous materials, the natural fibrous materials comprising: 5-25% by weight of hemp fiber or filler based on the total weight of fibrous material in the filter material; 20-50% by weight of abaca pulp or fiber based on the total weight of fibrous material in the filter material; and 10-30% by weight of cotton flock based on the total weight of fibrous material in the filter material.
In an implementation of the embodiment described immediately above the biodegradable cigarette filter material includes a non-woven fibrous web.
The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles described herein can be applied to other embodiments without departing from the spirit or scope of the invention. Thus, it is to be understood that the description and drawings presented herein represent a presently preferred embodiment of the invention and are therefore representative of the subject matter which is broadly contemplated by the present invention. It is further understood that the scope of the present invention fully encompasses other embodiments that may become obvious to those skilled in the art.

Claims

We claim:

1. A method for expanding cigarette filter fiber cell structure, comprising:

providing a cigarette filter fiber;

adding a liquid to the cigarette filter fiber to form a cigarette filter fiber and liquid solution;

expanding total fiber volume and cell cavities in the cigarette filter fiber by performing an expansion process on the filter fiber and liquid solution.

2. The method of claim 1, wherein adding a liquid to the cigarette filter fiber includes soaking the cigarette filter fiber with liquid CO2 under pressure.

3. The method of claim 2, wherein the expansion process to expand total fiber volume and cell cavities includes quick freezing the cigarette filter fiber and CO2 solution by decompression, and heat expanding the quick-frozen cigarette filter fiber in a dryer.

4. The method of claim 3, further comprising reconditioning the cigarette filter fiber to room temperature and increasing moisture in the cigarette filter fiber for repack.

5. The method of claim 4, further comprising utilizing the expanded cigarette filter fiber in a downstream process to be mixed with at least one of expanded cigarette filter fiber and non-expanded cigarette filter fiber in a slur blending and mixing process.

6. The method of claim 1, wherein adding a liquid to the cigarette filter fiber includes providing a duct having an inlet, an outlet, and a flow path; introducing a steam flow into the inlet of the duct; introducing moist cigarette filter fiber into the duct downstream from the steam inlet; entraining the cigarette filter fiber in the steam flow.

7. The method of claim 6, wherein the expansion process to expand total fiber volume and cell cavities includes conveying the steam and entrained cigarette filter fiber along the flow path and toward the outlet of the duct whereby the steam penetrates deeply into the cigarette filter fiber and increases filling capacity of the cigarette filter fiber.

8. The method of claim 7, further comprising collecting the steam and expanded cigarette filter fiber from the outlet of the duct; separating the steam from the expanded cigarette filter fiber by a heat treatment process.

9. The method of claim 8, further comprising reconditioning the cigarette filter fiber to room temperature and increasing moisture in the cigarette filter fiber for repack.

10. The method of claim 9, further comprising utilizing the expanded cigarette filter fiber in a downstream process to be mixed with at least one of expanded cigarette filter fiber and non-expanded cigarette filter fiber in a slur blending and mixing process.

11. The method of claim 1, wherein the cigarette filter fiber is at least one of Abaca, Tencel, Cotton Flock and Hemp.

12. The method of claim 11, further comprising utilizing the expanded cigarette filter fiber in a downstream process to be mixed with at least one of expanded cigarette filter fiber and non-expanded cigarette filter fiber including at least one of Abaca, Tencel, Cotton Flock and Hemp in a slur blending and mixing process.