JPH078253A - A method for recycling cellulose esters from cigarette manufacturing waste. - Google Patents

Abstract

(57) [Summary] [Structure] A method of recycling waste generated when a cigarette with a filter is manufactured is disclosed. The method comprises the following steps: providing a waste stream that occurs during the manufacture of filtered cigarettes. The waste stream includes tobacco, filter mouthpieces containing cellulose ester polymers, and paper. A substantial portion of the filter mouthpiece is separated from this waste stream. The filter mouthpiece is washed with a sufficient amount of water to release the bound mouthpiece paper and remove foreign material from the cellulose ester polymer. The cellulose ester polymer can then be dried, degraded and processed into commercially useful products.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to the recycling of waste products, especially cellulose esters produced during the manufacture of filtered cigarettes.

[0002]

BACKGROUND OF THE INVENTION Fibrous cellulose esters, especially cellulose acetate, are commercially preferred media for filtering smoke from filtered cigarettes. This commercial application consumes 100 million pounds of cellulose acetate worldwide per year. In the manufacture of these filtered cigarettes, a percentage of filtered cigarettes are not marketed for damage, out of specification, or other reasons. Those cigarettes that are not sold are generally exposed to regenerating methods. By this method, the tobacco portion of the cigarette is mechanically separated from the filter and the tobacco is removed by shaking in a sorter. An example of this method is shown in US Pat. No. 3,224,451, which is incorporated herein by reference.
No. After reconstitution of tobacco, it is known in the art as "ripper waste (composite plasticized with, for example, glycerol triacetate), paper, residual tobacco, and often also flavors and fragrances. There are tens of millions of pounds of residual material left behind, called "ripper waste"; this ripper waste is most commonly disposed of as landfill. It is a loss of natural resources and landfill issues.

The composition of ripper waste varies according to the cigarette product specification and the tobacco recycling method used.
The general composition of ripper waste is by weight: a) cellulose acetate 40-55%; b) plasticizer 1-
12%; c) paper 25-45%; d) residual tobacco 1
-15%; e) additives 2-3%; and f) flavors and fragrances <1%. Depending on the particular cigarette product, additional ingredients such as charcoal may be found in the waste stream.

In the past, the physical / mechanical separation used in regenerating cigarette components has been used to extract tobacco from other components, such as in US Pat. No. 3,224,451, or herein. U.S. Pat. No. 4,261,790, which is incorporated herein by reference, has been used to remove cellulose acetate filter media from paper liners. Another approach is to enzymatically degrade cellulose acetate to produce useful sugars, as described in US Pat. No. 4,298,013.

Isolation of cellulose acetate from ripper waste is insufficient to provide recycled products with a high degree of commercial utility. During the manufacture of cigarettes, cellulose acetate is treated with a plasticizer that improves the mechanical performance of the finished filter. Cellulose acetate is also a flavorant such as menthol.
Sometimes treated with t), cellulose acetate absorbs some levels of nicotine and other substances generated from tobacco. When a cellulose acetate / plasticizer / flavoring mixture is dissolved in a common cellulose acetate solvent and further processed into a product, these extraneous substances are both the mechanical and sensory properties of cellulose acetate. , So that the overall quality of products made with these recycled materials is reduced. Extraction with a conventional solvent, such as ethanol, can be used to remove most of the unwanted foreign material from the cellulose acetate, but this time the extraction solvent becomes an unwanted foreign material that reduces product quality. Let A further problem is raised with the use of such extraction solvents, which may require costly preventive measures, as their foreign substances may be discharged into the environment.

The problems associated with conventional organic extraction are described in US patent application Ser. No. 07 / 967,088, filed Oct. 27, 1992, which is hereby incorporated by reference: It can be avoided by using supercritical or near supercritical fluid extraction. In such supercritical or near supercritical fluid extraction methods, materials that are gases under normal atmospheric temperature and atmospheric pressure, such as carbon dioxide,
Convert to high pressure solvent. This high-pressure solvent can effectively dissolve the foreign substances present in the filter tip waste, and release these organic foreign substances when the pressure and temperature of the fluid are reduced. The extraction fluid used in this supercritical or near supercritical process can be effectively recycled in the process, leaving no residue in the recycled cellulose ester polymer product. This high pressure method can effectively clean the filter tip waste of unwanted organic contaminants and also under the relatively high pressures required to enter the supercritical or near supercritical region of the most desirable fluids. Does not require a significant capital investment to build equipment vessels that can be safely operated.

In US Pat. No. 4,191,199, water is used to soften the bond seams throughout the cigarette. Free tobacco can be mechanically removed by conventional means by opening the tobacco column, ie, the portion of the cigarette that actually contains tobacco.

The water washing steps used in making virgin cellulose ester polymers are known to those skilled in the art. The washing removes production residues from the cellulose ester polymer, such as long chain fatty acids and acetic acid. Water washing of such virgin cellulose ester polymers is described in US Pat. Nos. 2,264,828, 2,860,132, and “Cellulose Acetate”.
Kirk-Othmer Encyclopedia of Chemical Technology, 3
rd Edition, John Wiley and Sons, New York.

The water treatment used in the recycling of cigarette waste is also used in the reconstitution of small tobacco particles, ie tobacco fines, into tobacco sheets or paper by conventional shaking / sorting methods. To be An example of such a reconstruction method is US Pat. No. 3,012,914.
No.

The technical literature is replete with references to wet pulping of cellulose. The chemistry for cellulose acetate and cellulose, their references familiar with binding and dissolution properties, acknowledges that the two polymers have very few common properties and must be treated as different materials. There is. "Cellulose" and "cellulose acetate" Kirk
-Othmer Encyclopediaof Chemical Technology, 3rd Ed
See ition, John Wiley and Sons, New York.

[0011]

SUMMARY OF THE INVENTION Disclosed herein is a method for recycling waste generated during the manufacture of filtered cigarettes. The method provides the following steps: the waste stream that occurs when manufacturing cigarettes with filters. The waste stream includes tobacco, filter mouthpieces containing cellulose ester polymers, and paper. A substantial portion of the filter mouthpiece is separated from this waste stream. The filter mouthpiece is washed with a sufficient amount of water to free the bound tipping paper and remove foreign material from the cellulose ester polymer. Next, the cellulose ester polymer is dried,
It can be broken down and processed into commercially useful products.

The present invention is described in detail below with respect to a method for recycling waste resulting from the manufacture of filtered cigarettes.

The waste stream resulting from the manufacture of filtered cigarettes generally contains tobacco, paper, and cellulose ester filter materials. This waste stream may be ripper waste or a completely destroyed filtered cigarette, as discussed above (the difference between the latter and the former is that the latter has a higher tobacco content). It is a point that is considered to be). Cellulose ester filter materials are commonly used in the industry as “TO”.
W) ”, a fiber morphology of cellulose acetate and various foreign materials, as discussed below.

The cellulose ester filter material or cellulose ester polymer generally contains cellulose acetate (acetyl number about 38-41%),
It may also include other conventionally known or commercially available cellulose esters. Cellulose acetate filters are generally contaminated with plasticizers, adhesives, and flavor / fragrances during the manufacture of filter mouthpieces and the manufacture of cigarettes with filters. Non-limiting examples of plasticizers include triacetin (also known as glycerol triacetate or PZ), trimethylene glycol diacetate (TE
(Also known as GDA), and mixtures thereof. Examples of adhesives used to make cigarettes include, but are not limited to, polyvinyl acetate (PVA), ethylene vinyl acetate (EVA), cellulose acetate, and mixtures thereof. Flavors / fragrances can be absorbed from the tobacco by the filter material (eg nicotine) or added (eg menthol).

Preferably, the cellulose ester polymer is removed from the waste stream prior to removing foreign material from the cellulose ester polymer. The weight content of tobacco in the cellulose ester polymer should be less than about 1% by weight after separation.

The cellulose ester polymer can be separated from the waste stream using any conventional means.
Examples of such methods include: manually separating tobacco and paper from cellulose ester polymers; screening or sieving paper and tobacco from cellulose ester polymers; and cyclone or water from paper and tobacco from cellulose ester polymers. A method of separating with elutriation can be mentioned. Elutriation by air is a preferred method of separating cellulose ester polymers from waste streams.

[0017] Optionally, the waste stream can be exposed to any conventional particle size reduction method, either before or after the separation described above. As known to those skilled in the art, these particle size reduction methods facilitate separation. The method is not limited to,
There are crushing, chopping, pulverizing, and pelletizing.

After separating the loose paper and tobacco material from the cellulose ester filter mouthpiece,
Two additional separation steps are required for the final production of the contaminant-free or substantially contaminant-free recycled cellulose acetate. Cellulose ester filter material is typically packaged in a container or paper plug.
Wrapped in a paper plug wrap (or mouthpiece paper), the cellulose ester filter material generally
Adhere to itself or to the filter. This binder paper needs to be removed to ensure both the purity and filterability of the recycled cellulose ester solution.
Cellulose ester filter materials are also commonly contaminated with the tobacco flavors / fragrances, adhesives, and plasticizers described above.

Removal of tipping paper and foreign material contained in the cellulose ester filter material is accomplished by the present invention. The combined use of water and heat can almost completely remove the tipping paper from the cellulose ester. Under the appropriate conditions, the same washing method allows complete removal of plasticizers, adhesives, and flavors / fragrances within the detection limits of analytical instruments commonly used for chemical analysis.

The water used in the washing method is about 10 -1.
The temperature can be 00 ° C. The pH of water is 4.0
It can be 8.0. The ratio of water to cellulose ester can be 0.85: 1-200: 1. Low levels (less than about 1% by weight) of surfactant can be added to improve the efficiency of the cleaning method.
Alternatively, in the cleaning method of the present invention,
Steam below 00 psig can be used instead of or in addition to water. For example to improve the color of the mouthpiece and / or to serve as a pretreatment to promote the breaking of hydrogen bonds in the paper to further facilitate the removal of the paper during the hot water washing process step, such as peroxides. An oxidizing agent or a bleaching agent can be added.

The cleaning method can be accomplished using any suitable device or vessel. As such a device,
Without limitation, a static bas
ket), rotating basket, and screw or auger driven continuous w
asher). The cleaning devices described above are commercially available and known to those skilled in the art.

The conditions used during the cleaning process can be constant throughout the process or can be varied by steps or cycles. By using steps or cycles to change the conditions, cleaning efficiency can be optimized and energy and water consumption can be minimized.

In a preferred embodiment, the cellulose ester polymer is washed with liquid water maintained at 15-55 ° C in a multi-step process.

Once washed and freed of foreign material, it can be dried using any commercially available dryer suitable for the polymer. Such devices, and how they work, are known to those skilled in the art.

The water washing process of the present invention produces sufficiently good cellulose ester polymers that can be resolvated, filtered, and used as or with virgin polymers. .
However, it is believed that this recycled polymer can be exposed to further separation if necessary, ie if residual tobacco or paper remains.

Hereinafter, other details and aspects of the present invention will be described more completely with reference to Examples.

Example 1 This example illustrates the separation of waste streams, or ripper waste, from cigarette manufacturing operations. The waste stream mainly contained tobacco, paper, and filter mouthpieces (fiber cellulose acetate). This waste 29
All five pounds were separated into its three major components.
The final weight of each component stream is as follows: Tobacco-6
6.5 lbs; paper 65 lbs; filter mouthpiece 1
63.5 lbs.

Separation was achieved by elutriation. Eltriator Sterling Model 1608E, commercially available from Sterling Blower Company in Lynchburg, Virginia.
L was used. The Eltriator was operated at a flow rate of 5000 feet / minute of air.

295 lbs of waste was introduced into the elutriator for the first flow path of separation. At the end of this channel, a mixture of 48 pounds of tobacco and 48 pounds of paper was removed from the residual mass. The mixture of tobacco and paper, as is known, using a conventional vibrating screen device,
Separated into each component.

The residual mass was reintroduced into the Eltriator for the second channel. At the end of this channel, a mixture of 5 pounds of tobacco and 10 pounds of paper was removed from the residual mass and further broken down into its constituents by the vibrating screen method described above.

The residual mass from the second channel was reintroduced into the elutriator for the third channel. At the end of this channel,
A mixture of 0.5 pounds of tobacco and 7 pounds of paper was removed from the residual mass and separated into the components as described above. The residual mass, weighing 163.5 lbs, is mainly
It consisted of a filter mouthpiece, but contained trace amounts of tobacco and paper, as clearly identifiable by visual inspection.

Example 2 The waste with tobacco and paper, taken in the manner described in Example 1, for example, consisted essentially of a filter mouthpiece from a cigarette. The tipping paper surrounding the cellulose acetate filter media and the foreign material contained in the cellulose acetate were removed by a water wash method.

Prior to the water wash, the filter tip waste was analyzed to quantify the level of contamination. The amount of plasticizer (glycerol triacetate) was measured using conventional gas chromatography methods. The amount was 7.59% by weight. Samples having a strong tobacco aroma and taste were observed using industrially acceptable methods.

A water wash of the cellulose acetate filter mouthpiece was performed by flushing the water into a basket made of 316 stainless steel plates containing 0.125 inch circular perforations. A 50-100 g sample of the filter mouthpiece waste was weighed and placed on the basket. Water heated to 65 ° C
A volume of 10 liters was run on the filter for 10-20 minutes. After washing with water, cellulose acetate (dissolved in acetone and measured by gravimetric method,
> 99% paper free) was oven dried for 24 hours. After washing with water and drying, the samples were analyzed. Neither traces of plasticizer (detection limit of the analytical instrument was 0.0001%) nor traces of aroma and taste that were present in the feedstock were observed.

Example 3 The water wash / dry procedure described in Example 2 was repeated, except that the wash water was heated to 95 ° C. before flowing into the wash basket. After washing with water and drying, the samples were analyzed. Traces of plasticizer that were present in the feedstock,
No trace of aroma or taste was observed.

Example 4 The water wash / dry procedure described in Example 2 was repeated except that a steam autoclave was used in place of the wash basket. The filter waste mouthpiece (50 g) was flushed with 12 pounds of steam for 10 minutes. After washing with water and drying,
The sample was analyzed. No traces of plasticizer or aroma and taste that were present in the feedstock were noted.

Example 5 In this example, a commercially available commercial washer (American Laundry Machinery, Cincinnati, Ohio) is used.
Explain the use of Co.'s "American Cascade" model). A sample of filter tip waste (5-10 pounds) was placed in a 0.187 inch mesh nylon mesh laundry bag and then washed with water in a washer. The range of conditions for washing with water is shown in Table 1.

After washing with water and oven drying, the samples of Washes 2-7 in Table 1 were analyzed. No traces of plasticizer or aroma and taste that were present in the feedstock were noted. The sample obtained from wash 1 was relatively dark in color and had a slight tobacco odor.

Example 6 Cellulose acetate regenerated by the water washing method described in Example 5 (using wash conditions defined in Wash 4-7 of Table 1) was used in combination with virgin cellulose acetate, Dissolved in acetone, unused cellulose acetate: regenerated cellulose acetate 80% / 20%
A 26.8% solution containing was prepared. This solution is designated as 1
It was filtered through a 2 micron filter and spun into a 2.0-3.5 denier filament fiber in a dry spinner. A cigarette filter was finished from the obtained filament. Cigarettes were manufactured by assembling 80/20 virgin / regenerated filter samples and 100% virgin cellulose acetate filter samples using a commercially available tobacco column. These cigarettes were tested for taste at Tragon Associates, Redwood City, CA, an independent laboratory that tests tastes on a routine basis. 1 in taste panel testing
No statistically significant difference was observed between cigarettes made with a 00% virgin cellulose acetate filter and cigarettes made with 80/20% virgin / regenerated cellulose acetate. .

Example 7 When a pretreatment step with a peroxide solution was added to the method described in Example 2, removal of the paper was promoted and the mouthpiece became whiter. The improvement is 7 to 20-40 minutes.
Marion model # 1001 at 5-150 rpm
Horizontal Mixer (Marion Mixe, Marion, IA)
(commercially available from R. Inc.), a 11.0-17.5% hydrogen peroxide solution mixed with water while blending in a filter at 0.35 pounds of solution per pound of mouthpiece. Achieved by spraying on the mouthpiece. Also, water alone can achieve the same effect with paper removal (however, 2.66 pounds of water is required for every 1.0 pound of processed mouthpiece).
However, they also found that the mouthpiece pretreated with a peroxide solution had a visually whiter appearance compared to when it was water alone.

The present invention may be embodied in other specific forms without departing from its spirit or essential attributes of the invention. Therefore, reference should be made to the appended claims, rather than the above specification, as indicating the scope of the invention.

[0042]

[Table 1]

[Table 2]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Howard T. Bradshire, North Carolina 28273, USA 28273, Charlotte, Julep Lane 2726 (72) Inventor David O. Cootsshire 28270, Charlotte, North Carolina, United States Sardis Oaks Road 10539

Claims (13)

[Claims] 1. A process for providing a waste stream that occurs when manufacturing a cigarette with a filter, the waste stream comprising tobacco, a filter mouthpiece comprising a cellulose ester polymer, and paper; from the waste stream to the filter mouthpiece. A filter comprising a step of separating a substantial portion; and a step of washing the filter mouthpiece with a sufficient amount of water to take out the paper attached to the filter mouthpiece and remove foreign substances from the cellulose ester polymer. A method for recirculating waste resulting from the manufacture of cigarettes. 2. The method according to claim 1, wherein the separation is performed by elutriation. 3. The method according to claim 1, wherein the tobacco content in the filter mouthpiece is reduced to at least 1% by weight during the separation. 4. The method of claim 1, further comprising the step of reducing the particle size of the waste stream. 5. The ratio of water to cellulose ester polymer is about 0.85: 1 to 200: 1.
The method described. 6. The method of claim 1, wherein the water is at about 10-100 ° C. 7. The method of claim 1, wherein the water has a pH of about 4.0-8.0. 8. The method of claim 1, further comprising the step of adding at least less than 1.0% by weight of a surfactant during washing. 9. The method of claim 1, wherein the water is steam having a working pressure of less than or equal to about 100 psig. 10. The method of claim 1 wherein a portion of said water is about 10-100 ° C. and a portion of said water is steam having a working pressure of about 100 psig or less. 11. The method of claim 1, wherein the water comprises an oxidant. 12. The method of claim 1 further comprising the step of pre-treating the filter mouthpiece after separating from the waste stream with an oxidant. 13. A process for providing a waste stream comprising a filter mouthpiece and paper, the filter mouthpiece comprising a cellulose ester polymer; and washing the filter mouthpiece with a sufficient amount of water to provide a filter mouthpiece. A method for recirculating a filter mouthpiece from a cigarette with a filter, including the steps of removing the bound paper and removing foreign material from the cellulose ester polymer.