Method for making a web of reconstituted material of plant origin.

Abstract

A method for making a web (N) of reconstituted material of plant origin, comprising a step of feeding a first quantity of at least one liquid into a mixing space (V) of a mixer (100) and a step of feeding a second quantity of at least one dry product into the mixing space (V) of the mixer (100). 5 The at least one dry product comprises cellulose at least partly in the form of powder, in particular ground or powdered cellulose. The cellulose has a powder content between 50% and 100%, preferably between 80% and 100%.

Description

[0001] DESCRIPTION METHOD FOR MAKING A WEB OF RECONSTITUTED MATERIAL OF PLANT ORIGIN

[0002] Technical field

[0003] The present invention relates to the field of smoking articles and is directed to a method for making a continuous web of reconstituted material of plant origin.

[0004] Background art

[0005] Making a reconstituted web from a plant-based mixture, in particular based on cellulose in the form of fibres intended to make smoking articles is known. The web making method is characterised by preparing a mixture obtained by mixing the cellulose fibres with at least one liquid component and with any other dry components. The liquid component can include water, glycerine, and other chemicals which contribute to the desired features of the cellulose web. After preparing the mixture upon mixing the components, the method proceeds with the mixture pulping step. This process involves the amalgamation of the mixture and is necessary to further soften and fragment the cellulose fibres. During the pulping, the mixture can be treated with further liquids to obtain a workable consistency. The method then includes forming the web, and pressing, drying and cutting the web.

[0006] As is known, the use of cellulose in the form of fibres in the mixture offers several advantages. In particular, cellulose fibres can give the mixture an optimal structure and consistency. In fact, by adding the fibres, a cohesive and uniform mixture can be obtained, which facilitates the process of forming the plant-fibre webs. In other words, cellulose in the form of fibres ensures a mixture with a high tensile strength and a high elasticity.

[0007] Although this technology is well operable, the Applicant has noted that the use of cellulose fibres as a base for the mixture necessarily requires the pulping step, which is essential for softening and fragmenting the cellulose fibres. In fact, without the pulping step, the cellulose fibres would be too rigid to be processed so as to ensure a workable mixture and a final product of satisfactory quality.

[0008] However, the Applicant has noted that the pulping step causes a series of disadvantages which make the process for making the web improvable.

[0009] In particular, the pulping step adds complexity to the overall production process and increases the production costs thereof. It requires specific equipment and procedures to treat the solid mixture with the appropriate liquids, which can require additional time and resources as well as an increase in the overall raw material and production costs.

[0010] Moreover, the pulping step can affect the overall production efficiency. If the process requires longer treatment times or involves interruptions or slowdowns in the production chain, it could be necessary to devote more resources and time to making the cellulose webs.

[0011] Finally, the pulping step can in any case affect the organoleptic properties of the final product. The use of additional liquids and specific treatments could alter the taste, aroma or mouthfeel of the finished product, depending on the chemicals used and the methods employed.

[0012] Object of the invention

[0013] Therefore, in such a context, it is the technical task of the present invention to provide a method for making a continuous web of cellulose- based material which is free from the drawbacks of the prior art.

[0014] Therefore, it is the object of the present invention to provide a method for making a web of reconstituted material of plant origin which does not require the pulping step while being capable of ensuring a qualitatively satisfactory finished product.

[0015] In the context of the same technical task, it is a further object of the invention to provide a method for making a web of reconstituted material of plant origin which requires a compact and structurally simplified system. The above objects are substantially achieved by a method according to the features set forth in claim 1 and / or in one or more of the claims dependent thereon.

[0016] In particular, the Applicant has found that by using a certain quantity of powdered cellulose, a mixture with similar properties to mixtures obtained from cellulose pulping is obtained.

[0017] In an aspect of the invention, the cellulose fed for preparing the mixture has a powder content between 80% and 100%, preferably equal to about 100%.

[0018] Brief description of the drawings

[0019] Further features and advantages of the present invention will become more apparent from the indicative, and thus non-limiting, description of a preferred but not exclusive embodiment of a method for making a web of reconstituted material of plant origin, as shown in the accompanying figure 1 , which depicts a diagrammatic view of a preferred, exemplary and thus non-limiting embodiment of a system for implementing a method for making a continuous web of reconstituted material of plant origin in accordance with the invention.

[0020] Detailed description of preferred embodiments of the invention

[0021] As will be apparent from the continuation of the present description, the term "of plant origin" means a reconstituted material obtained by mixing at least one dry component containing cellulose with at least one liquid component.

[0022] Moreover, the percentages of the solid components indicated in the following description are to be referred to in terms of weight, preferably in terms of anhydrous weight.

[0023] The method is described below in an embodiment thereof with reference to a system used to implement it, indicated by reference numeral "1" in the accompanying figure. In accordance with the present invention, the method includes feeding a first quantity of at least one liquid into a mixing space "V" of a mixer 100 and feeding a second quantity of at least one dry product into the mixing space "V" of the mixer 100.

[0024] The mixer 100 can be of any type, as long as it is capable of carrying out the mixing of the solid and liquid components. Preferably, the mixer 100 has a batch operation and can be of the tilting type, for example.

[0025] As for the feeding of the first quantity, the term "at least one liquid" means, for example, the introduction of at least one material for generating aerosols and / or a binder and / or an additive in liquid or semi-liquid form (for example one or more of the following elements: glycerine, propylene glycol, nicotine, lactic acid, CMC).

[0026] In accordance with an aspect, the first quantity is fed so as to be a percentage of humidity on the final weight of the mixture between 15% and 60%, for example.

[0027] In an embodiment in which lactic acid is fed, this can preferably be a percentage of the final weight of the mixture between 0.01% and 0.5%, even more preferably equal to 0.1%.

[0028] In an embodiment in which propylene glycol is fed, this can preferably be a percentage of the final weight of the mixture between 0.5% and 15%.

[0029] According to an embodiment, the first quantity of at least one liquid does not comprise water.

[0030] Preferably, the first quantity of at least one liquid comprises glycerine. In the preferred embodiment, glycerine is fed in a quantity such as to be a percentage of the final weight of the mixture greater than 18%, preferably greater than 30%, even more preferably between 30% and 40%.

[0031] Preferably, the first quantity of at least one liquid further comprises at least one additional component in addition to those already mentioned, in particular nicotine and / or dyes. Preferably, any further additional components in liquid phase are fed in a total quantity not exceeding 15% of the final weight of the mixture. In order to feed the first quantity of at least one liquid, the system 1 comprises a feeding line 110 for the at least one liquid, connected to the mixer 100.

[0032] In accordance with the disclosed embodiment, the feeding line 110 comprises a plurality of feeding branches 111 , 112, each dedicated to one or more particular liquid components, and an intermediate tank 113, operatively arranged upstream of the mixer 100 and connected to the mixer 100 by means of a delivery branch 114. The liquid components are pre-loaded and pre-dosed into the intermediate tank 113. Preferably, the intermediate tank 113 is provided with mixing means configured to mix the liquid components. With reference to lactic acid, for example, it can be fed into the intermediate tank 113 in 100% pure form, for example, by means of a respective feeding line or in the form of a mix with a lactic acid content between 30% and 80%. Preferably, the mix contains glycerine and / or nicotine and / or lactic acid and / or propylene glycol and / or CMC. In accordance with an embodiment (not shown), the feeding line 110 comprises a plurality of feeding branches 111 , 112, each dedicated to one or more particular liquid components directly feeding the mixer 100. With reference to lactic acid, also in this case it can be fed into the mixer 100 in 100% pure form, for example, or preferably in the form of a mix with a lactic acid content between 30% and 80%. Preferably, the mix contains glycerine and / or nicotine and / or lactic acid and / or propylene glycol and / or CMC. With reference to the other additional components, they can be fed into the mixer 100 in 100% pure form, for example, by means of a respective feeding line or in the form of a mix.

[0033] In accordance with a preferred embodiment of the method according to the invention, the step of feeding the first quantity is carried out by feeding the liquid components in two or more separate and distinct sub-steps into the intermediate tank 113 while the intermediate tank 113 continuously implements the aforementioned mixing. Preferably, in accordance with an aspect of the invention, the feeding of the first quantity of the at least one liquid is carried out at least partially, preferably entirely, before feeding the second quantity of the at least one dry product, as will become more apparent in the continuation of the present description.

[0034] According to an embodiment of the invention, the first quantity of the at least one liquid does not comprise water and, upon mixing the first quantity of the at least one liquid and the second quantity of the at least one dry product, water can be fed. As for the feeding of the second quantity, the term "at least one dry product" means mainly cellulose. In the context of the present invention, the cellulose is fed at least partly in the form of powder.

[0035] In accordance with an aspect of the present invention, the cellulose has a powder content between 50% and 100%, preferably between 80% and 100%, even more preferably equal to about 100%. In the preferred embodiment, the powder particles of the powdered cellulose have an average length of not more than 200 pm, preferably between 40 pm and 200 pm. The average width of the powder particles is not more than 5 pm, for example.

[0036] Possibly, the second quantity can comprise at least one additional dry product, for example in fibre form, ground and / or powdered, preferably in small quantities. In particular, the additional dry product can comprise tobacco, cocoa, hemp, aromatic leaves, or others.

[0037] In the preferred embodiment, the cellulose (first dry product) is fed in quantities such as to be a percentage of the final weight of the mixture between 25% and 80%, preferably between 40% and 65%, and more preferably equal to about 55%.

[0038] Preferably, the mixture is made by of batch type feeding, i.e., feeding a predetermined quantity of each component. In order to feed the second quantity of at least one dry product, the system 1 comprises a feeding line 120 for the at least one dry product, connected to the mixer 100.

[0039] If one or more additional dry products are included, the feeding line 120 can comprise a plurality of feeding branches 121 , 122, each dedicated to a particular dry product. The feeding line 120 can further optionally comprise an intermediate tank 123, operatively arranged upstream of the mixer 100 and connected to the mixer 100 by means of a delivery branch 124, where the powdered cellulose and the additional products are pre-loaded and pre-dosed. In the intermediate tank 113, the different materials can take a stratified configuration, if fed in sequence, or premixed, if fed simultaneously.

[0040] The method then includes a step of mixing the second quantity of dry product with the first quantity of liquid in the mixer 100, obtaining a mixture. As previously described, the mixture obtained preferably has a humidity between 15% and 60% and a cellulose content between 25 and 80%, preferably between 40% and 65%, and more preferably equal to about 55%. In particular, it has been found that the mixture produced by mixing has a sandy and / or grainy texture, specifically with a particle size between 1 and 6 mm. More specifically, the mixture has a density between 500 Kg / m3and 1200 Kg / m3, even more specifically between 600 Kg / m3and 950 Kg / m3.

[0041] Moreover, it has been found that the mixture made employing the aforesaid components, in particular the presence of powdered cellulose (in the quantity indicated above), has optimal physical and chemical properties comparable to the properties of mixtures made from cellulose fibre, as described for the known methods. In particular, the mixture in accordance with the present invention has excellent elasticity and tensile strength, so as to ensure an excellent workability of the mixture. Furthermore, such properties of the mixture are achieved without the need to implement a pulping step on the mixture itself.

[0042] In accordance with a preferred embodiment of the method according to the invention, the feeding of the first quantity occurs entirely before the start of the mixing step. The steps of feeding the second quantity of at least one dry product and mixing the second quantity of dry product with the first quantity of liquid are also carried out by feeding the dry product in two separate sub-steps, including an intermediate mixing: according to an example, the dry product is fed in a first sub-step in a percentage between 20% and 40% of the total quantity thereof, more preferably equal to about 30%, and the remaining part of the dry product is fed in the second substep.

[0043] In other words, once the first portion of the second quantity of dry product is fed into the mixer 100, it is mixed by the mixer 100 together with the first quantity of the at least one liquid for a first preset period of time, obtaining a first diluted mixture. The second portion of the second quantity of dry product is then also added into the mixer 100 and is mixed with the diluted mixture so as to obtain the aforesaid mixture.

[0044] In accordance with a constructional variant of the method according to the invention, the feeding of the first quantity occurs entirely before the start of the mixing step and the second quantity of at least one dry product is carried out by entirely feeding the dry product in a single step.

[0045] In accordance with an alternative embodiment of the method, the steps of feeding the first quantity of at least one liquid and the second quantity of at least one dry product and the step of mixing the second quantity of dry product with the first quantity of liquid are carried out by feeding the liquid and the dry product in two separate sub-steps, including an intermediate mixing.

[0046] In other words, both the at least one liquid and the at least one dry product are fed in two or more distinct sub-steps, including one or more intermediate mixings so as to optimally mix the compound.

[0047] In accordance with a further alternative embodiment of the method, the feeding of the second quantity of the at least one dry product occurs before the start of the mixing. The steps of feeding the first quantity of at least one liquid and mixing the second quantity of dry product with the first quantity of liquid are also carried out by feeding the liquid in two separate sub-steps, including an intermediate mixing.

[0048] Regardless of how the feeding and mixing steps are carried out, once the kneading step is finished, the method includes forming a continuous web "N" from the mixture itself, by means of lamination.

[0049] In particular, in accordance with an aspect of the present invention, the formation of the continuous web "N" includes performing a first step of laminating the mixture by means of a first pair of rollers 200, obtaining a laminated semi-finished product and then performing a second step of laminating the laminated semi-finished product by means of a second pair of rollers 300 obtaining a continuous web "N".

[0050] Preferably, the mixture produced by the mixing is sent directly to the first pair of rollers 200, preferably by gravity (or tilting), to carry out the first lamination. In other words, preferably, there are no intermediate operations (capable of modifying or somehow affecting the mixture) between the mixing and the first lamination carried out by the first pair of rollers 200. According to an example, a conveying step can be included between the mixing and the first lamination, for example by means of a conveyor belt.

[0051] In accordance with an aspect of the present invention, at least one of the first step of laminating and the second step of laminating is a step of vertical laminating, i.e., a lamination in which the two rollers form an upwardly facing receiving recess and the mixture is fed into the recess from above with respect to the laminating rollers themselves. Preferably, both the first step of laminating and the second step of laminating are of the vertical type. To this end, the system 1 comprises a first pair of rollers 200 configured to carry out a vertical lamination and a second pair of rollers 300, arranged below the first rollers 200, configured to carry out a vertical lamination.

[0052] In accordance with an aspect of the invention, the method includes a step of scraping the semi-finished product off the first pair of rollers 200 and feeding, in particular by gravity feed or by a conveyor, the scraped semifinished product to the second pair of rollers 300. To this end, the system 1 can comprise one or more scraping tools, such as blades, operatively connected to the first pair of rollers 200 and configured to carry out the aforesaid scraping.

[0053] In fact, it has been noted that, in the case of cellulose-based mixtures and in particular with particular percentages of humidity and cellulose fraction, the laminated semi-finished product exiting from the first pair of rollers 200 has a discontinuous shape, in particular is flake-shaped.

[0054] In the present description, the term "flake shape" means a semi-finished product broken into a plurality of irregularly shaped fragments and having a plate-like shape (i.e., extending substantially on a plane) and adhering to the surface of the roller.

[0055] Therefore, the second pair of rollers 300 has the function of collecting such flakes and re-laminating them, obtaining a continuous web or flakes of larger size than the previous ones.

[0056] The two pairs of rollers 200, 300 thus preferably have the function of converting the grainy mixture into a web or a part of a web.

[0057] In accordance with an aspect of the present invention, the method can further comprise, downstream of the second lamination, a multi-stage laminating step, preferably horizontal, to reduce the thickness of the continuous web "N" in a controlled manner until reaching a calibrated thickness value. To this end, the system 1 can comprise a plurality of pairs of horizontal laminating rollers 400 arranged in series along a laminating path, which pairs of horizontal rollers 400 delimit an increasingly narrow passage therebetween in order to gradually reduce the thickness of the web "N" produced.

[0058] Preferably, following such a multi-stage laminating step, the web comprises a substantially constant thickness between 180 pm and 3000 pm, even more preferably between 210 pm and 270 pm.

[0059] Once the web "N" is made, the method further comprises a step of drying to obtain a dry continuous web "N". To this end, the system can comprise a drying device 500.

[0060] Preferably, the dry web "N" has a density between 0.5 g / cm3and 1.2 g / cm3, preferably between 0.6 g / cm31 .1 g / cm3.

[0061] The present invention achieves the preset objects, suppressing the drawbacks of the prior art.

[0062] The method of the present invention allows making a continuous web "N" of cellulose plant-based material of satisfactory quality. In particular, the Applicant has found that the mixture made employing powdered cellulose (in the quantity indicated above) has optimal physical and chemical properties comparable to the properties of mixtures made from cellulose fibre, as described for the known methods. In particular, the mixture in accordance with the present invention has excellent elasticity and tensile strength, so as to ensure an excellent workability of the mixture.

[0063] Moreover, advantageously, such a type of mixture does not require the aforesaid pulping step to soften and fragment the cellulose particles, making the process simplified, less expensive, and globally more efficient. Furthermore, the organoleptic properties of the final product are not altered by the use of the chemicals normally employed in the pulping step.

Claims

CLAIMS1. A method for making a web (N) of reconstituted material of plant origin, comprising the following steps:- a step of feeding a first quantity of at least one liquid into a mixing space (V) of a mixer (100);- a step of feeding a second quantity of at least one dry product into the mixing space (V) of the mixer (100); the at least one dry product comprising cellulose at least partly in the form of powder, in particular, ground or powdered cellulose;- a step of mixing the second quantity of dry product with the first quantity of liquid in the mixer (100) to obtain a mixture; and a cellulose content of between 25% and 80%, preferably between 40% and 60%, and still more preferably, approximately 55%;- a subsequent step of forming a continuous web (N) from said mixture; wherein the cellulose has a powder content of between 50% and 100%, preferably between 80% and 100%.

2. The method according to claim 1 , wherein the cellulose powder particles have an average length of not more than 200 pm, preferably between 40 pm and 200 pm.

3. The method according to claim 1 or 2, wherein the mixture comprises lactic acid, preferably between 0.01% and 0.10%, preferably approximately 0.1%.

4. The method according to any one of the preceding claims, wherein the first quantity of at least one liquid comprises glycerine in a quantity greater than 18%, preferably greater than 30% and still more preferably, between 30% and 40%.

5. The method according to any one of the preceding claims, wherein thefirst quantity of at least one liquid comprises propylene glycol in a quantity preferably greater than 0.5%, preferably less than 20% and still more preferably, between 0.5% and 15%.

6. The method according to any one of claims 3 to 5, wherein the lactic acid is premixed with glycerine and / or propylene glycol and / or nicotine.

7. The method according to any one of the preceding claims, wherein the first quantity of at least one liquid may comprise one or more between nicotine, propylene glycol, colourants and at least one binding agent.

8. The method according to any one of the preceding claims, wherein the steps of feeding a second quantity of at least one dry product and of mixing the second quantity of dry product with the first quantity of liquid are carried out by feeding the dry product in two separate sub-steps, and mixing them between one sub-step and the other; preferably, the percentage of the dry product fed during the first sub-step being between 20% and 40%, more preferably approximately 30%, and the rest of the dry product being fed during the second sub-step.

9. The method according to any one of claims 1 to 7, wherein the steps of feeding a second quantity of at least one dry product and of mixing the second quantity of dry product with the first quantity of liquid are carried out by feeding the dry product in a single sub-step.

10. The method according to any one of the preceding claims, wherein the mixture produced by the step of mixing has a sandy and / or grainy texture, with an average particle size of between 0.5 and 15 mm.11 . The method according to any one of the preceding claims, wherein the mixture has a density of between 500 kg / m3and 1200 kg / m3, preferablybetween 600 kg / m3and 900 kg / m3.

12. The method according to any one of the preceding claims, wherein said step of forming a continuous web (N) comprises the following substeps:- performing a first step of laminating the mixture via a first pair of rollers (200) to obtain a laminated semi-finished product;- performing a second step of laminating the laminated semi-finished product via a second pair of rollers (300) to obtain a web (N) or a portion of web.

13. The method according to claim 12, wherein the first and / or the second step of laminating is a step of vertical laminating.

14. The method according to claim 12 or 13, wherein the mixture produced by the step of mixing is sent directly to the first pair of rollers (200), preferably by gravity feed or by a conveyor, where the first step of laminating can be carried out.

15. The method according to any one of claims 12 to 14, comprising, between the steps of laminating, a step of scraping the semi-finished product off the first pair of rollers (200) and, once it has been scraped off, feeding the semi-finished product, in particular by gravity, to the second pair of rollers (300).

16. The method according to any one of the preceding claims 12 to 15, further comprising, after the second step of laminating, a step of multistage laminating, preferably horizontal, to reduce the thickness of the continuous web in controlled manner until reaching a calibrated thickness value.

17. The method according to any one of the preceding claims, further comprising a step of drying to obtain a dry continuous web (N) whose density is preferably between0.5 g / cm3and 1.2 g / cm3, and more preferably, between 0.6 g / cm3and 1.1

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