阅读说明：本技术 适用于加热不燃烧卷烟的再造烟叶及其改良干法制备方法 (Reconstituted tobacco suitable for heating non-burning cigarettes and improved dry preparation method thereof ) 是由 赵德清 邓永 黄玉川 韩咚林 梁坤 郑怡 包毅 史健阳 于 2019-09-27 设计创作，主要内容包括：本发明公开了一种适用于加热不燃烧卷烟的再造烟叶及其改良干法制备方法,利用干法气流成型技术制备涂布用干法片基,制备涂布液,利用喷涂结合帘式涂布的方式进行多次涂布,将涂布液分步多级涂布转移至片基及涂布基材表面,得到再造烟叶半成品；每一次涂布后进行一次干燥,经过干燥系统多级干燥、软压光系统压光整饰及压光后干燥定型,将所述再造烟叶半成品制成再造烟叶成品。本发明帘式涂布的引入以及采用喷涂与帘式涂布相结合的涂布工艺,较好地解决了干法再造烟叶定量、厚度波动较大、发烟剂含量和涂布均匀性稳定性不佳的问题,产品质量的稳定性显著提高。(the invention discloses reconstituted tobacco applicable to a cigarette which is not burnt by heating and an improved dry preparation method thereof.A dry film base for coating is prepared by utilizing a dry airflow forming technology, coating liquid is prepared, multiple times of coating are carried out by utilizing a spraying and curtain type coating combined mode, the coating liquid is transferred to the film base and the surface of the coating base material step by step in a multi-stage coating manner, and a semi-finished product of the reconstituted tobacco is obtained; and drying once after each coating, drying in a multi-stage way by a drying system, performing calendaring finishing by a soft calendaring system, drying and shaping after calendaring, and preparing the reconstituted tobacco semi-finished product into a reconstituted tobacco finished product. The curtain coating is introduced and the coating process combining spraying and curtain coating is adopted, so that the problems of quantitative dry reconstituted tobacco, large thickness fluctuation, poor stability of the content of the smoke agent and the uniformity of coating are solved, and the stability of the product quality is obviously improved.)

1. An improved dry preparation method of reconstituted tobacco suitable for heating non-burning cigarettes is characterized by comprising the following steps:

(1) Preparing a dry film base for coating by using a dry airflow forming technology, wherein the quantitative amount of the dry film base is 10-60g/m2, and the bulk is 2-10cm 3/g;

(2) Preparing a coating liquid, wherein the solid content of the coating liquid is 10-20%, and the viscosity of the coating liquid is 100-;

(3) performing multi-stage coating for multiple times by using a spray coating technology and a curtain coating technology combined to form a spray coating-curtain coating combined coating technology, namely, performing multi-spray coating on the coating liquid prepared in the step (2) and gradually transferring the coating liquid to the film base prepared in the step (1) and the surface of the coating base material through curtain coating to obtain a reconstituted tobacco semi-finished product; based on the absolute dry weight, the single coating weight of spray coating is 5-30g/m2, the single coating weight of curtain coating is 10-40g/m2, the quantitative amount of the semi-finished product of the reconstituted tobacco after the multi-stage spray coating is 40-120g/m2, and the quantitative amount of the semi-finished product of the reconstituted tobacco after the curtain coating is 100-200g/m 2;

(4) The reconstituted tobacco semi-finished product is subjected to multi-stage drying by a drying system, calendaring finishing by a soft calendaring system and drying and shaping after calendaring to form a reconstituted tobacco finished product; the hot air temperature of the drying system is 80-120 ℃, the moisture of the reconstituted tobacco semi-finished product is 13-18% when the soft calendaring system performs calendaring, and the moisture of the reconstituted tobacco finished product is 8-12%.

2. The improved dry process for the preparation of reconstituted tobacco suitable for heating non-combustible cigarettes according to claim 1, wherein the spray coating technique comprises one or a combination of air spraying, high pressure airless spraying and mixed air spraying, and the curtain coating technique comprises single-layer curtain coating, double-layer curtain coating and multi-layer curtain coating.

3. The improved dry preparation method of reconstituted tobacco suitable for heating non-burning cigarettes according to claim 1, characterized in that the fiber raw material of the dry film base is one or a combination of several of cabo pulp, tobacco stalk pulp, softwood pulp, hardwood pulp, linseed pulp and bamboo pulp.

4. The improved dry process for preparing reconstituted tobacco suitable for heating non-burning cigarettes according to claim 1, wherein the components of the coating liquid comprise tobacco particles, a smoke agent, an adhesive, a tobacco extract, a dispersing agent, a food additive, tobacco flavor and water.

5. the improved dry preparation method of reconstituted tobacco suitable for heating non-burning cigarettes according to claim 4, characterized in that the amount of the coating liquid formula is as follows in parts by weight: 5-20 parts of tobacco particles, 2-10 parts of a smoke agent, 2-6 parts of an adhesive, 1-5 parts of a tobacco extract, 1-3 parts of a dispersing agent, 1-5 parts of a food additive, 1-3 parts of a tobacco essence and 70-90 parts of water.

6. The improved dry preparation method of reconstituted tobacco suitable for heating non-burning cigarettes according to claim 4, wherein the particle size of the tobacco particles is 100-500 meshes.

7. The improved dry preparation method of reconstituted tobacco suitable for non-burning cigarettes according to claim 1, wherein the coating liquid has a solid content of 10-15% and a viscosity of 200-3000mPa s.

8. The improved dry process for the preparation of reconstituted tobacco suitable for heating non-burning cigarettes according to claim 1, characterized in that the single application amount of said spray coating is 10-25g/m2 and the single application amount of said curtain coating is 15-35g/m 2.

9. the improved dry-process preparation method of reconstituted tobacco suitable for heating non-burning cigarettes according to claim 1, characterized in that the hot air temperature of the drying system is 90-100 ℃, and the moisture of the reconstituted tobacco semi-finished product during calendering by the soft calendering system is 14-16%.

10. the reconstituted tobacco prepared by the method of any one of claims 1 to 9 is characterized in that the finished reconstituted tobacco product has the basis weight of 100-200g/m2, the thickness of 0.160-0.260mm, the tightness of 0.625-1.250g/cm3, the tensile strength of not less than 300N/m and the mass content of the smoke agent in the finished reconstituted tobacco product of 10-20%.

Technical Field

The invention relates to the technical field of reconstituted tobacco in tobacco industry, in particular to reconstituted tobacco suitable for heating non-combustible cigarettes and an improved dry preparation method thereof.

background

the heating of non-combustible cigarettes is one of the important forms of novel tobacco products, and endogenous and exogenous components in tobacco are released mainly by heating tobacco materials at a lower temperature (below 300 ℃), so that certain sensory enjoyment and physiological satisfaction of consumers are met. The cigarette which is not burnt is heated, and only the tobacco material is heated but not burnt, so that the harmful components generated by the cracking of the tobacco in the high-temperature burning process are reduced, and the release amount of the sidestream smoke and the environmental smoke is also obviously reduced.

The reconstituted tobacco is a main tobacco material used for heating the non-combustible cigarette and is also a core raw material for heating the non-combustible cigarette. The production process of the reconstituted tobacco mainly comprises a rolling method, a thick pulp method, a paper-making method, a dry method and the like. The tobacco leaf remaking by the rolling method is characterized in that tobacco materials such as tobacco stems, tobacco powder, tobacco sticks and the like are crushed and then mixed with materials such as an adhesive, a reinforcing agent, a humectant, water and the like according to a certain proportion and stirred uniformly to form loose granular shapes, then the loose granular shapes are rolled by a rolling machine to form sheets, the sheets are dried, and finally the sheets are cut into remaking tobacco leaf shreds by a shredder. The reconstituted tobacco prepared by the thick paste method is prepared by the steps of crushing tobacco materials, mixing the crushed tobacco materials into an aqueous solution with an adhesive, a reinforcing agent, a humectant and water, uniformly stirring the mixture to form a paste, uniformly spreading the paste on a stainless steel belt, drying the paste, and stripping the paste to form the reconstituted tobacco. The paper-making reconstituted tobacco originates from countries such as Austria, America, France, Germany and the like for the first time, mainly aims at recycling tobacco waste generated in the tobacco processing process, improving the utilization rate of tobacco raw materials, preparing wrapper materials of cigars and the like, and belongs to a product for recycling tobacco resources. The method mainly comprises a two-step papermaking method and a one-step papermaking method according to the development process, and the mainstream processing technology widely adopted at home and abroad at present is the two-step papermaking method technology. The two-step production process comprises the following steps: according to the requirements of the reconstituted tobacco raw material formula, the tobacco stems, the fragments and the tobacco powder are soaked and extracted by hot water and are subjected to solid-liquid separation, the obtained extracting solution is subjected to vacuum concentration and is blended into coating liquid, the residual solid residues are subjected to pulping and paper making on a specific paper machine to be formed into a film base, then the coating liquid is uniformly coated on the surface of the film base, and the reconstituted tobacco is obtained by drying.

The dry reconstituted tobacco process takes airflow as a fiber carrier and produces reconstituted tobacco through the processes of air sedimentation, hot rolling forming, spraying drying and the like. The crushing of the tobacco raw material, the treatment of the exogenous fiber and the substrate forming process all adopt an anhydrous mode, only a certain amount of water is used in the preparation and cleaning equipment of the spraying liquid, and most of the water can be recycled. Chinese patent CN103431514B discloses a dry paper-making reconstituted tobacco sheet package production line, which mainly comprises a raw material processing part, a tobacco forming part and a sheet forming part, wherein the material transportation is mainly carried out by a carrier roller and a mesh belt and is assisted by fan airflow for transfer, and the conveying part of the whole production line is provided with a cleaning device, a tensioning device and a deviation correcting device. The patent CN104824824B adds tobacco fragments into the base sheet forming process and the coating liquid slurry used in spraying respectively, and the method can reduce working procedures and reduce the phenomena of dust falling and flying caused by excessive tobacco powder. Patents CN201310157779, CN201310155869, CN201410083670, CN201410203820 and CN201510750577 disclose a method for producing reconstituted tobacco substrate and a substrate forming device by a dry paper-making method, and in addition, a defibering device, a drying device, a spraying device and corresponding production equipment are also disclosed (CN200410083714, CN201410203874, CN20140204049 and CN 101201455207). Patent CN108451001A discloses a dry reconstituted tobacco for heating non-combustible cigarettes, which comprises a fibrous thin-layer substrate, tobacco powder, a binder, a smoke agent, sugar, a flavoring substance and the like.

in the manufacturing process of the dry reconstituted tobacco, the coating process is a crucial link, the physical properties and sensory quality of the reconstituted tobacco are directly influenced by the coating method and the coating quality, and the coating technology is a key technology for preparing the dry reconstituted tobacco. The dry method film base adopted in the dry method reconstituted tobacco preparation process has the characteristics of loose and porous tissue structure, weak fiber bonding force and low tensile strength, and the adopted coating liquid is a high-solid-content and high-viscosity suspension system formed by components such as tobacco particles, tobacco extracts, smoke agents, adhesives and the like and water. Based on the characteristics of a film base and a coating liquid used by the dry reconstituted tobacco, the existing dry reconstituted tobacco preparation method adopts a spraying process, for example, a spraying manner based on atomization of a pipeline pressure supply nozzle is proposed in the patent of 'an air flow forming dry paper machine' (200610147421.2, 200610117771.4), and the spraying manner is only suitable for spraying glue of living paper and is difficult to adapt to spraying of slurry with high solid content and high viscosity. The spraying modes adopted by the patent 'reconstituted tobacco sheet whole-loading production line by dry paper-making method' (201310393610.8) and the patent 'pulp spraying device for producing reconstituted tobacco by dry paper-making method' (CN201410204049.9) are air spraying by using compressed air. Although the air spraying has good atomization effect, the air pressure is high, the overspray and rebound of the atomized coating are easily caused, the coating retention rate is low, and the atomization loss is large.

The existing dry-process reconstituted tobacco and the preparation method thereof have the following problems:

(1) The coating amount of the spraying process is unstable, the longitudinal and transverse thickness and quantitative fluctuation of the reconstituted tobacco are easy to be large, the uniformity of the coating thickness is poor, and the machine-loading adaptability and the sensory quality of the reconstituted tobacco are influenced.

(2) The spraying process is not easy to form closed-loop control, and the automatic control level is relatively low.

(3) In the aspect of physical properties, compared with a rolling method, a thick pulp method and a paper making method, the dry method reconstituted tobacco has the advantages of overhigh bulk, overhigh air permeability and porosity and lower tightness.

(4) In the aspect of sensory quality, compared with a rolling method and a thick pulp method, the concentration, plumpness, fullness, conglomeration and thickness of the smoke of the dry-method reconstituted tobacco are slightly insufficient. The number of effective suction openings of the dry reconstituted tobacco is only 6-7, and the suction resistance and the durability are to be improved.

air spraying is a coating method which utilizes compressed air to form a conical vacuum negative pressure area in front of an air nozzle of a spray gun when the compressed air is sprayed out through the air nozzle, sucks and atomizes a coating under the action of air flow, and sprays the coating on the surface of an object to be coated to form a continuous and complete coating, so the air spraying is also called as air pressure spraying. Air spraying is the most popular and widely used operation mode in history, and various atomization modes with different technical characteristics are developed. Such as high flow low pressure spray techniques, medium pressure low flow air spray techniques, mixed air spray techniques, and the like. In addition, there is a spray coating process using an ultrasonic atomization technique, i.e., ultrasonic spray coating.

Curtain coating, a non-contact coating, is a method of precision coating using a pre-metering method. It is characterized by that the free-falling liquid film (curtain) can produce impact on the coated base paper, and a layer of liquid film can be applied on the paper whose surface is not smooth enough under the condition of high speed. The curtain has a relatively high impingement speed compared to the speed at which the web moves vertically, and the high impingement speed removes air from above the web, allowing the machine to operate at high speeds. Since this non-contact coating method does not apply any mechanical stress to the base paper, the web breaks are reduced and good coating coverage is provided, eliminating paper defects such as scratches and streaks. Curtain coating has the advantages of wide operating range of coating speed and coating amount, good coverage on the surface of base paper, better coverage rate than doctor blade coating and film coating, very uniform coating thickness and better loose thickness retention of coated paper. Curtain coating provides a desirable conformal coating effect and provides good fiber coverage compared to conventional knife coating. The coating coverage is very uniform, which is beneficial to achieve high coating quality at low coating weight. Compared with air knife coating with the same profiling coating effect, the curtain coating has much higher vehicle speed and coating solid content, and the running cost is obviously reduced.

At present, the conventional air spraying process is adopted in the traditional dry method reconstituted tobacco production process, and no more advanced coating process technology is introduced. Although the spray coating and curtain coating are non-contact coating methods, the spray coating has problems of low solid content of the coating, easy blockage of a nozzle, uneven coating amount and coating thickness, and the like. In order to overcome the defects of physical performance and sensory quality of the conventional dry reconstituted tobacco, the invention provides a novel coating process technology based on the combination of spraying and curtain coating, and forms a novel method for preparing the improved dry reconstituted tobacco.

Disclosure of Invention

The invention aims to provide a new improved dry reconstituted tobacco which has moderate bulk, air permeability, porosity and tightness, aiming at the defects of over high bulk, air permeability and porosity and over low tightness in the aspect of physical properties of the existing dry reconstituted tobacco and the defects of slightly insufficient concentration, fullness, conglobation and thickness of smoke of the dry reconstituted tobacco in the aspect of sensory quality.

The invention also aims to provide a preparation method of the improved dry reconstituted tobacco.

The purpose of the invention is realized by the following technical scheme:

an improved dry preparation method of reconstituted tobacco suitable for heating non-burning cigarettes comprises the following steps:

(1) Preparing a dry film base for coating by using a dry airflow forming technology, wherein the quantitative amount of the dry film base is 10-60g/m2, and the bulk is 2-10cm 3/g;

(2) Preparing a coating liquid, wherein the solid content of the coating liquid is 10-20%, and the viscosity of the coating liquid is 100-;

(3) Performing multi-stage coating for multiple times by using a spray coating technology and a curtain coating technology combined to form a spray coating-curtain coating combined coating technology, namely, performing multi-spray coating on the coating liquid prepared in the step (2) and gradually transferring the coating liquid to the film base prepared in the step (1) and the surface of the coating base material through curtain coating to obtain a reconstituted tobacco semi-finished product; based on the absolute dry weight, the single coating weight of spray coating is 5-30g/m2, the single coating weight of curtain coating is 10-40g/m2, the quantitative amount of the semi-finished product of the reconstituted tobacco after the multi-stage spray coating is 40-120g/m2, and the quantitative amount of the semi-finished product of the reconstituted tobacco after the curtain coating is 100-200g/m 2;

(4) The reconstituted tobacco semi-finished product is subjected to multi-stage drying by a drying system, calendaring finishing by a soft calendaring system and drying and shaping after calendaring to form a reconstituted tobacco finished product; the hot air temperature of the drying system is 80-120 ℃, the moisture of the reconstituted tobacco semi-finished product is 13-18% when the soft calendaring system performs calendaring, and the moisture of the reconstituted tobacco finished product is 8-12%.

The spray coating technology comprises one or a combination of a plurality of air spraying, high-pressure airless spraying and mixed gas spraying, and the curtain coating technology comprises single-layer curtain coating, double-layer curtain coating and multi-layer curtain coating.

The fiber raw material of the dry method sheet base is one or a combination of more of tobacco stalk pulp, softwood pulp, hardwood pulp, linseed pulp and bamboo pulp.

The coating liquid comprises components of tobacco particles, a smoke agent, an adhesive, a tobacco extract, a dispersing agent, a food additive, tobacco essence and water.

the dosage of the coating liquid formula is as follows by weight: 5-20 parts of tobacco particles, 2-10 parts of a smoke agent, 2-6 parts of an adhesive, 1-5 parts of a tobacco extract, 1-3 parts of a dispersing agent, 1-5 parts of a food additive, 1-3 parts of a tobacco essence and 70-90 parts of water.

The particle size of the tobacco particles is 100-500 meshes, namely 38-150 mu m.

the solid content of the coating liquid is 10-15%, and the viscosity is 200-3000mPa & s.

The single coating weight of the spray coating is 10-25g/m2, and the single coating weight of the curtain coating is 15-35g/m 2.

The hot air temperature of the drying system is 90-100 ℃, and the moisture of the reconstituted tobacco semi-finished product during calendering of the soft calendering system is 14-16%.

The weight of the finished reconstituted tobacco product is 100-200g/m2, the thickness is 0.160-0.260mm, the tightness is 0.625-1.250g/cm3, the tensile strength is not less than 300N/m, and the mass content of the smoke agent in the finished reconstituted tobacco product is 10-20%.

Compared with the prior art, the invention has the following advantages and effects:

(1) the improved dry reconstituted tobacco prepared by the invention has moderate bulk, tightness, air permeability and porosity, and the physical properties of the improved dry reconstituted tobacco are greatly modified and improved.

(2) The improved dry reconstituted tobacco prepared by the invention has greatly improved sensory quality, obviously enhanced smoke concentration, plumpness, fullness and thickness, and strong and natural tobacco fragrance. Compared with the common dry reconstituted tobacco, the number of effective suction openings is increased from 6-7 openings to 10-12 openings, and the suction durability and the suction resistance are obviously enhanced.

(3) the curtain coating is introduced and the coating process combining spraying and curtain coating is adopted, so that the problems of quantitative dry reconstituted tobacco, large thickness fluctuation and poor uniformity of coating amount and coating thickness are solved, and the stability of product quality is obviously improved.

(4) The improved dry-process reconstituted tobacco prepared by the invention has the advantages of improved compactness, correspondingly improved tensile strength and further enhanced machine-installing adaptability.

Drawings

FIG. 1 is a process flow diagram of example 1.

FIG. 2 is a process flow diagram of example 2.

FIG. 3 is a process flow diagram of example 3

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.