CN110438576A - A kind of spinneret, the pipe tobacco prepared using the spinneret and preparation method thereof - Google Patents

Abstract

The invention provides a spinneret, tobacco tow prepared by using the spinneret and a preparation method thereof. Several spinneret holes are processed on the spinneret. The spinneret hole includes two hollow holes and one island-shaped hole. The hollow hole and the island-shaped hole are integrally connected to form a three-lobed shape; the island-shaped hole is equipped with a solid forming island. , the forming island is integrally formed with the main part of the spinneret, the forming island separates the island-shaped hole into a root and a free end, the root is connected to the hollow hole, and there is a forming gap between the root and the free end. The material of the tobacco tow produced by the spinneret is PLA, and the monofilament of the obtained tobacco tow has a three-dimensional crimped structure. Hollow holes are formed in the sides. The invention can solve the problems of poor curling effect and low rod yield of the tobacco tow.

Description

Spinneret, tobacco tow prepared by using the spinneret and its preparation method

technical field

The invention belongs to the technical field of tobacco tow, and in particular relates to a spinneret of tobacco tow, a tobacco tow prepared by using the spinneret and a preparation method thereof.

Background technique

In cigarettes, the filter tip undertakes the function of reducing tar and harm, and the tow for tobacco is the main material of the filter tip.

At present, the commercially used filter materials in the domestic and foreign markets are mainly cellulose acetate tow and polypropylene tow, of which the amount of cellulose acetate fiber accounts for more than 90%. Due to its excellent performance, it is mainly used in middle and high-end cigarettes. However, the raw materials of cellulose acetate tow are completely imported, and the technical equipment mainly relies on foreign companies. Some domestic enterprises use polypropylene tow instead of cellulose acetate tow. However, the filtering effect of polypropylene tow is not good, so it can only be used in low-grade cigarettes. .

The use of polylactic acid tow in cigarettes has the following advantages: 1) Polylactic acid has excellent adsorption performance and can replace cellulose acetate in middle and high-end cigarettes; 2) The source is renewable and biodegradable, and the main raw materials are corn, cassava, straw, etc. The popularization and application of crops and waste can alleviate the energy crisis, protect the ecological environment, and reduce greenhouse gas emissions; 3) The production process is simple and environmentally friendly, and polylactic acid tow is prepared by melt spinning, which solves the complex production process of cellulose acetate tow. Large investment and a large amount of acetone solvent environmental protection problems.

The crimping of tobacco tow in the prior art is mechanical crimping. The disadvantage of mechanical crimping is that it is difficult to maintain the degree of crimping, and the number and degree of crimping will be greatly reduced under a certain tension. The standard number of crimps of conventional cellulose acetate tow and polypropylene tow is 22-28/25mm. On the filter forming machine, the tow is opened under tension and then rolled into a mouth rod; According to the analysis, not only the number of crimps has decreased, but also the crimp angle has become significantly larger. The original high-density "peak-shaped" crimped tow has become a "wavy" tow, which reduces the filling and supporting effect of the tow and reduces the hit rate.

Contents of the invention

The object of the present invention is to provide a spinneret for tobacco tow, a tobacco tow prepared by using the spinneret and a method for preparing the tobacco tow, so as to solve the problem of poor curling effect of the tobacco tow.

The present invention provides following technical scheme:

A spinneret, on which several spinneret holes are processed, the spinneret holes include two hollow holes and an island-shaped hole, and the hollow hole and the island-shaped hole are integrally connected to form a three-lobe shape ; The inside of the island-shaped hole is provided with a solid forming island, the forming island is integrally formed with the main body of the spinneret, and the forming island separates the island-shaped hole into a root and a free end. The root is in communication with the hollow hole, and there is a forming gap between the root and the free end.

Preferably, the root and the free end are respectively provided with a first bonding compensation protrusion and a second bonding compensation protrusion at the forming gap, and the first bonding compensation protrusion on the same side The raised portion and the second bonding compensating raised portion are oppositely arranged.

Preferably, both the first adhesion compensation protrusion and the second adhesion compensation protrusion protrude toward the inner side of the forming island.

Preferably, the protrusion depth of the first adhesion compensation protrusion and the second adhesion compensation protrusion is 0.04-0.06 mm.

Preferably, the width of the forming gap is 0.05-0.07 mm; the width of the gap between the edge of the island-shaped hole and the forming island is 0.07-0.09 mm.

Preferably, the island-shaped hole has an overall oval shape.

The present invention also provides a tobacco tow produced by the above-mentioned spinneret, the material of the tobacco tow is PLA, the monofilament of the tobacco tow has a three-dimensional crimped structure, and the cross section of the monofilament is It is a single-hole trilobe type, and a hollow hole is formed in the side corresponding to the island-shaped hole on the monofilament.

The present invention also provides a method for producing the above-mentioned tobacco tow by using the above-mentioned spinneret, comprising the following steps:

1) Dry crystallization: polylactic acid slices are crystallized at 60-90°C, dried at 90-120°C, the crystallization and drying time is 13-20h, and the water content in the modified polylactic acid is controlled to be less than 30ppm;

2) Melt spinning: the diameter of the spinneret is 260mm, the number of holes in the spinneret is 600-1000; the diameter of the spinning screw is 120mm, the ratio of length to diameter is 33:1, the temperature is 210-250°C; the temperature of the box is 235-248 ℃, spinning speed 900-1500m/min; cooling temperature 18-25℃, wind pressure 400-700Pa, wind speed 0.2-0.6m/s, humidity 65-85%;

3) Traction: Six-stick traction machine, the rollers are distributed in a square shape, the surface is hard chrome-plated 0.1mm, and the plow surface is treated;

4) Feeding: The diameter of the feeding wheel is 480mm, and the surface is sprayed with pottery;

5) Reciprocating drop barrel: the reciprocating machine is of longitudinal chain plate type and horizontal guide rail; the size of the wire barrel is 1000x1000x1200mm; the longitudinal transmission is a servo motor, and the longitudinal speed is 5-10m/min; the horizontal transmission is a servo motor, and the lateral speed is 0.2-0.5m/min; The transmission power of entering and exiting the barrel is 1.5Kw, and the speed of entering and exiting the barrel is 5-10m/min;

6) Clustering: 48 barrels for clustering, 2-6 barrels per bundle; hanger rail made of stainless steel, plate thickness 2mm, with guide wire rod, tension adjustment device and upper guide wire frame; tension godet roller diameter 85mm, surface Hard chrome plating 0.1mm;

7) Drafting: drafting is a four-step stretching process, the drafting roller is heated by electromagnetic induction, and the surface of the drafting roller is plated with 0.1mm of hard chrome; the temperature of the first drafting roller is controlled at 45-50 ° C, and the second drafting The roll temperature is controlled at 60-65°C, the temperature of the third draft roll is controlled at 65-72°C, and the temperature of the fourth draft roll is controlled at 72-80°C; the speed ratio (drawing ratio) of the first and second draft rolls is 1.5, the speed ratio (drawing ratio) of the second and third drafting rollers is 1.8, and the speed ratio (drawing ratio) of the third and fourth drafting rollers is 1.3;

8) Preheating and curling: pass through the steam box before curling, the length of the steam box is 1 meter, and the temperature is controlled at 80-100°C; the circulating hot water is passed inside the curling wheel, and the temperature of the hot water is controlled at 50-60°C; the curling speed is 120 -180m/min, crimping wheel diameter 60mm, crimping wheel width 16-32mm; total density of tow is 2.0-5.5ktex;

9) Drying and heat setting: the oven adopts natural gas heating method, the temperature is controlled at 60-90°C, and the time is 12-15min;

10) Wobbling wire conveying: PVC steel buckle anti-skid belt, width 70, belt thickness 3-4mm, diameter of transmission roller 100mm; diameter of spinning wire feeding wheel 150mm, hard chrome plated surface 0.05mm, spinning bucket with supporting legs Blade arm mechanism;

11) Packing: main pressure cylinder Φ320xΦ250mm; suitcase cylinder Φ150xΦ85mm; positioning cylinder Φ50xΦ28mm; design pressure 35MPa, motor power 55Kw; package weight 200-250kg.

The beneficial effects of the present invention are:

1. The tow monofilament fiber produced by the spinneret of the present invention is a single-hole trilobal shape, and the position of the hole is biased towards one of the leaves. During the cooling process of the fiber, the difference in cooling rate causes the shrinkage asymmetry, so that the filament The tow presents a permanent three-dimensional crimp effect, superimposed mechanical crimps to form a two-dimensional and three-dimensional composite crimp, which maintains good tow crimp performance, reduces the packing density in the filter rod, increases the rod yield by 8-12%, and reduces the Cost of production.

2. The forming island of the spinneret divides the island-shaped hole into a root and a free end. There is a forming gap between the root and the free end. During the melt spinning process, the cooling air is blown into the fiber through the forming gap A hollow structure is formed, and the molten material that flows out expands rapidly in the forming gap to fill the forming gap, and is naturally bonded into one body to form a hollow hole inside the fiber, ensuring the forming stability of the hollow hole and the hollowness of the hollow hole.

3. The monofilament fiber structure of the tow of the present invention is a single-hole trefoil shape, and the hollow pore structure increases the filtering area and improves the filtering effect of smoke compared with the existing tow structure for vinegar tobacco. At the same time, the hollowness of the tow fiber in the invention reaches 18-25%, which reduces the packing density of the tow in the filter tip rod, improves the rod yield, and thus reduces the production cost.

4. Under the same circumferential conditions, the filter rod made of the tow provided by the present invention reduces the draw resistance by 10-15%, improves the smoking quality, and fills the gap in the market for tow products for low draw resistance cigarettes.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, and are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the attached picture:

Fig. 1 is a schematic view of spinneret structure of the present invention;

Fig. 2 is a schematic view of spinneret hole structure of the present invention;

Fig. 3 is a schematic diagram of the monofilament cross-sectional structure of the tobacco tow of the present invention;

Marked in the figure: 1. spinneret; 2. spinneret hole; 3. hollow hole; 4. island hole; 5. root; 6. free end; 7. forming island; 8. first bonding compensation Raised part; 9. Second bonding compensating raised part; 10. Monofilament of tobacco tow; 11. Hollow hole.

Detailed ways

As shown in Figures 1 and 2, a spinneret 1 for tobacco tow has several spinneret holes 2 processed on the spinneret 1, and the spinneret holes 2 include two hollow holes 3 and an island-shaped hole 4. The hollow hole 3 and the island-shaped hole 4 are integrally connected to form a trilobal shape; the island-shaped hole 4 is elliptical as a whole, and the interior of the island-shaped hole 4 is provided with a solid forming island 7, and the forming island 7 and the main body of the spinneret 1 The part is integrally formed, and the forming island 7 separates the island-shaped hole 4 into a root 5 and a free end 6. The root 5 communicates with the two hollow holes 3, and there is a forming gap between the root 5 and the free end 6. The width of the forming gap is a is 0.05-0.07mm; the pore width b between the edge of the island-shaped hole 4 and the forming island 7 is 0.07-0.09mm. During the melt spinning process, the cooling air next to the spinneret 1 is blown into the fiber from the forming gap to form a hollow structure, and the melt material flowing out of the spinneret hole 2 expands rapidly at the forming gap to fill the forming gap , naturally bonded together to form a hollow hole, ensuring the stability of the hollow hole and the hollowness of the hollow hole.

The root portion 5 and the free end portion 6 are respectively provided with a first bonding compensation protrusion 8 and a second bonding compensation protrusion 9 at the forming gap, and the first bonding compensation protrusion 8 and the second bonding compensation protrusion 9 on the same side The compensation raised portion 9 is oppositely arranged. The provision of the first bonding compensating raised portion 8 and the second bonding compensating raised portion 9 is beneficial for the melt material to reliably fill the molding gap and form a sealed hollow hole. The first bonding compensating raised portion 8 and the second bonding compensating raised portion 9 all protrude toward the inside of the molding island 7, and the protrusions of the first bonding compensating raised portion 8 and the second bonding compensating raised portion 9 The starting depth c is 0.04-0.06mm.

Fig. 3 shows the monofilament 10 cross-sectional structure of the tobacco tow that utilizes above-mentioned spinneret production, and the material of tobacco tow is PLA, and the monofilament 10 of tobacco tow is three-dimensional curly structure, and the monofilament 10 The cross-section is a single-hole three-leaf shape, and a hollow hole 11 is formed in the side corresponding to the island-shaped hole on the monofilament. The monofilament fiber of the tobacco tow is in the shape of a single hole and three leaves, and the position of the hollow hole 11 is biased toward one of the leaves. During the cooling process, the difference in the cooling rate of the fiber causes the shrinkage asymmetry, so that the tow presents a permanent three-dimensional shape. Curling effect, superimposed mechanical crimping, forming two-dimensional and three-dimensional composite crimping, maintaining good tow crimping performance, reducing the filling density in the filter rod, increasing the rod yield by 8-12%, and reducing production costs.

The present invention also provides a method for producing tobacco tow by using the above-mentioned spinneret, which will be specifically described with the following three examples and a comparative example.

Example 1

1. The intrinsic viscosity of polylactic acid sliced raw material is 1.57dl/g, the melt index is 26g/10min (210°C, 2160g), the glass transition temperature is 62°C, and the melting temperature is 175°C.

2. The preparation process of tow is:

(1) Dry crystallization. Pre-crystallize polylactic acid slices at 60°C and dry at 90°C. The dew point temperature is -90°C. The crystallization and drying time is 20 hours, and the water content of polylactic acid is 21ppm.

(2) Melt spinning, the diameter of the spinneret is 260mm, the number of holes in the spinneret is 1000, and the single hole is a hollow trilobal shape; the diameter of the spinning screw is 120mm, the aspect ratio is 33:1, and the temperature is 210-250°C (The first zone of the screw is 210°C, the second zone is 225°C, the third zone is 245°C, the fourth zone is 248°C, the fifth zone is 245°C); the box temperature is 245°C, the spinning speed is 1300m/min; the cooling temperature is 18°C, and the wind pressure is 680Pa , wind speed 0.6m/s, humidity 80%.

(3) Traction and feeding.

(4) Reciprocating falling barrel, longitudinal speed 10m/min; transverse speed 0.5m/min; speed of entering and leaving the barrel 10m/min.

(5) Clustering.

(6) drafting, the temperature of the first drafting roller is controlled at 45°C, the temperature of the second drafting roller is controlled at 60°C, the temperature of the third drafting roller is controlled at 68°C, and the temperature of the fourth drafting roller is controlled at 75°C; The speed ratio of the first and second drafting rolls is 1.5, the speed ratio of the second and third drafting rolls is 1.8, and the speed ratio of the third and fourth drafting rolls is 1.3.

(7) Preheating and curling, the temperature of the curling steam box is controlled at 100°C; the temperature of the circulating hot water inside the curling wheel is 50°C; the curling speed is 120m/min, and the width of the curling wheel is 32mm.

(8) Drying heat setting, the temperature of the first zone of the oven is 60°C, the temperature of the second zone is 68°C, the temperature of the third zone is 75°C, the temperature of the fourth zone is 82°C, the temperature of the fifth zone is 85°C, and the time is 12 minutes.

(9) Conveying and packing the spinning wire, the packing weight is 220kg/bag.

3. Tow specifications:

Hollowness of monofilament is 22%, linear density of monofilament is 3.0dtex, total density of tow is 4.2ktex, number of mechanical crimps is 27/25mm, number of three-dimensional crimps is 6/25mm, degree of crimp is 25%, compression rebound after opening rate 29%.

Example 2

1. The intrinsic viscosity of polylactic acid sliced raw material is 1.57dl/g, the melt index is 26g/10min (210°C, 2160g), the glass transition temperature is 62°C, and the melting temperature is 175°C.

2. The preparation process of tow is:

(1) Dry crystallization, pre-crystallize polylactic acid slices at 65°C, dry at 105°C, dew point temperature -90°C, crystallization drying time 13h, polylactic acid water content 20ppm.

(2) Melt spinning, the diameter of the melt spinning spinneret is 260mm, the number of holes in the spinneret is 600, and the single hole is a hollow trilobal shape; the diameter of the spinning screw is 120mm, the aspect ratio is 33:1, and the temperature is 210-250°C (screw zone 1 215°C, zone 2 228°C, zone 3 248°C, zone 4 250°C, zone 5 248°C); box temperature 248°C, spinning speed 1500m/min; cooling temperature 20°C , wind pressure 600Pa, wind speed 0.5m/s, humidity 75%.

(3) Traction and feeding.

(4) Reciprocating falling barrel, the vertical speed of reciprocating falling barrel is 8m/min; the transverse speed is 0.2m/min; the speed of entering and exiting the barrel is 5m/min.

(5) Clustering.

(6) drafting, the temperature of the first drafting roller is controlled at 48°C, the temperature of the second drafting roller is controlled at 62°C, the temperature of the third drafting roller is controlled at 70°C, and the temperature of the fourth drafting roller is controlled at 80°C; The speed ratio of the first and second drafting rolls is 1.5, the speed ratio of the second and third drafting rolls is 1.8, and the speed ratio of the third and fourth drafting rolls is 1.3.

(7) Preheating and curling, the temperature of the curling steam box is controlled at 95°C; the temperature of the circulating hot water inside the curling wheel is 60°C; the curling speed is 150m/min, and the width of the curling wheel is 32mm.

(8) Drying heat setting, the temperature of the first zone of the oven is 65°C, the temperature of the second zone is 65°C, the temperature of the third zone is 70°C, the temperature of the fourth zone is 75°C, the temperature of the fifth zone is 82°C, and the time is 15 minutes.

(9) Conveying and packing the spinning wire, the packing weight is 250kg/bag.

3. Tow specifications:

The monofilament hollowness is 25%, the monofilament linear density is 3.0dtex, the total density of the tow is 4.2ktex, the number of mechanical crimps is 28/25mm, the number of three-dimensional crimps is 7/25mm, the degree of crimp is 29%, the compression of the tow after opening The rebound rate is 32%.

Example 3

1. The intrinsic viscosity of polylactic acid sliced raw material is 1.57dl/g, the melt index is 26g/10min (210°C, 2160g), the glass transition temperature is 62°C, and the melting temperature is 175°C.

2. The preparation process of tow is:

(1) Dry crystallization, pre-crystallize the polylactic acid slices at 65°C, dry at 100°C, the dew point temperature is -90°C, the crystallization drying time is 15h, and the polylactic acid water content is 25ppm.

(2) Melt spinning, the diameter of the melt spinning spinneret is 260mm, the number of holes in the spinneret is 800, and the single hole is a hollow trilobal shape; the diameter of the spinning screw is 120mm, the aspect ratio is 33:1, and the temperature is 210-250°C (screw zone 1 212°C, zone 2 226°C, zone 3 246°C, zone 4 248°C, zone 5 246°C); box temperature 246°C, spinning speed 900m/min; cooling temperature 22°C , wind pressure 500Pa, wind speed 0.4m/s, humidity 65%.

(3) Traction and feeding.

(4) Reciprocating falling barrel, the longitudinal speed of reciprocating falling barrel is 6m/min; the transverse speed is 0.3m/min; the speed of entering and exiting the barrel is 6m/min.

(5) Clustering.

(6) drafting, the temperature of the first drafting roller is controlled at 50°C, the temperature of the second drafting roller is controlled at 65°C, the temperature of the third drafting roller is controlled at 72°C, and the temperature of the fourth drafting roller is controlled at 75°C; The speed ratio of the first and second drafting rolls is 1.5, the speed ratio of the second and third drafting rolls is 1.8, and the speed ratio of the third and fourth drafting rolls is 1.3.

(7) Preheating and curling, the temperature of the curling steam box is controlled at 80°C; the temperature of the circulating hot water inside the curling wheel is 58°C; the curling speed is 180m/min, and the width of the curling wheel is 32mm.

(8) Drying and heat setting, the temperature of the first zone of the oven is 68°C, the temperature of the second zone is 705°C, the temperature of the third zone is 78°C, the temperature of the fourth zone is 78°C, the temperature of the fifth zone is 90°C, and the time is 15 minutes.

(9) Conveying and packing the spinning wire, the packing weight is 250kg/bag.

3. Tow specifications:

The hollowness of monofilament is 23%, the linear density of monofilament is 3.0dtex, the total density of tow is 4.2ktex, the number of mechanical crimps is 26/25mm, the number of three-dimensional crimps is 7/25mm, the degree of crimp is 28%, the compression of tow after opening 30% rebound rate.

Example 4

1. The intrinsic viscosity of polylactic acid sliced raw material is 1.57dl/g, the melt index is 26g/10min (210°C, 2160g), the glass transition temperature is 62°C, and the melting temperature is 175°C.

2. The preparation process of tow is:

(1) Dry crystallization, pre-crystallize polylactic acid slices at 65°C, dry at 100°C, dew point temperature -90°C, time 15h, polylactic acid water content 25ppm.

(2) Melt spinning, the diameter of the melt spinning spinneret is 260mm, the number of holes in the spinneret is 800, and the single hole is a hollow trilobal shape; the diameter of the spinning screw is 120mm, the aspect ratio is 33:1, and the temperature is 210-250°C (screw zone 1 212°C, zone 2 226°C, zone 3 246°C, zone 4 248°C, zone 5 246°C); box temperature 246°C, spinning speed 900m/min; cooling temperature 22°C , wind pressure 500Pa, wind speed 0.4m/s, humidity 65%.

(3) Traction and feeding.

(4) Reciprocating falling barrel, the longitudinal speed of reciprocating falling barrel is 6m/min; the transverse speed is 0.3m/min; the speed of entering and exiting the barrel is 6m/min.

(5) Clustering.

(6) drafting, the temperature of the first drafting roller is controlled at 50°C, the temperature of the second drafting roller is controlled at 65°C, the temperature of the third drafting roller is controlled at 72°C, and the temperature of the fourth drafting roller is controlled at 75°C; The speed ratio of the first and second drafting rolls is 1.5, the speed ratio of the second and third drafting rolls is 1.8, and the speed ratio of the third and fourth drafting rolls is 1.3.

(7) Preheating and curling, the temperature of the curling steam box is controlled at 80°C; the temperature of the circulating hot water inside the curling wheel is 58°C; the curling speed is 180m/min, and the width of the curling wheel is 20mm.

(8) Drying and heat setting, the temperature of the first zone of the oven is 68°C, the temperature of the second zone is 705°C, the temperature of the third zone is 78°C, the temperature of the fourth zone is 78°C, the temperature of the fifth zone is 90°C, and the time is 15 minutes.

(9) Conveying and packing the spinning wire, the packing weight is 250kg/bag.

3. Tow specifications:

The hollowness of monofilament is 23%, the linear density of monofilament is 3.0dtex, the total density of tow is 2.0ktex, the number of mechanical crimps is 29/25mm, the number of three-dimensional crimps is 6/25mm, the degree of crimp is 33%, the compression of tow after opening The rebound rate is 35%.

Comparative example 1: the preparation method of polylactic acid tow (monofilament cross section is trilobal solid)

1. The intrinsic viscosity of polylactic acid sliced raw material is 1.57dl/g, the melt index is 26g/10min (210°C, 2160g), the glass transition temperature is 62°C, and the melting temperature is 175°C.

2. The preparation process of tow is:

The polylactic acid slices were pre-crystallized at 70°C, dried at 110°C, the dew point temperature was -90°C, the crystallization drying time was 13 hours, and the water content of polylactic acid was 22ppm. The diameter of the melt spinning spinneret is 260mm, the number of holes in the spinneret is 1000, and the single hole is trilobal; the diameter of the spinning screw is 120mm, the ratio of length to diameter is 33:1, and the temperature is 210-250°C (the first area of the screw 215°C, 235°C in the second zone, 242°C in the third zone, 242°C in the fourth zone, and 238°C in the fifth zone); the box temperature is 238°C, the spinning speed is 1200m/min; the cooling temperature is 21°C, the wind pressure is 460Pa, and the wind speed is 0.3m /s, humidity 70%. The longitudinal speed of reciprocating falling barrel is 8m/min; the transverse speed is 0.3m/min; the speed of entering and leaving the barrel is 8m/min. The temperature of the first drafting roll is controlled at 45°C, the temperature of the second drafting roll is controlled at 60°C, the temperature of the third drafting roll is controlled at 70°C, and the temperature of the fourth drafting roll is controlled at 76°C; The speed ratio is 1.5, the speed ratio of the second and third drafting rolls is 1.8, and the speed ratio of the third and fourth drafting rolls is 1.3. The temperature of the curling steam box is controlled at 90°C; the temperature of the circulating hot water inside the curling wheel is 55°C; the curling speed is 160m/min, and the width of the curling wheel is 32mm. The temperature in the first zone of the oven is 65°C, the temperature in the second zone is 68°C, the temperature in the third zone is 72°C, the temperature in the fourth zone is 75°C, the temperature in the fifth zone is 82°C, and the time is 13 minutes. Packing weight 220kg/bag.

3. Tow specifications:

The linear density of monofilament is 3.0dtex, the total density of tow is 4.2ktex, the number of mechanical crimps is 27/25mm, the degree of crimp is 20%, and the compression rebound rate after opening is 13%.

Embodiment 1-3 and comparative example 1 and the index comparative analysis of corresponding traditional tow are shown in the table below:

It can be seen from the above table that under the same specification condition of the linear density of the tow, the curl degree and compression rebound rate of the tow of the present invention are obviously higher, indicating that the filling performance of the tow of the present invention is good. The filter rod made has a lower suction resistance under the same circumferential conditions, which is beneficial to the smoking of cigarettes; although the suction resistance is low, the filtering effect is very outstanding. From the seven harmful substances (carbon monoxide, hydrogen cyanide, NNK, Ammonia, benzopyrene, phenol and crotonaldehyde) hazard index visible, filter effect is better than comparative example and traditional CA filter stick. With regard to the rod yield of key economic indicators, the tow of the present invention is about 30% higher than that of the comparative example with the same specification, and is 15-20% higher than that of the CA filter rod.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still understand the foregoing embodiments The recorded technical solutions are modified, or some of the technical features are equivalently replaced. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (8)

1. a spinneret, it is characterized in that, on the spinneret is processed with several spinneret holes, the spinneret comprises two hollow holes and an island hole, the hollow hole and the island hole The whole is connected into a three-lobe shape; the inside of the island-shaped hole is provided with a solid forming island, and the forming island is integrally formed with the main part of the spinneret, and the forming island separates the island-shaped hole into a root and a free end, the root communicates with the hollow hole, and there is a forming gap between the root and the free end. 2. The spinneret according to claim 1, characterized in that, the root portion and the free end portion are respectively provided with a first bonding compensation protrusion and a second bonding compensation protrusion at the forming gap. The raised portion, the first adhesive compensation raised portion and the second adhesive compensation raised portion on the same side are oppositely arranged. 3 . The spinneret according to claim 2 , characterized in that, both the first adhesion compensation protrusion and the second adhesion compensation protrusion protrude toward the inner side of the forming island. 4 . 4 . The spinneret according to claim 3 , characterized in that, the protrusion depth of the first adhesion compensation protrusion and the second adhesion compensation protrusion is 0.04-0.06 mm. 5. The spinneret according to claim 3, characterized in that, the width of the forming gap is 0.05-0.07 mm; the width of the pore between the edge of the island-shaped hole and the forming island is 0.07-0.09 mm mm. 6. The spinneret according to claim 3, characterized in that, the island-shaped holes are generally elliptical. 7. A tobacco tow prepared by using the spinneret described in any one of claims 1 to 6, wherein the material of the tobacco tow is PLA, and the monofilament of the tobacco tow is It is a three-dimensional crimped structure, the cross-section of the monofilament is a single-hole trilobal shape, and hollow holes are formed in the sides corresponding to the island-shaped holes on the monofilament. 8. A method for preparing tobacco tow using the spinneret according to any one of claims 1 to 6, characterized in that it comprises the following steps: 1) Dry crystallization: polylactic acid slices are crystallized at 60-90°C, dried at 90-120°C, the crystallization and drying time is 13-20h, and the water content in the modified polylactic acid is controlled to be less than 30ppm; 2) Melt spinning: the diameter of the spinneret is 260mm, the number of holes in the spinneret is 600-1000; the diameter of the spinning screw is 120mm, the ratio of length to diameter is 33:1, the temperature is 210-250°C; the temperature of the box is 235-248 ℃, spinning speed 900-1500m/min; cooling temperature 18-25℃, wind pressure 400-700Pa, wind speed 0.2-0.6m/s, humidity 65-85%; 3) Traction: Six-stick traction machine, the rollers are distributed in a square shape, the surface is hard chrome-plated 0.1mm, and the plow surface is treated; 4) Feeding: The diameter of the feeding wheel is 480mm, and the surface is sprayed with pottery; 5) Reciprocating drop barrel: the reciprocating machine is of longitudinal chain plate type and horizontal guide rail; the size of the wire barrel is 1000x1000x1200mm; the longitudinal transmission is a servo motor, and the longitudinal speed is 5-10m/min; the horizontal transmission is a servo motor, and the lateral speed is 0.2-0.5m/min; The transmission power of entering and exiting the barrel is 1.5Kw, and the speed of entering and exiting the barrel is 5-10m/min; 6) Clustering: 48 barrels for clustering, 2-6 barrels per bundle; hanger rail made of stainless steel, plate thickness 2mm, with guide wire rod, tension adjustment device and upper guide wire frame; tension godet roller diameter 85mm, surface Hard chrome plating 0.1mm; 7) Drafting: drafting is a four-step stretching process, the drafting roller is heated by electromagnetic induction, and the surface of the drafting roller is plated with 0.1mm of hard chrome; the temperature of the first drafting roller is controlled at 45-50 ° C, and the second drafting The temperature of the rolls is controlled at 60-65°C, the temperature of the third drafting roll is controlled at 65-72°C, and the temperature of the fourth drafting roll is controlled at 72-80°C; The speed ratio of the drafting rollers is 1.8, and the speed ratio of the third and fourth drafting rollers is 1.3; 8) Preheating and curling: pass through the steam box before curling, the length of the steam box is 1 meter, and the temperature is controlled at 80-100°C; the circulating hot water is passed inside the curling wheel, and the temperature of the hot water is controlled at 50-60°C; the curling speed is 120 -180m/min, crimping wheel diameter 60mm, crimping wheel width 16-32mm; total density of tow is 2.0-5.5ktex; 9) Drying and heat setting: the oven adopts natural gas heating method, the temperature is controlled at 60-90°C, and the time is 12-15min; 10) Wobbling wire conveying: PVC steel buckle anti-skid belt, width 70, belt thickness 3~4mm, diameter of transmission roller 100mm; diameter of spinning wire feeding wheel 150mm, hard chrome-plated surface 0.05mm, spinning bucket with supporting legs Blade arm mechanism; 11) Packing: main pressure cylinder Φ320xΦ250mm; suitcase cylinder Φ150xΦ85mm; positioning cylinder Φ50xΦ28mm; design pressure 35MPa, motor power 55Kw; package weight 200-250kg.