CN102704030A - Tow with high crimp index for polylactic acid cigarette and preparation method for tow - Google Patents

Abstract

The invention discloses a tow with a high crimp index for a polylactic acid cigarette and a preparation method for the tow. The tow is prepared from the following raw materials by a melt spinning method: 99-100 percent by weight of polylactic acid, 0.1-0.5 percent by weight of nanoscale titanium dioxide, 0.1-0.5 percent by weight of hydrated magnesium silicate ultrafine powder, wherein the linear density of the tow is 3.5-5.0 ktex, the linear density of a single filament is 2-5 dtex, the crimp number is 18-28/25 mm and the crimp index is 0.45-0.65. According to the tow and the preparation method disclosed by the invention, a nucleating agent is added into a polylactic acid raw material, so that the crystallization rate is increased and the crystallinity degree and the thermal performance of fibers are improved, and further the crimp temperature in the subsequent spinning crimp work procedures is increased to 85-95DEG C and the crimp performance is improved; and the crimp index of the whole tow is improved to about 0.55. The tow with high crimp index for the polylactic acid cigarette has better crimp performance; and under the same conditions, unit weight tows can be used for preparing more filter rods, and thus the economic benefits are increased.

Description

A kind of PLA pipe tobacco and preparation method of high crimp index

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Technical field

The present invention relates to cigarette filter tip materials and preparation method thereof, specifically is a kind of PLA pipe tobacco and preparation method of high crimp index.

Background technology

Cigarette filter is an important component part of cigarette.Use filter-tip material as cigarette, except have better spinnability can, also have a lot of unique requirements: (1) is rolled by it that the filter stick that forms is nontoxic, tasteless, security is good; (2) tow good stability can satisfy filter stick formation equipment and technological requirement; (3) have suitable rigidity and crimp property, make it to have better elastic and opening character, under the situation of less tow loading; After adding plasticizer or adhesive; Filter stick satisfies certain rigidity, resistance to suction and presentation quality requirement, and the higher excellent rate that goes out is arranged, and has practical value; (4) in the cigarette smoking process, filter tip does not subside, is out of shape; (5) filter stick has high filtration efficiency to harmful ingredients in flue gas.Up to now, a lot of fibers have been realized suitability for industrialized production, but real commercial cigarette filter tip materials has only cellulose diacetate and two kinds of polypropylene.

Cellulose diacetate fibers is a kind of function admirable, uses general filter-tip material that its selection is adopted the mode of dry spinning in perennial high-quality timber, makes and is suitable for the filter tow that cigarette is used.Contain the polar group of strong polarity on the fine molecule side chain of vinegar, the tow surface has micropore and harsh feeling, so diacetate fiber, has physical absorption and chemisorbed double effects simultaneously to the harmful components in the flue gas, it filters and the absorption property excellence; And, in the process of producing filter stick, carry out plasticising, bonding through adding triacetyl glycerine, under the situation of less tow loading, filter stick satisfies quality requirements such as hardness, resistance to suction, and the higher excellent rate that goes out is arranged.But the raw material of producing cellulose diacetate are perennial high-quality timber, and China at present can not be self-supporting, mainly relies on import; The more important thing is; Along with the continuous expansion of domestic tobacco enterprise output, the demand of the fine filter stick of vinegar is grown with each passing day, but domestic diacetate fiber manufacturing enterprise can not satisfy the demand of tobacco enterprise fully at present; Cause vinegar situation fine in short supply, limited further developing of China's tobacco business to a certain extent.In addition, more serious pollution problem is followed in wood pulp production, cellulose esterification and cellulose acetate spinning, and production cost is high, costs an arm and a leg, and compares the remarkable deterioration of the biodegradability of cellulose acetate with timber.

Advantages such as polypropylene cigarette as the distinctive a kind of filtering material of China's cigarette industry, has raw material abundance at initial stage of development with filter tow, and is cheap and being greatly developed, and make a great contribution for China's tobacco business cost efficiency.Pp material is taken from oil, adopts the mode of melt spinning, and the fibre bundle that makes is in the process of producing filter stick; Bond through adding special-purpose adhesive; Under the situation of less tow loading, filter stick satisfies quality requirements such as hardness, resistance to suction, and the higher excellent rate that goes out is arranged.But because polypropylene is the highly stable apolar substance of a kind of structure, itself does not have any polar group, the tow smooth surface; Its adsorption capacity can not show a candle to acetate fiber; Smoke filtering effect is poor, and stronger acid is arranged during suction, generally can only be used for Low-end Cigarettes; Simultaneously, polypropylene is a long chain hydrocarbon, can not biodegradation, environment is caused severe contamination; In addition, petroleum resources are exhausted day by day, and cost of material goes up fast, and polyacrylic price advantage is just progressively lost.In recent years, along with the adjustment of tobacco business product structure, China's cigarette class improves constantly, and the Low-end Cigarettes consumption descends year by year, and the third fine consumption reduces year by year, and trend is progressively withdrawn from the market.

No matter from the angle of resource; Still reduce the angle of environmental pollution, it is fine near vinegar to seek a kind of combination property, the novel pipe tobacco that price is cheap relatively again; Alternative polypropylene material is used for the production of low and middle-grade cigarette; And partly substitute the production that the vinegar fibre is used for medium-to-high grade cigarette, to remedy the deficiency of the fine supply of vinegar, be the tobacco business urgent problem.

PLA is a kind of novel environment friendly material, has good circular regeneration property and biological degradability.It is a raw material with reproducible plant resources (corn, wheat, beet, rice, potato, sweet potato etc.) and organic waste (root of corncob or other crops, stem, leaf, skin etc.); Broken away from dependence, met the requirement of international community's sustainable development timber and petroleum resources; The energy consumption of PLA is lower than various fibers such as polypropylene and cellulose diacetate, is a kind of macromolecular material of low-resource carrying capacity of environment; PLA can complete biodegradable; The process certain hour can natural decomposition be water and carbon dioxide in natural environment; Do not cause environmental pollution; The carbon dioxide that produces is utilized through photosynthesis of plants again, becomes a carbon cycle system eternal, sealing, is genuine " green material "; PLA has good processing properties, can adopt melt spinning method production; The fine structural similarity of acid fiber by polylactic and vinegar, molecular surface contains abundant polar group; Polar substances had stronger affinity; Can carry out chemical reaction with tar component and lower-molecular substance, reactant is firmly stayed fiber surface, simultaneously; The tow surface has micropore and harsh feeling; In adsorption process to flue gas, have physical absorption and chemisorbed double effects simultaneously, the filter stick that this tow is produced is obvious to the harmful substance filter effect in the flue gas.Therefore, PLA is expected to become the suitable material of preparation cigarette with filter filament.

Polylactic fibre product use filtering material as cigarette, have comprehensive advantages such as aboundresources, the excellent feature of environmental protection, good adsorption property, reliable security, good processing and forming property and economy; Applying of product, for China's tobacco business widen the raw material channel, cost efficiency has active operation significance, will produce favorable social and economic benefits, and will drive the development of China's poly-lactic acid material whole industry chain.

At present domestic existing several pieces of patents about the PLA pipe tobacco are in the patent No.: technology and the method for having introduced polylactic resin raw material spinning PLA pipe tobacco in 200610131699.0 " a kind of cigarette filter filaments and preparation method thereof "; In the patent No.: introduced the PLA pipe tobacco in 200710055310.3 " a kind of filter stick for cigarettes and preparation method thereof " and prepared the method for PLA filter stick for cigarettes, but had some insurmountable problems in these two pieces of patents through shredding, bonding, parcel, cutting and post processing.As: in the process of polylactic resin raw material spinning PLA pipe tobacco, need at high temperature curl and drying and shaping processing, to improve its crimp property and physical and mechanical properties; And poly-lactic acid material poor mechanical property at high temperature, heat-resistant stability is poor, is unable to undergo high temperature process; Cause the PLA pipe tobacco degradation of spinning, thus, under identical filtering rod, circumference and hardness etc. require; Must fill more tow, under equal conditions, compare with the made filter stick of cellulose diacetate and fibre beam for polypropylene cigarette; PLA filter stick individual cigarette weight will be heavy 0.1～0.3 gram/, be equivalent to excellent rate and will hang down 20～500,000/ton; Also bring the auxiliary material consumption to increase thus, the packed and transported cost improves, problems such as economic benefit reduction, thus the application on cigarette produces than limitations to the PLA pipe tobacco.

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Summary of the invention

The object of the invention is exactly the problem that exists to above-mentioned prior art, and a kind of PLA pipe tobacco and preparation method of high crimp index are provided, and this tow crimp index reaches about 0.55, and the higher excellent rate that goes out is arranged during filter stick formation, has practical value.

The principles of science of institute of the present invention foundation is: influence the technical process of poly-lactic acid material hot property from depolymerization and Study on Crystallization Process, select the rapid nucleating agent of suitable PLA draw-spinning process; In polylactic acid raw material, add crystallization nucleating agent and improve crystalline rate; Improve the degree of crystallinity and the hot property of fiber; Spin the temperature of curling in the operation of curling after making and improve (85～95 ℃), crimp property is able to promote, and whole synnema bundle crimp index is brought up to about 0.55 from about 0.40.When filter stick formation, with less tow loading, after adding plasticizer or adhesive, filter stick satisfies certain rigidity, resistance to suction and presentation quality requirement, and it is similar to go out excellent rate and cellulose diacetate and fibre beam for polypropylene cigarette.This tow has formedness price ratio and practical value.

The objective of the invention is to realize through following technical scheme:

A kind of PLA pipe tobacco of high crimp index is to be made through melt spinning method by following raw material, PLA 99～100 wt%, nano grade titanium white powder 0.1%～0.5wt%; Hydrated magnesium silicate superfine powder 0.1%～0.5wt% ,Its tow line density is 3.5～5.0ktex, and monofilament linear density is 2～5dtex, and crispation number is 18～28/25mm, and crimp index is 0.55 ± 0.10.

Said nano grade titanium white powder main component titanium dioxide, TiO2, the size of particulate is below 0.1 micron, CAS:13463-67-7.Hydrated magnesium silicate superfine powder (3MgO4SiO ₂H ₂O, CAS:14807-96-6).

The preparation method of the PLA pipe tobacco of high crimp index of the present invention is that polylactic acid raw material and titanium white powder and hydrated magnesium silicate superfine powder is dry, behind blend melt spinning, through drawing-off, curl, operation such as drying and shaping, obtain the PLA pipe tobacco.Specifically may further comprise the steps:

1) be 2～4g/10min with melt index, fusing point is that 163～173 ℃ polylactic acid raw material is dried to moisture less than 200ppm, 60～120 ℃ of baking temperatures, 4～8 hours drying times; Simultaneously, titanium white powder and hydrated magnesium silicate superfine powder are dried to moisture less than 200ppm, 50～60 ℃ of baking temperatures, 4～8 hours drying times;

2) with dried polylactic acid raw material with send into the spinning system after titanium white powder and hydrated magnesium silicate superfine powder are mixed, in 200～220 ℃ of fusions, filtration, quantitatively import filament spinning component through measuring pump; Melt is extruded through spinnerets; The spinnerets hole count is 8000～15000, and the spinneret orifice profile is a trilobal cross;

3) adopting process air-conditioning cooling device carries out cooling forming to new spun tow, 10～20 ℃ of cooling wind-warm syndrome; Finish oil disc through rotating is coated in the tow surface to improve road, back machinability with finish (TAKEMOTO OIL&FAT CO., the DELION board finish of LTD company);

4) be temporary in the fiber barrel after under the coiling speed of 300～1000m/min, tow being reeled;

5) in the water-bath of uniform temperature, tow is carried out drawing-off, drawing temperature is 50～80 ℃, and the drawing-off multiplying power is 2～3 times;

6) entering of the tow after drawing-off crimping machine curls, and curling temperature is 85～95 ℃;

7) obtain above-mentioned PLA pipe tobacco after the tow drying and shaping after curling, the drying and shaping temperature is at 60～90 ℃, drying and shaping time 10～15min.

Cigarette filter filament provided by the invention can directly be processed cigarette filter rod through known cigarette filter rod forming machine, and the filter stick of production has stronger adsorption capacity to the harmful substance in the flue gas.Through filter stick formation, tipping, flue gas analysis and smoke panel test; Made filter stick individual cigarette weight of this tow and cellulose diacetate and fibre beam for polypropylene cigarette are similar; Institute's cigarette that connects is in aspiration procedure; Harmful substance Filtration Adsorption effect in the flue gas is obvious, and keeps the suction flavor of cigarette not have too about-face (testing result sees the following form).

         

Filter stick index behind the different wire-beam formings of table 1 (24.1mm * 120mm)

Test specimen	Length m m	Weight g	Circumference mm	Resistance to suction pa	Hardness %
						Vinegar is fine	144	0.92	24.1	3480	90.2
PLA	144	0.89	24.1	3494	89.2
						Polypropylene	144	0.88	24.1	3457	89.9

Annotate: it is more than PLA, polypropylene tows that the vinegar fibre adds glue (plasticizer) amount, and removing list after glue (plasticizer) amount, to prop up excellent heavy phase imitative.

Cigarette main stream flue gas index under the table 2 variety classes filter stick detects table

Cigarette organoleptic attribute under the table 3 variety classes filter stick record sheet of smokeing panel test

Annotate: " ↑ " expression has improvement slightly and promotes; " ↑ ↑ " obviously improvement and lifting of expression; " ↓ " expression has variation slightly; " ↓ ↓ " represent obvious variation; "=" expression no change.

The present invention compared with prior art has following beneficial effect:

1. owing in polylactic acid raw material, add crystallization nucleating agent (being titanium white powder and hydrated magnesium silicate superfine powder); Improve crystalline rate; Thereby improve the degree of crystallinity and the hot property of fiber; Fiber can at high temperature be curled and drying and shaping processing, obtain the good cigarette of crimp property and physical and mechanical properties and use filter tow, its crimp index reaches about 55%.This tow is when filter stick formation; Through adding plasticizer or adhesive, made filter stick satisfies quality requirements such as the hardness, resistance to suction of technological requirement, and the filter stick individual cigarette weight is similar with vinegar fibre and the made filter stick of fibre beam for polypropylene cigarette; The higher excellent rate that goes out is arranged, have practical value.

2. through analyzing and testing, the made filter stick of PLA tow provided by the present invention has stronger adsorption capacity to the harmful substance in the flue gas, and keeps the suction flavor of cigarette not have too about-face.

3. in addition,, can reduce pollution on the environment because PLA has biodegradable characteristics.

 

The specific embodiment

To combine embodiment to be described further below the present invention, but content of the present invention is not limited to this.

Embodiment 1

Selecting a kind of melt index for use is 2.58g/10min, and fusing point is 168 ℃ a polylactic resin, adopts the vacuum drum drying machine 80 ℃ of dryings 8 hours, and moisture is less than 100ppm; Simultaneously in special-purpose drying tower, polylactic acid raw material and titanium white powder and hydrated magnesium silicate superfine powder are dried to moisture less than 200ppm, 58 ℃ of baking temperatures, 8 hours drying times; Dried above-mentioned raw materials is mixed, and its raw material is formed the PLA that comprises 99.85 wt%; The nano grade titanium white powder of 0.10wt%, 0.05wt% hydrated magnesium silicate superfine powder; In 210 ℃ of following fusions, filtration, quantitatively import filament spinning component through measuring pump, the spinnerets hole count is 11400, the spinneret orifice profile is a trilobal cross; Adopt 11 ℃ cooling air to carry out cooling forming, finish is coated in the tow surface through finish oil disc; Be temporary in the fiber barrel after under the coiling speed of 550m/min, tow being reeled; In 75 ℃ water-bath, tow is carried out drawing-off, draft speed 100～200m/min, the drawing-off multiplying power is 2.3; Tow behind the counter extensioin curls on crimping machine, and curling temperature is 90 ℃; Tow after curling gets into drying and setting machine, and the drying and shaping temperature is at 65～75 ℃, drying and shaping time 12min; Finally, obtaining monofilament linear density is 3.4dtex, and tow line density is 3.89ktex, and crispation number is 23/25mm, and crimp index is 0.59 PLA tow.

Embodiment 2

Selecting a kind of melt index for use is 2.72g/10min, and fusing point is 167 ℃ a polylactic resin, adopts the vacuum drum drying machine 80 ℃ of dryings 8 hours, and moisture is less than 100ppm; Simultaneously in special-purpose drying tower, polylactic acid raw material and titanium white powder and hydrated magnesium silicate superfine powder are dried to moisture less than 200ppm, 55 ℃ of baking temperatures, 8 hours drying times; Dried above-mentioned raw materials is mixed, and its raw material is formed the PLA that comprises 99.75 wt%; The nano grade titanium white powder of 0.15wt%, 0.10wt% hydrated magnesium silicate superfine powder; In 215 ℃ of following fusions, filtration, quantitatively import filament spinning component through measuring pump, the spinnerets hole count is 11400, the spinneret orifice profile is a trilobal cross; Adopt 11 ℃ cooling air to carry out cooling forming, finish is coated in the tow surface through finish oil disc; Be temporary in the fiber barrel after under the coiling speed of 450m/min, tow being reeled; In 75 ℃ water-bath, tow is carried out drawing-off, draft speed 100～200m/min, the drawing-off multiplying power is 2.5; Tow behind the counter extensioin curls on crimping machine, and curling temperature is 95 ℃; Tow after curling gets into drying and setting machine, and the drying and shaping temperature is at 70～85 ℃, drying and shaping time 12min; Finally, obtaining monofilament linear density is 3.7dtex, and tow line density is 4.22ktex, and crispation number is 23/25mm, and crimp index is 0.60 PLA tow.

Embodiment 3

Selecting a kind of melt index for use is 2.37g/10min, and fusing point is 170 ℃ a polylactic resin, adopts the vacuum drum drying machine 80 ℃ of dryings 8 hours, and moisture is less than 100ppm; Simultaneously in special-purpose drying tower, polylactic acid raw material and titanium white powder and hydrated magnesium silicate superfine powder are dried to moisture less than 200ppm, 58 ℃ of baking temperatures, 8 hours drying times; Dried above-mentioned raw materials is mixed, and its raw material is formed the PLA that comprises 99.75 wt%; The nano grade titanium white powder of 0.10wt%, 0.15wt% hydrated magnesium silicate superfine powder; In 210 ℃ of following fusions, filtration, quantitatively import filament spinning component through measuring pump, the spinnerets hole count is 13200, the spinneret orifice profile is a trilobal cross; Adopt 11 ℃ cooling air to carry out cooling forming, finish is coated in the tow surface through finish oil disc; Be temporary in the fiber barrel after under the coiling speed of 450m/min, tow being reeled; In 75 ℃ water-bath, tow is carried out drawing-off, draft speed 100～200m/min, the drawing-off multiplying power is 2.5; Tow behind the counter extensioin curls on crimping machine, and curling temperature is 85 ℃; Tow after curling gets into drying and setting machine, and the drying and shaping temperature is at 65～75 ℃, drying and shaping time 12min; Finally, obtaining monofilament linear density is 3.4dtex, and tow line density is 4.44ktex, and crispation number is 21/25mm, and crimp index is 0.53 PLA tow.

Claims (4)

1. the PLA pipe tobacco of a high crimp index is characterized in that: be to make through melt spinning method by following raw material, and PLA 99～100 wt%, nano grade titanium white powder 0.1%～0.5wt%, hydrated magnesium silicate superfine powder 0.1%～0.5wt%; Its tow line density is 3.5～5.0ktex, and monofilament linear density is 2～5dtex, and crispation number is 18～28/25mm, and crimp index is 0.55 ± 0.10.

2. the PLA pipe tobacco of high crimp index according to claim 1 is characterized in that: said nano grade titanium white powder main component titanium dioxide, and TiO2, the size of particulate is below 0.1 micron, CAS:13463-67-7.

3. the preparation method of the PLA pipe tobacco of the described high crimp index of claim 1; It is characterized in that: with polylactic acid raw material and titanium white powder and hydrated magnesium silicate superfine powder drying; Behind blend melt spinning; Through drawing-off, curl, operation such as drying and shaping, obtain the PLA pipe tobacco.

4. the preparation method of the PLA pipe tobacco of high crimp index according to claim 3, it is characterized in that: concrete preparation method may further comprise the steps:

1) be 2～4g/10min with melt index, fusing point is that 163～173 ℃ polylactic acid raw material is dried to moisture less than 200ppm, 60～120 ℃ of baking temperatures, 4～8 hours drying times; Simultaneously, titanium white powder and hydrated magnesium silicate superfine powder are dried to moisture less than 200ppm, 50～60 ℃ of baking temperatures, 4～8 hours drying times;

2) with sending into the spinning system after dried polylactic acid raw material, titanium white powder and the mixing of hydrated magnesium silicate superfine powder,, quantitatively import filament spinning component through measuring pump in 200～220 ℃ of fusions, filtration; Melt is extruded through spinnerets; The spinnerets hole count is 8000～15000, and the spinneret orifice profile is a trilobal cross;

3) adopting process air-conditioning cooling device carries out cooling forming to new spun tow, 10～20 ℃ of cooling wind-warm syndrome; Finish oil disc through rotating is coated in the tow surface to improve road, back machinability with finish;

4) be temporary in the fiber barrel after under the coiling speed of 300～1000m/min, tow being reeled;

5) in the water-bath of uniform temperature, tow is carried out drawing-off, drawing temperature is 50～80 ℃, and the drawing-off multiplying power is 2～3 times;

6) entering of the tow after drawing-off crimping machine curls, and curling temperature is 85～95 ℃;

7) obtain above-mentioned PLA pipe tobacco after the tow drying and shaping after curling, the drying and shaping temperature is at 60～90 ℃, drying and shaping time 10～15min.