The dry wet preparation method of acetate fiber
Technical field
The present invention relates to production technology and the production method of acetate fiber.
Background technology
Acetate fiber is called again cellulose acetate fibre, is to develop in the world one of chemical fibre relatively early, and be the second largest kind that is only second to viscose in regenerated celulose fibre at present.Compared with the regenerated celulose fibre such as viscose glue, day silk, performance approaches mulberry silk.Use disperse dyeing bright-colored, COLOR FASTNESS is high, regain is low, good springiness, do not crease easily, and separately have good drapability, thermoplasticity, DIMENSIONAL STABILITY, but itself also exists the shortcoming that mechanical strength is lower; The rear process technology difficulty such as be out of shape, weave larger in addition, make its application and popularization in weaving be subject to certain influence; And the durability of acetate fiber fabric is poor, this is also weaving cellulose acetate filament consumption figure in one of the reason of continuous decrease recent years.Therefore,, since acetate fiber starts suitability for industrialized production, research staff is just devoted to promote that acetate fiber industrial development, developing acetate fiber are applied as a series of research work of object always both at home and abroad.
Acetate fiber is mainly to make taking acetone as solvent dry spinning both at home and abroad at present, in order to improve dissolubility in acetone and the mobility of spinning solution in spinning process, the degree of polymerization of cellulose acetate is conventionally lower, general control is at 200-400, therefore the acetate fiber mechanical property obtaining is relatively poor, dry is only by force 1.05-1.25 Cn/dtex, and elongation at break, below 28%, has limited its Application Areas greatly.And adopt when wet spinning, must be equipped with configuration, circulation and the reclaimer of coagulating bath, technological process complexity, factory building and equipment investment expense are all larger, and spinning speed is low, and cost is high, and environmental pollution is more serious.Therefore, how to develop a ripe high-performance acetate fiber production technology and become the hot issue of recent domestic research.
Number of patent application is the preparation method that 201110142220.4 invention relates to a kind of cellulose diacetate fibers, particularly relate to a kind of preparation method who carries out the cellulose diacetate fibers of dry-jet wet-spinning taking ionic liquid as solvent, comprise the following steps: dissolve cellulose diacetate in ionic liquid (1), form the spinning solution of stable homogeneous; (2) spinning solution is carried out to dry-jet wet-spinning, obtain described cellulose diacetate fibers.Number of patent application is the preparation method that 201210574610.3 invention relates to a kind of acetate fiber, a method of particularly being prepared acetate fiber taking ionic liquid warp after plasticizer Dichlorodiphenyl Acetate cellulose carries out plasticization and modification by melt-spinning technology, comprises the following steps: (1) cellulose acetate is extruded after evenly mixing with ionic liquid; (2) by spinning drying material in vacuum; (3) melt spinning: spinning material is through measuring pump, spinnerets spinning, through hot-rolling drawing-off, extract, washing; (4) again through oiling, be dried, coiling operation, obtain the acetate fiber that fibrous fracture intensity is 2.2~6cN/dtex.Number of patent application is that 201010512167.8 invention relates to a kind of low vinegar esterify cellobiose cellulose fiber and preparation method thereof, wherein cellulosic hydroxyl is replaced by part acetate groups, substitution value is 0.01~0.5, fibrillation index≤2, fibrous fracture intensity >=2.0cN/dtex, extension at break is 6%~30%, fiber number≤3.5dtex.The ion solvent of these three invention employings is expensive, and energy consumption is higher, can not carry out the production application of scale.
The invention that number of patent application is 200710011485.4 provides a kind of high-adsorbability acetate fibre preparing process, taking wood pulps or cotton linter as initiation material, taking acetic anhydride as esterifying agent, sulfuric acid is catalyst, glacial acetic acid is solvent, makes triacetate, makes diacetate by hydrolysis, after acetone solution, add the high adsorption material with nanostructured, after filtration, be spun into high-adsorbability acetate fibre through dry method.The acetone that this invention adopts holds agent, heavy contamination.
Summary of the invention
Goal of the invention: the invention provides a kind of dry wet preparation method of acetate fiber, solve the problem that cellulose acetate fibre poor mechanical property, production cost are high, environmental pollution is serious that prior art is produced.
Technical scheme:
The dry wet preparation method of a kind of acetate fiber disclosed by the invention, contains following preparation process:
(1) preparation of cellulose acetate spinning solution:
In dissolution kettle, taking the glacial acetic acid of moisture content 1%-15% as solvent, be 2.0-2.9 by substitution value, the degree of polymerization is the preferred substitution value 2.25-2.49 of 300-800(, degree of polymerization 450-600, in this method, adopt mouldability and the mechanical property of the acetate fiber that such raw material obtains all better) cellulose acetate (cellulose acetate is hydroxyl aceticanhydride acetylation in cellulosic molecule, and the high polymer of a kind of chemical modification obtaining after hydrolysis, substitution value refers to that hydroxyl in every mole of dehydration glucose unit on cellulose molecular chain is by the acetylizad molal quantity of aceticanhydride) raw material (sheet, graininess) be mixed with the solution that concentration is 12%-24%, the preferred 50-60 of stirring and dissolving 2-6h(DEG C stirring and dissolving 3-4h at 30-80 DEG C, now solution dissolves fully, evenly, stable), pass through again vacuum defoamation, form cellulose acetate spinning solution.
(2) configuration of coagulation bath:
Taking water as solvent, glacial acetic acid is solute, the aqueous acetic acid that configuration concentration is 5%-25%, forms coagulation bath; When coagulating bath concentration is 10-15% acetate fiber as-spun fibre to separate out mouldability better.
(3) dry-wet spinning:
By filtering and spinning appts, the spinneret orifice extrusion solution thread that is 0.01-0.1mm by diameter by cellulose acetate spinning solution, be preferably 100-200mm through a segment length apart from 50-500mm(, now solution thread diameter tends towards stability, steam volatility is moderate) air layer, pass through or be immersed in 20-60 DEG C of temperature (30 DEG C of optimum temperatures, now separate out best in quality) coagulation bath (pass through or dip time is 1-10s), cellulose acetate high polymer is separated out and is formed acetate fiber as-spun fibre in coagulation bath; Glacial acetic acid solvent in solution thread spreads to coagulation bath, and the coagulating agent in coagulation bath is to the diffusion inside of solution thread.
(4) stretch processing:
Adopt stretching device that acetate fiber as-spun fibre is stretched, stretch percentage elongation is the preferred 30%-40% of 10%-60%(, and now mechanical strength and pliability are moderate), become acetate fiber finished product.
Beneficial effect:
The acetate fiber that the present invention produces than traditional dry technology for production, the degree of polymerization is higher, and percentage elongation is moderate, and the mechanical property of acetate fiber is greatly improved.
The long filament of acetate fiber out produced according to the invention and short fiber, its line density is measured according to GB GB/T14343-2008 " filament linear density experimental technique ", GB/14335-2008 " staple line density experiment method " respectively, and mechanical property is measured according to GB GB/14344-2008 " filament draw method for testing performance ", GB/T14337-2008 " staple fibre Erichsen test method " respectively.Result shows: the monofilament linear density of acetate fibre filament is 1.5-15dtex, fracture strength 1.0-1.4 Cn/dtex, elongation at break 15%-35%; The monofilament linear density of acetate fiber staple fibre is 2.0-20dtex, fracture strength 1.0-1.3 Cn/dtex, elongation at break 20%-35%.Improve the Application Areas of acetate fiber, can be widely used in and manufacture textiles, filter tip, medical and hygiene article, sheet base, plastic products etc. for cigarette.
The present invention is than the acetate fiber of wet production, and required factory building and equipment investment expense are lower, reduces in a large number configuration, circulation and the reclaimer of coagulating bath, and technological process is simplified, and spinning speed improves, and product cost is lower.
The present invention, than traditional acetate fiber manufacturing technique methods such as simple dry method and simple wet methods, does not use acetone as solvent, only adopts aqueous acetic acid, and plant operations personnel's harm is alleviated, and plant area's environmental protection index is had to good improvement.
Brief description of the drawings
Fig. 1 is preparation technology's schematic flow sheet of the present invention.
Detailed description of the invention
Embodiment 1:
As shown in drawings, the glacial acetic acid taking moisture 10% is solvent, is 2.0 by substitution value, and the solution that the cellulose acetate sheet compound concentration that the degree of polymerization is 500 is 18%, adds in the dissolution kettle with agitator, thermometer, dissolved solution 4h, vacuum defoamation; By filter and measuring pump, to be extruded by spinneret orifice, spinning head surface to the distance between coagulating bath is set as 100mm; After one section of air layer of 100mm distance, pass through coagulating bath from the solution thread of extruding spinning head, in coagulating bath, glacial acetic acid content is 10%, and coagulation bath temperature is 40 DEG C.Solvent in solution thread spreads to coagulating bath, and the coagulating agent in bath, to thread diffusion inside, forms acetate fiber so polymer is separated out in coagulating bath.Then be 25% to carry out stretch processing at percentage elongation, the monofilament linear density of the acetate fibre filament obtaining is 6.1dtex, fracture strength 1.21 Cn/dtex, elongation at break 25.4%.
Embodiment 2:
Glacial acetic acid taking moisture 5% is solvent, is 2.5 by substitution value, and the solution that the cellulose acetate sheet compound concentration that the degree of polymerization is 550 is 22%, adds in the dissolution kettle with agitator, thermometer, dissolves 3h, vacuum defoamation at 20 DEG C; By filter and measuring pump, to be extruded by spinneret orifice, spinning head surface to the distance between coagulating bath is set as 130mm; After this section of air layer, enter and pass through coagulating bath 2s duration from the solution thread of extruding spinning head, coagulating bath glacial acetic acid content 15%, coagulation bath temperature is 50 DEG C, polymer is separated out and is formed acetate fiber in coagulating bath; Then be 40% to carry out stretch processing at percentage elongation, the monofilament linear density of the acetate fibre filament obtaining is 7.0dtex, fracture strength 1.36 Cn/dtex, elongation at break 28.0.1%.In production, almost there is no exhaust emission discharge, be conducive to environmental protection.
Embodiment 3:
As shown in drawings, the glacial acetic acid taking moisture 15% is solvent, is 2.9 by substitution value, and the solution that the cellulose acetate particle formulation concentration that the degree of polymerization is 600 is 12%, adds in the dissolution kettle with agitator, thermometer, dissolves 6h, vacuum defoamation at 30 DEG C; By filter and measuring pump, extruded by spinneret orifice, after one section of air layer of 200mm distance, be immersed in coagulating bath 5 seconds (5s) from the solution thread of extruding spinning head.In coagulating bath, glacial acetic acid content is 20%, and coagulation bath temperature is 20 DEG C.Solvent in solution thread spreads to coagulating bath, and the coagulating agent in bath, to thread diffusion inside, forms acetate fiber so polymer is separated out in coagulating bath.Then be 60% to carry out stretch processing at percentage elongation, the density of the acetate fiber silk thread obtaining, fracture strength, elongation at break are all better than the acetate fibres of conventional wet explained hereafter.