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  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The present invention provides a process for making a cellulose solution. NMMO with a relatively low concentration and non-activated mass are continuously mixed online, the mixed premix is dewatered in an evaporative dewatering device until an NMMO concentration is reached which is suitable for swelling, then sufficient swelling is carried out under this condition and the uniform Mixed and sufficiently swollen pre-swell solution is subjected to pressure-released evaporation drainage and dissolution by a thin film evaporator, whereby a uniformly dissolved cellulose solution of high concentration and excellent uniformity is obtained. The present invention further provides a continuous manufacturing apparatus for the process of making a cellulose solution. According to the present invention, the conflict between uniform mixing and sufficient swelling during the manufacture of a high concentration cellulose solution is solved and storage and transportation safety problems caused by using high concentration NMMO in the conventional technologies are avoided. And the mass used does not have to be activated so that the energy consumption is low. According to the process provided by the present invention, the technological process is safer, more energy-efficient and more efficient, and continuous industrial production is facilitated.
    公开号:AT521560A2
    申请号:T9240/2016
    申请日:2016-05-10
    公开日:2020-02-15
    发明作者:
    申请人:China Textile Academy；
    IPC主号:
    专利说明:

    description
    Process for the production of a cellulose solution and device therefor
    TECHNICAL AREA
    The present invention belongs to a field of cellulose and in particular relates to a process for producing a cellulose solution and an apparatus for the same
    Method.
    BACKGROUND because of her
    Raw material,
    Cellulose fibers as
    Properties excellent preferred.
    keep it up from that
    Those are performance, extensive application and reusable by people
    Machining technologies Cellulose fiber is still dominated by current conventional viscose processes. Pollution generated by processes during production is slowly being taken into account by people, so green and environmentally friendly machining technology is urgently needed. In the 90s of the last century, processing technology that produces a stock solution by directly dissolving cellulose with an organic, i.e., N-methylmorpholine-N-oxide (NMMO), and then spinning, thoroughly solves the problem of pollution of the viscose process. And fibers made by this technology are manufactured by BISFA (The
    Standardization of Man-made Fibers) is called Lyocell.
    Solvent that
    International Bureau for
    During the process of using cellulose by dissolving
    Production of Lyocell fibers of an aqueous NMMO2 / 38
    -2Solution, the swelling and dissolving processes of cellulose through NMMO and effects are directly related to the spinning stability and performance of end products. And the concentration of a spinning solution and whether a technical process saves energy or not are directly related to the economic benefits of process technology. Given the importance of the stair solution for spinning during the production of the Lyocell fibers, an energy-saving and efficient process for producing a well-distributed cellulose stock solution in high concentration for spinning is urgently required.
    During the manufacture of a cellulose solution, several steps, i.e. mixing, swelling and dissolving a mass and NMMO, have to be carried out in different devices. And, given the multiple stages and overall swelling and dissolving process, different swelling and dissolving methods and devices are described in different patents.
    In manufacturing processes of Lyocell fiber disclosed by CN1635203A, CN1981075A and CN1635203A, the entire mass is activated by activating enzyme and mixed with NMMO and swollen and then dewatered under decompression and dissolved to obtain the solution for spinning.
    A method for producing a cellulose solution is disclosed in CN1468889A and is characterized in that a cellulose solution made of cellulose powder with a diameter of not more than 1000 µm and NMMO with a concentration of 88% by heating, mixing, kneading,
    3/38
    -3 Dissolve and homogenize in a twin screw extruder.
    An apparatus for producing cellulosic films and fibers and an integrated system are disclosed in CN1157012A, wherein the production of a cellulosic solution is carried out by two thin film evaporators connected in series and for depressurizing and heating a liquid mixture of bulk and NMMO can be used to achieve swelling, thereby obtaining the cellulose solution.
    The mass may be activated or not activated for the existing main processes for producing a cellulose solution. And solvents can have a high concentration or a certain concentration, and mixing, swelling and dissolving processes for the mass and the solvent can be carried out separately or accomplished in the same device. Currently, all of the disclosed and industrialized methods, such as CN1635203A, CN1981075A and CN1635203A, use NMMO in high concentration (80% to 86.7%) and activated mass, and include the steps of exporting mixes and sources in a blender and then performing a resolution a thin film evaporator.
    Although the generation of gel particles can be reduced to some extent, the activated mass introduces a large volume of moisture, the problem of energy consumption caused by repeated evaporation, and certain safety risks are associated with evaporation, storage and Levy
    4/38
    -4 of solvents present in high concentration. If comminuted bulk and NMMO are used in high concentration and subjected to mixing, swelling and dissolving in a screw extruder, the problem of moisture introduction during activation can be prevented, but the requirements for a comminuted particle size are too high, a large-scale implementation is difficult and the problem of dust contamination during shredding is also difficult to avoid.
    In addition, if NMMO suitable for swelling is used in high concentration, there are problems of a high degree of swelling and a relatively low liquor ratio during mixing and swelling, and it is difficult to prepare a homogeneous solution in high concentration (12% to 15%) for spinning. By using a method of mixing NMMO of a certain concentration with mass and performing swelling and dissolving of the mass by the two thin film evaporators, NMMO with a relatively low concentration is theoretically used and the problem of poor uniformity caused by an insufficient liquor ratio during the manufacture of a High concentration solution caused for spinning can be effectively resolved. However, during the actual implementation of this process, there are problems that films are difficult to form in a liquid mixture and phase division occurs when a solid phase falls off and a liquid phase flows along a wall when the liquid mixture undergoes pressure relief dewatering and swelling in a first stage— Thin film evaporation device
    5/38
    -5 is suspended so that the uniformity of a previously resolved solution is difficult to guarantee.
    SUMMARY
    The present invention aims to improve existing blending, swelling and dissolving processes of cellulose to alleviate the problems in a conflict between uniform blending and sufficient swelling and energy consumption during the mixing, swelling and dissolving processes of high concentration and activated mass NMMO to solve the technological process according to the state of the art and to produce a homogeneous solution of high concentration for spinning from NMMO with a relatively low concentration and non-activated mass online and in a continuous manner.
    A technical scheme of the present invention is as follows:
    A process for making a cellulose solution involves the following steps:
    (1) uniformly mixing cellulose pulp and an aqueous NMMO solution at a temperature of 70 ° C to 100 ° C to obtain a premix, a mass of the aqueous NMMO solution being 5 to 10 times that of the cellulose pulp, and the NMMO aqueous solution has a water / NMMO mass ratio in a range of 28:72 to 60:40;
    (2) subjecting the premix to evaporation drainage to obtain a pre-swell solution, the
    6/38
    -6 pre-swelling solution has a water / NMMO mass ratio in a range from 16:84 to 28:72;
    (3) Heat pre-swell in a swelling vessel for sufficient swell to swell. To get solution; and (4) subjecting the swollen solution to drainage by depressurized evaporation and dissolution to obtain the cellulose solution.
    The cellulose mass is dry-cut mass or dry-cracked mass and can also be wet-crushed mass. And the .Variety of the cellulose mass includes, but is not limited to, one or more of wood pulp, bamboo mass and cotton mass.
    According to the present invention, NMMO with a relatively low concentration and non-activated mass are continuously mixed online, the mixed premix is dewatered in an evaporative dewatering device until an NMMO concentration suitable for swelling is reached, then sufficient swelling among the Conditions are carried out and the uniformly mixed and sufficiently swollen pre-swelling solution is subjected to drainage through pressure-relieved evaporation and dissolution. subjected to an evaporative dewatering apparatus, thereby obtaining a uniformly dissolved cellulose solution of excellent uniformity with a concentration in a range from 12% to 15%.
    7/38
    In the research process, researchers of the present invention found that by thoroughly mixing an aqueous NMMO solution of a relatively low concentration in a range from 70 ° C to 100 ° C with the cellulose mass, the cellulose mass is dispersed rapidly and uniformly in the aqueous NMMO solution can, a uniform mixing of the mass and the NMMO solution is guaranteed and a basis for sufficient swelling and dissolving of the cellulose mass is established.
    In aqueous NMMO solutions with a 'relatively low concentration, however, the swelling of the cellulose mass is insufficient. The NMMO concentration in the present invention is raised to a range suitable for swelling by pressure-released evaporation dewatering, the cellulose mass is sufficiently swelled in a shorter time at a lower temperature, and the production of the cellulose solution on a continuous large scale is facilitated .
    By using the technological process, the uniformity of mixing and the sufficient swelling are effectively guaranteed, the conflict between uniform mixing and sufficient swelling in the production of a cellulose solution of high concentration is resolved, the generation of a large amount of gel particles, during the dissolution is prevented, the spinning stability of the cellulose solution is improved and the pressure of a spinning filter device is reduced. And by using a non-activated mass, the problem of energy consumption resulting from repeated evaporation is avoided.
    8/38
    -8 In step (1), the aqueous NMMO solution has a water / NMMO mass ratio in a range of 28:72 to 50:50.
    In step (1), the aqueous NMMO solution preferably has a water / NMMO mass ratio in a range from 28:72 to 35:65.
    In step (2), the pre-swell solution has a water / NMMA mass ratio in a range from 18:82 to 27:73.
    Preferably in step (2) the pre-swell solution has a water / NMMO mass ratio in a range from 19:81 to 25:75.
    In step (1), the mass of the aqueous NMMO solution is 8 to 10 times that of the cellulose mass and the aqueous NMMO solution has a temperature of 80 ° C to 90 ° C.
    In step (1), a process for uniformly mixing the cellulosic mass and the aqueous NMMO solution includes adding the cellulosic mass and the aqueous NMMO solution to a continuous mixer and performing continuous mixing for 5 minutes to 30 minutes at a linear stirring speed in one area from 60 m / min to 180 m / min.
    In step (2), a process for drainage by evaporation drainage by drainage by pressure-relieved evaporation is carried out at a drainage temperature of 80 ° C to 110 ° C under a drainage pressure of 4 kPa to 10 kPa.
    9/38
    -9 By using dewatering by depressurized evaporation, the dewatering temperature can be lowered, the dewatering efficiency can be increased and the continuous process of the entire production of the cellulose solution is facilitated.
    In step (3), the pre-swell solution is swollen sufficiently at a temperature in a range from 55 ° C to 95 ° C for a residence time in a range from 3 min to 60 min to obtain a swollen solution in the swelling vessel.
    Preferably, the pre-swell solution in step (3) is sufficiently swollen at a temperature in a range from 65 ° C to 95 ° C for a residence time in a range from 10 min to 45 min to obtain a swollen solution in the swelling vessel.
    Particularly preferably, the pre-swelling solution in step (3) is swollen sufficiently at a temperature in a range from 75 ° C. to 85 ° C. for a residence time in a range from 15 minutes to 30 minutes in order to obtain a swollen solution in the swelling vessel.
    The swelling device used for pre-swelling in the present invention is a swelling device of the horizontal flow agitation type, so that the cellulose mass has the same residence time, the continuous production of the cellulose solution is facilitated, and the swollen solution produced is sufficiently and uniformly swollen.
    10/38
    -10 In step (4), a process for dewatering by depressurized evaporation and dissolution is a thin film evaporation dewatering and dissolution and is carried out at a dewatering temperature in a range from 100 ° C to 150 ° C under a dewatering pressure in a range from 4 kPA to 10 kPA a linear thin film wiping speed of 2m / s to 6m / s.
    A continuous cellulosic solution manufacturing apparatus includes a continuous feeder, a continuous mixer, a continuous pressure relief and heating device, a swelling vessel, and a thin film evaporation / dissolution device, which are connected in series by a string, the continuous feeder being a continuous bulk feeder and comprises a continuous aqueous NMMO solution feeder, and the continuous bulk feeder and the continuous aqueous NMMO solution feeder are each connected to feed portions of the continuous mixer.
    The continuous mixer is a continuous mixing device such as a single shaft continuous mixer, a twin shaft continuous mixer or a kneading type continuous twin screw mixer, and can be used for rapid and sufficient mixing of NMMO and cellulose pulp, and a premix is obtained after mixing.
    11/38
    -IlThe continuous pressure relief and heating device is selected from a continuous mixer equipped with a vacuum heater.
    The continuous pressure relief and heating device can be used for further intensive stirring and mixing of the premix. A stirring component of the device can be used to heat the pre-mix through a contact surface and the pre-mix is subjected to drainage by depressurized evaporation under a certain vacuum until a given volume of moisture has evaporated so that a concentration of NMMO reaches an optimal source concentration range and a pre-swell solution is obtained.
    The swelling vessel enables the pre-swelling solution, the concentration of NMMO of which reaches the optimum swelling concentration range, to be swollen sufficiently at a suitable temperature after a certain dwell time, and the pre-swelling solution to be converted into the swollen solution. The swelling vessel is provided with a stirring device of the horizontal flow type, so that the liquid mixture is subject to a first-in and first-out principle and has the same swelling residence time and the temperature of an outer jacket (an inner wall) of the swelling vessel can be regulated and controlled by a heating medium.
    The thin film evaporator / dissolver is a vertical type thin film evaporator / dissolver and the swollen solution can be on the surface of a vertical inner wall of the thin film evaporator 12/38
    -12 / Dissolver is distributed to form a thin film shape, and is dewatered under proper temperature and vacuum conditions and converted into a cellulose solution at a concentration of 10% to 15%.
    The continuous cellulose solution manufacturing apparatus provided by the present invention further includes a molding machine, wherein the molding machine can be used to convert the cellulose solution for spinning into products such as fibers, films and nonwovens.
    The continuous cellulose solution manufacturing apparatus further includes a storage vessel and a first feed pump, the storage vessel and the first feed pump being arranged in sequence on a string between the continuous mixer and the continuous pressure relief and heating device.
    The continuous cellulose solution manufacturing apparatus further includes a second feed pump, the second feed pump being arranged on a string between the swelling vessel and the thin film evaporation / dissolution device.
    The present invention discloses a process for making a cellulose solution and an apparatus for the process. According to the present invention, a continuous feed mode is used, a low concentration aqueous NMMO solution is premixed with cellulosic mass, additives, etc. in a blender, then the premix passes into a continuous pressure relief and heating device
    13/38
    -13horizontal type and is subjected to pressure-relieved drainage, so that the NMMO concentration can reach an optimal source concentration range. And the cellulose pulp is sufficiently swelled for a certain time at a certain temperature, and then dehydration and dissolution are further carried out in a vertical type thin film evaporator using thin film evaporation technology to form a solution with good process capability.
    Compared to the prior art, the process for producing the cellulose solution disclosed by the present invention has the advantages that the conflict between uniform mixing and sufficient swelling is resolved during the manufacture of a high concentration cellulose solution and both uniform mixing and sufficient swelling is achieved.
    Using low concentration NMMO avoids storage and transportation safety problems caused by using high concentration NMMO in conventional technologies.
    The mass used does not have to be activated, so that the problem of energy consumption resulting from the repeated evaporation caused by a large volume of moisture introduced by activation is avoided.
    Therefore, the method provided by the present invention has the advantages over the prior art that the solution produced is more uniform, the whole technological process
    14/38
    -14 is safer, more energy efficient and more efficient and continuous industrial production is facilitated.
    The cellulose solution made by the process of the present invention has a higher concentration in a range of 12% to 15%, the solution is uniform and excellent in uniformity, gel particles are small in particle size and in narrow particle size distribution. Spinning is carried out at a design multiple of 5 to produce fibers, the spinning stability is excellent, and there are no broken ends in a 2 hour spinning period. The cellulose solution produced by the process is suitable for the production of products such as cellulose fibers, cellulose films and nonwovens and has extremely wide-ranging market application prospects.
    BRIEF DESCRIPTION OF THE DRAWINGS
    1 is a flow diagram of a process of the present invention.
    2 is a schematic structural diagram of a continuous manufacturing apparatus for a
    Cellulose solution of the present invention.
    Reference sign:
    continuous mass feeder continuous aqueous NMMO solution-
    Continuous Mixer Feeder Continuous Pressure Relief and Heater
    Swelling vessel
    Thin film evaporator / dissolver
    15/38
    Forming device
    Vacuum device
    DETAILED DESCRIPTION
    Embodiment 1 (1) 20 kg of cellulose mass (dry-cut mass COSMO DP500, moisture content 6%) and 167 kg of aqueous NMMO solution of 70 ° C. were continuously introduced into a continuous mixer 3 by means of a continuous mass feeder 1 or a continuous aqueous NMMO solution. Feeder 2 added and stirred for 30 minutes in continuous mixer 3 at a linear stirring speed of 60 m / min to be mixed uniformly to obtain a premix. The aqueous NMMO solution had a water / NMMO mass ratio of 28:72.
    (2) The premix was continuously pumped into a pressure relief and heating device 4, and was subjected to pressure evaporation dehydration to obtain a pre-swell solution. In the continuous pressure relief and heater 4, a drain pressure was 6 kPA and a drain temperature was 105 ° C. And the pre-swell solution at an outlet of the pressure relief and heater 4 had a water / NMMA mass ratio of 19:81.
    (3) The pre-swell solution was continuously fed into a swelling vessel 5. The pre-swell solution was swollen sufficiently at the temperature of 80 ° C for a residence time of 15 min inside the swelling vessel to obtain a swollen solution.
    16/38 (4) The swollen solution was continuously pumped into the thin film evaporator / dissolver 6 and was subjected to pressure-released evaporation and dissolution dehydration to obtain a cellulose solution with a cellulose concentration of 12%. In the thin film evaporation / dissolving device 6, a dewatering temperature was 100 ° C, a dewatering pressure was 4 kPA, and a thin film wiping speed was 2 m / s.
    The solution had excellent uniformity, as confirmed by a test. Under the condition that the cellulose solution produced was used for spinning by a spinning device with a design multiple of 5, the cellulose solution had excellent spinning stability and had no broken ends in a spinning period of 2 hours.
    Embodiment 2 (1) 20 kg of cellulose mass (dry cut mass, bamboo mass DP500, moisture content 6%) and 200 kg of aqueous NMMO solution at 85 ° C. were continuously introduced into a continuous mixer 3 by means of a continuous mass feeder 1 or a continuous aqueous NMMO Solution feeder 2 added and stirred for 20 minutes in the continuous mixer 3 at a linear stirring speed of 120 m / min to be mixed uniformly to obtain a premix. The aqueous NMMO solution had a water / NMMO mass ratio of 40:60.
    17/38 (2) The premix was continuously pumped into a pressure relief and heating device 4 and was subjected to pressure evaporation dehydration to obtain a pre-swell solution. In the continuous pressure relief and heater 4, a drain pressure was 4 kPA and a drain temperature was 110 ° C. And the pre-swell solution at an outlet of the pressure relief and heater 4 had a water / NMMA mass ratio of 21:79.
    (3) The pre-swell solution was continuously fed into a swelling vessel 5. The pre-swell solution was swelled sufficiently at the temperature of 85 ° C for a residence time of 30 min inside the swelling vessel to obtain a swollen solution.
    (4) The swollen solution was continuously pumped into the thin film evaporator / dissolver 6 and was subjected to pressure-evaporation and dissolution drainage to obtain a cellulose solution having a cellulose concentration of 12%. In the thin film evaporation / dissolving device 6, a dewatering temperature was 120 ° C, a dewatering pressure was 6 kPA, and a thin film wiping speed was 4 m / s.
    The solution had excellent uniformity, as confirmed by a test. Under the condition that the cellulose solution produced was used for spinning by a spinning device with a design multiple of 5, the cellulose solution had excellent spinning stability and had no broken ends in a spinning period of 2 hours.
    18/38
    Embodiment 3 (1) 20 kg of cellulose mass (dry cut mass, cotton mass DP500, moisture content 6%) and 168 kg of aqueous NMMO solution at 90 ° C. were continuously introduced into a continuous mixer 3 by means of a continuous mass feeder 1 or a continuous aqueous NMMO Solution feeder 2 added and stirred for 5 minutes in the continuous mixer 3 at a linear stirring speed of 180 m / min to be mixed uniformly to obtain a premix. The aqueous NMMO solution had a water / NMMO mass ratio of 35:70.
    (2) The premix was continuously pumped into a pressure relief and heating device 4, and was subjected to pressure evaporation dehydration to obtain a pre-swell solution. In the continuous pressure relief and heater 4, a drain pressure was 4 kPA and a drain temperature was 80 ° C. And the pre-swell solution at an outlet of the pressure relief and heater 4 had a water / NMMA mass ratio of 25:75.
    (3) The pre-swell solution was continuously fed into a swelling vessel 5. The pre-swell solution was swelled sufficiently at the temperature of 55 ° C for the dwell time of 60 min inside the swelling vessel to obtain a swollen solution.
    (4) The swollen solution was continuously pumped into the thin film evaporator / dissolver 6 and was subjected to pressure evaporation and pressure drainage
    19/38
    -19 subjected to a resolution
    Cellulose concentration of 13% evaporator / dissolver dewatering temperature 150 ° C, 10 kPA and a thin film wiper
    To get cellulose solution with one. In the thin film6, a drainage pressure was 34 m / s.
    The solution had excellent uniformity, as confirmed by a test. Under the condition that the cellulose solution produced was used for spinning by a spinning device with a design multiple of 5, the cellulose solution had excellent spinning stability and had no broken ends in a spinning period of 2 hours.
    Embodiment 4 (1) 20 kg of cellulose mass (dry-cut mass, COSMO DP450, moisture content 6%) and 100 kg of aqueous NMMO solution at 100 ° C. were continuously introduced into a continuous mixer 3 through a continuous mass feeder 1 or a continuous aqueous NMMO solution. Feeder 2 added and stirred for 15 minutes in continuous mixer 3 at a linear stirring speed of 120 m / min to be mixed uniformly to obtain a premix. The aqueous NMMO solution had a water / NMMO mass ratio of 45:55.
    (2) The premix was continuously pumped into a pressure relief and heating device 4, and was subjected to pressure evaporation dehydration to obtain a pre-swell solution. In the continuous pressure relief and heater 4 was one
    20/38
    -20 Drainage pressure 4 kPA and a drainage temperature was 90 ° C. And the pre-swell solution at an outlet of the pressure relief and heater 4 had a water / NMMA mass ratio of 22:78.
    (3) The pre-swell solution was continuously fed into a swelling vessel 5. The pre-swell solution was swelled sufficiently at the temperature of 95 ° C for a dwell time of 3 min inside the swelling vessel to obtain a swollen solution.
    (4) The swollen solution was continuously pumped into the thin film evaporator / dissolver 6 and was subjected to pressure-reduced evaporation and dissolution dehydration to obtain a cellulose solution having a cellulose concentration of 15%. In the thin film evaporation / dissolving device 6, a dewatering temperature was 120 ° C, a dewatering pressure was 6 kPA, and a thin film wiping speed was 6 m / s.
    The solution had excellent uniformity, as confirmed by a test. Under the condition that the cellulose solution produced was used for spinning by a spinning device with a design multiple of 5, the cellulose solution had excellent spinning stability and had no broken ends in a spinning period of 2 hours.
    Embodiment 5 (1) 25 kg cellulose mass (wet powder mass, COSMO DP500,
    Moisture content 25%) and 167 kg of aqueous NMMO solution of 85 ° C were continuously in a continuous
    21/38
    -21Mixer 3 was added by a continuous bulk feeder 1 or a continuous aqueous NMMO solution feeder 2 and stirred for 30 minutes in the continuous mixer 3 at a linear stirring speed of 120 m / min to be uniformly mixed to obtain a premix. The aqueous NMMO solution had a water / NMMO mass ratio of 28:72.
    (2) The premix was continuously pumped into a pressure relief and heating device 4, and was subjected to pressure evaporation dehydration to obtain a pre-swell solution. In the continuous pressure relief and heater 4, a drain pressure was 5 kPA and a drain temperature was 105 ° C. And the pre-swell solution at an outlet of the pressure relief and heater 4 had a water / NMMA mass ratio of 20:80.
    (3) The pre-swell solution was continuously fed into a swelling vessel 5. The pre-swelling solution was swollen sufficiently at the temperature of 80 ° C. for a residence time of 25 min inside the swelling vessel in order to obtain a swollen solution.
    (4) The swollen solution was continuously mixed
    Thin-film evaporation / dissolving device 6 was pumped and underwent drainage by means of pressure-reduced evaporation and
    Subjected to a resolution
    Cellulose concentration of 12% evaporator / dissolver dewatering temperature 130 ° C, 10 kPA and a thin film wiper
    To get cellulose solution with one. In the thin film6, a drainage pressure was 4 m / s.
    22/38
    As confirmed by a test, the solution had excellent uniformity. Under the condition that the cellulose solution produced was used for spinning by a spinning device with a design multiple of 5, the cellulose solution had excellent spinning stability and had no broken ends in a spinning period of 2 hours.
    Embodiment 6
    A process for making a cellulose solution involves the following steps:
    (1) Cellulose pulp and an aqueous NMMO solution of 70 ° C. were uniformly mixed to obtain a premix, the mass of the aqueous NMMO solution being five times that of the cellulose pulp and the aqueous NMMO solution being a water / NMMO- Mass ratio of 60:40 had.
    (2) The premix was subjected to evaporation drainage to obtain a pre-swell solution. The pre-swell solution had a water / NMMO mass ratio of 16:84.
    (3) The pre-swell solution was subjected to heat preservation in a swelling vessel for sufficient swelling to obtain a swollen solution.
    (4) The swollen solution was subjected to pressure-reduced evaporation and dissolution dehydration to obtain the cellulose solution.
    23/38
    As confirmed by a test, the solution had excellent uniformity. Under the condition that the cellulose solution produced was used for spinning by a spinning device with a design multiple of 5, the cellulose solution had excellent spinning stability and had no broken ends in a spinning period of 2 hours.
    Embodiment 7
    A process for making a cellulose solution involves the following steps:
    (1) Cellulose pulp and an aqueous NMMO solution at 100 ° C were mixed uniformly to obtain a premix. The mass of the aqueous NMMO solution was ten times that of the cellulose mass; and the aqueous NMMO solution had a water / NMMO mass ratio of 35:65.
    (2) The premix was subjected to evaporation drainage to obtain a pre-swell solution. The pre-swell solution had a water / NMMO mass ratio of 27:73.
    (3) The pre-swell solution was subjected to heat preservation in a swelling vessel for sufficient swelling to obtain a swollen solution.
    (4) The swollen solution was subjected to pressure-reduced evaporation and dissolution dehydration to obtain the cellulose solution.
    24/38 • · · 4 4 · 4 · · 4: :::. ··,
    4 4 4 4 4 · · · ♦ · · ♦ · »4 · ·· · ·
    The solution, as confirmed by a test, had excellent uniformity. Under the condition that the cellulose solution produced was used for spinning by a spinning device with a design multiple of 5, the cellulose solution had excellent spinning stability and had no broken ends in a spinning period of 2 hours.
    Embodiment 8
    A process for making a cellulose solution involves the following steps:
    (1) Cellulose pulp and an aqueous NMMO solution at 85 ° C were mixed uniformly to obtain a premix. The mass of the aqueous NMMO solution was eight times that of the cellulose mass; and the aqueous NMMO solution had a water / NMMO mass ratio of 28:72.
    (2) The premix was subjected to evaporation drainage to obtain a pre-swell solution. The pre-swell solution had a water / NMMO mass ratio of 19:81.
    (3) The pre-swell solution was subjected to heat preservation in a swelling vessel for sufficient swelling to obtain a swollen solution.
    (4) The swollen solution was subjected to pressure-relieved drainage by evaporation and dissolution to obtain the cellulose solution. The solution had excellent uniformity, as confirmed by a test. On the condition that the
    25/38
    -25 made cellulose solution was used for spinning by a spinner having a design multiple of 5, the cellulose solution had excellent spinning stability and had no broken ends in a spinning period of 2 hours.
    Embodiment 9
    A process for making a cellulose solution involves the following steps:
    (1) Cellulose pulp and an aqueous NMMO solution at 90 ° C were mixed uniformly to obtain a premix. The mass of the aqueous NMMO solution was nine times that of the cellulose mass and the aqueous NMMO solution had a water / NMMO mass ratio of 29:62.
    (2) The premix was subjected to evaporation drainage to obtain a pre-swell solution. The pre-swell solution had a water / NMMO mass ratio of 20:79.
    (3) The pre-swell solution was subjected to heat preservation in a swelling vessel for sufficient swelling to obtain a swollen solution.
    (4) The swollen solution was subjected to pressure-reduced evaporation and dissolution dehydration to obtain the cellulose solution.
    The solution had excellent uniformity, as confirmed by a test. On condition that the cellulose solution prepared for spinning by a
    26/38
    When a design multiple of 5 was used, the cellulose solution had excellent spinning stability and had no broken ends in a spinning period of 2 hours.
    Embodiment 10
    Referring to Fig. 2, a continuous cellulose solution manufacturing apparatus as provided by the present invention includes a continuous feed apparatus, a continuous mixer 3, a continuous pressure relief and heating apparatus 4, a kneading vessel 5, and a thin film evaporation / dissolution apparatus
    6. The continuous feeder comprises a continuous mass feeder 1 and a continuous aqueous NMMO solution feeder 2, and the mass feeder 1 and the continuous aqueous NMMO solution feeder 2 are each connected to feed portions of the continuous mixer 3. A discharge end of the continuous mixer 3 is connected to a loading end of the continuous pressure relief and heating device 4 by a string. A discharge end of the continuous pressure relief and heating device 4 is connected to a loading end of the swelling vessel 5 by a strand, and a delivery end of the swelling vessel 5 is connected to a loading end of the thin film evaporation / dissolving device.
    The continuous mixer 3 may be equipped with a continuous mixing function, such as a continuous one
    Single shaft mixer, one
    27/38
    -27 continuous twin-shaft mixer or a continuous twin-screw mixer of the knead type.
    The continuous pressure relief and heater 4 is selected from a continuous mixer equipped with a vacuum heater. The thin film evaporation / dissolution device 6 may be a vertical type thin film evaporation / dissolution device. Each of the pressure relief and heating device 4 and the thin film evaporation / dissolution device 6 is connected to a vacuum device 8.
    The continuous cellulose solution manufacturing apparatus provided by the present invention may further include a molding apparatus 7. A feed end of the molding machine 7 is connected to a discharge end of the thin film evaporator / dissolver.
    The continuous cellulose solution manufacturing apparatus may further include a storage vessel and a
    first feed pump include. The Storage vessel and the first feed pump are your turn after on one strand between the continuous mixer 3 and the continuous Pressure relief and heater 4th arranged.
    The continuous cellulose solution manufacturing apparatus may further include a second feed pump. The second feed pump is arranged on a line between the swelling vessel 5 and the thin-film evaporation / dissolution device 6.
    28/38
    A specific embodiment of the continuous cellulose solution manufacturing apparatus is as follows:
    (1) Cellulose pulp and an aqueous NMMO solution were introduced into the continuous mixer 3 through the continuous mass feeder 1 and the continuous aqueous NMMO solution feeder 2, respectively, and were sufficiently and uniformly mixed in the continuous mixer 3 to obtain a premix. and the premix was continuously introduced into the storage vessel.
    (2) The premix in the storage vessel was introduced into the continuous pressure relief and heating device 4 by a first feed pump, so that the premix is stirred and mixed even more intensely. A stirring component of the continuous pressure relief and heating device 4 heats the premix through a contact surface, the premix was subjected to a drainage by pressure-relieved evaporation under a certain vacuum until a given volume of moisture had evaporated and thus an NMMO concentration reached an optimal source concentration range in order to provide a pre-swelling solution receive.
    (3) The pre-swell solution was continuously introduced into the swelling vessel 5 through a pipe, and after a certain dwell time was swelled sufficiently under proper temperature conditions to be converted into a swollen solution, and a temperature of an outer jacket of the swelling vessel was regulated and controlled by a heating medium .
    29/38 (4) The swollen solution was continuously pumped into the thin film evaporator / dissolver 6 by a second feed pump, was spread on the surface of a vertical inner wall of the thin film evaporator / dissolver 6 to form a thin film shape, and became further dewatered under the correct temperature and vacuum conditions to be converted into a cellulose solution with a concentration of 10% to 15%.
    (5) The cellulose solution was introduced into the molding machine 7 and was able to be used in products such as
    Fibers,
    Films and
    Nonwovens are implemented.
    Comparative example:
    (1) 50 kg of cellulase activated mass (COSMO DP500, moisture content 53%) and 178 kg of aqueous NMMO solution at 85 ° C were stirred for 30 minutes at a linear stirring speed of 120 m / min to be mixed uniformly to make a premix receive. The aqueous NMMO solution had a water / NMMO mass ratio of 84:16.
    (2) The premix was placed in a swelling vessel, heated to a temperature of 85 ° C, and heat-preserved in a swelling vessel for sufficient swelling to obtain a swollen solution.
    (3) The swollen solution was placed in a thin film evaporation / dissolver and subjected to pressure evaporation and pressure drainage
    30/38
    -30 subjected to dissolution to obtain a cellulose solution with a cellulose concentration of 12%. The thin film evaporation / dissolution device had a dewatering temperature of 130 ° C, a dewatering pressure of 10 kPA and a thin film wiping speed of 4 m / s.
    The solution, as confirmed by a test, was inferior in uniformity compared to the solutions of the embodiments and had a larger gel particle size. Under the same condition that filtering was not performed and that the cellulose solution was used for spinning by a design multiple of 5, the solution had poorer spinning stability and broken ends occurred more frequently in a 2 hour spinning period on.
    The uniformity of the cellulose solution can be characterized by observing the state of dissolution of cellulose in the solution by a polarized microscope and detecting the particle size and particle size distribution of gel particles in the solution by a laser particle size analyzer. The smaller the particle size of the gel particles in the solution and the narrower the particle size distribution, the greater the uniformity of the solution. And if the gel particles in the solution are of a relatively large size and a relatively wide particle size distribution, the spinning stability of the solution is impaired and a thread break phenomenon occurs if the design multiple is relatively large.
    31/38
    Uniformity of the solution Spinning stability Polarizedmicroscope D50around D90around The spinning solution is not filtered by a filter device and is subjected to spinning with a design multiple of 5 for 2 hours Embodiment 1 No unsolvedFabrics 9 30th Stable spinning, no broken thread Embodiment 2 No unsolvedFabrics 11 29 Stable spinning, no broken thread Embodiment 3 No unsolvedFabrics 8th 31 Stable spinning, no broken thread Embodiment 4 No unsolvedFabrics 10th 28 Stable spinning, no broken thread Embodiment 5 No unsolvedFabrics 8.5 27 Stable spinning, no broken thread Embodiment 6 No unsolvedFabrics 9.5 28 Stable spinning, no broken thread Embodiment 7 No unsolvedFabrics 8th 30th Stable spinning, no broken thread Embodiment 8 No unsolvedFabrics 8.5 29 Stable spinning, no broken thread Embodiment 9 No unsolvedFabrics 10th 30th Stable spinning, no broken thread Comparative example No unsolvedFabrics 35 122 Poorer stability,more frequent thread breaks
    From the table above, it can be seen that the cellulose solution produced by the process provided by the present invention is excellent
    32/38
    -32 has uniformity and high spinning stability and is free of the thread break phenomenon in 2 hours of spinning.
    The embodiments of the present invention have been described in detail above, but the content cited only relates to preferred embodiments of the present invention and cannot be regarded as limiting the scope of the present invention. All equivalent variations, improvements, etc. made in accordance with the scope of the present invention are intended to be within the scope of the present invention.
    权利要求:
    Claims (10)
    [1]
    (1) Uniformly mixing cellulose pulp and an aqueous NMMO solution at a temperature in a range of 70 ° C to 100 ° C to obtain a premix, wherein a mass of the NMMO aqueous solution is 5 to 10 times that of the cellulose pulp , and the aqueous NMMO solution has a water / NMMO mass ratio in a range of 28:72 to 60:40;
    1. A process for making a cellulose solution comprising:
    [2]
    2. Process for producing the cellulose solution according to claim 1, characterized in that in step (1) the aqueous NMMO solution has the water / NMMO mass ratio in a range from 28:72 to 50:50 and
    34/38
    -34 preferably in step (1) the aqueous NMMO solution has the water / NMMO mass ratio in a range from 28:72 to 35:65.
    (2) subjecting the premix to evaporation drainage to obtain a pre-swell solution, the pre-swell solution having a water / NMMO mass ratio in a range from 16:84 to 28:72;
    [3]
    3. Process for producing the cellulose solution according to claim 1, characterized in that in step (2) the pre-swelling solution has the water / NMMO mass ratio in a range from 18:82 to 27:73 and preferably in step (2) the pre-swelling solution
    Water / NMMO mass ratio in a range from 19:81 to
    25:75 has.
    (3) subjecting the pre-swell solution to heat conservation in a swelling vessel for sufficient swelling to obtain a swollen solution; and (4) subjecting the swollen solution to drainage by depressurized evaporation and dissolution to obtain the cellulose solution.
    [4]
    4. Process for producing the cellulose solution according to claim 1, characterized in that in step (1) the mass of the aqueous NMMO solution is 8 to 10 times that of the cellulose mass and the aqueous NMMO solution has a temperature in a range of 80 ° C to 90 ° C.
    [5]
    5. A process for producing the cellulose solution according to claim 1, characterized in that in step (1) a process for uniformly mixing the cellulose mass and the aqueous NMMO solution, adding the cellulose mass and the aqueous NMMO solution into a continuous mixer and exporting continuous mixing for 5 minutes to 30 minutes at a linear stirring speed in a range of 60 m / min to 180 m / min.
    [6]
    6. Process for producing the cellulose solution according to claim 1, characterized in that in step (2) a process for dewatering by evaporation by dewatering by pressure-relieved evaporation at a
    35/38
    -35 dewatering temperature in a range from 80 ° C to 110 ° C under a dewatering pressure in a range from 4 kPa to 10 kPa.
    [7]
    7. Process for producing the cellulose solution according to one of claims 1 to 6, characterized in that in step (3) the pre-swelling solution at a temperature in a range from 55 ° C to 95 ° C for a residence time in a range from 3 min to Sufficiently swollen for 60 min
    becomes, by one swollen solution in the Swelling vessel to received, and preferably in Step 3) the Pre-swell solution at one temperature in one Area from 65 ° C to 95 ° C For a Dwell time in one Area from 10 min to 45 min
    is swollen sufficiently to provide a swollen solution in the
    To obtain swelling vessel, and the Pre-swell solution at more preferred in Step 3) a temperature in an area from 75 ° C to 85 ° C For a dwell time in an area from 15 min to 30 min
    is swollen sufficiently to provide a swollen solution in the
    Obtain a swelling vessel.
    [8]
    8. Process for the production of the cellulose solution according to one of claims 1 to 6, characterized in that in step (4) a process for dewatering by pressure-relieved evaporation and dissolution is a thin-film evaporation and dissolution and at a dewatering temperature in a range of 100 ° C up to 150 ° C under a dewatering pressure in a range from 4 kPa to 10 kPa at a linear thin film wiping speed in a range from 2 m / s to 6 m / s.
    36/38
    [9]
    9. The continuous manufacturing apparatus for the cellulose solution manufacturing process according to claim 1, comprising a continuous feed apparatus, a continuous mixer, a continuous pressure relief and heating apparatus, a swelling vessel and a thin film evaporation / dissolution apparatus which are connected in series by a strand wherein the continuous feeder comprises a continuous bulk feeder and a continuous aqueous NMMO solution feeder, and the continuous bulk feeder and the continuous aqueous NMMO solution feeder are each connected to feed portions of the continuous mixer.
    [10]
    10. Continuous manufacturing device for the cellulose solution according to claim 9, characterized in that the continuous pressure relief and heating device is selected from a continuous mixer which is equipped with a vacuum heating device.
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    同族专利:
    公开号 | 公开日
    US20180134851A1|2018-05-17|
    WO2016192512A1|2016-12-08|
    CN105037753B|2017-12-05|
    CN105037753A|2015-11-11|
    US10676576B2|2020-06-09|
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    CN105037753B|2015-06-01|2017-12-05|中国纺织科学研究院|The preparation technology and its equipment of a kind of cellulose solution|CN105037753B|2015-06-01|2017-12-05|中国纺织科学研究院|The preparation technology and its equipment of a kind of cellulose solution|
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    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    CN201510293004.8A|CN105037753B|2015-06-01|2015-06-01|The preparation technology and its equipment of a kind of cellulose solution|
    PCT/CN2016/081488|WO2016192512A1|2015-06-01|2016-05-10|Preparation process for cellulose solution and device for same|
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