Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F2/00—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/06—Wet spinning methods
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/08—Melt spinning methods
  • D01D5/088—Cooling filaments, threads or the like, leaving the spinnerettes
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/2964—Artificial fiber or filament
  • Y10T428/2965—Cellulosic

Definitions

• the invention relates to a process for the production of cellulosic shaped articles, a solution of cellulose in a tertiary amine N-oxide and optionally water being shaped in a warm state and the shaped solution being cooled with air before being introduced into a coagulation bath, and a Cellulosic filament yarn.
• the cooling being to take place immediately after molding.
• the aim of this process is to reduce the stickiness of the freshly extruded moldings, so that a spinneret with a high hole density can be used in the production of cellulosic threads.
• the shaped solution is preferably exposed to a gas stream.
• the warm shaped solution is already cooled when the shaped solution leaves the shaping element, for example a spinneret, in which temperatures are typically above 90 ° C., and reaches the so-called air gap.
• the area between the shaping element and the coagulation bath in which the cellulose is precipitated is referred to as the air gap.
• the temperature in the air gap is lower than in the spinneret, but is significantly higher than room temperature due to the heat radiation from the spinneret and the heating of the air resulting from the enthalpy flow of the moldings. Due to the permanent evaporation of water, which is usually used as a coagulation bath, the air gap is humid and warm. With the measure proposed in WO 93/19230 to cool the shaped solution immediately after shaping, a faster cooling is brought about, so that the stickiness of the shaped solution decreases accordingly faster.
• the object of the present invention is to improve such a method, but in particular also to improve the properties of the moldings produced therewith, preferably filaments or a filament yarn.
• This object is achieved by a process for the production of cellulosic moldings, a solution of cellulose being formed in a tertiary amine N-oxide and optionally water in a warm state and the shaped solution being cooled with air before being introduced into a coagulation bath, with the Cooling-conditioned air is used which has a water content of 0.1 to 7 g of water vapor per kg of dry air and whose relative humidity is less than 85%.
• the water content of the conditioned air is preferably 0.7 to 4 g of water vapor per kg of dry air, in particular 0.7 to 2 g.
• the cooling can take place with flowing air, whereby it is blown against the shaped solution or is sucked off from it.
• the suction can be carried out in such a way that conditioned air is provided and this is sucked through, for example, a bundle of freshly spun fibers or filaments. A combination of blowing and suction is particularly advantageous.
• the shaped solution can be exposed to the conditioned air over the entire distance up to the introduction into the coagulation bath or only over part of this distance, it being advantageous to apply the air in the first part, i.e. in the area of the air gap which directly adjoins the shaping element.
• the conditioned air should flow at an angle of 0 to 120 °, preferably 90 °, relative to the direction of movement of the shaped solution, the angle of 0 ° corresponding to an inflow opposite to the direction of travel of the shaped solution.
• fibers in particular filaments, films, hollow fibers, membranes, for example for use in dialysis, oxygenation or filtration, can be produced in an advantageous manner.
• the solution can be shaped into a desired cellulosic shaped body using known spinnerets for the production of fibers, slot nozzles or hollow fiber spinnerets. After the shaping, ie before the shaped solution is introduced into the coagulation bath, it can be stretched.
• a yarn made of cellulosic filaments, produced from a solution of cellulose in a tertiary amine N-oxide and optionally water, is characterized in that the cross-sectional areas of the filaments have a coefficient of variation less than 12%, preferably less than 10%.
• cooling of the freshly extruded molded articles in the air gap is advantageous in order to reduce their stickiness more quickly.
• the gas flow must of course have a temperature which is below that of the shaped solution.
• a gas stream is used which has a temperature of -6 to 24 ° C.
• the water content of air in g of water vapor per kg of dry air is often referred to as the mixing ratio.
• the unit g / kg is used for this purpose.
• the influence of the water content or the mixing ratio is particularly evident in filament production in irregularities in the filament cross sections.
• the coefficient of variation of the filament cross-sectional areas is 30% in a yarn with 50 individual filaments.
• the coefficient of variation decreases to 5.8% at the same temperature.
• it is therefore essential to condition the air gap with dry air.
• the temperature of the cooling air plays a minor role.
• air was blown at a blowing speed of 0.8 m / s perpendicular to the thread bundle.
• the air was blown onto the bundle on one side, and the air was distributed homogeneously with very fine-mesh sieves with a width of 10 cm, and the blowing was carried out over a distance of 10 cm from the nozzle outlet.
• the filaments were drawn in the air gap by a factor of 16 and dried after passing through a water bath for coagulation and downstream washing baths to remove the NMMO.
• the take-off speed was 420 m / min.
• the filament bundles obtained in each case were cut twice at a distance of one meter perpendicular to the bundle axis.
• the cross-sectional areas of the filaments were transferred to a computer image analysis system (Quantimet 970) and evaluated using a light microscope (magnification 570: 1) and a video camera. The area of each filament was determined.
• the coefficient of variation of the filament cross-sectional area in percent was calculated from the mean value of the filament cross-sections of each bundle examined, two sectional images being evaluated per bundle, and the standard deviation as the ratio of standard deviation to mean.
• the resulting air stream was then cooled to the desired temperature with a heat exchanger.
• the relative humidity and the water content were determined with a psychrometer (ALMEMO 2290-2 with psychrometer sensor AN 846 or humidity / temperature sensor AFH 9646-2).
• the air was previously condensed Pre-dried air further dried with a dehumidifier (model 120 KS from Munters GmbH). The dry air was also reheated using a heat exchanger. The determination of the relative humidity and the water content of the air, which was dried to a water content of less than 4 g / kg, was carried out with a mirror-cooled dew point meter (S4000 RS from MICHELL Instruments).
• Table II shows that outside the range according to the invention the variation coefficients of the filament cross-sectional areas are above 14% and values of over 30% are even reached. Such high fluctuations are in the production of filament yarn is undesirable, since these have a negative effect on processing into textile fabrics and in particular lead to a non-uniform coloring of the fabric. Processing problems may also arise due to the different strengths of the individual filaments among one another and with respect to the yarn.
• Examples 16 and 22 show that both requirements, ie a water content below 7 g of water vapor per kg of dry air and a relative humidity below 85%, must be guaranteed for the present invention. In example 16, although the water content was in the range claimed, the air had a higher relative humidity and a coefficient of variation of 16.1% resulted.
• Example 22 shows the conditions of the ambient air at a temperature of 21 ° C, at a relative humidity of 60% and a water content of 9.2 g / kg.
• the relative humidity is in the claimed range, the water content is not, and a coefficient of variation of 23.4% results.
• This example further illustrates that it is not sufficient to cool with ambient air and that it is not sufficient to simply blow on with ambient air that is cooler than the temperature usually prevailing in the air gap in order to achieve an improvement in textile properties .

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Artificial Filaments (AREA)
• Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Paper (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

Applications Claiming Priority (3)

Publications (3)

Family

ID=6534703

Family Applications (1)

Country Status (16)

Cited By (1)

Families Citing this family (13)

Family Cites Families (13)

• 1995
  • 1995-11-24 HU HU9702123A patent/HU220367B/hu not_active IP Right Cessation
  • 1995-11-24 CZ CZ19971674A patent/CZ288742B6/cs not_active IP Right Cessation
  • 1995-11-24 WO PCT/EP1995/004634 patent/WO1996017118A1/fr active IP Right Grant
  • 1995-11-24 AU AU41177/96A patent/AU695212B2/en not_active Ceased
  • 1995-11-24 DE DE59502659T patent/DE59502659D1/de not_active Expired - Lifetime
  • 1995-11-24 CA CA002205466A patent/CA2205466A1/fr not_active Abandoned
  • 1995-11-24 CN CN95196572A patent/CN1066214C/zh not_active Expired - Lifetime
  • 1995-11-24 ES ES95939293T patent/ES2120243T5/es not_active Expired - Lifetime
  • 1995-11-24 JP JP8518159A patent/JPH10510011A/ja active Pending
  • 1995-11-24 US US08/849,553 patent/US5902532A/en not_active Expired - Fee Related
  • 1995-11-24 SK SK676-97A patent/SK67697A3/sk unknown
  • 1995-11-24 PL PL95320507A patent/PL183097B1/pl not_active IP Right Cessation
  • 1995-11-24 AT AT95939293T patent/ATE167709T1/de not_active IP Right Cessation
  • 1995-11-24 KR KR1019970703672A patent/KR100398294B1/ko not_active IP Right Cessation
  • 1995-11-24 EP EP95939293A patent/EP0795052B2/fr not_active Expired - Lifetime
• 1996
  • 1996-03-28 TW TW085103928A patent/TW300924B/zh active
• 1998
  • 1998-12-18 US US09/215,216 patent/US6042944A/en not_active Expired - Lifetime

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events