CN1247578A

CN1247578A - Drawing device and method for producing drawn synthetic filaments

Info

Publication number: CN1247578A
Application number: CN 98802490
Authority: CN
Inventors: J·巴拉维安; G·里伯勒特; H·雷纳; R·格罗坦
Original assignee: Carl Freudenberg KG
Current assignee: Carl Freudenberg KG
Priority date: 1997-02-12
Filing date: 1998-01-26
Publication date: 2000-03-15
Also published as: EP0961844A1; CA2280872A1; DE19705113A1; JP2000509770A; DE19705113C2; WO1998036110A1; BR9807833A

Abstract

Drawing device and method for producing drawn synthetic filaments (2,3), comprising a spinning device (1) and a drawing device comprising pneumatic tools for generating a drawing force on synthetic filaments (2,3) A stretching device (10), wherein a heating device (5) is installed between the spinning device (1) and the drawing device (10) for countercurrently introducing a heating medium flow (8) to the synthetic filaments (2, 3).

Description

Be used to produce the draft apparatus and the method for drawn synthetic filaments

The present invention relates to comprise device for spinning and contain be useful on the draft apparatus that on synthetic thread, produces the air tool stretching device of pulling force, with the method for producing drawn synthetic filaments, according to said method filament number is being cooled under the temperature in freezing point behind the device for spinning at least greater than the melt-spun synthetic thread of 1dtex, with drafted by means of pneumatic stretching device, this drafting is used to produce synthetic yarn, staple fibre and non-weaving cloth.

Producing synthetic thread with the melt-spun method is made up of three processing steps basically.At first polymer is melted by means of extruder, then carry out the spinning of long filament with a spinnerets or an a plurality of spinnerets that has pore.At last the long filament that is spun into is carried out drawing-off, diminish so that reach the cross section.The long filament cross section that is spun into diminish to many industrial and the weaving on purposes be basic prerequisite.

Drawing-off is to provide the decisive processing step that continues application possibility to long filament, and it can be direct, is connected continuously and/or automatically in the spinning process or carries out in process of production as processing step independently.

The drawing-off of long filament is undertaken by nozzle by deflector roll or with Pneumatic method with mechanical means by means of stretching device.

With the stretching device kind that is connected, pneumatic or mechanical is irrelevant, when high-speed spinning, promptly greater than 3500m/min, the mechanical property of the long filament that spins at the one-step method device for example intensity and modular ratio is spun speed with low, and it is significantly poor promptly to be lower than the 3500m/min spinning and to carry out the long filament of first break draft in additional operation.

Although high-speed spinning spins speed and helps forming improved mechanical property than low in one-step method, simultaneously long filament this between the surface of silk and inside, produce structural differences.This has caused to compare with the first break draft long filament and has lowered intensity and elastic modelling quantity.

The no special-purpose draft apparatus of US 2,604 667 explanations is used to carry out rear haulage and produces orientated yarns, but by using the draw speed of 4700m/min at least.Need for obtaining the high like this speed of high strength.If speed descends, the long filament that makes has high elongation.For reaching this draw speed, can adopt the deflector roll and the air nozzle of transmission.US 2,604 667 at first inquires into the yarn manufacturing, makes stretching device manufacturing staple fibre but also discuss with the air nozzle.

Knownly producing the non-woven fabric from the continuous filament yarn that is spun into, the drawing-off of the long filament that is come out by spinnerets is to carry out by means of the pneumatic nozzle at the stretching device of ultrasonic range transmission.For making non-woven fabric the many long filaments that solidify are delivered to shop silk equipment by means of nozzle.Because the power that the friction of air on long filament applies might be regulated draw speed and therefore be influenced the mechanical property of long filament.Show that at this to the long filament Effect on Performance be limited, though owing to import the raising of the air pressure of nozzle draw speed is improved, intensity does not almost further improve and elongation does not almost further reduce yet.

Make the method for yarn and fiber by synthetic line polymer by the melt-spun of filament from DE-OS 2 117 659 is known, it is processed to 3500m/min with draw speed.Draw speed is to give given by the right speed of deflector roll.Be that the influence elongation installs a heating arrangements between spinnerets and draw-off godet, therein the synthetic threads of forming by 50 rhizoid bars more than the freezing point and the temperature below the fusing point heat, reach draw ratio to 1 thus: 2.Discussed in addition by the thin long filament of filament number and be used to make non-woven fabric with specially suitable intensity and elongation, but not further narration of this respect.

Drawing-off has been discussed on the one hand to the effect of intensity with the effect of drawing-off to elongation and contraction has been discussed aspect other in DE-OS 29 25006.Set forth long filament and obtained higher intensity, and elongation and contraction reduce by drawing-off.Comparing the higher draft speed of 4100-6000m/min can directly contact with long filament by the heating arrangements that adopts slight red heat and reach with DE-OS 2117659.

For by polymer, polyamide particularly, polyester or polypropylene are produced synthetic fiber with melt spun processes, from DE-4021545 as can be known, have a spinnerets at least, spinning shaft, the heating path, the equipment that oils, the device of draw-off godet equipment and winding apparatus, wherein heat the path blowing device that produces adverse current, the nozzle of for example drying are arranged.Can produce the synthetic yarn and the synthetic fiber of full drawing-off with this device, wherein filament or filament linear-density are less than 1dtex.This device on and according to said method do not have the synthetic thread that post processing can be made full drawing-off, they can be processed into fabric very fine and next to the shin.Whether this device has the enough drawing-off performances of higher Denier range, does not set forth in this patent.

Task of the present invention is to make a device and provide a kind of method, this device or method can be applicable to that the production fiber number has higher-strength and hangs down the long filament of elongation greater than drawn synthetic filaments and the production of 1dtex.

Have a pair of synthetic fiber adverse current that has of between device for spinning and stretching device, arranging by draft apparatus of the present invention and import the heater of heating-medium flow.

On this device by thermoplastic synthetic material, polyester for example, polyamide, polypropylene, polyethylene is by the continuous filament yarn of simple spinning or composite spinning (double-deck, segmentation, the coaxial or the like) manufacture or the purposes of weaving.The mechanical property of the long filament by melt-spun production has clear improvement, and has particularly improved fracture strength, elongation, elastic modelling quantity and thermal contraction when same fiber number.

The hot-air that heater can import with adverse current or other heat, preferred neutral gas, but the mist of also available adding additive drives.The temperature heating of air more than the long filament setting temperature.

The effect of heater forms heated tow based on, the thermal medium that imports by adverse current and enters " fixing " (Festhalten) or " braking " (Bremsen) scope between device for spinning and stretching device.Therefore the drawing-off that might grip further drafting force and add by means of the stretching device that connects later in this scope.Drawing-off is to enter the speed of heater and speed that silk enters stretching device is determined by silk.

Find surprisingly, according to the pneumatic stretching device of the principle work of air friction also can with the heater combination with countercurrent direction work.The long filament that obtains like this improves intensity and the elongation reduction at same draw speed.Significant advantage is that the long filament draw speed that has certain performance for production can sharply reduce.

Design has the instrument of producing non-weaving cloth in further embodiment, and this instrument makes the synthetic thread lapping of carrying by pneumatic stretching device form the plane tissue, i.e. non-woven fabric does not wherein need other mechanical transportation means to synthetic thread.

Draft apparatus also can be replenished by the instrument of making staple fibre, wherein with the synthetic thread cutting short-forming fiber.This fiber is specially adapted to the producd fibers net.

With a kind of method of producing drawn synthetic filaments, according to said method the long filament of melt-spun cools off and uses pneumatic stretching device to carry out drawing-off in the temperature of freezing point at least behind device for spinning, for the purpose of drawing-off then heats in heater, wherein long filament in heater by gas phase, the medium of the temperature heating more than freezing point can be produced the synthetic thread that has higher intensity when lower elongation by reverse blowing.

This long filament does not need to carry out implementing of further first break draft and the method may carry out under than lower so far draw speed.

The method is preferably carried out in this manner, and promptly the draw ratio of first break draft is 1.1 to 1.5 between heater and stretching device.

What have advantage in addition is if long filament is 200 ℃ to 250 ℃ in temperature, preferably to carry out reverse blowing at 225 ℃ to 300 ℃ under PET or PA66 situation.Air capacity can be from 5M ³/ h to 25M ³/ min changes.

For reaching the obvious improvement of intensity and elongation, also be enough if long filament is introduced by inverted draft with the draw speed of 2000m/min to 4700m/min.Still also can obtain improved performance in higher speed.

Can influence the performance of the synthetic thread of being produced with the method.Counter-flow air amount and temperature may be carried out such adjusting, make the elongation of yarn be less than 60% or might be with the draw speed of long filament, the tolerance and the temperature of counter-flow air are regulated like this, the tensile strength that promptly makes the first break draft long filament under same draw speed reaches relative raising 20% at least than the long filament of simple drawing-off, wherein the tensile strength of long filament reaches 32CN/Tex at least, especially preferably reach 34-45CN/Tex, perhaps the tolerance of counter-flow air and temperature are regulated like this, hot-air is shunk be up to 6% (at 180 ℃, 15 minutes).This is particularly suitable for adopting PES (polyester) is raw material.

In addition advantageously, the draw speed of long filament, the tolerance and the temperature of counter-flow air are regulated like this, make the elastic deformation scope carry out the transition to the plastic deformation scope and only just can carry out under high at least 20% power.

Though long filament is high drawing-off, might carry out a first break draft more continuously or in the treatment process of separating after the countercurrent treatment by long filament.

Be used to make that non-weaving cloth can be layered on it on base cloth or for making staple fibre it is cut off as further treatment process synthetic thread, wherein the long filament of Qie Duaning can supply later process process.

Particularly advantageous is that synthetic thread is used to produce non-weaving cloth, and wherein the tensile strength of long filament is at least 32CN/Tex and extends less than 60%.For producing non-woven fabric, synthetic thread can be used as continuous yarn and carries out lapping.For producing fiber web, synthetic thread can be used as the staple fibre lapping.

Advantageously synthetic thread is used to make yarn in addition, and wherein the tensile strength of long filament is at least 32CN/Tex and extends less than 60%.And yarn also can spin by continuous synthetic thread manufacturing or by staple fibre.

Briefly showed the draft apparatus that is used to produce drawn synthetic filaments in the drawings:

The basic structure group of Fig. 1 indication device,

Fig. 2 represents to compare with common system by the rate curve of tow of the present invention,

Fig. 3 represents the indicatrix of different mechanical properties.

The draft apparatus that is used for production drawing-off synthetic fiber that Fig. 1 shows comprises device for spinning 1, with the synthetic material adding device for spinning of known method with fusion.Flow out long filament 2 corresponding to the silk number of spinnerets hole count by the spinnerets of installing in device for spinning 1, these silks form tow 3 together.Common 16,32 or 64 rhizoids are gathered into a tow.Flow out back long filament 2 from spinnerets and below setting temperature, cool off, an additional cooling device 4 is wherein arranged, in each long filament, form crystallization and amorphous region there.

The long filament 2 of cooling is sent into heater 5, boundling there, and parallel process is undertaken by heater 5 like this.Heater 5 have the heating path 6, therein from the lower end 7 to device for spinning send into hot-air 8 and in the top 9 air flow out again.8 pairs of tow 3 adverse currents of air are sent in heating path 6.

Stretching device 10 being installed, on tow 3, apply drafting force with this equipment with heating 6 a distance, path.This is to be undertaken by venturi nozzle 11 with Pneumatic method, imports pressure-air 12 therein, reaches the velocity of sound like this on smallest cross-sectional, surpasses the velocity of sound in next process.

The tow 3 that is come out by stretching device 10 can be processed into synthetic threads with known method, can or be used to make non-woven fabric with its cut-out for making staple fibre.The latter for example has explanation in FR 74 20254.

The overview of showing the rate curve of the long filament that spins with different device and method at Fig. 2.Under general condition long filament is with direct fabrics and drawing-off one-step method with down high-speed, and draw speed is 6000m/min here, owing to make fiber stand rapid cooling axially and radially having very high velocity gradient, sees curve A.Prolonging the Silk Road, velocity gradient is greater than 2 * 10 ⁴1/s and cooling velocity are in the 26000 ℃/s order of magnitude.This extreme condition make the silk shell and the center between cause different, uneven texture.Comparing consequently with the silk of first break draft in the multistep processes, certain mechanical property reduces.

Draw speed eases down to 4400m/min lower speed significantly gradient and cooling velocity, as by the curve B finding.Certain fracture load also reduces with extension at break and improves.

Though low draw speed is favourable, to improve fracture load and reduce extension at break in order to reach, so adopt two step mechanical means, first scope with high velocity gradient and second scope with high velocity gradient.This is illustrated in curve C.

By being applied in the heater between spinnerets and the stretching device, the hot-air that adds that this equipment is introduced by adverse current is dried to long filament, reaches the process that curve D is showed during for 4400m/min at draw speed.Surpass the long filament generation first break draft of freezing point by the length L heating of heater 5.

In table 1, compare 290 ℃ of different tests results during for the polyethylene terephthalate of 190Psa (PET) different material throughput adopting and do not adopt heater to be 256 ℃ and viscosity to fusing point.

T adopts the draft apparatus of being made up of device for spinning 1 and stretching device 10 to be used to produce long filament at first test order.

Second test order V tests the order difference with first and be that a heater 5 is arranged between device for spinning 1 and stretching device 10, and long filament is with the air heat that is heated to the above temperature of freezing point of reverse introducing therein.This is also possible, and long filament 3 is surpassing its freezing point temperature heating, but still does not reach fusing point.

For the test of two order, one of them each hole with the thruput spinnerets is that (another each hole with thruput spinnerets V1.2) and wherein is that (T2 V2) carries out 0.62g/min to 1g/min for T1, V1.1.

Can confirm at first in the comparison of the key property of the long filament of in first experimental series, making that the draw speed of silk has been compared obvious reduction with T in test V1.1 and V1.2.This can explain like this, because the pressure rising does not obtain due to the balance frictional force in the heater fully in stretching device.Two same draw speeds of usefulness are tested order T by two, and the long filament that V makes is the direct contrast that impossible carry out mechanical property at this.

But can discern, though draw speed is from 4700m/min, be reduced to 3330m/min, but intensity is brought up to 39.7CN/Tex and elongation is reduced to 57.1% (T1 and V1.2) from 72.6% from 30.3CN/Tex, therefore might can process in medium pulling rate degree scope for the production high strength filaments.In having the test order of heater, speed is brought up to 4000m/min, cause the again improvement of intensity from 39.7CN/Tex to 42.5CN/Tex to be reduced to 43.7% (V1.2 compares with V1.1) from 57.1% with elongation.

At second experimental series V2, among the T2 thruput is adjusted to every hole 0.62g polymer/minute.Also can reduce at thinner Denier range draw speed, intensity significantly improves from 27.7CN/Tex to 36.6CN/Tex and extends equally and obviously is reduced to 47.6% from 82.6%.

Table 1

Test	V1.1	?V1.2	?T1	?V2	?T2
Test	V1.1	?V1.2	?T1	?V2	?T2	Thruput polymer/hole (g/mn hole)	1.00	?1.00	?1.00	?0.62	?0.62
Fiber number (dTex)	2.5	?3.0	?2.1	?2.0	?1.5	Thruput polymer/hole (g/mn hole)	1.00	?1.00	?1.00	?0.62	?0.62
Fiber number (dTex)	2.5	?3.0	?2.1	?2.0	?1.5	Draw speed (m/min)	4000	?3330	?4770	?3100	?4130
Intensity (cN/tex)	42.5	?39.7	?30.3	?36.6	?27.7	Draw speed (m/min)	4000	?3330	?4770	?3100	?4130
Intensity (cN/tex)	42.5	?39.7	?30.3	?36.6	?27.7	Elongation (%)	43.7	?57.1	?72.6	?47.6	?82.6
Thermal contraction (%) (180 ℃, the 15min hot-air)	4.5	?4.5	?3.4	?4.4	?3.2	Elongation (%)	43.7	?57.1	?72.6	?47.6	?82.6

Concluded from test T1, V1, V1.1, V1.2 at Fig. 3; Power-the extension curve of the long filament that T2, V2 obtain.Can see that heater all has great influence to intensity and elongation.Especially meaningfully surpassing the elongation of 10CN/Tex scope in power has clear improvement.The long filament that improves can absorb obviously many loads, and does not cause excessive elongation.This specific character performance in the long filament of producing with less draw speed according to V1.2 and V2 itself is more obvious.

The long filament that is come out by the device for spinning of about 300 ℃ of heat is by cooling off with the horizontal blowing of air at room temperature, in heater silk with volume flow at 10-15M ³270-300 ℃ the air of the being heated to between/h heats.Certainly, the temperature of the fluid 8 of gas phase must correspondingly be suitable for its melt temperature to polyolefin.The flow of gaseous fluid 8 depends on the amount for the treatment of drafted fibre especially in addition, and the polymer that is adopted gives drawing-off between drawing-off degree and device for spinning 1 and the heater 5.

Long filament is because the mechanical property of its improvement is particularly suitable for making non-weaving cloth, wherein can consider thermoplastic synthetic material as material, PET particularly, but also can consider polyester (PES), polyamide (PA), polyamide 6 .6 (PA6.6), polypropylene (PP) or polybutylene terephthalate (PBT).Long filament also can be used known spining technology by multiple different materials manufacturing.

Claims

1. A drafting plant for the production of drawn synthetic filaments (2, 3), comprising a spinning unit (1) and comprising a pneumatic tool for generating stretching forces on the synthetic filaments (2, 3) (11) the stretching device (10), it is characterized in that, between the spinning device (1) and the stretching device (10), a pair of synthetic filaments (2,3) countercurrently introduced heat medium flow (8) is installed The heating device (5).

2. The drafting device as claimed in claim 1, characterized in that a tool for producing the spunbonded nonwoven is provided.

3. The drafting device according to claim 1, characterized in that a tool for producing short fibers is provided, for example for producing a fiber web.

4. A method for producing drawn synthetic filaments (2, 3), by which melt-spun filaments (2, 3) with a monofilament fineness greater than 1 dtex are cooled at least at the coagulation temperature after the spinning device (1) and by means of The drawing is carried out by a pneumatic stretching device (10), which is characterized in that, for the purpose of drawing, the filament is then heated in a heating device (5), wherein the filament is heated in the gas phase at a temperature above the freezing point in the heating device The fluid (8) reversely blows.

5. The method as claimed in claim 4, characterized in that post-drawing with a draw ratio of 1.1 to 1.5 takes place between the heating device (5) and the stretching device (10).

6. The method according to claim 4 or 5, characterized in that the filaments (2, 3) are blown countercurrently at a temperature of 200°C to 350°C, preferably at a temperature of 225°C to 300°C.

7. The method as claimed in one of claims 4 to 6, characterized in that the filaments are blown countercurrently with an air quantity of 5 M ³ /h to 25 M ³ /h.

8. The method as claimed in one of claims 4 to 7, characterized in that the filaments are drawn off countercurrently with a drawing speed of 2000 m/min to 4700 m/min.

9. The method as claimed in one of claims 4 to 8, characterized in that the volume and temperature of the counterflow air are adjusted in such a way that an elongation of the yarn of less than 60% is achieved.

10. The method according to one of claims 4 to 9, characterized in that the drawing speed of the filament, the gas volume and temperature of the countercurrent air are adjusted such that the tensile strength of the drawn filament after the same drawing speed is equal to A relative increase of at least 20% compared to simple drawing of the filaments is achieved, wherein the tensile strength of the filaments preferably reaches at least 32 CN/Tex, particularly preferably reaches 40 to 50 CN/Tex.

11. Process according to one of claims 4 to 10, characterized in that the drawing speed of the filaments, the volume and temperature of the countercurrent air are adjusted such that the transition from the elastic deformation zone to the plastic deformation zone is only increased by 20% Realized under force.

12. The method according to one of claims 4 to 11, characterized in that the volume and temperature of the countercurrent air are adjusted such that the hot air shrinks the filaments by up to 6% (at 180° C. for 15 minutes).

13. The method as claimed in one of claims 4 to 12, characterized in that the countercurrent treatment of the filaments is followed by continuous post-drawing or in separate treatment steps.

14. The method as claimed in one of claims 4 to 13, characterized in that the synthetic filaments (2, 3) are laid on the base fabric for the production of the fiber web.

15. The method as claimed in one of claims 4 to 13, characterized in that the synthetic filaments (2, 3) are chopped for the production of staple fibers.

16. have the non-woven fabric that application is made by the stretching equipment of one of claims 1 to 3 or the stretching synthetic filament produced by the method of one of claim 4 to 15, it is characterized in that, long filament has at least 32CN /Tex tensile strength and less than 60% elongation.

17. Nonwoven fabric according to claim 16, characterized in that the synthetic filaments are laid as continuous yarns.

18. The fleece according to claim 16, characterized in that the synthetic filaments are present as staple fibers.

19. have the yarn that uses one of claim 1 to 3 drafting equipment or by the yarn that the drawing synthetic filament of one of claim 4 to 15 method production is made, it is characterized in that, long filament has at least 32CN/ Tex tensile strength and elongation less than 60%.

20. Yarn according to claim 19, characterized in that the synthetic filaments are continuous yarns.

21. Yarn according to claim 19, characterized in that the synthetic filaments are present as staple fibers.