CA2265059A1 - Process for producing polytetramethylene adipamide fibers - Google Patents
Process for producing polytetramethylene adipamide fibers Download PDFInfo
- Publication number
- CA2265059A1 CA2265059A1 CA002265059A CA2265059A CA2265059A1 CA 2265059 A1 CA2265059 A1 CA 2265059A1 CA 002265059 A CA002265059 A CA 002265059A CA 2265059 A CA2265059 A CA 2265059A CA 2265059 A1 CA2265059 A1 CA 2265059A1
- Authority
- CA
- Canada
- Prior art keywords
- filaments
- melt
- extruder
- pellets
- polymer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
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
- D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
- D01F6/58—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products
- D01F6/60—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polyamides
-
- 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
Abstract
In a process for producing fibers from polytetramethylene adipamide (nylon 4,6), pellets pressed from polymer powder are used as the starting material. This enables problem-free spinning of nylon 4,6.
Description
Process for producing polytetramethylene adipamide fibers Description:
The invention relates to a process for producing fibers made from polytetramethylene adipamide using the melt-spinning proc-ess, with the process steps of melting the starting polymer in an extruder, feeding the polymer, possibly containing addi-tives, to a melt-spinning apparatus, pressing this molten poly-mer through spinnerets to form filaments, cooling the spun filaments by subjecting them to forced air, applying a finish to the filaments, removing the filaments with a suitable draw-ing-off apparatus, drawing the spun filaments, and relaxing the drawn filaments.
The manufacture of polytetramethylene adipamide fibers is known. Fibers spun from this polymer, normally referred to as nylon 4,6, are used primarily for industrial textiles. One of the major advantages of polytetramethylene adipamide fibers is their increased thermal resistance compared to other aliphatic polyamides such as nylon 6,6 (polyhexamethylene adipamide) or nylon 6 (polycaproamide).
One process for producing fibers from this polymer is described in JP-A 59 - 088 910. The fibers are spun in a conventional manner using the melt-spinning process at a melt temperature of 300-340°C. To produce the melt, the use of a twin-screw ex-truder is recommended when using polymer powder as a starting material. A non-aqueous finish is applied to the freshly spun filaments, and drawing is performed continuously in a one-stage spinning/drawing process.
Another description of a spinning process is contained in JP-A
05 - 132 820. In this case, a granulate is converted to a melt at a temperature of 290-320°C. Spinning is performed in this temperature range. The freshly spun material is drawn continu-ously after applying a non-aqueous finish.
A spinning process for polyamide fibers in general, in which polytetramethylene adipamide can also be used as the starting polymer, is described in US 4 859 389. In this case as well, the use of a non-aqueous finish is proposed.
A spinning temperature of 300°C +/- 3°C and granulate as a starting material is recommended by Schmack et al. (Chemical Fibers International 45 (1995), pp. 475-477. This document con-tains no information concerning the finish.
The previously described processes have two serious disadvan-tages, namely the expensive steps required to melt the polymer, such as via a twin-screw extruder, and the use of a non-aqueous finish. The latter is quite unfavorable chiefly for ecological reasons.
In polymer production, polytetramethylene adipamide is neces-sarily produced in the form of powder. On normal extruders such as are commonly used for fiber production, this powder cannot be melted in such a way that results in a homogeneous melt for problem-free melt spinning. For this reason, as JP-A 59 - 088 910 teaches, the process must be conducted with a twin-screw extruder when polymer powder is to be melted. This type of ex-truder is often not available in fiber manufacturing plants, so that costly investment is required in order to process polytet-ramethylene adipamide into fibers.
The invention relates to a process for producing fibers made from polytetramethylene adipamide using the melt-spinning proc-ess, with the process steps of melting the starting polymer in an extruder, feeding the polymer, possibly containing addi-tives, to a melt-spinning apparatus, pressing this molten poly-mer through spinnerets to form filaments, cooling the spun filaments by subjecting them to forced air, applying a finish to the filaments, removing the filaments with a suitable draw-ing-off apparatus, drawing the spun filaments, and relaxing the drawn filaments.
The manufacture of polytetramethylene adipamide fibers is known. Fibers spun from this polymer, normally referred to as nylon 4,6, are used primarily for industrial textiles. One of the major advantages of polytetramethylene adipamide fibers is their increased thermal resistance compared to other aliphatic polyamides such as nylon 6,6 (polyhexamethylene adipamide) or nylon 6 (polycaproamide).
One process for producing fibers from this polymer is described in JP-A 59 - 088 910. The fibers are spun in a conventional manner using the melt-spinning process at a melt temperature of 300-340°C. To produce the melt, the use of a twin-screw ex-truder is recommended when using polymer powder as a starting material. A non-aqueous finish is applied to the freshly spun filaments, and drawing is performed continuously in a one-stage spinning/drawing process.
Another description of a spinning process is contained in JP-A
05 - 132 820. In this case, a granulate is converted to a melt at a temperature of 290-320°C. Spinning is performed in this temperature range. The freshly spun material is drawn continu-ously after applying a non-aqueous finish.
A spinning process for polyamide fibers in general, in which polytetramethylene adipamide can also be used as the starting polymer, is described in US 4 859 389. In this case as well, the use of a non-aqueous finish is proposed.
A spinning temperature of 300°C +/- 3°C and granulate as a starting material is recommended by Schmack et al. (Chemical Fibers International 45 (1995), pp. 475-477. This document con-tains no information concerning the finish.
The previously described processes have two serious disadvan-tages, namely the expensive steps required to melt the polymer, such as via a twin-screw extruder, and the use of a non-aqueous finish. The latter is quite unfavorable chiefly for ecological reasons.
In polymer production, polytetramethylene adipamide is neces-sarily produced in the form of powder. On normal extruders such as are commonly used for fiber production, this powder cannot be melted in such a way that results in a homogeneous melt for problem-free melt spinning. For this reason, as JP-A 59 - 088 910 teaches, the process must be conducted with a twin-screw extruder when polymer powder is to be melted. This type of ex-truder is often not available in fiber manufacturing plants, so that costly investment is required in order to process polytet-ramethylene adipamide into fibers.
Another possibility consists of re-melting the polymer powder and forming a granulate, which can then be melted on conven-tional extruders prior to spinning into fibers. This process is not only costly, but there is also the danger of oxidative or thermal damage to the polymer due to the double melting proc-ess.
Another significant disadvantage arises from the necessity men-tioned in the prior art of using non-aqueous finishes, because according to the statements made in these descriptions the in-fluence of aqueous finishes can result in formation of so-called spherulites on the fiber surface, which have a negative impact on the drawing properties of the spun material. Such non-aqueous solutions contain the actual finish in mineral oil, for example.
In addition to the higher costs compared to aqueous finishing systems, the disadvantage of the non-aqueous finish can be seen primarily in the reduced ability to remove the finish by wash-ing and in increased waste water pollution.
For this reason, the object arose to provide a process that does not exhibit the disadvantages mentioned herein and that thus meets the prerequisite for a more cost-effective produc-tion of polytetramethylene adipamide fibers.
Surprisingly, it has been discovered that production of 'these fibers is especially advantageous if pellets pressed from the powder resulting from polymer production are used as the start-ing material for melting.
These pellets preferably have a cylinder-like shape. The length of the pellets is normally between 0.1 and 8 mm, preferably be-tween 1 and 6 mm. The diameter of the pellets is between 0.1 and 5 mm, preferably between 1.5 and 4 mm, with a range of 2.5 to 3.5 mm being especially preferred.
In using these pellets as a starting material, the conventional single-screw extruders common in fiber production can be em-ployed, and the polymer selected for fiber production can be melted without difficulty.
The polytetramethylene adipamide used as the polymer for fiber production is understood to be not only a homopolymer with this composition but also a copolymer with at least 85$ polytet-ramethylene adipamide units. Caprolactam is primarily used as the comonomer. Preferred fractions of caprolactam in the poly-mer are 3-10~. The use of the comonomer influences the thermal properties of the polytetramethylene adipamide, i.e., an in-creased comonomer fraction results in a reduction of the melt-ing point.
The polymer can contain additives such as stabilizing agents.
These can be added during polymer production or measured into the molten polymer via a master batch. Other possibilities are to introduce the additive into the molten polymer in the ex-truder or to sprinkle the additive onto the pellets prior to melting.
If a polymer with a caprolactam fraction in the aforementioned range is used, the melt temperature can be about 300°C. Fiber production occurs in the manner conventionally used in the melt-spinning process, by feeding the melt to spinnerets and pressing the melt through the spinneret openings, thereby form-ing the fibers. Downstream from the spinneret is a cooling zone, conventional in melt spinning, in which forced air is di-rected onto the fibers.
An aqueous-based finish is applied to the freshly spun fila-ments. Products that are not water-soluble are present in the finish batch in the form of an emulsion.
It has been shown that the use of an aqueous finish also en-ables fully satisfactory operation in the subsequent drawing stage and that it is possible to dispense with using a non-aqueous, i.e., benzine-based, finish, in contrast to the teach-ings of the prior art.
Fiber production can be continuous, using a spinning/drawing process, or discontinuous. In the first case, the freshly spun product is not wound up but rather fed directly following spin-ning to a drawing zone, where it is drawn.
In the discontinuous process, the freshly spun product is wound up. The resulting spools are fed to a drawing machine. In pro-ducing filament yarns, drawing is performed using galette sys-tems that are operated at different speeds and temperatures.
The difference in speeds provides the adjustment of the draw ratio. Drawing can be performed in one or two stages. After drawing is completed, the yarn can be fed through a so-called relaxation zone, whereby the galettes arranged at the exit from this zone are operated at a slower speed than the galettes on the feed side. Another possibility is to transfer the relaxa-tion process to the wind-up zone, i.e., to operate the wind-up machinery at a slower speed that the feed machinery.
The described procedure results in a filament yarn that is es-pecially suitable for use in industrial textiles. However, the filament yarns produced according to the invention are also well suited for non-industrial applications such as clothing.
The described process is preferably conducted to produce polytetramethylene adipamide filament yarns. It can also be em-ployed for producing staple fibers, however. Moreover, spunbon-ded nonwovens can be made from this polymer under the condi-tions described for the spinning stage.
Embodiment example A polymer containing 94~ polytetramethylene adipamide and 6~
caprolactam was used in the form of pellets to produce a fila-ment yarn. The pellet length had a mean of 4.2 mm and a stan-dard deviation of 1.3 mm. The mean of the pellet diameter was determined to be 2.7 mm. The standard deviation was 0.08 mm.
The pellets were melted in an extruder having four separately heated zones. The following temperatures were set in the indi-vidual heating zones:
Zone 1 315C
Zone 2 310C
Zone 3 305C
Zone 4 290C
The temperature in the melt duct was 302°C. The melt was fed to and pressed through a spinneret with 36 openings. The freshly spun filaments were cooled by forced air at 150 m3/h. Subse-quently, the aqueous finish was applied via finishing galettes.
The concentration of the finishing agent in the finishing batch was about 15$. The filaments spun in this manner were wound up at a rate of 600 m/min.
The spools were fed to a drawing machine that drew the yarn at a rate of 580 m/min. On the drawing machine, drawing was per-formed at a ratio of 1:3.91 over a so-called hot plate whose temperature was set at 210°C. The temperature of the feed galettes was 105°C and that of the removal galettes was 215°C.
Subsequently, relaxation was performed at a ratio of 1:0.97.
The yarn produced in this manner exhibited the following prop-erties:
Yarn titer 235 dtex Number of filaments 36 Tensile strength 69.8 cN/tex Elongation at break ~ 15.9 Hot-air shrinkage (190°C) 3.3~
Another significant disadvantage arises from the necessity men-tioned in the prior art of using non-aqueous finishes, because according to the statements made in these descriptions the in-fluence of aqueous finishes can result in formation of so-called spherulites on the fiber surface, which have a negative impact on the drawing properties of the spun material. Such non-aqueous solutions contain the actual finish in mineral oil, for example.
In addition to the higher costs compared to aqueous finishing systems, the disadvantage of the non-aqueous finish can be seen primarily in the reduced ability to remove the finish by wash-ing and in increased waste water pollution.
For this reason, the object arose to provide a process that does not exhibit the disadvantages mentioned herein and that thus meets the prerequisite for a more cost-effective produc-tion of polytetramethylene adipamide fibers.
Surprisingly, it has been discovered that production of 'these fibers is especially advantageous if pellets pressed from the powder resulting from polymer production are used as the start-ing material for melting.
These pellets preferably have a cylinder-like shape. The length of the pellets is normally between 0.1 and 8 mm, preferably be-tween 1 and 6 mm. The diameter of the pellets is between 0.1 and 5 mm, preferably between 1.5 and 4 mm, with a range of 2.5 to 3.5 mm being especially preferred.
In using these pellets as a starting material, the conventional single-screw extruders common in fiber production can be em-ployed, and the polymer selected for fiber production can be melted without difficulty.
The polytetramethylene adipamide used as the polymer for fiber production is understood to be not only a homopolymer with this composition but also a copolymer with at least 85$ polytet-ramethylene adipamide units. Caprolactam is primarily used as the comonomer. Preferred fractions of caprolactam in the poly-mer are 3-10~. The use of the comonomer influences the thermal properties of the polytetramethylene adipamide, i.e., an in-creased comonomer fraction results in a reduction of the melt-ing point.
The polymer can contain additives such as stabilizing agents.
These can be added during polymer production or measured into the molten polymer via a master batch. Other possibilities are to introduce the additive into the molten polymer in the ex-truder or to sprinkle the additive onto the pellets prior to melting.
If a polymer with a caprolactam fraction in the aforementioned range is used, the melt temperature can be about 300°C. Fiber production occurs in the manner conventionally used in the melt-spinning process, by feeding the melt to spinnerets and pressing the melt through the spinneret openings, thereby form-ing the fibers. Downstream from the spinneret is a cooling zone, conventional in melt spinning, in which forced air is di-rected onto the fibers.
An aqueous-based finish is applied to the freshly spun fila-ments. Products that are not water-soluble are present in the finish batch in the form of an emulsion.
It has been shown that the use of an aqueous finish also en-ables fully satisfactory operation in the subsequent drawing stage and that it is possible to dispense with using a non-aqueous, i.e., benzine-based, finish, in contrast to the teach-ings of the prior art.
Fiber production can be continuous, using a spinning/drawing process, or discontinuous. In the first case, the freshly spun product is not wound up but rather fed directly following spin-ning to a drawing zone, where it is drawn.
In the discontinuous process, the freshly spun product is wound up. The resulting spools are fed to a drawing machine. In pro-ducing filament yarns, drawing is performed using galette sys-tems that are operated at different speeds and temperatures.
The difference in speeds provides the adjustment of the draw ratio. Drawing can be performed in one or two stages. After drawing is completed, the yarn can be fed through a so-called relaxation zone, whereby the galettes arranged at the exit from this zone are operated at a slower speed than the galettes on the feed side. Another possibility is to transfer the relaxa-tion process to the wind-up zone, i.e., to operate the wind-up machinery at a slower speed that the feed machinery.
The described procedure results in a filament yarn that is es-pecially suitable for use in industrial textiles. However, the filament yarns produced according to the invention are also well suited for non-industrial applications such as clothing.
The described process is preferably conducted to produce polytetramethylene adipamide filament yarns. It can also be em-ployed for producing staple fibers, however. Moreover, spunbon-ded nonwovens can be made from this polymer under the condi-tions described for the spinning stage.
Embodiment example A polymer containing 94~ polytetramethylene adipamide and 6~
caprolactam was used in the form of pellets to produce a fila-ment yarn. The pellet length had a mean of 4.2 mm and a stan-dard deviation of 1.3 mm. The mean of the pellet diameter was determined to be 2.7 mm. The standard deviation was 0.08 mm.
The pellets were melted in an extruder having four separately heated zones. The following temperatures were set in the indi-vidual heating zones:
Zone 1 315C
Zone 2 310C
Zone 3 305C
Zone 4 290C
The temperature in the melt duct was 302°C. The melt was fed to and pressed through a spinneret with 36 openings. The freshly spun filaments were cooled by forced air at 150 m3/h. Subse-quently, the aqueous finish was applied via finishing galettes.
The concentration of the finishing agent in the finishing batch was about 15$. The filaments spun in this manner were wound up at a rate of 600 m/min.
The spools were fed to a drawing machine that drew the yarn at a rate of 580 m/min. On the drawing machine, drawing was per-formed at a ratio of 1:3.91 over a so-called hot plate whose temperature was set at 210°C. The temperature of the feed galettes was 105°C and that of the removal galettes was 215°C.
Subsequently, relaxation was performed at a ratio of 1:0.97.
The yarn produced in this manner exhibited the following prop-erties:
Yarn titer 235 dtex Number of filaments 36 Tensile strength 69.8 cN/tex Elongation at break ~ 15.9 Hot-air shrinkage (190°C) 3.3~
Claims (7)
1. Process for producing fibers from polytetramethylene adipamide using the melt-spinning process, comprising the steps of a. melting the starting polymer in an extruder b. feeding the molten polymer, possibly containing additives, to a melt-spinning apparatus c. pressing this molten polymer through spinnerets to form filaments d. cooling the spun filaments by forced air e. applying a finish to the filaments f. removing the filaments with a suitable drawing-off apparatus g. drawing the spun filaments h. relaxing the drawn filaments characterized in that the powder produced during polymer production is pressed into pellets prior to being melted in the extruder, introduced into the extruder in the form of pellets, and melted therein.
2. Process according to Claim 1, characterized in that the pellets have an essentially cylindrical shape.
3. Process according to at least one of Claims 1-2, characterized in that the pellet length is from 0.1-8 mm.
4. Process according to at least one of Claims 1-3, characterized in that the pellet diameter is 0.1-5 mm.
5. Process according to at least one of Claims 1-4, characterized in that an aqueous finish is applied.
6. Process according to at least one of Claims 1-5, characterized in that the additives are introduced by adding during polymer production, sprinkling them onto the pellets, measuring them into the melt in the extruder, or measuring them into the melt downstream from the extruder using a master batch.
7. Polytetramethylene adipamide fiber material produced according to at least one of Claims 1-6.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19809979 | 1998-03-09 | ||
| DE19809979.7 | 1998-03-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2265059A1 true CA2265059A1 (en) | 1999-09-09 |
Family
ID=7860173
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002265059A Abandoned CA2265059A1 (en) | 1998-03-09 | 1999-03-08 | Process for producing polytetramethylene adipamide fibers |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0942079A3 (en) |
| JP (1) | JPH11315413A (en) |
| KR (1) | KR19990077675A (en) |
| BR (1) | BR9900983A (en) |
| CA (1) | CA2265059A1 (en) |
| ZA (1) | ZA991846B (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61194209A (en) * | 1985-02-20 | 1986-08-28 | Toyobo Co Ltd | High-tenacity polyamide fiber and production thereof |
| NL8601893A (en) * | 1986-07-22 | 1988-02-16 | Stamicarbon | PREPARATION OF HIGH MOLECULAR POLYTETRAMETHYLENE ADIPAMIDE. |
| JPH0791727B2 (en) * | 1986-11-04 | 1995-10-04 | ユニチカ株式会社 | Method for producing polyamide multifilament fabric |
| KR930010631B1 (en) * | 1989-08-05 | 1993-11-02 | 디에스엠 엔. 브이. | Polyamide composition |
-
1999
- 1999-03-02 EP EP99104127A patent/EP0942079A3/en not_active Withdrawn
- 1999-03-08 JP JP11060662A patent/JPH11315413A/en active Pending
- 1999-03-08 CA CA002265059A patent/CA2265059A1/en not_active Abandoned
- 1999-03-08 ZA ZA9901846A patent/ZA991846B/en unknown
- 1999-03-08 KR KR1019990007487A patent/KR19990077675A/en not_active Application Discontinuation
- 1999-03-09 BR BR9900983-8A patent/BR9900983A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| KR19990077675A (en) | 1999-10-25 |
| EP0942079A3 (en) | 1999-12-22 |
| EP0942079A2 (en) | 1999-09-15 |
| BR9900983A (en) | 2001-02-28 |
| ZA991846B (en) | 1999-09-22 |
| JPH11315413A (en) | 1999-11-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |