Method for high speed stranding of aramid yarns

Abstract

A method for stranding aramid yarn around an endless core includes a stranding step that involves a stranding apparatus having at least one yarn bobbin. The bobbin revolves around its own axis and the bobbin revolves around the core, wherein the yarn unwinds from the bobbin and winds around the core. The yarn is a continuous aramid yarn provided with 0.05 to 0.95 wt %, based on the weight of the aramid, of a finish including an organophosphorus compound. The organophosphorus compound is a compound of the formula X1X2X3P═O. X1, X2, and X3 are independently selected from Y1-, Y1-O—, and M-O. Y1 is a branched or straight-chain C1-C20 alkyl, aryl or alkenyl. M is selected from Li, Na, K, or ammonium. At least one of X1, X2, or X3 is selected from Y1- or Y1-O—.

Claims

1. A method for stranding aramid yarn around an endless core, the method comprising: providing the endless core to a stranding apparatus comprising at least one yarn bobbin, wherein the bobbin revolves around its own axis and the bobbin revolves around the core during operation of the stranding apparatus; and stranding the yarn around the core at a speed of more than 190 RPM by unwinding the yarn from the bobbin and surrounding the core with the yarn, wherein the yarn is a continuous aramid yarn provided with 0.05 to 0.95 wt %, based on the weight of the aramid, of a finish substantially free of fatty acid esters and comprising an organophosphorus compound; wherein the continuous aramid yarn comprises continuous filaments, the organophosphorus compound is a compound of the formula X1X2X3P═O or a dimer thereof; X1, X2, and X3 are independently selected from the group consisting of Y1-, Y1-O—, and M-O; Y1 is a branched or straight-chain C1-C20 alkyl, aryl or alkenyl; M is Li, Na, K, or ammonium; and at least one of X1, X2, or X3 is Y1- or Y1-O—, and the different types of Y1 are the same or different, and the organophosphorus compound comprises: a monoalkyl ester of phosphoric acid; a dialkyl ester of phosphoric acid; and a dialkyl ester of pyrophosphoric acid.

2. The method according to claim 1, wherein the organophosphorus compound comprises a phosphine oxide according to formula 1 below: ##STR00009## wherein R1, R2 and R3 are each independently a branched or a straight-chain C.sub.1-C.sub.20 alkyl, aryl or alkenyl.

3. The method according to claim 1, wherein: the monoalkyl ester of phosphoric acid and the dialkyl ester of phosphoric acid have the formula: ##STR00010## wherein R1 is a branched or straight-chain C.sub.1-C.sub.15 alkyl, R2 is H, Li, Na, K or NH.sub.4 in the case of the monoalkyl ester of phosphoric acid, or a branched or straight-chain C.sub.1-C.sub.15 alkyl in the case of the dialkyl ester of phosphoric acid, and M is Li, Na, K or NH.sub.4.

4. The method according to claim 1, wherein Y1 is a straight-chain C1-C20 alkyl, aryl or alkenyl.

5. The method according to claim 3, wherein: the dialkyl ester of pyrophosphoric acid has the formula: ##STR00011## wherein M is Li, Na, K or ammonium; and R1 is a branched or straight-chain C.sub.1-C.sub.15 alkyl, and the finish comprises up to 30 wt % of the dialkyl ester of pyrophosphoric acid.

6. The method according to claim 1, wherein the aramid is poly(p-phenylene terephthalamide) or poly(p-phenylene terephthalamide) containing 3,4′-diaminodiphenylether and 5(6)-amino-2-(p-aminophenyl)benzimidazole units.

7. The method according to claim 1, wherein the stranding apparatus includes at least two yarn bobbins that revolve around the core.

8. The method according to claim 1, wherein the aramid is applied with a lay length in the range of 100 to 500 mm.

9. The method according to claim 1, wherein the core comprises one or more optical glass fibers such that stranding the yarn around the core produces an optical fiber cable.

10. The method according to claim 1, further comprising: an extruding step after the stranding step, wherein a sheathing of a polymer material is extruded around the core provided with strands of aramid yarn.

11. The method according to claim 9, wherein the core further comprises a sheathing of a thermoplastic material that surrounds the optical glass fibers.

12. The method according to claim 1, wherein: the organophosphorus compound further comprises a phosphinate according to formula 2 below: ##STR00012## wherein R1 is a branched or straight-chain C.sub.1-C.sub.20 alkyl, aryl or alkenyl, Li, Na, K or NH.sub.4; and R2 and R3 are each independently a branched or straight-chain C.sub.1-C.sub.20 alkyl, aryl or alkenyl.

13. The method according to claim 1, wherein: the organophosphorus compound further comprises a phosphonate according to formula 3 below: ##STR00013## wherein R1 and R2 are each independently a branched or straight-chain C.sub.1-C.sub.20 alkyl, aryl or alkenyl, Li, Na, K or NH.sub.4; and R3 is a branched or straight-chain C.sub.1-C.sub.20 alkyl, aryl or alkenyl.

14. The method according to claim 1, wherein: the organophosphorus compound comprises a phosphate ester according to formula 4 below: ##STR00014## R1 is a branched or straight-chain C.sub.1-C.sub.20 alkyl, aryl, alkenyl; and R2 and R3 are each independently H, Li, Na, K or NH.sub.4, or a branched or straight-chain C.sub.1-C.sub.20 alkyl, aryl, or alkenyl.

15. The method according to claim 1, wherein the organophosphorus compound consists of: a monoalkyl ester of phosphoric acid; a dialkyl ester of phosphoric acid; a dialkyl ester of pyrophosphoric acid; and optionally, a trialkyl ester of phosphoric acid.

16. The method according to claim 15, wherein the solid components of the finish consist of the organophosphorus compound.

17. The method according to claim 1, wherein the stranding step is operated at a speed of at least 200 RPM.

18. The method according to claim 1, wherein the stranding step is operated at a speed of at least 205 RPM.

19. A method for stranding aramid yarn around an endless core, the method comprising: providing the endless core to a stranding apparatus comprising at least one yarn bobbin, wherein the bobbin revolves around its own axis and the bobbin revolves around the core during operation of the stranding apparatus; and stranding the yarn around the core at a speed of more than 190 RPM by unwinding the yarn from the bobbin and surrounding the core with the yarn, wherein the yarn is a continuous aramid yarn provided with 0.05 to 0.95 wt %, based on the weight of the aramid, of a finish substantially free of fatty acid esters and comprising an organophosphorus compound; wherein the continuous aramid yarn comprises continuous filaments, the organophosphorus compound is a compound of the formula X1X2X3P═O or a dimer thereof; X1, X2, and X3 are independently selected from the group consisting of Y1-, Y1-O—, and M-O; Y1 is a branched or straight-chain C1-C20 alkyl, aryl or alkenyl; M is Li, Na, K, or ammonium; and at least one of X1, X2, or X3 is Y1- or Y1-O—, and the different types of Y1 are the same or different, and the organophosphorus compound comprises: a monoalkyl ester of phosphoric acid; a dialkyl ester of phosphoric acid; and a trialkyl ester of phosphoric acid.

20. The method according to claim 19, wherein: the trialkyl ester of phosphoric acid has the formula: ##STR00015## and R.sub.1, R.sub.2 and R.sub.3 are each independently a branched or straight-chain C.sub.1-C.sub.15 alkyl groups, and the finish comprises up to 20 wt % of the trialkyl ester of phosphoric acid.

21. The method according to claim 19, wherein the organophosphorus compound consists of: a monoalkyl ester of phosphoric acid; a dialkyl ester of phosphoric acid; a trialkyl ester of phosphoric acid; and optionally, a dialkyl ester of pyrophosphoric acid.

22. The method according to claim 21, wherein the solid components of the finish consist of the organophosphorus compound.

23. The method according to claim 19, wherein the stranding step is operated at a speed of at least 200 RPM.

24. The method according to claim 19, wherein the stranding step is operated at a speed of at least 205 RPM.

Description

EXAMPLE 1

(1) A finish stock solution based on Stantex ARA® (10 wt %) was made by diluting Stantex ARA® (56 wt %; ex Pulcra) into a 10% solution in warm (40° C.) demi-water. To obtain the final spin finish solution (2.8 wt %) the Stantex ARA® stock solution was further diluted in warm demi-water (40° C.) and stirred for 15 minutes, after which it was ready to apply onto the yarn. Unfinished Twaron® multifilament yarn with a linear density of 2790 dtex and filament count 2000 produced in a single spinning trial at a spinning speed of 320 m/min and treated in-line with Stantex ARA® finish at a dosing level of 0.30 wt % using a slit applicator. The reference yarn sample was finished subsequently under the exact same spinning conditions with Breox 50A50® finish (consisting of random exthoxylated and propylated butanol, ex Ilco-Chemie, BASF) at 0.80 wt %. All samples are wound on a 290 mm length×106 mm outer diameter tube using a precision winder. The weight of the yarn packages and tube was 11 kg for the reference sample with Breox 50A50® and for the sample with Stantex ARA®. The density of the yarn packages was the same for the sample with Breox 50A50® and the sample with Stantex ARA®.

(2) Package stability was measured according the above described Roblon server test set-up 1. The results are given in the following tables.

(3) TABLE-US-00002 TABLE package width determination Server Breox 50A50 ® Stantex ARA ® relative speed 0.8 wt % (prior art) 0.3 wt % (invention) Δwidth setting width Δwidth width Δwidth decrease RPM (mm) (mm) (mm) (mm) (%) 0 (start) 265.90 0 266.0 0 145 267.70 1.80 266.25 0.25 86 160 269.65 3.75 266.40 0.40 89 175 273.15 7.25 266.85 0.85 88 190 279.55 16.65 267.10 1.10 92 205 MAX* MAX* 267.60 1.60 NAN* 220 MAX* MAX* 275.15 9.15 NAN* MAX*: maximum package deformation of 20 mm was reached, safety stop activated, NAN*: relative Δwidth decrease can not be calculated

(4) TABLE-US-00003 TABLE Package angular rotation Server speed Breox 50A50 ® Stantex ARA ® Relative setting 0.8 wt % (prior art) 0.3 wt % (invention) angular rotation RPM Rotation (degrees) Rotation (degrees) decrease (%) 145 0 0 160 3 0 100 175 15 0 100 190 38 0 100 205 —* 0 NAN* 220 —* 18 NAN* *maximum package deformation of 20 mm was reached, safety stop activated, NAN*: relative decrease in angular rotation can not be calculated

EXAMPLE 2

(5) A finish stock solution based on Stantex ARA® (10 wt %) was made by diluting Stantex ARA® (56 wt %; ex Pulcra) into a 10% solution in warm (40° C.) demi-water. To obtain the final spin finish solution (2.8 wt %) the Stantex ARA® stock solution was further diluted in warm demi-water (40° C.) and stirred for 15 minutes, after which it was ready to apply onto the yarn. Unfinished Twaron® multifilament yarn with a linear density of 1610 dtex and filament count 1000 produced in a single spinning trial at a spinning speed of 400 m/min and treated in-line with Stantex ARA® finish at a dosing level of 0.20 wt % using a kiss roll. The reference yarn sample was finished subsequently under the exact same spinning conditions with Breox 50A50® finish (consisting of random exthoxylated and propylated butanol, ex Ilco-Chemie, BASF) at 0.80 wt %. All samples are wound on a 216 mm length tube with an outer diameter of 106 mm using a precision winder. The weight of the yarn packages and tube was 8.8 kg for both the reference sample with Breox 50A50® and the sample with Stantex ARA®. The density of the yarn packages was the same for the sample with Breox 50A50® and the sample with Stantex ARA®.

(6) Package stability was measured according the above described Roblon server test set-up 1. The results are given in the following tables.

(7) TABLE-US-00004 TABLE package width determination Server Breox 50A50 ® Stantex ARA ® relative speed 0.8 wt % (prior art) 0.2 wt % (invention) Δwidth setting width Δwidth width Δwidth decrease RPM (mm) (mm) (mm) (mm) (%) 0 (start) 198.50 0 196.00 0 146 198.80 0.30 196.20 0.20 33 160 200.10 1.60 196.20 0.20 88 176 203.2 4.70 196.20 0.20 96 190 208.00 9.50 196.20 0.20 98 204 MAX* MAX* 196.20 0.20 NAN* 218 MAX* MAX* 196.80 0.80 NAN* 232 MAX* MAX* 197.40 1.40 NAN* 250 MAX* MAX* 200.10 4.10 NAN* 264 MAX* MAX* 204.40 8.40 NAN* 278 MAX* MAX* MAX* MAX* NAN* MAX*: maximum package deformation of 20 mm was reached, safety stop activated, NAN*: relative Δwidth decrease can not be calculated

(8) TABLE-US-00005 TABLE Package angular rotation Server speed Breox 50A50 ® Stantex ARA ® Relative setting 0.8 wt % (prior art) 0.2 wt % (invention) angular rotation RPM Rotation (degrees) Rotation (degrees) decrease (%) 0 (start) 0 0 146 0 0 160 5 0 100 176 30 0 100 190 75 0 100 204 —* 0 NAN* 218 —* 0 NAN* 232 —* 0 NAN* 250 —* 15 NAN* 264 —* 30 NAN* 278 —* 120 NAN* *maximum package deformation of 20 mm was reached, safety stop activated, NAN*: relative decrease in angular rotation can not be calculated

EXAMPLE 3

(9) A finish stock solution based on Stantex ARA® (10 wt %) was made by diluting Stantex ARA® (56 wt %; ex Pulcra) into a 10% solution in warm (40° C.) demi-water. To obtain the final spin finish solution (2.8 wt %) the Stantex ARA® stock solution was further diluted in warm demi-water (40° C.) and stirred for 15 minutes, after which it was ready to apply onto the yarn. Unfinished Twaron® multifilament yarn with a linear density of 2680 dtex and filament count 2000 produced in a single spinning trial at a spinning speed of 320 m/min and treated in-line with Stantex ARA® finish at a dosing level of 0.4 wt % using a kiss roll. The reference yarn sample was finished subsequently under the exact same spinning conditions with Breox 50A50® finish (consisting of random exthoxylated and propylated butanol, ex Ilco-Chemie, BASF) at 0.80 wt %. All samples are wound on a 216 mm length tube with an outer diameter of 106 mm using a precision winder. The weight of the yarn packages and tube was 7 kg for both the reference sample with Breox 50A50® and the sample with Stantex ARA®. The density of the yarn packages was the same for the sample with Breox 50A50® and the sample with Stantex ARA®.

(10) Package stability was measured according the above described Roblon server test set-up 1. The results are given in the following tables.

(11) TABLE-US-00006 TABLE package width determination Server Breox 50A50 ® Stantex ARA ® relative speed 0.8 wt % (prior art) 0.4 wt % (invention) Δwidth setting width Δwidth width Δwidth decrease RPM (mm) (mm) (mm) (mm) (%) 0 (start) 196.00 0 194.00 0 146 197.20 1.20 194.00 0 100 160 198.10 2.10 194.00 0 100 176 201.10 5.10 194.00 0 100 190 205.30 9.30 194.00 0 100 204 210.50 14.50 194.00 0 100 218 MAX* MAX* 194.00 0 NAN*: 232 MAX* MAX* 194.00 0 NAN*: 250 MAX* MAX* 194.00 0 NAN*: 264 MAX* MAX* 194.00 0 NAN*: 278 MAX* MAX* 194.00 0 NAN*: 292 MAX* MAX* 194.00 0 NAN*: MAX*: maximum package deformation of 20 mm was reached, safety stop activated, NAN*: relative Δwidth decrease can not be calculated

(12) TABLE-US-00007 TABLE Package angular rotation Server speed Breox 50A50 ® Stantex ARA ® Relative setting 0.8 wt % (prior art) 0.4 wt % (invention) angular rotation RPM Rotation (degrees) Rotation (degrees) decrease (%) 0 (start) 0 0 146 0 0 0 160 0 0 0 176 5 0 100 190 20 0 100 204 65 0 100 218 160 0 100 232 —* 0 NAN* 250 —* 0 NAN* 264 —* 0 NAN* 278 —* 0 NAN* 292 —* 0 NAN* *maximum package deformation of 20 mm was reached, safety stop activated, NAN*: relative decrease in angular rotation can not be calculated

EXAMPLE 4

(13) Two samples produced under the exact same conditions as described under example 3, one with Breox 50A50® and one sample with Stantex ARA® underwent a static package stability test at a fixed rotation speed as described above. The maximum server rotation speed in the static package stability test is 250 RPM for sample with Stantex ARA® whereas the maximum server rotation speed for the sample with Breox 50A50® is 176 RPM. So an increase of 42% in server rotation speed is found for the sample with Stantex ARA® over the sample with Breox 50A50®.

EXAMPLE 5

(14) Two series of three Twaron multifilament yarn with a linear density of 2680 dtex and a filament count of 2000 produced under the exact same conditions as under example 3, one series with Breox 50A50® and one series with Stantex ARA® are unwound to form one bundle of Twaron multifilament yarn with a linear density of 8050 dtex and a filament count of 6000. This yarn is subsequently wound on a 290 mm length tube with an outer diameter of 106 mm using a precision winder. The weight of the yarn package and tube was 10.8 kg for both samples.

(15) Package stability was measured according the above described Roblon server test set-up 1. The results are given in the following tables.

(16) TABLE-US-00008 TABLE package width determination Server Breox 50A50 ® Stantex ARA ® relative speed 0.8 wt % (prior art) 0.4 wt % (invention) Δwidth setting width Δwidth width Δwidth decrease RPM (mm) (mm) (mm) (mm) (%) 0 (start) 266.30 0 268.90 0 146 267.10 0.80 269.00 0.10 86 160 268.00 1.70 269.00 0.10 94 176 269.00 2.70 269.00 0.10 96 190 271.20 4.90 269.00 0.10 98 204 276.20 9.90 269.00 0.10 99 218 MAX* MAX* 269.40 0.50 NAN* 232 MAX* MAX* 269.50 0.60 NAN* 250 MAX* MAX* 270.50 1.60 NAN* 264 MAX* MAX* 275.60 6.70 NAN* MAX*: maximum package deformation of 20 mm was reached, safety stop activated, NAN*: relative Δwidth decrease can not be calculated

(17) TABLE-US-00009 TABLE Package angular rotation Server speed Breox 50A50 ® Stantex ARA ® Relative setting 0.8 wt % (prior art) 0.4 wt % (invention) angular rotation RPM Rotation (degrees) Rotation (degrees) decrease (%) 0 (start) 0 0 146 0 0 100 160 5 0 100 176 10 0 100 190 30 0 100 204 65 0 100 218 —* 5 NAN* 232 —* 10 NAN* 250 —* 30 NAN* 264 —* 60 NAN* *maximum package deformation of 20 mm was reached, safety stop activated, NAN*: relative decrease in angular rotation can not be calculated