Title of Invention	"METHOD OF HEAT SETTING POLYESTER BRAIDED CORDAGE SO AS TO OBTAIN HIGH DEGREE OF ELASTIC RECOVERY UPON CYCLIC LOADING"
Abstract	The present invention relates to a method of heat setting of nylon or polyester braided cordages and narrow fabric (tapes/webbings) in order to obtain a high degree of elastic recovery' upon cyclic loading.

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FIELD OF INVENTION The present invention relates fo a method of heat setting of nylon or polyester braided cordages and narrow fabric (tapes/webbings) so as to obtain a high degree of elastic recovery upon cyclic loading. BACKGROUND AND PRIOR ART The cordages and narrow fabrics can be elongated in the machine direction, but the elongation has limited recovery, and the recovery disadvantageously decreases after each successive elongation. The US Patent 5,578,374 discloses the manufacturing of "very low creep, ultra high modulus, low shrink, and high tenacity polyolefin fiber having good strength retention at high temperatures". However, the document teaching is applicable to Poly-olefms only. In the drawing process the denier of the material used to be reduced significantly with respect to the control material. One another US patent 6,375,889 concerns with a method of making machine direction stretchable non-woven fabrics, which has a high degree of recovery upon elongation, the end uses for* such recoverable stretch fabrics include waistbands, undergarment components and interlinings. In the cited patent the method is applicable to only non-woven or with 75% polyester liber only. Since the rigging line material with better elastic recovery property is desirable hence the cordages and narrow fabric were subjected to heat setting at particular conditions of temperature, time and stretch to get the better recovery property than that of control. Therefore, there is urgent need to develop woven narrow fabric and braided cordages which is useful in aerospace cordages & webbings, marine ropes & cordages, tents, sports and mountaineering equipments, various high performance military application, etc. OBJEC TIVE OF THE INVENTION The main objective of the present invention is to establish a heat setting process through which the properties of the cordages and narrow fabric are improved in such a way that it is capable of recovering its length near to original, upon relaxation after successive loadings in the machine direction, as well as to get resultant material with low creep and high recovery from creep properties. Another objective of the present invention is to provide a rigging line material of the parachute (generally a load bearing cordage/narrow fabric) with better elastic recovery properly (minimum permanent set) after repeated deployment use. Yet another objective of the present invention is to provide cordage/narrow fabric for cyclic loading up to specific load in the tensile testing machine and measuring the recoverable component of the elongation does a static simulation of such repeated deployment use. Yet another objective of the present invention is to obtain recoverable component (elastic recovery) and the unrecoverable component (permanent set), which have been taken as one of the indices of the recovery behaviour of the cordages and narrow fabric under consideration. Yet another objective of the present invention is to develop a low creep (time dependent extension at constant load) and high recovery from creep for aerospace applications, the cordages and narrow fabric, both control and heat set have been investigated for the said properties. Yet another objective of the present invention is to effect both control and heat set cordages and narrow fabric have been subjected to creep at 30% of specified breaking load for particular period which has been decided based on the observation of the time after which ihe increase in extension ceases. Later relaxation for particular period has also been allowed similarly. SUMMARY OF THE INVENTION The present invention contemplates with the method of heat setting braided cordages and narrow fabric to obtain better elastic recovery after cyclic loading. The heat setting process herein involves heating the braided cordages and narrow fabric to a temperature between its glass transition temperature and its melting temperature at particular stretch followed by quenching at a temperature less than glass transition temperature in a continuous process The cyclic loading herein comprises of 50 cycles at -30% of the specified breaking load of the braided cordages and narrow fabric. The elastic recovery referred herein is the ratio of elastic extension to that of the total extension at the specified load (-30%) and has been measured upon 24 hours of relaxation after cyclic loading. The elastic recovery of the cordages and narrow fabric under consideration after the said heat setting process has been significantly improved as summarized below: • For polyester cordage: Elastic recovery of-90% for heat-set as compared to -60% of unheat set (control) • For nylon cordage: Elastic recovery of -90% for heat-set as compared to -75% of control • For nylon webbing: Elastic recovery of -90% for heat-set as compared to -80% of control As a spin-off benefit the resulting materials also have low creep and high recovery from as summarized below: For polyester cordage: -25% lesser creep than that of control as measured after around five days of loading at -30% of specified breaking load and -9% higher recovery from creep after thirteen days of relaxation than that of control. For nylon cordage: -35% lesser creep than that of control as measured after around five days of loading at ~30% of specified breaking load and -13% higher recovery from creep after five days of relaxation than that of control. BRIEF DESCRIPTION OF FIGURES Figure 1 shows a heat setting machine for carrying out a method of heat setting nylon, polyester braided cordages and narrow fabric (tapes/webbings). BRIEF DESCRIPTION OF THE TABLE Table 1 shows the effect of heat setting on polyester braided cordage, 318 kgf BS. Table 2 shows the effect of heat setting on nylon-66 braided cordage, 250 kgf BS. Table 3 shows the effect of heat setting on webbing nylon-66, 26mm, 850 kgf BS. Table 4 shows the physical properties of the polyester braided cordage, 318 kgf BS (unheated) subjected to heat setting. Table 5 shows the physical properties of the nylon-66 braided cordage, 250 kgf BS (unheated) subjected to heat setting. Table 6 shows the physical properties of webbing nylon-66, 26 mm, 850 kgf BS (untreated) subjected to heat setting. DETAILED DESCRIPTION OF THE INVENTION Accordingly, the present invention relates to a method of processing braided cordages for high elastic recovery, said method comprising the steps of: a. feeding the braided cordages or webbing for into preheating zone of heat setting machine, b. obtaining preheated cordages or webbing and feeding the same into main heating zone of said machine, c. stretching the cordages or webbings in main heating zone, d. feeding the stretched cordages or webbings of step (c) into the cooling /one of said machine for a time period in the range of 1 to 30 minutes in order to obtain desired braided cordages. Yet another embodiment of the invention is wherein in step (a), preheating zone is maintained at temperature in the range of room temperature to 100°C. Yet another embodiment of the invention is wherein in step (a), the braided cordages or webbings are kept for time period in the range of 1 to 10 minutes. Still another embodiment of the invention is wherein in step (b), the main heating zone is kept at a temperature in the range of 100°C to 300°C for a time period in the range of 1 to 10 minutes. One another embodiment ol'the invention is wherein in step (c), stretching of cordages is carried out in a range of 2 % to 20 %. Yet one another embodiment of the invention is wherein in step (d), cooling zone is kept at a temperature in the range of 1°C to 10°C for at time period in the range of 1 to 20 minutes. Yet another embodiment of the invention is wherein in step (d), cooling zone is kept at a temperature in the range of 5( C to 8 C for at time period in the range of 7 to 16 minutes. Yet another embodiment of the invention is wherein the braided cordages comprise 100 "/(. polyester high tenacity multifilament yarn. Yet another embodiment of the invention is wherein in step (d), thus produced polyester / nylon braided cordages / webbing having elastic recovery up to 90 %. Yet another embodiment of the invention is wherein in step (d), thus produced polyester or nylon braided cordages or webbing having creep properties increase up to 8.6 %. Yet another embodiment of the invention is wherein in step (d), thus produced polyester or nylon braided cordages or webbing having creep recovery up to 95 %. The textile material used in the present work are nylon-66 and polyester braided cordages and narrow fabric (tapes/webbings), which are 1. Braided Polyester cordage, 318 kgf Breaking Strength (BS) 2. Braided nylon-66 cordage, 318 kgf BS 3. Woven nylon narrow fabric - Webbing nylon-66, 26mm, 850 kgf BS A process called braiding produces braided cordages. Braiding is the process of interlacing three or more strands of yarn in such a way that each strand passes over and under one or more of the others and are laid together in diagonal formation. A narrow fabric for load bearing application (webbing/tape) is produced by weaving process with resultant width upto 100 mm and weight over 3.4g/rn/cm-width. Such cordages and narrow fabrics can be elongated in the machine direction, but the elongation has limited recovery, and the recovery disadvantageously decreases after each successive elongation. Since the rigging line material with better elastic recovery property is desirable hence the cordages and narrow fabric were subjected to heat setting at particular conditions of temperature, time and stretch to get the better recovery property than that of control. In the present work the specified and actual technical particulars of polyester braided cordage, nylon braided cordage and webbing nylon procured from the standard suppliers are given in table 1 to 3. The processing parameters in the heat setting machine: To heat set the braided cordages and narrow fabrics; a heat setting machine has been especially developed with special features of 'stretch in main heating zone' and the 'air cooling /.one with air cooling device'. Briefly, this heat setting machine has following features: Pre-heating Zone: This is the zone where material enters in the first instance as shown in Fig.l. The temperature is kept relatively low (-60°C) so as to remove the moisture to some extent and provide some temperature gradient to the material. Main-heating zone: The material after passing through pre-heating zone enters this zone. The temperature in this zone can be varied from 100° - 300°C and the material is simultaneously stretched in this zone. The ratio of dwell time of the material in this zone to the pre-heating zone and cooling zone is 1 and 0.6, respectively. Cooling zone: The material after coming out of main heating zone is quenched in this zone. The temperature in this zone can be maintained in the range of 5°-lO°e. The stretch is maintained in this zone as well so that the orientation set in main heating zone is frozen in this zone. Time: The time for which the material is subjected to in the main heating zone can be varied form 1 to 10 minutes. Stretch: the material during heat treatment in the main heating zone & cooling zone is subjected to a stretch, preset by the ratio of speed of input and delivery rollers and can be varied from 2 - 20%. Passage of the material The material enters the pre-heating zone and passes continuously from pre-heating to main heating zone, followed by quenching in the cooling zone before final delivery. A material of similar construction is used as carrier material for feeding the material into the machine so as to form a continuous flow of material. Evaluation of the material The material after heat setting has been evaluated for various properties such as breaking strength, elongation at break, recovery after 24 hours of relaxation after 50 load cycles at -30% of breaking load, creep at -30% of breaking load, creep recovery and boiling water shrinkage. The advantages of the disclosed invention are thus attained in an economical, practical, and facile manner. While preferred embodiments and example configurations have been shown and described, it is to be understood that various further modifications and additional configurations will be apparent to those skilled in the art. It is intended that the specific embodiments and configurations herein disclosed are illustrative of the preferred and best modes for practicing the invention, and should not be interpreted as limitations on the scope of the invention. shown and described, it is to be understood that various further modifications and additional configurations will be apparent to those skilled in the art. It is intended that the specific embodiments and configurations herein disclosed are illustrative of the preferred and best modes for practicing the invention, and should not be interpreted as limitations on the scope of the invention. EXAMPLE 1: A polyester braided cordage with the physical characteristics as seen in Table 1 has been subjected to heat setting on heat setting machine as already described, at number of conditions of temperature, time and stretch and finally a best condition has been selected based on the results. The conditions maintained during the heat setting are described below: a. Temperature in the preheating zone - 60°C b. Temperature in the main heating zone - 220°C c. Temperature in the cooling zone - 8°C d. Dwell time of the material in the main heating zone - 65 seconds e. Stretch - 9% The results of the control and heat set polyester braided cordage are given in Table 4. Table 1: Effect of heat setting on polyester braided cordage, 318 kgf BS S.No. Property Untreated Heat- sample sample^ 1. Mass, g/lOOm 832.7 829.1 2. Breaking Strength, kgf 326.6 345.5 3. Extension at break, % 14.7 12.3 4. Breaking Strength, kgf (after 50 cyclic loadings 339.2 343.2 at 30% of specified breaking load) 5. Extension at break, % (after 50 cyclic loadings at 10.3 12.3 30% of specified breaking load) 6. Recovery after 24 hours, % 61.3 92.1 7. Boiling water shrinkage, % 4.73 4.40 8. Creep, % (at - 30% of specified breaking load for twelve days) i.e. 98 kg 10s 5.50 3.87 1000000 s (-1 1.5 days) 6.56 4.94 1035540 s(-12 days) 6.56 4.94 9. Recovery from Creep, % (after thirteen days of load removal) 10s 59.05 70.89 100s 63.81 73.42 l()00s(~17min.) 69.52 79.75 10000 s (~ 2 hrs & 47 min.) 75.24 86.08 100000 s(~ 1.1 day) 80.95 89.87 539200 s (~ 6.2 days) 85.14 93.67 884100 s(~ 10.2 days) 85.14 93.67 1143300s (-13.2 days) 85.14 93.67 From the above results, it is clear that the recovery properties of the braided cordage have been improved without adversely affecting the other desirable properties such as breaking strength, extension at break and mass. Based on test results, it has been found out that elastic recovery value of about 60% in case of un-heat set samples (control) improved to about 90% in case of heat set samples. At the same time the breaking strength has marginally improved (-5%) while boiling water shrinkage has remained the same suggesting that the modified structure so obtained after heat setting is stable. A slight loss in elongation is observed in the material (-2-3%). EXAMPLE 2: A braided cordage of nylon-66 with the physical properties as seen in Table 3 has been subjected to heat setting on heat setting machine as already described, at number of conditions of temperature, time and stretch and finally a best condition has been selected based on the results. The conditions maintained during the heat setting are described below: a. Temperature in the preheating zone - 60°C b. Temperature in the main heating zone - 220"C c. Temperature in the cooling zone - 8°C d. Dwell time of the material in the main heating zone - 200 seconds e. Stretch - 9% (Table Removed)1000s(~17min.) 62.26 79.71 10000s(-2hrs&47 min.) 66.98 85.51 100000 s (-1.1 day) 74.06 91.3 332100s (-3.8 days) 80.19 92.75 450000 s (~ 5.2 days) 82 94.93 From the above results, it is clear that the recovery properties of the nylon-braided cordage have been improved without adversely affecting the other desirable properties such as breaking strength, extension at break and mass. EXAMPLE 3: A webbing of nylon-66, 850 kgf BS with the physical characteristics as seen in Table 3 has been subjected to heat setting on heat setting machine as already described, at number of conditions of temperature, time and stretch and finally a best condition has been selected based on the results. The conditions maintained during the heat setting are described below: a. Temperature in the preheating zone - 60°C b. Temperature in the main heating zone - 220°C c. Temperature in the cooling /one - 8°C d. Dwell time of the material in the main heating zone - 210 seconds e. Stretch in the main heating zone - 14% The results of the control and heat set braided cordage are given in Table 3. Table 3: Effect of heat setting on webbing nylon-66, 26mm, 850 kgf BS S.No. Property Untreated Heat-set sample sample 1. Mass, g/m 16.64 16.23 2. Breaking Strength, kgf 954.4 973.4 3. Extension at break, % 24.2 23.9 4. Breaking Strength, kgf (after 50 cyclic loadings 972.4 998.9 at 30% ol specified breaking load) 5. Extension at break, % (after 50 cyclic loadings at 30% of specified breaking load) 23.9 23.4 6. Thickness, mm at 2()0g/cm2 0.93 0.78 (Table Removed) Sheath-1500x3 Core-500 x 2 braided Polyester Sheath-1016x4 Core-1013x 1 braided Polyester Table 5: Physical properties of the nylon-66 braided cordage, 250 kgfBS (unheatset) subjected to heal setting Parameters Specified Particulars Actual Particulars a. Mass, g/lOOm (max) 550 WE CLAIM 1. A method of processing braided cordages for high elastic recovery, said method comprising the steps of: a. feeding the braided cordages or webbing for into preheating zone of heat setting machine, b. obtaining preheated cordages or webbing and feeding the same into main heating zone of said machine, c. stretching the cordages or webbings in main heating zone, d. feeding the stretched cordages or webbings of step (c) into the cooling zone of said machine for a time period in the range of 1 to 30 minutes in order to obtain desired braided cordages. 2. The method as claimed in claim 1 wherein in step (a), preheating zone is maintained at temperature in the range of room temperature to 100°C. 3. The method as claimed in claim 1 wherein in step (a), the braided cordages or webbings are kept for time period in the range of 1 to 10 minutes. 4. The method as claimed in claim 1 wherein in step (b), the main heating zone is kept at a temperature in the range of 100°C to 300°C for a time period in the range of 1 to 10 minutes. 5. The method as claimed in claim 1 wherein in step (c), stretching of cordages is carried out in a range of 2 % to 20 %. 6. The method as claimed in claim 1 wherein in step (d), cooling zone is kept at a temperature in the range of 1°C to 10°C for at time period in the range of 1 to 20 minutes. 7. The method as claimed in claim 1 wherein in step (d), cooling zone is kept at a temperature in the range of 5°C to 8°C for at time period in the range of 7 to 16 minutes. 8. The method as claimed in claim 1 wherein the braided cordages comprise 100 % polyester high tenacity multifilament yarn. 9. The method as claimed in claim 1 wherein in step (d), thus produced polyester / nylon braided cordages / webbing having elastic recovery up to 90 %. 10. The method as claimed in claim 1 wherein in step (d), thus produced polyester or nylon braided cordages or webbing having creep properties increase up to 8.6 1 1 . The method as claimed in claim 1 wherein in step (d), thus produced polyester or nylon braided cordages or webbing having creep recovery up to 95 %. 12. An improved elastically recover braided cordage is obtained by a process as claimed in claim 1 . 13. A method of processing braided cordages and webbings is substantially herein described with reference to the accompanying figures and examples.

Documents:

246-del-2006-abstract.pdf

246-del-2006-Claims-(26-07-2011).pdf

246-del-2006-claims.pdf

246-del-2006-Correspondence Others-(26-07-2011).pdf

246-del-2006-correspondence-others-1.pdf

246-del-2006-correspondence-others.pdf

246-del-2006-description (complete).pdf

246-del-2006-Drawings-(26-07-2011).pdf

246-del-2006-drawings.pdf

246-del-2006-Form-1-(26-07-2011).pdf

246-del-2006-form-1.pdf

246-del-2006-form-18.pdf

246-del-2006-Form-2-(26-07-2011).pdf

246-del-2006-form-2.pdf

246-del-2006-form-26.pdf

246-del-2006-Form-3-(26-07-2011).pdf

246-del-2006-form-3.pdf

246-del-2006-Form-5-(26-07-2011).pdf

246-del-2006-form-5.pdf

246-del-2006-GPA-(26-07-2011).pdf

246-del-2006-Petition-137-(26-07-2011).pdf