Elastic composite fiber and fabrication method therefor

Abstract

Disclosed is an elastic composite fiber, comprising a fiber body, wherein according to weight percentage, the material composition of the fiber body is made by composite spinning 10%-90% low viscosity PET, 10%-90% high viscosity PET, 10-80% PTT and 10-80% PBT. The present invention combines the advantages of the PET, PTT and PBT fibers into one, and not only has the advantages of good spinnability, high strength, good elasticity, softness, comfortableness, easy dyeing, moisture absorption and the like, but also utilizes reasonable cooperation between materials and the difference between physical and chemical properties to make the three-dimensional structure of the composite fiber more remarkable and the thermal stability better.

Claims

1. Elastic composite fiber, comprising a fiber body, characterized in that, the fiber body is formed by compound spinning of the following components in weight percentage: low viscosity PET10%-90%, high viscosity PET10%-90%, PTT10-80%, PBT10-80%.

2. The elastic composite fiber of claim 1, wherein a viscosity of the low viscosity PET is 0.4-0.7 dL/g, a viscosity of the high viscosity PET is 0.7-0.9 dL/g, a viscosity of the PTT is 0.7-1.3 dL/g, and a viscosity of the PBT is 0.7-1.3 dL/g, and a number of crimps of the fiber body is 5-15 per cm.

3. The elastic composite fiber of claim 2, wherein the weight percentage of the low viscosity PET is 20%, the weight percentage of the high viscosity PET is 20%, the weight percentage of the PTT is 30%, and the weight percentage of the PBT is 30%.

4. A method of producing elastic composite fiber, comprising the following steps: step A: drying low viscosity PET, high viscosity PET, PTT, and PBT, until water content is less than 15 ppm; wherein a viscosity of the low viscosity PET is 0.4-0.7 dL/g, a viscosity of the high viscosity PET is 0.7-0.9 dL/g, a viscosity of the PTT is 0.7-1.3 dL/g, and a viscosity of the PBT is 0.8-1.2 dL/g; step B: placing the low viscosity PET, the high viscosity PET, the PTT, and the PBT into a screw extruder to carry out melt extrusion procedure to obtain molten material; transferring the molten material into a compound spinning assembly under measurements determined through a metering pump, wherein a weight percentage of the low viscosity PET accounts for 10-90% of total molten material transferred to the compound spinning assembly, a weight percentage of the high viscosity PET accounts for 10-90% of the total molten material transferred to the compound spinning assembly, a weight percentage of the PTT accounts for 10-80% of the total molten material transferred to the compound spinning assembly, and a weight percentage of the PBT accounts for 10-80% of the total molten material transferred to the compound spinning assembly: introducing the molten material out from the compound spinning assembly into a spinneret where the molten material is extruded to form parallel vacuum staples which are then subject to spinning, circular cooling, oil application, winding, and arrangement around a bobbin, thereby obtaining a non-crimped top fiber precursor; step C: balancing the fiber precursor obtained in step B for 20 hours and then performing setting procedure by tension heat setting or relax heat setting; wherein said tension heat setting achieves setting through stretching by using a first traction roller, a second traction roller, a third traction roller and a fourth traction roller.

5. The method of producing elastic composite fiber of claim 4, wherein the compound spinning assembly is a spinning component of a large-capacity dual-channel composite spinning device comprising an upper housing, a filter cavity, a distribution plate A, a distribution plate B, a distribution plate C, a spinneret, a pressing block and a lower shell.

6. The method of producing elastic composite fiber of claim wherein the first traction roller operates at a speed of 220-280 m/min and a temperature of 150-170° C.; the second traction roller operates at a speed of 222-282 m/min and a temperature of 170-180° C.; the third traction roller operates at a speed of 225-285 m/min and a temperature of 170-180° C.; and the fourth traction roller operates at a speed of 230-290 m/min and a temperature of 180° C.

7. The method of producing elastic composite fiber of claim 4, wherein said relax heat setting is operated under a temperature of 80-120° C. for 2-6 min.

8. The method of producing elastic composite fiber of claim 5, wherein the first traction roller operates at a speed of 220-280 m/min and a temperature of 150-170° C.; the second traction roller operates at a speed of 222-282 m/min and a temperature of 170-180° C.; the third traction roller operates at a speed of 225-285 m/min and a temperature of 170-180° C.; and the fourth traction roller operates at a speed of 230-290 m/min and a temperature of 180° C.

9. The method of producing elastic composite fiber of claim 5, wherein said relax heat setting is operated under a temperature of 80-120° C. for 2-6 min.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention is further described below in detail with reference to some embodiments. However, the present invention is not limited to the described embodiments. Various changes or alternative configurations made in accordance with the common technical knowledge and prior art means of this field of art without deviating from the technical concept of the present invention should also fall within the scope of the present invention.

Embodiment 1

[0024] A method of producing elastic composite fiber, comprising the following steps:

[0025] Step A: Drying low viscosity PET, high viscosity PET, PTT, and PBT, until water content is less than 15 ppm; wherein a viscosity of the low-viscosity PET is 0.42 dL/g, a viscosity of the high viscosity PET is 0.83 dL/g, a viscosity of the PTT is 0.92 dL/g, and a viscosity of the PBT is 0.92 dL/g;

[0026] Step B: placing the low viscosity PET, the high viscosity PET, the PTT, and the PBT into a screw extruder to carry out melt extrusion procedure to obtain molten material; transferring the molten material into a compound spinning assembly under measurements determined through a metering pump, wherein the compound spinning assembly is a spinning component of a large-capacity dual-channel composite spinning device and a weight percentage of the low viscosity PET accounts for 20% of total molten material transferred to the compound spinning assembly, a weight percentage of the high viscosity PET accounts for 20% of the total molten material transferred to the compound spinning assembly, a weight percentage of the PTT accounts for 30% of the total molten material transferred to the compound spinning assembly, and a weight percentage of the PBT accounts for of the total molten material transferred to the compound spinning assembly; introducing the molten material out from the compound spinning assembly into a spinneret where the molten material is extruded to form parallel vacuum staples which are then subject to spinning, circular cooling, oil application, winding, and arrangement around a bobbin, thereby obtaining a non-crimped top fiber precursor;

[0027] Step C: balancing the fiber precursor obtained in step B for 20 hours and then performing setting procedure by tension heat setting; wherein said tension heat setting achieves setting through stretching by using a first traction roller, a second traction roller, a third traction roller and a fourth traction roller; wherein the first traction roller operates at a speed of 250 m/min and a temperature of 160′C; the second traction roller operates at a speed of 250 m/min and a temperature of 175′C; the third traction roller operates at a speed of 250 m/min and a temperature of 175° C.; and the fourth traction roller operates at a speed of 250 m/min and a temperature of 180′C, In the present embodiment, the first traction roller, the second traction roller, the third traction roller and the fourth traction roller can each be used in a quantity more than one. The operating temperatures of the traction rollers increase gradually from the first to the fourth traction roller, so that the fiber receives more even heating and reflects a more even temperature so as to obtain a better formed structure which is also more stable.

[0028] Properties of the composite fiber obtained according to embodiment 1 are illustrated below:

TABLE-US-00001 Strength (cN/dtex) 4.3 Modulus (cN/dtex) 50 Fracture elongation (%) 38 Shrinkage in boiling water (%) 12 Number of crimps (number/cm) 23 Fluffiness (150 g) 85%

Embodiment 2

[0029] Step A: Drying low viscosity PET, high viscosity PET, PTT, and PBT, until water content is less than 15 ppm; wherein a viscosity of the low-viscosity PET is 0.42 dL/g, a viscosity of the high viscosity PET is 0.83 dL/g, a viscosity of the PTT is 0.92 dL/g, and a viscosity of the PBT is 0.92 dL/g;

[0030] Step B: placing the low viscosity PET, the high viscosity PET, the PTT, and the PBT into a screw extruder to carry out melt extrusion procedure to obtain molten material; transferring the molten material into a compound spinning assembly under measurements determined through a metering pump, wherein the compound spinning assembly is a spinning component of a large-capacity dual-channel composite spinning device, and a weight percentage of the low viscosity PET accounts for of total molten material transfer red to the compound spinning assembly, a weight percentage of the high viscosity PET accounts for 20% of the total molten material transferred to the compound spinning assembly, a weight percentage of the PTT accounts for 30% of the total molten material transferred to the compound spinning assembly, and a weight percentage of the PBT accounts for 30% of the total molten material transferred to the compound spinning assembly; introducing the molten material out from the compound spinning assembly into a spinneret where the molten material is extruded to form parallel staples which are then subject to spinning, circular cooling, oil application, winding, and arrangement around a bobbin, thereby obtaining a non-crimped top fiber precursor;

[0031] Step C: performing setting procedure of the fiber precursor obtained in step B by relax heat setting; wherein said relax heat setting is operated under a temperature of 100′C for 4 min. During the process of fiber setting, internal stress is released; arrangement of macromolecules has not reached the most stable condition; crimping condition of the fiber is stable; by using a tension-free condition, said relax heat setting allows the fiber to be fully relax to eliminate the internal stress of the fiber so as to perfect the fiber structure and make it stable.

[0032] Properties of the composite fiber obtained according to embodiment 2 are illustrated below:

TABLE-US-00002 Strength (cN/dtex) 4.1 Modulus (cN/dtex) 53 Fracture elongation (%) 44 Shrinkage in boiling water (%) 11 Number of crimps (number/cm) 23 Fluffiness (150 g) 87%

Embodiment 3

[0033] A method of producing elastic composite fiber, comprising the following steps:

[0034] Step A: Drying low viscosity PET, high viscosity PET, PTT, and PBT, until water content is less than 15 ppm; wherein a viscosity of the low-viscosity PET is 0.55 dL/g, a viscosity of the high viscosity PET is 0.75 dL/g, a viscosity of the PTT is 095 dL/g, and a viscosity of the PBT is 0.95 dL/g;

[0035] Step B: placing the low viscosity PET, the high viscosity PET, the PTT, and the PBT into a screw extruder to carry out melt extrusion procedure to obtain molten material; transferring the molten material into a compound spinning assembly under measurements determined through a metering pump, wherein the compound spinning assembly is a spinning component of a large-capacity dual-channel composite spinning device, and a weight percentage of the low viscosity PET accounts for 20% of total molten material transferred to the compound spinning assembly, a weight percentage of the high viscosity PET accounts for 20% of the total molten material transferred to the compound spinning assembly, a weight percentage of the PTT accounts for 30° of the total molten material transferred to the compound spinning assembly, and a weight percentage of the PBT accounts for 30% of the total molten material transferred to the compound spinning assembly; introducing the molten material out from the compound spinning assembly into a spinneret where the molten material is extruded to form parallel staples which are then subject to spinning, circular cooling oil application, winding, and arrangement around a bobbin, thereby obtaining a non-crimped top fiber precursor;

[0036] Step C: balancing the fiber precursor obtained in step B for 20 hours and then performing setting procedure by tension heat setting; wherein said tension heat setting achieves setting through stretching by using a first traction roller, a second traction roller, a third traction roller and a fourth traction roller wherein the first traction roller operates at a speed of 250 m/min and a temperature of 160° C.; the second traction roller operates at a speed of 250 m/min and a temperature of 175° C.; the third traction roller operates at a speed of 250 m/min and a temperature of 175° C.; and the fourth traction roller operates at a speed of 250 m/min and a temperature of 180° C.

[0037] Properties of the composite fiber obtained according to embodiment 3 are illustrated below:

TABLE-US-00003 Strength (cN/dtex) 4.0 Modulus (cN/dtex) 48 Fracture elongation (%) 45 Shrinkage in boiling water (%) 13 Number of crimps (number/cm) 26 Fluffiness (150 g) 90%

Embodiments 4-6

[0038] Except for the weight ratio between the low viscosity PET, the high viscosity PET, the PTT and the PBT, embodiments 4-6 have the same method as described in embodiment 3. Properties of the composite elastic fiber obtained according to embodiments 4-6 are illustrated below:

TABLE-US-00004 1:1:4:4 2:4:1:1 4:2:1:1 (weight ratio (weight ratio (weight ratio between low between low between low viscosity PET:high viscosity PET:high viscosity PET:high viscosity viscosity viscosity PET:PTT:PBT) PET:PTT:PBT) PET:PTT:PBT) Strength (cN/dtex) 4.5 5.3 4.0 Modulus (cN/dtex) 52 56 47 Fracture 40 35 42 elongation (%) Shrinkage in 10 12 13 boiling water (%) Number of crimps 20 22 23 (number/cm) Fluffiness (150 g) 89% 92% 95%

Embodiments 7-9

[0039] Except for the difference in viscosity between the low viscosity PET, the high viscosity PET the PIT and the PBT, embodiments 7-9 have the same method as described in embodiment 3. Properties of the composite fiber obtained according to embodiments 7-9 are illustrated below

TABLE-US-00005 low viscosity PET low viscosity PET low viscosity PET 0.5 dL/g, high 0.6 dL/g, high 0.67 dL/g, high viscosity PET viscosity PET viscosity PET 0.7 dL/g, PTT 0.78 dL/g, PTT 0.8 dL/g, PTT 0.7 dL/g and PBT 0.9 dL/g and PBT 1.1 dL/g and PBT 0.75 dL/g 0.9 dL/g 1.1 dL/g Strength (cN/dtex) 4.2 4.5 5.0 Modulus (cN/dtex) 47 52 55 Fracture 35 32 30 elongation (%) Shrinkage in 12 15 11 boiling water (%) Number of crimps 21 20 22 (number/cm) Fluffiness (150 g) 87% 90% 93%

[0040] In the present invention, the described screw extruder is divided into five zones. Temperatures of the five zones are 265° C., 275° C., 280° C., 280° C. and 275° C. respectively.

[0041] In the present invention, the staple fibers extruded from the spinneret are cooled by circular blow air at a temperature of 20° C. and a speed of 2 m/s.

[0042] In the present invention, the low viscosity PET can be obtained by polymerizing terephthalic acid and excess diol. During polymerization, the excess diol is in excess by 33% (molar ratio), wherein the diol comprises propane-1,2-diol (propylene glycol) and diethylene glycol. A molar ratio of glycol, propane-1,2-diol and diethylene glycol is controlled in a range of 70:30-50:50. With the increase in proportion of the diethylene glycol in the molar ratio, fluidity of the low viscosity PET will increase, and its strength will gradually decrease. High viscosity PET can be obtained by thickening conventional PET, specifically, through a liquid phase thickening procedure which purifies and increases the viscosity of conventional PET by extracting small liquid molecules. After thickening treatment, the strength of PET increases, and such increase in strength is of great importance to increase the hardness of the resulting composite fiber. The PIT and the PBT used in the present invention can be conventional PTT and PBT available in the market.

Control Embodiment

[0043] Technical solutions provided by CN10937137A (application number 201810987214.0)

[0044] Except for the difference in weight ratio between low viscosity PET, high viscosity PET, and PTT, the method of production is the same as described in embodiment 3. Properties of the elastic composite fiber obtained according to embodiments 7-9 are illustrated below:

TABLE-US-00006 1:1:8 1:2:1 2:1:1 (weight ratio (weight ratio (weight ratio between low between low between low viscosity PET:high viscosity PET:high viscosity PET:high viscosity PET:PTT) viscosity PET:PTT) viscosity PET:PTT) Strength (cN/dtex) 3.7 4.5 3.2 Modulus (cN/dtex) 40 52 35 Fracture 40 35 42 elongation (%) Shrinkage in 30 28 32 boiling water (%) Number of crimps 10 4 6 (number/cm) low viscosity PET low viscosity PET low viscosity PET 0.5 dL/g, high 0.6 dL/g, high 0.67 dL/g, high viscosity PET viscosity PET viscosity PET 0.7 dL/g, and PTT 0.78 dL/g, and PTT 0.8 dL/g, and PTT 0.75 dL/g 0.9 dL/g 1.1 dL/g Strength (cN/dtex) 3.6 3.9 4.2 Modulus (cN/dtex) 40 45 47 Fracture 35 32 30 elongation (%) Shrinkage in 36 32 28 boiling water (%) Number of crimps 10 7 5 (number/cm)

[0045] By comparing the properties of the composite fiber produced according to embodiments 1-9 of the present invention and according to the control embodiment provided by CN109137137A (application number 201810987214.0) it is observed that the composite fiber produced by the present invention has greater strength and is significantly better in terms of three-dimensional crimping and heat stability.

[0046] Although some embodiments of the present invention have been described above, a person skilled in the art may make other changes and modifications based on the described embodiments in accordance with the basic inventive concept of tee present invention. Therefore: the described embodiments are only illustrative examples of the present invention and should not limit the scope of protection of the present invention. Any alternative configurations or alternative sequence of steps based on the description of the present invention, or the use of the present invention directly or indirectly in other fields of art should as ell fall within the scope of protection of the present invention.