Mechanical interlocking reinforced round-imitating high-strength TPU polyester core-spun yarn and preparation method thereof

Abstract

The invention belongs to the technical field of yarn manufacturing, and particularly relates to a mechanical interlocking reinforced round-imitating high-strength TPU polyester core-spun yarn and a preparation method thereof. The preparation method comprises the following steps: twisting polyester filament yarns, immersing the twisted polyester filament yarns in a nonionic emulsifier aqueous solution for deoiling treatment, washing the twisted polyester filament yarns with water, immersing the washed polyester filament yarns in a NaOH aqueous solution for alkali treatment, washing the washed polyester filament yarns with water, and drying the washed polyester filament yarns; and heating and melting TPU, coating the surface of the obtained polyester filament yarn with the TPU, cooling, drafting, sizing, oiling and then winding. According to the invention, the roundness of the cross section of the polyester filament yarn is reduced from 45.42% to about 17%; the interfacial strength reaches 5.5 cN / tex through the cooperative treatment of filament twisting, surface oil removal and alkali etching, which is improved by 358% compared with that of untreated polyester, so that the nonlinear leap of the interfacial strength is realized; and the interface bonding problem of the high-strength composite yarn is solved with lower cost.

Description

Technical Field

[0001] The invention belongs to the technical field of yarn manufacturing, and particularly relates to a mechanically interlocked reinforced imitation round high-strength TPU polyester core-spun yarn and a preparation method thereof. Background Art

[0002] As the core material of synthetic fibers, polyester filament is widely used in special textile fields such as safety ropes and cables, high-strength industrial webbing, etc., but its inherent defects seriously restrict the upper limit of performance. Traditional polyester filament is prone to groove wear in high-frequency friction scenarios, resulting in a sharp reduction in product life. Although the TPU melt extrusion coating process is used to improve wear resistance, new defects are caused by the uncontrolled rheological behavior of the melt. The TPU melt shrinks and collapses upon cooling, forming an elliptical cross-section, resulting in uneven light transmittance and mechanical anisotropy of the fabric; poor melt infiltration produces bubble pits (density > 35 / 100m), which deteriorates the weaving yield; due to insufficient interface compatibility, the bonding strength between the cortex and the core layer is poor when the filament cross-section is subjected to stress, causing delamination and fracture, reducing its wear resistance. There is an urgent need to improve the uniformity and interface bonding strength of TPU-coated polyester filaments, so that the cross-section of the TPU-coated polyester filaments has good roundness, wear resistance and durability. Summary of the Invention

[0003]

Technical Issues

[0004] The TPU melt extrusion coating process can improve the wear resistance of polyester filaments, but it can easily cause problems such as non-round cross-sections and poor interface strength. There is an urgent need to improve the uniformity and interface bonding strength of TPU-coated polyester filaments to ensure that the cross-section of TPU-coated polyester filaments is round, wear-resistant and durable.

[0005]

Technical solution

[0006] The first object of the present invention is to provide a method for preparing a mechanically interlocked reinforced imitation round high-strength TPU polyester core-spun yarn, comprising the steps of:

[0007] (1) Degreasing and alkali treatment of polyester filaments: The twisted polyester filaments are immersed in a non-ionic emulsifier aqueous solution for degreasing, washed with water, and then immersed in a NaOH aqueous solution for alkali treatment, washed with water, and dried;

[0008] (2) Preparation of TPU / polyester core-spun yarn: TPU is heated and melted and coated on the surface of the polyester filament obtained in step (1), and then cooled, drawn, shaped, oiled and wound.

[0009] In one embodiment of the present invention, in step (1), the twist of the twisted polyester filament is 50 to 200 T / m.

[0010] In one embodiment of the present invention, in step (1), the twist direction of twisting is Z.

[0011] In one embodiment of the present invention, in step (1), the fineness of the polyester filament is 70-600D.

[0012] In one embodiment of the present invention, in step (1), the fineness of the polyester filament is preferably 70 to 300D.

[0013] Twisting causes individual fibers to spirally wrap into a tight cylindrical structure, squeezing the individual filaments against each other. This increases the density of the multifilament yarn and reduces porosity, resulting in a dense, regular yarn surface. This facilitates uniform coating and reduces surface irregularities. Furthermore, the low porosity allows the TPU melt to spread evenly across the surface, improving product yield. The internal stress generated by twisting creates mechanical constraints during TPU curing and shrinkage, suppressing dents, maintaining roundness, and improving the fabric's uniform light transmission and mechanical isotropy.

[0014] In one embodiment of the present invention, in step (1), the nonionic emulsifier is a fatty alcohol polyoxyethylene ether surfactant.

[0015] In one embodiment of the present invention, in step (1), the concentration of the nonionic emulsifier aqueous solution is 1 to 3 wt%.

[0016] In one embodiment of the present invention, in step (1), the concentration of the NaOH aqueous solution is 5 to 15 wt%.

[0017] In one embodiment of the present invention, in step (1), the degreasing treatment is performed at a temperature of 50 to 70° C. for 10 to 30 minutes.

[0018] In one embodiment of the present invention, in step (1), the alkali treatment is performed at a temperature of 60 to 80° C. for 5 to 15 minutes.

[0019] Caustic soda can selectively etch the amorphous areas on the polyester surface to form micron / nanoscale pits or groove structures, thereby increasing the specific surface area of ​​the polyester fiber. It can also hydrolyze the ester groups in the polyester molecular chain to generate polar groups such as carboxylic acid groups and hydroxyl groups, which can form hydrogen bonds and van der Waals forces with TPU, thereby enhancing the adhesion of the TPU melt to the polyester surface.

[0020] In one embodiment of the present invention, in step (2), the TPU is polyester or polyether TPU; and the hardness is 60 to 96A.

[0021] In one embodiment of the present invention, in step (2), the TPU is dried to remove water before being heated and melted.

[0022] In one embodiment of the present invention, in step (2), the heating and melting temperature is 120°C to 200°C.

[0023] In one embodiment of the present invention, in step (2), the mass ratio of TPU to polyester is 0.3:1 to 5:1.

[0024] In one embodiment of the present invention, in step (2), the cooling method is water bath cooling; the molten TPU is fully cooled and solidified; the inner water bath flow rate is 0.2 to 0.8 m 3 / min, outer water bath flow rate 1~10m 3 / min.

[0025] In one embodiment of the present invention, in step (2), the flow rate of the outer water bath is preferably 4 to 6 m 3 / min

[0026] In one embodiment of the present invention, in step (2), the drafting speed is 50 to 300 m / min. The drafting speed determines the amount of TPU applied and the specific gravity of TPU to polyester. As the drafting speed increases, the length of polyester coated per unit time increases, and the mass of TPU coated per unit length of polyester filament decreases.

[0027] In one embodiment of the present invention, in step (2), the setting temperature is 40-60° C. The setting treatment can eliminate the internal stress generated during the TPU coating and stretching process.

[0028] In one embodiment of the present invention, in step (2), the oiling agent used for oiling is a silicone spinning oil.

[0029] In one embodiment of the present invention, in step (2), the oil content of the oiling is 0.05-0.5%.

[0030] In one embodiment of the present invention, in step (2), the winding tension is 6 to 60 cN. Appropriate winding tension can prevent irreversible plastic deformation of TPU under excessively high tension.

[0031] In one embodiment of the present invention, in step (2), the winding tension is preferably a constant tension, and the winding tension is preferably 7 to 13 cN.

[0032] The second object of the present invention is to provide a round-like high-strength TPU polyester core-spun yarn prepared by the above preparation method.

[0033] The third object of the present invention is to provide the application of the above-mentioned imitation round high-strength TPU polyester core-spun yarn in the field of textiles.

[0034] Beneficial effects:

[0035] (1) By using twisted filaments with appropriate cooling intensity and winding tension, the cross-sectional roundness is reduced from 45.42% to about 17%. Through a controllable melt forming method and a stable cooling and solidification process, the cross-sectional roundness and coating uniformity are improved.

[0036] (2) The synergistic treatment of filament twisting, surface degreasing and alkaline etching makes the interface strength reach 5.5 cN / tex, which is 358% higher than that of untreated polyester, achieving a nonlinear leap in interface strength.

[0037] (3) Overcome the interface bonding problem of high-strength composite yarns at a lower cost. DETAILED DESCRIPTION

[0038] Comparative Example 1

[0039] The method for preparing TPU polyester core-spun yarn comprises the following steps:

[0040] Will HT-890TPU (melting point 120℃, hardness 90A) was dried and dehydrated, and the dried TPU slices were added to the extruder and heated to 160℃ for melt extrusion. At the same time, untreated 150D polyester elongated filaments were pulled onto the extruder die, and TPU was coated on the surface of the polyester elongated filaments to obtain TPU / polyester core-spun yarn. The mass ratio of TPU to polyester was 2.3:1, and the yarn was placed in a 10℃ cold water tank for cooling. The inner water bath flow rate was 0.3m 3 / min, outer water bath flow rate 1m 3 / min, drawing rate 120m / min, 50℃ hot air setting, oiling of oil roller (organic silicone spandex spinning oil HS-8060CA, manufacturer: Yantai Ruize Chemical Co., Ltd., oil content 0.23%), and finally winding and reeling.

[0041] Comparative Example 2

[0042] The method for preparing TPU polyester core-spun yarn comprises the following steps:

[0043] (1) Polyester filament twisting: 150D polyester elongated filament is twisted with Z twist, 80T / m;

[0044] (2) HT-890TPU (melting point 120℃, hardness 90A) was dried and dehydrated, and the dried TPU slices were added to the extruder and heated to 160℃ for melt extrusion. At the same time, untreated 150D polyester elongated filaments were pulled onto the extruder die at a rate of 120m / min, and TPU was coated on the surface of the polyester elongated filaments to obtain TPU / polyester core-spun yarn. The mass ratio of TPU to polyester was 2.3:1, and the yarn was placed in a 10℃ cold water tank for cooling. The inner water bath flow rate was 0.3m 3 / min, outer water bath flow rate 1m 3 / min, drawing rate 120m / min, hot air setting at 50℃, oiling of oil roller (organic silicone spandex spinning oil HS-8060CA, oil content 0.23%), and finally winding and reeling.

[0045] Comparative Example 3

[0046] The method for preparing TPU polyester core-spun yarn comprises the following steps:

[0047] (1) Polyester filament twisting: 150D polyester elongated filament is twisted with Z twist, 80T / m;

[0048] (2) Degreasing polyester filaments: The twisted polyester filaments obtained in step (1) were immersed in a 2 wt% aqueous solution of a special polyoxyethylene ether YT-118 (Rizhao Yongtu Industry and Trade Co., Ltd.), degreased at 60° C. for 10 min, washed with water, and dried;

[0049] (3) HT-890TPU (melting point 120℃, hardness 90A) was dried and dehydrated, and the dried TPU slices were added to the extruder and heated to 160℃ for melt extrusion. At the same time, the polyester filament obtained in step (2) was pulled onto the extruder die at a rate of 120m / min, and TPU was coated on the surface of the polyester elongated filament to obtain TPU / polyester core-spun yarn. The mass ratio of TPU to polyester was 2.3:1, and the yarn was placed in a 10℃ cold water tank for cooling. The inner water bath flow rate was 0.3m 3 / min, outer water bath flow rate 5m 3 / min, drawing rate 120m / min, hot air setting at 50℃, oiling of oil roller (organic silicone spandex spinning oil HS-8060CA, oil content 0.23%), and finally winding and reeling.

[0050] Comparative Example 4

[0051] The method for preparing TPU polyester core-spun yarn comprises the following steps:

[0052] (1) Polyester filament twisting: 150D polyester elongated filament is twisted with Z twist, 80T / m;

[0053] (2) HT-890TPU (melting point 120℃, hardness 90A) was dried and dehydrated, and the dried TPU slices were added to the extruder and heated to 160℃ for melt extrusion. At the same time, the twisted polyester filaments obtained in step (1) were pulled onto the extruder die at a rate of 120m / min, and TPU was coated on the surface of the polyester elongated filaments to obtain TPU / polyester core-spun yarn. The mass ratio of TPU to polyester was 2.3:1, and the yarn was placed in a 10℃ cold water tank for cooling. The inner water bath flow rate was 0.3m 3 / min, outer water bath flow rate 5m 3 / min, drawing rate 120m / min, hot air setting at 50℃, oiling of oil roller (organic silicone spandex spinning oil HS-8060CA, oil content 0.23%), and finally winding with constant tension 10cN.

[0054] Comparative Example 5

[0055] The method for preparing TPU polyester core-spun yarn comprises the following steps:

[0056] (1) Polyester filament twisting: 150D polyester elongated filament is twisted with Z twist, 80T / m;

[0057] (2) Degreasing polyester filaments: The twisted polyester filaments obtained in step (1) were immersed in a 2 wt% aqueous solution of a special polyoxyethylene ether YT-118, degreased at 60° C. for 10 min, washed with water, and dried;

[0058] (3) HT-890TPU (melting point 120℃, hardness 90A) was dried and dehydrated, and the dried TPU slices were added to the extruder and heated to 160℃ for melt extrusion. At the same time, the twisted polyester filaments obtained in step (1) were pulled onto the extruder die at a rate of 120m / min, and TPU was coated on the surface of the polyester elongated filaments to obtain TPU / polyester core-spun yarn. The mass ratio of TPU to polyester was 2.3:1, and the yarn was placed in a 10℃ cold water tank for cooling. The inner water bath flow rate was 0.3m 3 / min, outer water bath flow rate 5m 3 / min, drawing rate 120m / min, hot air setting at 50℃, oiling of oil roller (organic silicone spandex spinning oil HS-8060CA, oil content 0.23%), and finally winding with constant tension 10cN.

[0059] Comparative Example 6

[0060] The method for preparing TPU polyester core-spun yarn comprises the following steps:

[0061] (1) Polyester filament twisting: 150D polyester elongated filament is twisted with Z twist, 80T / m;

[0062] (2) Alkali treatment of polyester filaments: The twisted polyester filaments obtained in step (1) were immersed in a 10 wt% NaOH aqueous solution, treated with alkali at 70° C. for 5 min, washed with water, and dried;

[0063] (3) HT-890TPU (melting point 120℃, hardness 90A) was dried and dehydrated, and the dried TPU slices were added to the extruder and heated to 160℃ for melt extrusion. At the same time, the twisted polyester filaments obtained in step (1) were pulled onto the extruder die at a rate of 120m / min, and TPU was coated on the surface of the polyester elongated filaments to obtain TPU / polyester core-spun yarn. The mass ratio of TPU to polyester was 2.3:1, and the yarn was placed in a 10℃ cold water tank for cooling. The inner water bath flow rate was 0.3m 3 / min, outer water bath flow rate 5m 3 / min, drawing rate 120m / min, hot air setting at 50℃, oiling of oil roller (organic silicone spandex spinning oil HS-8060CA, oil content 0.23%), and finally winding with constant tension 10cN.

[0064] Example 1

[0065] The method for preparing TPU polyester core-spun yarn comprises the following steps:

[0066] (1) Polyester filament twisting: 150D polyester elongated filament is twisted with Z twist, 80T / m;

[0067] (2) Degreasing and alkali treatment of polyester filaments: The twisted polyester filaments obtained in step (1) were immersed in a 2 wt% aqueous solution of special polyoxyethylene ether YT-118, degreased at 60°C for 10 min, washed with water, immersed in a 10 wt% aqueous solution of NaOH, treated with alkali at 70°C for 5 min, washed with water, and dried;

[0068] (3) HT-890TPU (melting point 120℃, hardness 90A) was dried and dehydrated, and the dried TPU slices were added to the extruder and heated to 160℃ for melt extrusion. At the same time, the polyester filament obtained in step (2) was pulled onto the extruder die at a rate of 120m / min, and TPU was coated on the surface of the polyester elongated filament to obtain TPU / polyester core-spun yarn. The mass ratio of TPU to polyester was 2.3:1, and the yarn was placed in a 10℃ cold water tank for cooling. The inner water bath flow rate was 0.3m 3 / min, outer water bath flow rate 5m 3 / min, drawing rate 120m / min, hot air setting at 50℃, oiling of oil roller (organic silicone spandex spinning oil HS-8060CA, oil content 0.23%), and finally winding with constant tension 10cN.

[0069] The performance of the TPU / polyester core-spun yarns prepared in the above examples and comparative examples was tested, and the test results are shown in Table 1:

[0070] Table 1

[0071] Cross-sectional roundness Interface strength Comparative Example 1 45.42％ 1.2cN / tex Comparative Example 2 31.67％ 1.4cN / tex Comparative Example 3 26.83％ 1.4cN / tex Comparative Example 4 16.96％ 1.4cN / tex Comparative Example 5 16.39％ 2.3cN / tex Comparative Example 6 16.71％ 3.6cN / tex Example 1 16.93％ 5.5cN / tex

[0072] Test method:

[0073] 1. The cross-section roundness adopts the minimum circumscribed circle method:

[0074]

[0075] 2. Interface strength using single wire pull-out method:

[0076] Interface strength (cN / tex) = maximum pull-out force (cN) / single-filament linear density (tex)

[0077] Based on the comparative analysis of the seven examples, the pre-treatment process of polyester filament significantly affects the cross-sectional roundness and interface strength of TPU / polyester core-spun yarn. The twisting treatment (Comparative Example 2) significantly reduces the cross-sectional roundness from 45.42% to about 31.67%. Increase the outer flow rate of the cooling water bath to 5m 3 / min (Comparative Example 3) and constant tension hand-winding (10cN) (Comparative Example 4) further reduced the cross-sectional roundness, but the interface strength did not change much, indicating that the core yarn twist, cooling intensity and winding tension jointly optimized the cross-sectional roundness, mainly due to the melt molding controllability and cooling solidification stability. The interface strength was slightly increased to 1.4cN / tex; while surface degreasing (Comparative Example 5) enhanced the interfacial bonding force by removing the oil agent, and the strength jumped to 2.3cN / tex, an increase of 91.7% over the untreated; alkali etching (Comparative Example 6) formed a microstructure anchoring TPU by corroding the fiber surface, and the strength was increased to 3.6cN / tex, an increase of 200% over the untreated. The optimal process is a three-step coordinated treatment (Example 1): twisting to ensure coating uniformity, cleaning to remove the surface oil agent, increasing the surface tension of the material, and alkali etching to construct a mechanical interlocking structure. The final interface strength reached 5.5cN / tex (an increase of 358% over the untreated), while maintaining a cross-sectional roundness of 17%. This shows that the polyester filament has achieved a nonlinear leap in interface strength through the coordinated treatment of physical twisting, surface degreasing and alkaline etching.

[0078] The embodiments provided above are not intended to limit the scope of the present invention, nor are the steps described to limit their execution order. Any obvious improvements to the present invention made by those skilled in the art in combination with existing common knowledge shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing a mechanically interlocked reinforced circular high-strength TPU polyester core-spun yarn, characterized in that: Including steps: (1) Degreasing and alkali treatment of polyester filaments: The twisted polyester filaments are immersed in a non-ionic emulsifier aqueous solution for degreasing, washed with water, and then immersed in a NaOH aqueous solution for alkali treatment, washed with water, and dried; (3) Preparation of TPU / polyester core-spun yarn: TPU is heated and melted and coated on the surface of the polyester filament obtained in step (1), and then wound after cooling, drawing, shaping, and oiling.

2. The preparation method according to claim 1, characterized in that In step (1), the twist of the twisted polyester filament is 50 to 200 T / m; the fineness of the polyester filament is 70 to 600D.

3. The preparation method according to claim 1, characterized in that In step (1), the nonionic emulsifier is a fatty alcohol polyoxyethylene ether surfactant.

4. The preparation method according to claim 1, characterized in that In step (1), the concentration of the nonionic emulsifier aqueous solution is 1 to 3 wt%; the concentration of the NaOH aqueous solution is 5 to 15 wt%.

5. The preparation method according to claim 1, characterized in that In step (1), the degreasing treatment is carried out at a temperature of 50 to 70° C. for 10 to 30 minutes; and the alkali treatment is carried out at a temperature of 60 to 80° C. for 5 to 15 minutes.

6. The preparation method according to claim 1, characterized in that In step (2), the TPU is polyester or polyether TPU; and the hardness is 60 to 96A.

7. The preparation method according to claim 1, characterized in that In step (2), the heating and melting temperature is 120° C. to 200° C.; and the mass ratio of TPU to polyester is 0.3:1 to 5:

1.

8. The preparation method according to claim 1, characterized in that In step (2), the cooling method is water bath cooling; the molten TPU is fully cooled and solidified; the inner water bath flow rate is 0.2 to 0.8 m 3 / min, outer water bath flow rate 1~10m 3 / min; drawing speed is 50-300m / min; setting temperature is 40-60℃; winding tension is 10-60cN.

9. Imitation round high-strength TPU polyester core-spun yarn produced by the preparation method according to any one of claims 1 to 8.

10. Use of the circular high-strength TPU polyester core-spun yarn according to claim 9 in the field of textiles.

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