A modified polyester fiber in rabbit hair style, a preparation method thereof and a plush fabric

Abstract

The application provides a modified polyester fiber with a rabbit hair style, a preparation method thereof and a plush fabric. The preparation method comprises the following steps: introducing polyethylene glycol and surface-treated nano-silicon dioxide into PET polymerization for copolymerization modification, and performing low-temperature heat setting, relaxation and vacuum heat setting treatment on the modified chips; then, melt spinning is performed, and a spinneret capable of forming a continuous concave-convex profile cross section is used for spinning. The application reduces the fiber crystallinity and modulus through chemical modification, and increases the fiber surface friction and cohesion through physical profile modification, so that the obtained polyester fiber has the soft and smooth touch of imitated rabbit hair, high elastic recovery rate and strong fluffy supporting force. The plush fabric made of the 100% polyester fiber realizes high simulation of the natural rabbit hair style and performance surpassing, and is suitable for high-end toys, home and clothing fields.

Description

Technical Field

[0001] This invention relates to the field of chemical fiber and textile technology, and more specifically, to a modified polyester fiber with a rabbit fur-like appearance, its preparation method, and a plush fabric. Background Technology

[0002] Ordinary PET polyester plush is the most widely used conventional plush fabric on the market, but it has several disadvantages due to the characteristics of the material itself and traditional processing technology, as follows:

[0003] PET (polyethylene terephthalate) has a molecular chain composed of alternating rigid benzene rings and flexible ester groups. Its good molecular chain symmetry and low steric hindrance make it highly prone to forming a highly regular crystalline structure, with a crystallinity typically reaching 40%–60%. This high crystallinity results in strong intermolecular forces within the fiber, leading to a higher fiber modulus (resistance to bending deformation). This results in stiffer individual fibers with less resilience, making it difficult to achieve a soft feel when made into plush.

[0004] The flexibility of PET molecular chains mainly depends on ester groups, and the molecular chains are arranged linearly. After being squeezed or washed by external force, the molecular chains are prone to irreversible slippage and are difficult to quickly rebound to their original state. This is the fundamental reason why PET plush tends to clump and lose fluffiness after long-term daily use.

[0005] Ordinary PET plush fibers are mostly smooth and round in cross-section. The friction between fibers is small and the cohesion is weak. The fiber bundles of plush are easy to loosen or lie flat, and cannot form a dense and elastic plush layer. It lacks the "fluffy and soft" support in terms of touch, and instead feels "dry and stiff".

[0006] Given the shortcomings of ordinary PET polyester plush fabrics, there is an urgent need for a fabric that can improve softness, enhance elastic recovery, and provide a fluffy and crisp feel. Summary of the Invention

[0007] The primary objective of this invention is to provide a method for preparing modified polyester fibers. This method, through specific copolymerization modification and spinning processes, fundamentally reduces fiber crystallinity and optimizes fiber cross-sectional morphology, thereby producing polyester fibers with a soft, rabbit-hair-like feel, excellent elastic recovery, and strong bulkiness.

[0008] To address the aforementioned problems, in a first aspect, the present invention provides a method for preparing rabbit fur-like modified polyester fibers, comprising the following steps:

[0009] S1. PET copolymerization modification and chip stabilization treatment: During the PET polymerization process, polyethylene glycol and nano silica are added to carry out copolymerization reaction. After the polymerization is completed, the obtained modified PET material is subjected to low temperature short-time heat setting, relaxation treatment and vacuum drum heat setting in sequence to obtain structurally stable modified PET chips.

[0010] S2. Spinning of irregularly shaped cross-section fibers: The modified PET chips are melt-spun using a spinneret with a continuous concave-convex structure in the cross-section of the spinneret holes to produce modified polyester fibers with a rabbit fur-like style and corresponding irregular cross-sections.

[0011] Furthermore, in step S1, the number average molecular weight of the polyethylene glycol is 2000-4000, and its addition amount is 3%-8% of the total mass of the PET polymer monomers; the average particle size of the nano silica is 20-50 nm, and its addition amount is 0.5%-2% of the total mass of the PET polymer monomers. Moreover, the nano silica is surface-treated with silane coupling agent and anhydrous ethanol and added to the polymerization system in the form of pre-dispersed masterbatch.

[0012] Furthermore, in step S1, the conditions for the low-temperature short-time heat setting are: temperature 80-100℃, time 5-15 minutes; the conditions for the relaxation treatment are: temperature 40-60℃, relative humidity 60%-80%, time 20-30 minutes; the vacuum drum heat setting includes three stages: preheating, heat preservation and constant temperature, and slow cooling.

[0013] Furthermore, in step S1, in the initial stage of adding polyethylene glycol and nano silica masterbatch, the vacuum degree of the polymerization system is controlled at 100-500 Pa; after it is evenly dispersed, the vacuum degree is reduced to 10-50 Pa to continue the polycondensation reaction.

[0014] Furthermore, in step S2, the cross-sectional shape of the spinneret hole satisfies the following conditions: the ratio of the width of the concave portion to the width of the convex portion on the cross-sectional contour is 3:4, and the ratio of the length to the width of the outer contour of the cross-section is 3:1.

[0015] Furthermore, in step S2, the melt temperature of melt spinning is 250-255℃, the winding speed is 800-1200 m / min, and the cooling conditions are: side blowing temperature 20-25℃, wind speed 0.8-1.2 m / s, blowing distance 8-12 cm, and ambient humidity 60%-70%.

[0016] Secondly, the present invention provides a rabbit fur-like modified polyester fiber, which is prepared by the above-described preparation method.

[0017] Thirdly, the present invention provides a rabbit fur-style plush fabric, wherein the pile portion is composed entirely or mainly of the aforementioned rabbit fur-style modified polyester fibers.

[0018] Furthermore, the fabric is a warp-knitted plush fabric, a weft-knitted plush fabric, or a woven plush fabric.

[0019] Fourthly, the present invention provides a textile comprising the aforementioned rabbit fur-style plush fabric, the textile including plush toys, blankets, clothing linings, or shoe and hat linings. Attached Figure Description

[0020] Figure 1 This is a flowchart of the modified polyester fiber preparation process in an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the ideal cross-sectional shape of the rabbit fur-like modified polyester fiber in an embodiment of the present invention. Detailed Implementation

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0023] Please see Figure 1 This invention provides a method for preparing rabbit fur-like modified polyester fiber, comprising the following steps:

[0024] S1, PET copolymerization modification and chip stabilization treatment:

[0025] During the polymerization reaction of PET, two modifiers are introduced simultaneously for copolymerization modification.

[0026] Polyethylene glycol (PEG) is introduced as a flexible segment modifier: its number average molecular weight (Mn) is 2000-4000, and the amount added is 3%-8% of the total mass of terephthalic acid or its ester monomers. PEG segments are embedded in the main chain or end of the PET macromolecule, effectively disrupting the regular arrangement of the molecular chain and inhibiting the growth of crystalline regions.

[0027] Nano-sized silica is introduced as a crystallization inhibitor and dispersed phase: its average particle size is 20-50 nm, and the addition amount is 0.5%-2% of the total monomer mass. The nano-SiO2 needs to undergo surface modification treatment beforehand, preferably by coating with a silane coupling agent (such as γ-aminopropyltriethoxysilane KH-550) in anhydrous ethanol solvent through a wet process to prepare a high-concentration PET-based pre-dispersed masterbatch. This masterbatch is added in the middle of polymerization to ensure the uniform and stable dispersion of nanoparticles in the PET melt, which can physically block the regular arrangement and aggregation of PET chain segments and synergistically inhibit crystallization.

[0028] Key polymerization process control: The polymerization temperature is controlled at 260-275℃. In the initial stage of adding PEG and masterbatch, the system vacuum is maintained at a low level of 100-500 Pa to minimize the hydrolysis and thermal volatilization loss of PEG under high-temperature acidic conditions. After the modifier is uniformly dispersed, the vacuum is gradually reduced to a high vacuum state of 10-50 Pa to efficiently remove the reaction byproduct ethylene glycol and promote the complete polycondensation reaction.

[0029] Stress relief and structural stabilization of modified PET chips: After polymerization and granulation, the modified PET chips undergo special treatment:

[0030] a) Low-temperature short-time heat setting: Treat at 80-100℃ for 5-15 minutes. This mild heat treatment allows the macromolecular chains to acquire limited mobility, partially releases the internal stress generated during polymerization and cooling, and initially stabilizes the amorphous region structure.

[0031] b) Controlled relaxation treatment: Treat in an environment with a temperature of 40-60℃ and a relative humidity of 60%-80% for 20-30 minutes. This process, through gentle hydrothermal conditions, promotes further relaxation of the amorphous chain segments, freezes a more stable loose conformation, and effectively prevents "secondary crystallization" in subsequent spinning and post-processing.

[0032] c) Vacuum drum heat setting: The chips are placed in a vacuum drum heat setter and processed according to the following procedure: the temperature is raised from room temperature to 80-90℃ at a certain rate (preheating stage, 10-15 min); the temperature is held constant at 100-110℃ for 20-30 min (temperature stabilization stage); then the temperature is slowly lowered to room temperature (slow cooling stage, 30-40 min). This process is carried out under vacuum, which can completely eliminate internal stress and obtain modified PET chips with stable structure and excellent spinnability.

[0033] S2. Melt spinning of irregularly shaped cross-section fibers:

[0034] The modified PET chips processed in step S1 are melt-spun.

[0035] Temperature control: The melt temperature is precisely controlled at 250-255℃. The screw temperature settings for each zone are as follows: feed zone 200-210℃, first compression zone 220-230℃, second compression zone 240-250℃, metering zone 255-260℃, and spinneret zone 250-255℃.

[0036] Spinning speed: winding speed is 800-1200 m / min.

[0037] Please see Figure 2The key spinning component—the irregularly shaped spinneret—is a specially designed spinneret with a non-circular, continuous concave-convex cross-sectional shape for its spinneret orifices (preferably a biomimetic structure resembling a "caterpillar"). Through precision die processing, the shape of the spinneret orifices is controlled, resulting in fibers with the following cross-sectional characteristics: along the cross-sectional contour, the ratio of the width of the concave portion (W1) to the width of the convex portion (W2) is W1:W2 ≈ 3:4; the ratio of the length (L) to the width (W) of the overall cross-sectional contour is L:W ≈ 3:1. This irregular design aims to significantly increase the fiber surface area and surface irregularity.

[0038] Cooling and curing process: After the filaments are extruded from the spinneret, they are rapidly cooled and cured using a side-blowing method to "freeze" the modified, low-crystallinity, highly randomized molecular chain structure. The cooling process parameters are: cooling air temperature 20-25℃, air velocity 0.8-1.2 m / s, distance between the air blowing window and the spinneret 8-12 cm, and ambient humidity 60%-70%.

[0039] This invention also provides a rabbit fur-like modified polyester fiber prepared by the above-described method. The core characteristic of this fiber is its low-crystalline structure (as demonstrated by differential scanning calorimetry (DSC), whose enthalpy of fusion is significantly lower than that of conventional PET fibers of the same specifications), and its cross-section is the aforementioned specific continuous convex-concave profile. This fiber combines low modulus (softness), high extensibility (smoothness), and high surface friction coefficient (strong cohesion).

[0040] This invention also provides a rabbit fur-style plush fabric, characterized in that its pile surface is entirely or primarily composed of the rabbit fur-style modified polyester fibers. Preferably, the fabric is made by warp knitting (such as Raschel warp knitting), weft knitting, or weaving, wherein the modified polyester fibers are used as the pile yarn. This fabric achieves a high degree of simulation of the soft, fluffy, and elastic feel of natural rabbit fur, and its composition is 100% polyester fiber, possessing excellent durability and easy care.

[0041] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0042] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for preparing rabbit fur-like modified polyester fiber, characterized in that, Includes the following steps: S1. PET copolymerization modification and chip stabilization treatment: During the PET polymerization process, polyethylene glycol and nano silica are added to carry out copolymerization reaction. After the polymerization is completed, the obtained modified PET material is subjected to low temperature short-time heat setting, relaxation treatment and vacuum drum heat setting in sequence to obtain structurally stable modified PET chips. S2. Spinning of irregularly shaped cross-section fibers: The modified PET chips are melt-spun using a spinneret with a continuous concave-convex structure in the cross-section of the spinneret holes to produce modified polyester fibers with a rabbit fur-like style and corresponding irregular cross-sections.

2. The method for preparing rabbit fur-style modified polyester fiber according to claim 1, characterized in that, In step S1, the number average molecular weight of the polyethylene glycol is 2000-4000, and its addition amount is 3%-8% of the total mass of PET polymer monomers; the average particle size of the nano silica is 20-50 nm, and its addition amount is 0.5%-2% of the total mass of PET polymer monomers. The nano silica is surface-treated with silane coupling agent and anhydrous ethanol and added to the polymerization system in the form of pre-dispersed masterbatch.

3. The method for preparing rabbit fur-like modified polyester fiber according to claim 1, characterized in that, In step S1, the conditions for the low-temperature short-time heat setting are: temperature 80-100℃, time 5-15 minutes; the conditions for the relaxation treatment are: temperature 40-60℃, relative humidity 60%-80%, time 20-30 minutes; the vacuum drum heat setting includes three stages: preheating, heat preservation and constant temperature, and slow cooling.

4. The method for preparing rabbit fur-style modified polyester fiber according to claim 1, characterized in that, In step S1, at the initial stage of adding polyethylene glycol and nano silica masterbatch, the vacuum degree of the polymerization system is controlled at 100-500 Pa; after it is evenly dispersed, the vacuum degree is reduced to 10-50 Pa to continue the polycondensation reaction.

5. The method for preparing rabbit fur-style modified polyester fiber according to claim 1, characterized in that, In step S2, the cross-sectional shape of the spinneret hole satisfies the following conditions: the ratio of the width of the concave part to the width of the convex part on the cross-sectional contour is 3:4, and the ratio of the length to the width of the outer contour of the cross-section is 3:

1.

6. The method for preparing rabbit fur-style modified polyester fiber according to claim 1, characterized in that, In step S2, the melt temperature of melt spinning is 250-255℃, the winding speed is 800-1200 m / min, and the cooling conditions are: side blowing temperature 20-25℃, wind speed 0.8-1.2 m / s, blowing distance 8-12 cm, and ambient humidity 60%-70%.

7. A modified polyester fiber with a rabbit fur-like appearance, characterized in that, The modified polyester fiber with a rabbit fur-like appearance is prepared by any one of claims 1 to 6.

8. A rabbit fur-style plush fabric, characterized in that, Its napped portion is composed entirely or primarily of the rabbit fur-like modified polyester fiber as described in claim 7.

9. The rabbit fur-style plush fabric according to claim 8, characterized in that, The fabric is warp-knitted plush fabric, weft-knitted plush fabric, or woven plush fabric.

10. A textile product, characterized in that, The textile includes the rabbit fur-style plush fabric as described in claim 8 or 9, and the textile includes plush toys, blankets, clothing linings, or shoe and hat linings.

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