Wavy spinneret plate for producing special-shaped wool-like colored polyester yarn and obtained polyester yarn

Abstract

The invention discloses a wavy spinneret plate for producing special-shaped wool-like colored polyester yarns, relates to the technical field of polyester yarn production equipment, and aims to solve the problems of poor texture, poor high-speed spinning stability, poor multi-color forming effect and the like of existing wool-like polyester yarns. The spinneret plate comprises a circular base plate and a plurality of sets of spinneret units, and each set of spinneret unit is formed by coaxially connecting symmetrical wave-shaped spinneret hole channels, gradient wall thickness flow channels and flow dividing cavities in the melt extrusion direction to form an integrated melt conveying and forming channel. The symmetrical wave-shaped spinneret pore channel adopts a curve structure, the roughness Ra of the inner wall is less than or equal to 0.1 mu m, and the fiber is directly endowed with a directional micro-corrugated section; the gradient wall thickness runner is designed in a linear wall thickness decreasing mode, and it is guaranteed that melt flows stably during high-speed spinning; and the shunting cavity is provided with a multi-cavity concentric structure and a radial flow guide rib plate, so that independent and uniform shunting of multicolor melts is realized. And the polyester yarn with vivid wool-like texture, clear and uniform color and stable mechanical property can be produced by matching specific spinning process parameters and multi-color melt MI difference value control requirements. The method does not need to depend on a multi-component polymer or a post-dyeing process, is high in production efficiency and good in environmental protection property, can be widely applied to the field of high-end textiles, and has remarkable economic and social benefits.

Description

Technical Field

[0001] This invention relates to the field of polyester filament production equipment technology, and in particular to a wavy spinneret for producing irregularly shaped wool-like colored polyester filaments and the resulting polyester filaments. Background Technology

[0002] Polyester yarn is widely used in the textile industry due to its high strength, good abrasion resistance, and ease of care. With the upgrading of consumption, the market has put forward higher requirements for the appearance, texture, and color performance of polyester yarn. Colored polyester yarn with a wool-like texture has become a hot spot in industry research and development because it can replace natural wool and reduce production costs.

[0003] The spinneret is the core component in polyester filament forming, and its structural design directly determines the cross-sectional shape, surface texture, and properties of the fiber. Existing wool-like polyester filament spinnerets often simulate wool cross-sections using simple irregularly shaped channels (such as triangular or star-shaped), making it difficult to create the natural micro-wave texture of wool surfaces. Furthermore, the traditional spinneret flow channel design is unreasonable, resulting in poor melt flow stability during high-speed spinning and a tendency for filament breakage and fuzzing. In addition, current multi-color polyester filament production often employs post-dyeing processes, leading to uneven dyeing, low color fastness, and significant environmental pressures. When using co-extrusion molding, ordinary spinnerets struggle to achieve uniform flow and synchronous forming of multi-color melts, resulting in blurred fiber color boundaries and poor consistency in wave morphology.

[0004] Patent CN102260902A employs a two-component melt + core-sheath composite spinneret, with an outer layer of PET and an inner layer of PBT, utilizing the difference in their shrinkage rates to create a wave shape. However, this patent relies on the difference in thermal shrinkage between the two polymers and cannot be used with single-component PET, resulting in inconsistent mechanical properties of the product. The wave structure consists of macroscopic wrinkles, lacking microscale directional ripples, resulting in a poor wool-like feel and a warmth improvement of only 12.3%.

[0005] Therefore, developing a spinneret that can achieve a wool-like micro-textured pattern, ensure high-speed spinning stability, and support multi-color synchronous molding has become the key to solving the current technological bottlenecks. Summary of the Invention

[0006] The purpose of this invention is to provide a corrugated spinneret for producing irregularly shaped colored polyester filaments that mimic wool, in order to solve the problems mentioned in the background art.

[0007] The above-mentioned objective of the present invention is achieved through the following technical solution: a wavy spinneret for producing irregularly shaped wool-like colored polyester filaments, comprising a circular substrate and multiple sets of spinneret units, characterized in that each set of spinneret units is sequentially connected along the melt extrusion direction by symmetrical wavy spinneret channels, gradient wall thickness flow channels and flow distribution chambers to form an integrated melt conveying and forming channel; the three are coaxially connected from top to bottom.

[0008] The symmetrical wavy spinneret channel adopts a curved structure, with both ends of the channel communicating with the outlet section of the gradient wall thickness flow channel and the outer surface of the substrate, respectively. The roughness of the inner wall of the channel Ra≤0.1μm. The gradient wall thickness flow channel is divided into an inlet section, a middle section and an outlet section along the extrusion direction. The inlet section is connected to the radial flow guide channel at the bottom of the flow distribution chamber. The center lines of the three flow channels are collinear and smoothly transition to the center line of the symmetrical wavy spinneret channel. The axis of the flow divider is aligned with the extrusion direction, and each chamber has an independent radial flow guide channel at its bottom, which is individually connected to the corresponding spinneret channel.

[0009] Among them, the symmetrical wave-shaped channel determines the microwave texture of the fiber surface to achieve a wool-like effect; the gradient wall thickness flow channel ensures the stability of high-speed spinning; the flow divider supports the synchronous formation of multi-color wave yarns; the three work together to form an inseparable precision coupling system.

[0010] Preferably, the upper and lower ends of the symmetrical wavy spinneret channel are smoothly connected to the outlet section of the gradient wall thickness flow channel and the outer surface of the substrate, respectively.

[0011] Preferably, the upper convex peak and lower concave valley of the symmetrical wavy spinneret are mirror-symmetrical in the cross section perpendicular to the extrusion direction, and the diameter of the spinneret is kept constant along the extrusion direction, and the length of the spinneret is adapted to the length of the outlet section of the gradient wall thickness flow channel.

[0012] Preferably, in the flow splitting cavity, radial guide ribs are provided between each cavity, and the ribs are evenly distributed at equal intervals along the circumferential direction.

[0013] Preferably, the ends of the radial guide ribs are rounded and chamfered, and the number of radial guide channels is the same as the number of spinnerets, with each guide channel corresponding to one spinneret orifice.

[0014] Preferably, the spinneret is used to prepare irregularly shaped, wool-like wavy polyester yarn, and its spinning process parameters are: melt temperature 285 ℃±2 ℃, side-blowing air temperature 22 ℃±1 ℃, and draw ratio 3.5–4.2 times.

[0015] Preferably, when using three-color colored PET melt, the difference in melt index (MI) (190 ℃ / 2.16 kg) between each melt is ≤±1.5 g / 10 min to ensure consistency of wave shape and clarity of color segments.

[0016] The polyester filament obtained from the preparation of the wavy spinneret used for producing irregularly shaped wool-like colored polyester filament is characterized in that the wavy morphology corresponds to the structure of the symmetrical wavy spinneret channels, and the cross-section of the irregularly shaped wool-like colored polyester filament has a directional microwave texture.

[0017] The beneficial effects of this invention are: In this invention, the spinneret unit adopts an integrated structure with symmetrical wave-shaped spinneret channels, gradient wall thickness flow channels, and flow distribution chambers connected coaxially from top to bottom. The three components work together to form an inseparable melt delivery and forming system, achieving three core requirements: imitation wool microwave texture, ensuring high-speed spinning stability, and supporting multi-color synchronous forming. This breaks through the design bottleneck of isolated functions of traditional spinneret components.

[0018] The polyester yarn produced by this invention has a directional microwave textured cross section, which simulates the surface texture of natural wool. It has a soft and delicate feel and its similarity to wool yarn is improved by more than 40% compared with existing macro-wrinkled wool yarn. The warmth retention rate is greatly improved.

[0019] The spinneret described in this invention is compatible with various production scenarios such as single-component PET and multi-color PET co-extrusion, without the need to replace the main structure of the spinneret, thus reducing equipment investment and production switching costs. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the wavy spinneret in an embodiment of the present invention.

[0021] Figure 2 This is a cross-sectional view of the wavy spinneret in an embodiment of the present invention.

[0022] Figure 3 This is a cross-sectional view of the spinneret channel in an embodiment of the present invention. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings.

[0024] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

[0025] Example 1: like Figure 1 Figure 2 As shown, a circular substrate with a diameter of 150 mm and a thickness of 30 mm is used. The material is high-temperature resistant alloy steel, which is quenched and tempered to achieve a hardness of HRC45-50, ensuring structural stability during the spinning process. Thirty sets of spinnerets are evenly distributed on the substrate in a circular array, with a center-to-center distance of 5 mm between adjacent spinnerets. Each set of spinnerets is symmetrically distributed along the center of the substrate to ensure uniform melt distribution.

[0026] like Figure 3As shown, the symmetrical wavy spinneret channel is a continuous curve along the extrusion direction, with a curve amplitude of 0.8 mm and a wavelength of 3 mm. The channel diameter is constant at 0.3 mm, and the total channel length is 12 mm, which matches the 4 mm length of the outlet section of the gradient wall thickness flow channel. The inner wall of the channel is precision polished to a roughness of Ra = 0.08 μm, and the upper convex peak and lower concave valley are strictly mirror-symmetrical on the cross section perpendicular to the extrusion direction.

[0027] Gradient wall thickness flow channel: The total length is 10 mm, divided into an inlet section of 3 mm, a middle section of 4 mm, and an outlet section of 3 mm, with wall thicknesses of 2.5 mm, 1.8 mm, and 1.1 mm respectively, showing a linear decreasing trend. The centerline of the flow channel is collinear with the centerline of the symmetrical wavy spinneret channel, and the transition radius at the junction is 0.5 mm to ensure that the melt flows without stagnation.

[0028] The outer, middle, and inner cavities of the flow divider are all concentric annular cavities, with their axes aligned with the extrusion direction. The outer cavity has an inner diameter of 80 mm and an outer diameter of 100 mm; the middle cavity has an inner diameter of 50 mm and an outer diameter of 70 mm; and the inner cavity has an inner diameter of 20 mm and an outer diameter of 40 mm. Each cavity has a height of 8 mm. Twelve radial guide ribs are installed between the cavities, evenly spaced along the circumference. The ribs are 3 mm thick, with a 2 mm radius chamfer at the ends to reduce melt flow resistance. Each cavity has 60 independent radial flow channels at its bottom, with a channel diameter of 1.2 mm. Each flow channel is connected to the inlet section of the gradient wall thickness flow channel of a set of spinnerets, realizing independent symmetrical wave-shaped spinnerets for the three cavities. The spinnerets are continuous curves along the extrusion direction, with an upper peak height of 0.18 mm, a lower valley depth of 0.12 mm, a wavelength of 1.6 mm, and an amplitude ratio of 1:1. Both ends are smoothly connected to the outlet section of the gradient wall thickness flow channel and the outer surface of the substrate, respectively, without steps or sharp angles. The inner wall of the channel is polished with ultra-precision polishing. The gradient wall thickness flow channel has an inlet section length of 2.0 mm and a wall thickness of 0.35 mm, a middle section length of 3.8 mm (wall thickness of 0.22 mm), and an outlet section length of 1.5 mm and a wall thickness of 0.15 mm. The total length of the three sections is 7.3 mm. The center lines are collinear, and the radius of the transition arc with the channel center line is R=0.5 mm. PET chips were melted at 285 ℃±2 ℃, cooled by side blowing at 22 ℃±1 ℃, and stretched 3.8 times to obtain monochrome imitation wool wavy yarn.

[0029] Example 2 A large circular substrate, 160 mm in diameter and 32 mm thick, is used, with its size appropriately increased compared to a single-color spinneret to accommodate the installation and layout of the flow distribution chamber. The substrate is also made of H13 high-temperature alloy steel, and its hardness is increased to HRC48-52 after heat treatment, providing higher structural strength and wear resistance to meet the stability requirements of high-pressure extrusion of three-color melt. A total of 48 spinneret units are arranged in a regular hexagonal array on the substrate, with the center-to-center distance between adjacent spinneret units reduced to 4.5 mm. All spinneret units are symmetrically distributed along the center of the substrate to ensure uniform distribution of the three color segments on the filaments.

[0030] The wavy spinneret channel has a peak height of 0.20 mm, a valley depth of 0.15 mm, a wavelength extended to 1.8 mm, a channel diameter of 0.32 mm, and a total length of 13 mm. The two ends of the channel are designed with a rounded transition to the flow channel and the outer surface of the substrate, with a transition radius R=0.2 mm. The inlet section is 2.2 mm long and 0.40 mm thick; the middle section is 4.0 mm long and 0.25 mm thick; and the outlet section is 1.8 mm long and 0.18 mm thick. The wall thickness of the three sections decreases linearly.

[0031] The flow distribution chamber consists of two independent cavities, an outer cavity and an inner cavity, concentrically arranged inside the substrate, with their axes aligned with the melt extrusion direction. The outer cavity has an inner diameter of 90 mm and an outer diameter of 110 mm; the middle cavity has an inner diameter of 60 mm and an outer diameter of 80 mm; and the inner cavity has an inner diameter of 30 mm and an outer diameter of 50 mm. Each cavity has a height of 10 mm, corresponding to the containment and distribution of the three colored melts. Sixteen radial guide ribs, evenly spaced along the circumference, are installed between the cavities. The ribs are 4 mm thick and have rounded chamfered ends.

[0032] Spinning raw materials: Three types of colored PET melts are used, namely navy blue, off-white, and light gray. The melt index (MI) of navy blue PET melt (190℃ / 2.16kg) is 8.2 g / 10 min, off-white PET melt MI is 9.0 g / 10 min, and light gray PET melt MI is 8.7 g / 10 min. The difference in MI among the three melts is ≤±1.5 g / 10 min to ensure the consistency of wave morphology and the clarity of color segments.

[0033] Melt delivery and molding: Three types of colored PET melt are injected into the outer, middle, and inner cavities of the distribution chamber through independent feeding channels. The melt injection pressure in each cavity is precisely controlled at 12MPa to ensure that the three melt streams enter the corresponding radial guide channels synchronously and at a uniform speed. After a smooth transition through the gradient wall thickness flow channel, the melt is simultaneously extruded through symmetrical wavy spinneret orifices to form tightly bonded filaments of the three colors.

[0034] Spinning process parameters: The melt temperature is controlled at 285℃±2℃, and a multi-segment temperature control system ensures uniform melt temperature in each chamber; the side blowing temperature is 22℃±1℃, and the wind speed is adjusted to 0.9 m / s to ensure rapid and uniform cooling and shaping of the filament; a two-stage drafting process is adopted, with a total drafting ratio of 3.9 times, a first-stage drafting ratio of 2.1 times, a second-stage drafting ratio of 1.86 times, and a drafting speed of 5200 m / min; the winding speed is 5000 m / min, and the winding tension is maintained at 18-22 cN to avoid filament stretching deformation or color segment deviation.

Claims

1. A corrugated spinneret for producing irregularly shaped, wool-like colored polyester filaments, comprising a circular substrate and multiple spinneret units, characterized in that, Each group of spinnerets consists of symmetrical wave-shaped spinneret channels, gradient wall thickness flow channels and flow distribution chambers connected sequentially along the melt extrusion direction to form an integrated melt conveying and forming channel. The three are coaxially connected from top to bottom. The symmetrical wavy spinneret channel adopts a curved structure, with both ends of the channel communicating with the outlet section of the gradient wall thickness flow channel and the outer surface of the substrate, respectively. The roughness of the inner wall of the channel Ra≤0.1μm. The gradient wall thickness flow channel is divided into an inlet section, a middle section and an outlet section along the extrusion direction. The inlet section is connected to the radial flow guide channel at the bottom of the flow distribution chamber. The center lines of the three flow channels are collinear and smoothly transition to the center line of the symmetrical wavy spinneret channel. The axis of the flow divider is aligned with the extrusion direction, and each chamber has an independent radial flow guide channel at its bottom, which is individually connected to the corresponding spinneret channel.

2. The corrugated spinneret for producing irregularly shaped, wool-like colored polyester filaments according to claim 1, characterized in that, The upper and lower ends of the symmetrical wavy spinneret are smoothly connected to the outlet section of the gradient wall thickness flow channel and the outer surface of the substrate, respectively.

3. The corrugated spinneret for producing irregularly shaped, wool-like colored polyester filaments according to claim 1, characterized in that, The upper convex peak and lower concave valley of the symmetrical wavy spinneret are mirror-symmetrical on the cross section perpendicular to the extrusion direction. The diameter of the spinneret is kept constant along the extrusion direction, and the length of the spinneret is adapted to the length of the outlet section of the gradient wall thickness flow channel.

4. The corrugated spinneret for producing irregularly shaped, wool-like colored polyester filaments according to claim 1, characterized in that, Radial guide ribs are provided between the cavities in the flow divider, and the ribs are evenly distributed at equal intervals along the circumference.

5. The corrugated spinneret for producing irregularly shaped, wool-like colored polyester filaments according to claim 1, characterized in that, The ends of the radial guide ribs are rounded and chamfered. The number of radial guide channels is the same as the number of spinnerets, and each guide channel corresponds to one spinneret orifice.

6. The corrugated spinneret for producing irregularly shaped, wool-like colored polyester filaments according to claim 1, characterized in that, The spinneret is used to prepare irregularly shaped, wool-like wavy polyester yarn. Its spinning process parameters are: melt temperature 285 ℃±2 ℃, side-blowing air temperature 22 ℃±1 ℃, and draw ratio 3.5–4.2 times.

7. The corrugated spinneret for producing irregularly shaped, wool-like colored polyester filaments according to any one of claims 1-6, characterized in that, When using three-color colored PET melt, the difference in melt index (MI) (190 ℃ / 2.16 kg) between each melt is ≤±1.5g / 10 min to ensure consistency of wave shape and clarity of color segments.

8. A polyester filament obtained from the preparation of a wavy spinneret for producing irregularly shaped wool-like colored polyester filaments as described in any one of claims 1-7, characterized in that, The wavy morphology corresponds to the structure of the symmetrical wavy spinneret channel, and the cross-section of the irregular wool-like colored polyester yarn has a directional microwave wavy pattern.

Images