Method for producing polyethylene / polyester composite fiber and use thereof

Abstract

This invention discloses a method for preparing polyethylene / polyester composite fibers and their applications, belonging to the field of composite fiber technology. It solves the problems of poor compatibility, easy separation of the core and sheath, and poor mechanical properties in existing technologies. The method involves preparing polyethylene / polyester composite fibers by combining sheath and core materials using a core-sheath composite spinning process. The sheath material is polyethylene, and the core material is a blend of polyester and a compatibilizer. The compatibilizer is a graft copolymer of polyethylene and poly(ethylene-co-glycidyl methacrylate). The polyethylene / polyester composite fibers are then carded into a web, heat-dried, and shaped to form polyethylene / polyester composite fiber sheets. The areal density of the polyethylene / polyester composite fiber sheets is 17.8 g / m³. 2 The transverse breaking strength is 5.0~5.6N, and the longitudinal breaking strength is 30.7~35.3N. The preparation method of this invention can effectively reduce the separation and slippage of the core and sheath of polyethylene / polyester composite fibers, and the composite fiber flocs made from polyethylene / polyester composite fibers have excellent mechanical properties.

Description

Technical Field

[0001] This invention belongs to the field of composite fiber technology, and relates to a method for preparing polyethylene / polyester composite fibers and their applications. Background Technology

[0002] PE (polyethylene) / PET (polyethylene terephthalate) hot-melt fiber is a bicomponent fiber made by core-sheath composite spinning. PET, as the core material, is inexpensive and readily available, giving it a significant cost advantage over other fiber materials. PE, with its low melting point, forms the sheath component, while the core layer is PET, which has a higher melting point. Through a unique hot-air bonding process, the resulting hot-air nonwoven fabric is safe, non-toxic, fluffy, and highly permeable, making it widely applicable in the medical and health fields.

[0003] Hot air bonding imparts excellent bulkiness, breathability, and high liquid conductivity to sanitary materials through point bonding of fibers. Conventional core-sheath composite fibers, due to the affinity between the core and sheath materials, employ a parallel or eccentric spinning method, utilizing the difference in melting points and stress imbalance between the two materials to achieve fiber crimp and bulkiness after stretching. However, due to the poor compatibility of PET and PE, and the complex processing of composite fibers, when the cross-section is parallel or eccentric, core-sheath separation and slippage are prone to occur, affecting subsequent processing and the comfort of the final sanitary product fabric layer.

[0004] However, existing PE / PET composite materials generally suffer from poor compatibility and low strength, which leads to sheath-core layer slippage and separation during multiple stretching processes after spinning. Invention patent CN201910517649.3 discloses a method to prevent sheath-core separation of bicomponent fibers by modifying the process. This method involves injection molding a PE / PET melt base into a hollow concentric structure, with PE tightly coating the PET surface as a sheath-core layer. This results in lower mechanical properties of the fibers, increased fuzz during production, and poor longitudinal and transverse mechanical properties of the PE / PET fiber fabric.

[0005] Therefore, it is of practical significance to reduce the separation and slippage of the core and sheath of PE / PET composite fibers and improve the mechanical properties of composite fibers. Summary of the Invention

[0006] The purpose of this invention is to solve the above-mentioned problems existing in the prior art and to provide a method for preparing polyethylene / polyester composite fibers and their applications.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for preparing polyethylene / polyester composite fiber includes the following steps:

[0009] (1) Preparation of compatibilizer;

[0010] After being dried separately, polyethylene and poly(ethylene-co-glycidyl methacrylate) (EGMA) are added to a mixer and granulated by mixing to obtain the compatibilizer.

[0011] (2) Spinning;

[0012] After drying, S1 polyethylene is melted by a screw, and the metered polyethylene melt enters spinning box A;

[0013] After the polyester dried by S2 is mixed with the compatibilizer, it is successively melted by a screw and vented. The metered mixed melt enters the spinning box B.

[0014] The melt in spinning boxes A and B of S3 is ejected through a composite spinneret to form a core-sheath structure filament, which is then sequentially spun, cooled, bundled, stretched, crimped, cut and dried to obtain polyethylene / polyester composite fiber.

[0015] The outer layer material is polyethylene (PE), and the core layer material is a blend of polyester (PET) and a compatibilizer;

[0016] The compatibilizer is a polyethylene and poly(ethylene-co-glycidyl methacrylate) graft copolymer (PE-EGMA).

[0017] As a preferred technical solution:

[0018] The method for preparing a polyethylene / polyester composite fiber as described above, wherein the polyethylene / polyester composite fiber has a monofilament fineness of 1.8~2.2 dtex, a breaking strength of 2.8~3.3 cN / dtex, a breaking elongation of 60.0±20.0%, a crimp number of 13~17 / 25mm, a crimp degree of 15~20%, and a fiber length of 35~40mm.

[0019] In the preparation method of the polyethylene / polyester composite fiber described above, the weight ratio of the cladding material to the core material is 40~50:50~60.

[0020] The method for preparing a polyethylene / polyester composite fiber as described above, wherein the polyethylene is subjected to a temperature of 190°C and a pressure of 0.3 MPa (3 kgf / cm²). 2 The melt index measured under pressure was 20±2 g / 10 min, and the intrinsic viscosity of the polyester was 0.65~0.68 dL / g.

[0021] In the preparation method of polyethylene / polyester composite fiber as described above, the temperature of the internal mixer in step (1) is 180~190℃, the rotation speed is 50~60rpm, and the mixing time is 10~15min.

[0022] In the preparation method of the polyethylene / polyester composite fiber described above, the mass ratio of polyethylene and poly(ethylene-co-glycidyl methacrylate) in step (1) is 100:3~5.

[0023] In the preparation method of polyethylene / polyester composite fiber as described above, the screw melting temperature in step S1 is 220~250℃, and the polyethylene melt conveying temperature is 260~265℃.

[0024] In step S2, the screw melting temperature is 270~280℃, and the mixed melt conveying temperature is 280~285℃;

[0025] In step S3, the spinning temperature is 280~285℃, the spinning speed is 1000~1200m / min; cooling is achieved by ring blowing, with a ring blowing air temperature of 14~18℃ and a ring blowing air speed of 1.0~1.2m / s; the first stretching temperature is 70~75℃, the second stretching temperature is 100℃, and the total stretching ratio is 2.8~3.2 times; the drying temperature is 100~110℃.

[0026] In the preparation method of the polyethylene / polyester composite fiber described above, the mass ratio of polyester to compatibilizer in step S2 is 100:2~3.

[0027] The present invention also provides the application of polyethylene / polyester composite fibers obtained by the method described in any of the preceding claims, wherein the polyethylene / polyester composite fibers are carded into a web, heat-dried and shaped to produce polyethylene / polyester composite fiber wadding.

[0028] The areal density of the polyethylene / polyester composite fiber wadding is 17.8 g / m³. 2 The transverse breaking strength is 5.0~5.6N, and the longitudinal breaking strength is 30.7~35.3N; in the prior art, the longitudinal breaking strength of polyethylene / polyester composite fiber flocculents is 23.3~30.2N, and the transverse breaking strength is 3.8~4.7N.

[0029] Invention Mechanism:

[0030] In existing PE / PET core-sheath fibers, the PE in the sheath layer and the PET in the core layer have poor compatibility, which makes the sheath fibers and core fibers easy to detach when stretched, resulting in low tensile strength in both the longitudinal and transverse directions of PE / PET fabrics.

[0031] To address this technical problem, the present invention aims to provide a PE / PET fiber with good compatibility. A PE graft copolymer is added to the PET core layer of the PE / PET fiber as a compatibility agent. This compatibility agent is made by grafting polyethylene with poly(ethylene-co-glycidyl methacrylate).

[0032] The compatibilizer contains two hydroxyl groups in its glycidyl methacrylate molecule. These two hydroxyl groups can form ether bonds with the terminal hydroxyl groups of PET and react with the terminal carboxyl groups to form esters.

[0033] Because of the viscosity difference between PET and the compatibilizer, the low-viscosity component of the compatibilizer migrates from the central low-shear rate region to the outer high-shear rate region and accumulates on the outside of the core polyester fiber. On the one hand, the compatibilizer, by introducing polar groups, improves the compatibility with polar polyester, thereby enhancing the interaction force between the compatibilizer and the polyester. On the other hand, because the compatibilizer aggregates outside the core polyester fiber and is preferentially distributed at the interface between the two phases, the poly(ethylene-co-glycidyl methacrylate) in the compatibilizer reduces the interfacial tension between PET and PE, appropriately increasing the interfacial adhesion between PET and PE, reducing the interfacial energy between the two phases, and increasing the compatibility between PET and PE. The polyolefin portion in the compatibilizer is similarly compatible with the polyethylene in the skin layer. The compatibilizer increases the tightness of the bonding between the core PET and the skin PE, connecting the macromolecular chains of PET and PE, improving the compatibility of the two materials, thereby increasing the interaction force between the skin layer and the core layer. The bonding force between the skin and the core layer becomes stronger, and the incompatibility phenomena such as the slippage of the skin and core fibers are effectively improved, solving the problems of skin-core layer separation and poor strength caused by poor compatibility. Beneficial effects

[0034] (1) In the preparation method of polyethylene / polyester composite fiber of the present invention, the compatibilizer contains two hydroxyl groups in the glycidyl methacrylate molecule. These two hydroxyl groups can form ether bonds with the terminal hydroxyl groups of PET and react with the terminal carboxyl groups to form esters. The compatibilizer improves the compatibility with polar polyester by introducing polar groups, thereby enhancing the interaction between the compatibilizer and the polyester.

[0035] (2) The preparation method of polyethylene / polyester composite fiber of the present invention uses a compatibilizer to reduce the interfacial tension between PET and PE, which can appropriately increase the interfacial adhesion between PET and PE, increase the tightness of the core layer PET and the skin layer PE, connect the macromolecular chains of PET and PE, improve the compatibility of the two materials, thereby improving the interaction force between the skin layer and the core layer, and solving the problems of skin-core layer separation and poor strength caused by poor compatibility.

[0036] (3) The polyethylene / polyester composite fiber of the present invention is used to prepare polyethylene / polyester composite fiber flocs, and the polyethylene / polyester composite fiber flocs obtained have excellent mechanical properties. Detailed Implementation

[0037] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0038] In the embodiments of the present invention, the raw materials used have a melt index of polyethylene of 20 g / 10 min (test conditions: temperature 190°C, pressure 0.3 MPa) and an intrinsic viscosity of polyester of 0.67 dL / g. Example

[0039] A method for preparing polyethylene / polyester composite fibers, the specific steps of which are as follows:

[0040] (1) Preparation of compatibilizer;

[0041] After being dried separately, polyethylene and poly(ethylene-co-glycidyl methacrylate) are added to a mixer at a mass ratio of 100:3. After mixing and granulation, a graft copolymer of polyethylene and poly(ethylene-co-glycidyl methacrylate) is obtained, which is the compatibilizer. The temperature of the mixer is 180℃, the speed is 50rpm, and the mixing time is 15min.

[0042] (2) Spinning;

[0043] After drying, the polyethylene in S1 is melted by a screw, and the metered polyethylene melt enters the spinning box A; wherein, the screw melting temperature is 220℃, and the polyethylene melt conveying temperature is 260℃;

[0044] After drying, the polyester and compatibilizer are mixed at a mass ratio of 100:2 and then sequentially melted and vented by a screw. The metered mixed melt enters the spinning box B. The screw melting temperature is 270℃ and the mixed melt conveying temperature is 280℃.

[0045] The melt in spinning boxes A and B of S3 is ejected through a composite spinneret at a mass ratio of 40:60 to form a core-sheath structure filament. This filament then undergoes a series of processes including spinning, cooling, bundling, stretching, crimping, cutting, and drying to obtain polyethylene / polyester composite fiber. The spinning temperature is 280℃, and the spinning speed is 1000 m / min. Cooling is achieved using an annular airflow system with a temperature of 18℃ and a velocity of 1.0 m / s. The first stretching temperature is 70℃, the second stretching temperature is 100℃, and the total stretching ratio is 3.2 times. The drying temperature is 100℃.

[0046] The obtained polyethylene / polyester composite fiber has a single filament fineness of 2.2 dtex, a breaking strength of 3.1 cN / dtex, a breaking elongation of 70%, a crimp number of 13 / 25 mm, a crimp degree of 18%, and a fiber length of 35 mm.

[0047] The above-mentioned polyethylene / polyester composite fibers were carded into a web, dried, and set to produce polyethylene / polyester composite fiber wadding. The drying temperature was 150℃; the setting temperature was 155℃ for the upper roller and 165℃ for the lower roller. The areal density of the resulting polyethylene / polyester composite fiber wadding was 17.8 g / m². 2 The transverse breaking strength is 5.1 N, and the longitudinal breaking strength is 30.7 N. Example

[0048] A method for preparing polyethylene / polyester composite fibers, the specific steps of which are as follows:

[0049] (1) Preparation of compatibilizer;

[0050] After being dried separately, polyethylene and poly(ethylene-co-glycidyl methacrylate) are added to a mixer at a mass ratio of 100:3. After mixing and granulation, a graft copolymer of polyethylene and poly(ethylene-co-glycidyl methacrylate) is obtained, which is the compatibilizer. The temperature of the mixer is 180℃, the speed is 50rpm, and the mixing time is 15min.

[0051] (2) Spinning;

[0052] After drying, the polyethylene in S1 is melted by a screw, and the metered polyethylene melt enters the spinning box A; wherein, the screw melting temperature is 225℃, and the polyethylene melt conveying temperature is 262℃;

[0053] After S2 drying, the polyester and compatibilizer are mixed at a mass ratio of 100:2.2 and then sequentially melted by a screw and vented. The metered mixed melt enters the spinning box B. The screw melting temperature is 275℃ and the mixed melt conveying temperature is 282℃.

[0054] The melt in spinning boxes A and B of S3 is ejected through a composite spinneret at a mass ratio of 50:50 to form a core-sheath structure filament. This filament then undergoes spinning, cooling, bundling, stretching, crimping, cutting, and drying to obtain polyethylene / polyester composite fiber. The spinning temperature is 282℃, and the spinning speed is 1100 m / min. Cooling is achieved using an annular airflow system with a temperature of 15℃ and a velocity of 1.1 m / s. The first stretching temperature is 73℃, the second stretching temperature is 100℃, and the total stretching ratio is 3.0. The drying temperature is 110℃.

[0055] The obtained polyethylene / polyester composite fiber has a single filament fineness of 2.0 dtex, a breaking strength of 3.2 cN / dtex, a breaking elongation of 50%, a crimp number of 15 / 25 mm, a crimp degree of 15%, and a fiber length of 40 mm.

[0056] The above-mentioned polyethylene / polyester composite fibers were carded into a web, dried, and set to produce polyethylene / polyester composite fiber wadding. The drying temperature was 152℃; the setting temperature was 157℃ for the upper roller and 168℃ for the lower roller. The areal density of the resulting polyethylene / polyester composite fiber wadding was 17.8 g / m². 2 The transverse breaking strength is 5.6 N, and the longitudinal breaking strength is 35.3 N. Example

[0057] A method for preparing polyethylene / polyester composite fibers, the specific steps of which are as follows:

[0058] (1) Preparation of compatibilizer;

[0059] After being dried separately, polyethylene and poly(ethylene-co-glycidyl methacrylate) were added to a mixer at a mass ratio of 100:3.5. After mixing and granulation, a graft copolymer of polyethylene and poly(ethylene-co-glycidyl methacrylate) was obtained, which is the compatibilizer. The temperature of the mixer was 182℃, the speed was 55rpm, and the mixing time was 12min.

[0060] (2) Spinning;

[0061] After drying, the polyethylene in S1 is melted by a screw, and the metered polyethylene melt enters the spinning box A; wherein, the screw melting temperature is 230℃, and the polyethylene melt conveying temperature is 265℃;

[0062] After drying, the polyester and compatibilizer are mixed at a mass ratio of 100:2.5 and then sequentially melted by a screw and vented. The metered mixed melt enters the spinning box B. The screw melting temperature is 278℃ and the mixed melt conveying temperature is 285℃.

[0063] The melt in spinning boxes A and B of S3 is ejected through a composite spinneret at a mass ratio of 50:50 to form a core-sheath structure filament. This filament then undergoes a series of processes including spinning, cooling, bundling, stretching, crimping, cutting, and drying to obtain polyethylene / polyester composite fiber. The spinning temperature is 283℃, and the spinning speed is 1150 m / min. Cooling is achieved using a ring-blown air system with a temperature of 16℃ and a velocity of 1.2 m / s. The first stretching temperature is 71℃, the second stretching temperature is 100℃, and the total stretch ratio is 2.9 times. The drying temperature is 120℃.

[0064] The obtained polyethylene / polyester composite fiber has a single filament fineness of 1.9 dtex, a breaking strength of 2.9 cN / dtex, a breaking elongation of 60%, a crimp number of 17 / 25 mm, a crimp degree of 18%, and a fiber length of 38 mm.

[0065] The above-mentioned polyethylene / polyester composite fibers were carded into a web, dried, and set to produce polyethylene / polyester composite fiber wadding. The drying temperature was 155℃; the setting temperature was 160℃ for the upper roller and 170℃ for the lower roller. The areal density of the resulting polyethylene / polyester composite fiber wadding was 17.8 g / m². 2 The transverse breaking strength is 5.0 N, and the longitudinal breaking strength is 33.6 N. Example

[0066] A method for preparing polyethylene / polyester composite fibers, the specific steps of which are as follows:

[0067] (1) Preparation of compatibilizer;

[0068] After being dried separately, polyethylene and poly(ethylene-co-glycidyl methacrylate) are added to a mixer at a mass ratio of 100:4. After mixing and granulation, a graft copolymer of polyethylene and poly(ethylene-co-glycidyl methacrylate) is obtained, which is the compatibilizer. The temperature of the mixer is 186℃, the speed is 60rpm, and the mixing time is 10min.

[0069] (2) Spinning;

[0070] After drying, the polyethylene in S1 is melted by a screw, and the metered polyethylene melt enters the spinning box A; wherein, the screw melting temperature is 240℃, and the polyethylene melt conveying temperature is 265℃;

[0071] After drying, the polyester and compatibilizer are mixed at a mass ratio of 100:3 and then sequentially melted by a screw and vented. The metered mixed melt enters the spinning box B. The screw melting temperature is 280℃ and the mixed melt conveying temperature is 285℃.

[0072] The melt in spinning boxes A and B of S3 is ejected through a composite spinneret at a mass ratio of 50:50 to form a core-sheath structure filament. This filament then undergoes spinning, cooling, bundling, stretching, crimping, cutting, and drying to obtain polyethylene / polyester composite fiber. The spinning temperature is 285℃, and the spinning speed is 1200 m / min. Cooling is achieved using an annular airflow system with a temperature of 15℃ and a velocity of 1.2 m / s. The first stretching temperature is 75℃, the second stretching temperature is 100℃, and the total stretch ratio is 3.1. The drying temperature is 120℃.

[0073] The obtained polyethylene / polyester composite fiber has a single filament fineness of 1.8 dtex, a breaking strength of 3.3 cN / dtex, a breaking elongation of 40%, a crimp number of 16 / 25 mm, a crimp degree of 20%, and a fiber length of 38 mm.

[0074] The above-mentioned polyethylene / polyester composite fibers were carded into a web, dried, and set to produce polyethylene / polyester composite fiber wadding. The drying temperature was 155℃; the setting temperature was 165℃ for the upper roller and 175℃ for the lower roller. The areal density of the resulting polyethylene / polyester composite fiber wadding was 17.8 g / m². 2 The transverse breaking strength is 5.5N, and the longitudinal breaking strength is 35.0N. Example

[0075] A method for preparing polyethylene / polyester composite fibers, the specific steps of which are as follows:

[0076] (1) Preparation of compatibilizer;

[0077] After being dried separately, polyethylene and poly(ethylene-co-glycidyl methacrylate) are added to a mixer at a mass ratio of 100:5. After mixing and granulation, a graft copolymer of polyethylene and poly(ethylene-co-glycidyl methacrylate) is obtained, which is the compatibilizer. The temperature of the mixer is 190℃, the speed is 60rpm, and the mixing time is 10min.

[0078] (2) Spinning;

[0079] After drying, the polyethylene in S1 is melted by a screw, and the metered polyethylene melt enters the spinning box A; wherein, the screw melting temperature is 250℃, and the polyethylene melt conveying temperature is 265℃;

[0080] After drying, the polyester and compatibilizer are mixed at a mass ratio of 100:3 and then sequentially melted by a screw and vented. The metered mixed melt enters the spinning box B. The screw melting temperature is 280℃ and the mixed melt conveying temperature is 285℃.

[0081] The melt in spinning boxes A and B of S3 is ejected through a composite spinneret at a mass ratio of 60:40 to form a core-sheath structure filament. This filament then undergoes spinning, cooling, bundling, stretching, crimping, cutting, and drying to obtain polyethylene / polyester composite fiber. The spinning temperature is 285℃, and the spinning speed is 1200 m / min. Cooling is achieved using an annular airflow system with a temperature of 14℃ and a velocity of 1.2 m / s. The first stretching temperature is 75℃, the second stretching temperature is 100℃, and the total stretching ratio is 2.8 times. The drying temperature is 120℃.

[0082] The obtained polyethylene / polyester composite fiber has a single filament fineness of 2.1 dtex, a breaking strength of 2.8 cN / dtex, a breaking elongation of 80%, a crimp number of 17 / 25 mm, a crimp degree of 20%, and a fiber length of 38 mm.

[0083] The above-mentioned polyethylene / polyester composite fibers were carded into a web, dried, and set to produce polyethylene / polyester composite fiber wadding. The drying temperature was 155℃; the setting temperature was 165℃ for the upper roller and 175℃ for the lower roller. The areal density of the resulting polyethylene / polyester composite fiber wadding was 17.8 g / m². 2 The transverse breaking strength is 5.0 N, and the longitudinal breaking strength is 31.0 N.

Claims

1. A method for preparing polyethylene / polyester composite fibers, characterized in that, The steps include the following: (1) Preparation of compatibilizer; After being dried separately, polyethylene and poly(ethylene-co-glycidyl methacrylate) are added to a mixer and granulated by mixing to obtain the compatibilizer. The mass ratio of polyethylene to poly(ethylene-co-glycidyl methacrylate) is 100:3~5; (2) Spinning; After S1 is dried, the polyethylene is melted by a screw, and the metered polyethylene melt enters the spinning box A. After the polyester S2 is dried, it is mixed with the compatibilizer and then successively melted by a screw and vented. The metered mixed melt enters the spinning box B. The melt in spinning boxes A and B of S3 is ejected through a composite spinneret to form a core-sheath structure filament, which is then sequentially spun, cooled, bundled, stretched, crimped, cut and dried to obtain polyethylene / polyester composite fiber. The outer layer material is polyethylene, and the core layer material is a blend of polyester and a compatibilizer, wherein the compatibilizer is a graft copolymer of polyethylene and poly(ethylene-co-glycidyl methacrylate). The weight ratio of cortex material to core material is 40~50:50~60; In step S2, the mass ratio of polyester to compatibilizer is 100:2~3.

2. The method for preparing a polyethylene / polyester composite fiber according to claim 1, characterized in that, The polyethylene / polyester composite fiber has a single filament fineness of 1.8~2.2 dtex, a breaking strength of 2.8~3.3 cN / dtex, a breaking elongation of 60.0±20.0%, a crimp number of 13~17 / 25mm, a crimp degree of 15~20%, and a fiber length of 35~40mm.

3. The method for preparing a polyethylene / polyester composite fiber according to claim 1, characterized in that, The polyethylene has a melt index of 20±2 g / 10 min measured at 190°C and 0.3 MPa, and the polyester has an intrinsic viscosity of 0.65~0.68 dL / g.

4. The method for preparing a polyethylene / polyester composite fiber according to claim 1, characterized in that, In step (1), the temperature of the internal mixer is 180~190℃, the speed is 50~60rpm, and the mixing time is 10~15min.

5. The method for preparing a polyethylene / polyester composite fiber according to claim 1, characterized in that, In step S1, the screw melting temperature is 220~250℃, and the polyethylene melt conveying temperature is 260~265℃. In step S2, the screw melting temperature is 270~280℃, and the mixed melt conveying temperature is 280~285℃. In step S3, the spinning temperature is 280~285℃, and the spinning speed is 1000~1200m / min. Cooling is achieved using ring-blown air cooling, with a ring-blown air temperature of 14~18℃ and a ring-blown air speed of 1.0~1.2m / s. The first stretching temperature is 70~75℃, the second stretching temperature is 100℃, the total stretching ratio is 2.8~3.2 times, and the drying temperature is 100~110℃.

6. The application of the polyethylene / polyester composite fiber prepared by the method according to any one of claims 1 to 5, characterized in that: The polyethylene / polyester composite fibers are carded into a web, heat-dried, and shaped to produce polyethylene / polyester composite fiber wadding, the areal density of which is 17.8 g / m³. 2 The transverse fracture strength is 5.0~5.6N, and the longitudinal fracture strength is 30.7~35.3N.