Sheath-core composite polyethylene fiber and method for manufacturing the same

Abstract

To provide a sheath-core composite polyethylene fiber in which the cut resistance of the sheath-core composite polyethylene fiber is significantly improved and the problems of powder falling, discoloration, and equipment damage when the sheath-core composite polyethylene fiber is used in a subsequent process are effectively solved, and a method for manufacturing the same.SOLUTION: There is provided a sheath-core composite polyethylene fiber, comprising: a fiber core layer; and a fiber sheath layer. The fiber sheath layer wraps around the fiber core layer. The fiber sheath layer contains an ultra-high molecular weight polyethylene A, and the fiber core layer contains an ultra-high molecular weight polyethylene B, a first auxiliary agent, and a second auxiliary agent. The first auxiliary agent includes mineral fibers. The second auxiliary agent contains at least one of inorganic ultrafine powder and graphene. The second auxiliary may or may not include a color paste and an antioxidant.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention belongs to the technical field of polymeric materials, and specifically relates to a sheath-core composite polyethylene fiber and a method for producing the same. [Background technology]

[0002] Ultra-high molecular weight polyethylene fiber is a high-performance chemical fiber with ultra-high strength and ultra-high elastic modulus. Its products are widely used in the military field (body armor, bulletproof helmets, other personal protective equipment, tanks, ships, helicopters, other armored protective equipment, etc.) and industrial fields (marine ropes, farmed fish, sporting goods, radomes, etc.). Conventional ultra-high molecular weight polyethylene fibers have long molecular chains and are highly entangled, so the cut-resistant grade of the main body is generally only about grade 2 (if ultra-high molecular weight polyethylene fibers are mixed and woven with glass fibers, steel wires, etc., the blended fibers become uncomfortable to wear). In addition, ultra-high molecular weight polyethylene fibers are difficult to dye and have poor color fastness because of their non-polar molecular structure and high crystallinity.

[0003] In the prior art, research on ultra-high molecular weight polyethylene fibers, for example, patent application CN109322006A discloses colored high-strength polyethylene fibers and their manufacturing methods, in which the cut resistance of ultra-high molecular weight polyethylene fibers can be improved to a certain extent without compromising comfort by filling with components such as surface-modified nano boron fibers, and the combination of dope dyeing and sheath-core composite technology can facilitate dyeing and improve color fastness to a certain extent. However, the sheath-core composite polyethylene fibers of the prior art still have problems in that they are prone to powder shedding and color fading when applied to subsequent use processes, and are prone to wear on the equipment of subsequent processes, and there are limitations to improving cut resistance.

[0004] Therefore, new technical solutions are needed to solve the above technical problems. Summary of the Invention

[0005] The object of the present invention is to provide a sheath-core composite polyethylene fiber and a manufacturing method thereof, thereby solving the technical problems existing in the prior art in the above-mentioned background art, that is, when the sheath-core composite polyethylene fiber is applied to a subsequent use process, it is prone to powder shedding and discoloration, it wears down the equipment in the subsequent process, and there is a limit to improving the cut resistance.

[0006] In order to achieve the above object, the present invention employs the following technical means.

[0007] A sheath-core composite polyethylene fiber, comprising a fiber core layer and a fiber sheath layer, the fiber sheath layer enveloping the fiber core layer, the fiber sheath layer containing ultra-high molecular weight polyethylene A, the fiber core layer containing ultra-high molecular weight polyethylene B, a first auxiliary agent and a second auxiliary agent, the first auxiliary agent containing mineral fiber, the second auxiliary agent containing at least one of inorganic ultrafine powder and graphene, and the second auxiliary agent may or may not contain color paste and antioxidant. The amounts of the first auxiliary agent and the second auxiliary agent used are 0.1-60% and 0.1-30% of the total mass of the ultra-high molecular weight polyethylene B, the first auxiliary agent and the second auxiliary agent, respectively. Specifically, the amounts of the inorganic ultrafine powder, graphene, color paste and antioxidant used are 0-20%, 0-10%, 0-20% and 0-2% of the total mass of the ultra-high molecular weight polyethylene B, the first auxiliary agent and the second auxiliary agent, respectively. The mineral fiber is one of glass fiber, ceramic fiber, and carbon fiber, or a combination thereof. The inorganic ultrafine powder is one of aluminum, titanium, silicon, boron, carbide, nitride, and zirconium oxide, each having an average radius of 0.1 to 300 μm, or a combination thereof. The weight average molecular weights of the ultra-high molecular weight polyethylene A and ultra-high molecular weight polyethylene B are both 1 to 4 million.

[0008] According to the present invention, there is further provided a method for producing the above-mentioned sheath-core bicomponent polyethylene fiber, the method comprising the steps of: S1: The mineral fiber is added to the solvent A, and the first auxiliary agent is prepared by carrying out the pretreatment of dispersion and stirring, followed by sanding. Here, the solvent A is white oil. S2: Add at least one of inorganic ultrafine powder and graphene to solvent B, with or without adding color paste and antioxidant, and after the addition is completed, perform pretreatment of dispersion and stirring, and then sand to produce the second auxiliary agent. Here, solvent B is white oil. S3: Ultra-high molecular weight polyethylene B, the first auxiliary agent, and the second auxiliary agent are added to the solvent C and mixed uniformly, then introduced into a twin-screw extruder, heated, extruded and dissolved to prepare a fiber core layer spinning solution. Here, the heating temperature is 200 to 300°C, and the solvent C is white oil. S4: Ultra-high molecular weight polyethylene A is added to solvent D, mixed uniformly, and then introduced into a twin-screw extruder and extruded to dissolve, thereby preparing a fiber sheath layer spinning solution. Here, the heating temperature is 200 to 300°C, and solvent D is white oil. S5: The fiber core layer spinning solution is wrapped in the fiber sheath layer spinning solution and spun, and then extracted, dried and hot drawn to obtain the finished sheath-core composite polyethylene fiber. Here, the spinning temperature is 220 to 260°C.

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0010] 1. In the present invention, mineral fiber, inorganic ultrafine powder and graphene are introduced to perform interface interaction, and ultra-high molecular weight polyethylene is filled in, and the synergistic effect of the sheath-core compounding process forms a synergistic reinforcement of two components, thereby greatly improving the cut resistance of the sheath-core compounded polyethylene fiber without affecting the comfort of the sheath-core compounded polyethylene fiber. On this basis, in the sheath-core compounding process of the present invention, the fiber core layer is made using ultra-high molecular weight polyethylene containing inorganic ultrafine powder, graphene, mineral fiber, color paste and antioxidant, and the fiber sheath layer is made using ordinary ultra-high molecular weight polyethylene, thereby achieving the effect of protecting the fiber core layer, thereby effectively solving the problems that the sheath-core compounded polyethylene fiber is prone to powder shedding, color fading and equipment wear when used in the subsequent use process.

[0011] 2. The color of the sheath-core composite polyethylene fiber of the present invention is determined by the content of mineral fiber, inorganic ultrafine powder, graphene, color paste and antioxidant in the fiber core layer. By changing the content of the above components, especially the color paste, it is possible to produce high-strength sheath-core composite polyethylene fibers of various colors, further improving the cut resistance of the sheath-core composite polyethylene fiber, and further improving the convenience of coloring without affecting the color fastness of the sheath-core composite polyethylene fiber. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be further described below with reference to examples, but the present invention is not limited to these examples.

[0013] The raw materials in the present invention are commercially available raw materials.

[0014] Example 1 Manufacturing of sheath-core composite polyethylene fibers S1: The ceramic powder was added to white oil, and the pretreatment was carried out by dispersing and stirring. Then, the powder was machined by a sand mill to control the particle size to 10-300 μm and the aspect ratio to 1-30, to obtain the first auxiliary agent. S2: Antioxidant 1076, magnesium oxide powder with an average radius of 0.1 μm was added to white oil, and after addition, the pretreatment of dispersion and stirring was carried out, and then sanding was carried out to obtain the second auxiliary agent. S3: Ultra-high molecular weight polyethylene B (ultra-high molecular weight polyethylene powder with a weight average molecular weight of 1 million), the first auxiliary agent, and the second auxiliary agent were added to white oil and mixed uniformly, then introduced into a twin-screw extruder, heated at 200 to 300°C, and extruded to dissolve, thereby obtaining a fiber core layer spinning solution. S4: Ultra-high molecular weight polyethylene A (ultra-high molecular weight polyethylene powder with an average molecular weight of 4 million) was added to white oil and mixed uniformly, then introduced into a twin-screw extruder, heated at 200-300°C, and extruded to dissolve, thereby obtaining a fiber sheath layer spinning solution. S5: Using a spinneret, the fiber sheath layer spinning solution was wrapped in the fiber core layer spinning solution, spun at 220-260°C, cooled in a water bath to harden into a gel fiber, and then extracted, dried and hot-drawn to obtain a white sheath-core composite polyethylene fiber. In the above manufacturing process, the amounts of the ceramic powder, magnesium oxide, and antioxidant 1076 used were 22%, 5%, and 0.5% of the total mass of the ultra-high molecular weight polyethylene B, the first auxiliary agent, and the second auxiliary agent, respectively. The resulting white polyethylene fiber was used to produce fabrics, and the cut resistance of the fabrics was A3 (200D) and A4 (400D) or higher.

[0015] Example 2 Manufacturing of sheath-core composite polyethylene fibers S1: Nanocrystalline silicon carbide powder and ceramic powder were added to white oil, and the mixture was pretreated by dispersion and stirring. Then, the mixture was machined using a sand mill to control the particle size to 10-300 μm and the aspect ratio to 1-30 to obtain the first auxiliary agent. S2: Color paste, antioxidant 300 and graphene powder (modified graphene powder may be used as necessary) are added to white oil. After the addition is completed, the mixture is pre-treated by dispersion and stirring, and then sanded to obtain the second auxiliary agent. S3: Ultra-high molecular weight polyethylene B (ultra-high molecular weight polyethylene powder with a weight average molecular weight of 2.5 million), the first auxiliary agent, and the second auxiliary agent were added to white oil and mixed uniformly, then introduced into a twin-screw extruder, heated at 200 to 300°C, and extruded to dissolve, thereby obtaining a fiber core layer spinning solution. S4: Ultra-high molecular weight polyethylene A (ultra-high molecular weight polyethylene powder with an average molecular weight of 2.5 million) was added to white oil and mixed uniformly, then introduced into a twin-screw extruder, heated at 200-300°C, extruded and dissolved to obtain a fiber sheath layer spinning solution. S5: Using a spinneret, the fiber sheath layer spinning solution was wrapped in the fiber core layer spinning solution, spun at 220 to 260°C, cooled in a water bath to harden into a gel fiber, and then extracted, dried and hot-drawn to obtain a gray sheath-core composite polyethylene fiber. In the above manufacturing process, the amounts of nanocrystalline silicon carbide powder, ceramic powder, color paste, antioxidant 300 and graphene powder used were 5%, 15%, 8%, 0.5% and 2% of the total mass of ultra-high molecular weight polyethylene B, first auxiliary agent and second auxiliary agent, respectively. The resulting gray polyethylene fiber was used to fabricate a fabric, and the cut resistance of the fabric was A4 (200D / 400D) or higher.

[0016] Example 3 Manufacturing of sheath-core composite polyethylene fibers S1: Nanocrystalline silicon carbide powder was added to white oil, and the powder was pretreated by dispersion and stirring. Then, the powder was machined using a sand mill to control the particle size to 10-300 μm and the aspect ratio to 1-30, to obtain the first auxiliary agent. S2: Color paste, antioxidant 168 and graphene powder (modified graphene powder may be used as necessary) were added to white oil, and after addition, the mixture was pretreated by dispersion and stirring, and then sanded to obtain the second auxiliary agent. S3: Ultra-high molecular weight polyethylene B (ultra-high molecular weight polyethylene powder with a weight average molecular weight of 4 million), the first auxiliary agent, and the second auxiliary agent were added to white oil and mixed uniformly, then introduced into a twin-screw extruder, heated at 200 to 300°C, and extruded to dissolve, thereby obtaining a fiber core layer spinning solution. S4: Ultra-high molecular weight polyethylene A (ultra-high molecular weight polyethylene powder with a weight average molecular weight of 1 million) was added to white oil and mixed uniformly, then introduced into a twin-screw extruder, heated at 200 to 300°C, and extruded to dissolve, thereby obtaining a fiber sheath layer spinning solution. S5: Using a spinneret, the fiber sheath layer spinning solution was wrapped in the fiber core layer spinning solution, spun at 220 to 260°C, cooled in a water bath to harden into a gel fiber, and then extracted, dried and hot-drawn to obtain a black sheath-core composite polyethylene fiber. In the above manufacturing process, the amounts of nanocrystalline silicon carbide powder, color paste, antioxidant 168 and graphene powder used were 20%, 5%, 0.5% and 5% of the total mass of ultra-high molecular weight polyethylene B, first auxiliary agent and second auxiliary agent, respectively. The black sheath-core composite polyethylene fibers were used to produce fabrics, and the cut resistance of the fabrics was A4 (200D) and A5 (400D) or higher.

[0017] The white, gray, and black composite polyethylene fibers each have a fiber density of 0.9 to 2.0 g / cm. 3 It was.

[0018] Furthermore, the sheath-core composite polyethylene fibers of each color produced in Examples 1, 2 and 3 were tested according to the standards in GB / T 14344-2022 "Tensile Properties of Chemical Fiber Filaments". As a result, their breaking strengths all reached 15-20cN / dtex and their breaking elongations were ≦3.5%.

Claims

1. A sheath-core composite polyethylene fiber, 1. A sheath-core composite polyethylene fiber comprising: a fiber core layer; and a fiber sheath layer, the fiber sheath layer enveloping the fiber core layer, the fiber sheath layer comprising ultra-high molecular weight polyethylene A, the fiber core layer comprising ultra-high molecular weight polyethylene B, a first auxiliary agent, and a second auxiliary agent, the first auxiliary agent comprising mineral fiber, the second auxiliary agent comprising at least one of inorganic ultrafine powder and graphene, and the second auxiliary agent may or may not comprise a color paste and an antioxidant.

2. The sheath-core composite polyethylene fiber according to claim 1, characterized in that the amounts of the first auxiliary and the second auxiliary used are 0.1 to 60% and 0.1 to 30%, respectively, of the total mass of the ultra-high molecular weight polyethylene B, the first auxiliary, and the second auxiliary.

3. The sheath-core composite polyethylene fiber according to claim 2, wherein the amounts of the inorganic ultrafine powder, the graphene, the color paste and the antioxidant used are 0-20%, 0-10%, 0-20% and 0-2%, respectively, of the total mass of the ultra-high molecular weight polyethylene B, the first auxiliary and the second auxiliary.

4. The sheath-core composite polyethylene fiber according to claim 1, wherein the mineral fiber is one of glass fiber, ceramic fiber, and carbon fiber, or a combination thereof.

5. The sheath-core composite polyethylene fiber according to claim 1, characterized in that the inorganic ultrafine powder is one of aluminum, titanium, silicon, boron, carbide, nitride, and zirconium oxide, or a combination thereof, and the inorganic ultrafine powder has an average radius of 0.1 to 300 μm.

6. 2. The sheath-core composite polyethylene fiber according to claim 1, wherein the weight average molecular weight of the ultra-high molecular weight polyethylene A and the weight average molecular weight of the ultra-high molecular weight polyethylene B are both 1 to 4 million.

7. A method for producing the sheath-core composite polyethylene fiber according to any one of claims 1 to 6, comprising the steps S1 to S5 below: S1: Add mineral fibers to solvent A, carry out pretreatment of dispersion and stirring, and then sand to prepare a first auxiliary agent; S2: Add at least one of inorganic ultrafine powder and graphene to solvent B, with or without adding color paste and antioxidant. After the addition is completed, perform pretreatment of dispersion and stirring, and then sand to prepare a second auxiliary; S3: Ultra-high molecular weight polyethylene B, the first auxiliary agent, and the second auxiliary agent are added to the solvent C and mixed uniformly, and then introduced into a twin-screw extruder, heated, and extruded to dissolve the mixture to prepare a fiber core layer spinning solution; S4: The ultra-high molecular weight polyethylene A is added to the solvent D, mixed uniformly, and then introduced into a twin-screw extruder and extruded to dissolve the mixture to prepare a fiber sheath layer spinning solution; S5: A manufacturing method comprising wrapping the fiber core layer spinning solution with the fiber sheath layer spinning solution, spinning the resulting mixture, extracting, drying and hot drawing to obtain a finished sheath-core composite polyethylene fiber.

8. The manufacturing method according to claim 7, wherein in step S1, the grain size is controlled to 10 to 300 μm and the aspect ratio is controlled to a range of 1 to 30 when sanding.

9. In step S3, the heating temperature is 200 to 300° C. In step S4, the heating temperature is 200 to 300° C. The method according to claim 7, wherein in step S5, the spinning temperature is 220 to 260°C.

10. The method according to claim 7, wherein the solvents A, B, C and D are all white oils.