KR102264020B1 - High-strength composite yarn having improved cut resistance - Google Patents

Abstract

The present invention relates to a high-strength composite yarn in which a hard fiber forms a core yarn and a high-strength spun yarn is formed on the outer periphery of the core yarn, wherein the high-strength spun yarn is formed of a polyethylene resin and the main repeating unit is ethylene. Including, wherein the polyethylene fiber has a melt index of 0.6 to 2 g / 10 min, is formed of a polyethylene resin having a molecular weight distribution index of 5 to 10, the degree of crystallinity of the polyethylene fiber is 75% or more, and the crystal size is 10 Å or more, The high-strength composite yarn relates to a high-strength composite yarn with improved cut resistance satisfying the following formula (2).
Equation (2) 0 ≤ X ∠ A/2
X: the distance between the center point of the composite yarn and the center point of the core yarn
The center point of the composite yarn: the center of the circle with the shortest length (A) of the composite yarn as the diameter (M)
The center point of the core yarn: the center of the circle with the shortest length (a) of the core yarn as the diameter (m)

Description

High-strength composite yarn with improved cut resistance {HIGH-STRENGTH COMPOSITE YARN HAVING IMPROVED CUT RESISTANCE}

The present invention relates to a high-strength composite yarn having improved cut resistance, and more particularly, to a high-strength composite yarn having improved cut resistance by using a high-strength polyethylene multifilament.

In various industrial fields, certain materials, raw materials or parts are cut so that they can be used, and in these industries, work clothes with cut resistance are required to protect workers from being cut for the safety of workers.

Examples of spun yarns suitable for this purpose are fibers made of aramid, high strength polyethylene or polybenzoxazole.

In particular, high-strength polyethylene resins are inexpensive and have excellent chemical resistance and product processability, so their use is increasing for engineering plastics, films, fibers and non-woven fabrics. In the textile field, monofilaments and multifilaments are manufactured and used for clothing, Its use is expanding for industrial purposes. In particular, according to the latest fiber trends, interest in high-functional polyethylene fibers requiring high strength and high modulus of elasticity is increasing.

In US Patent No. 4,228,118, a polyethylene resin having a number average molecular weight of 20,000 or more and a weight average molecular weight of 125,000 or less is melted at a spinning temperature of 220 to 335° C. After winding at a temperature of 200 to 335° C. at a minimum spinning speed of 30 m/min, it was stretched 20 times or more to prepare a fiber of 10 to 20 g/d. However, this method has limitations in production due to the low number of nozzles and the spinning speed according to the spin draw method in the commercial production of polyethylene fibers, and produces polyethylene fibers with excellent uniformity and spinning workability when producing tens to hundreds of multifilaments. have difficulty doing

In addition, in Korean Patent Registration No. 0909559, the weight average molecular weight is 300,000 or less, the ratio of the weight average molecular weight to the number average molecular weight (Mw/Mn), which is a molecular weight distribution index, is 4.0 or less, and high strength polyethylene fibers that express high strength are specified. are doing However, it is difficult to control the molecular weight distribution index of the raw material to 4.0 or less, and since the molecular weight distribution index is formed low, high stretching of 10 times or more is required to express high strength, so there is a problem in that spinning workability and fairness are lowered.

In general, high-strength polyethylene fibers have excellent cutting resistance and are widely used as industrial products such as industrial safety gloves. However, the cutting resistance of conventional high-strength polyethylene fibers is expressed only by the strength of polyethylene fibers. If the strength is not uniform or the strength is weakened in a specific part, there is a problem that the cutting resistance may be reduced.

In addition, as described above, the high-strength polyethylene fiber was continuously improved to improve the cut resistance, but it was difficult to obtain a cut level of 4 or higher in the yarn formed by the high-strength polyethylene fiber alone, and the cutting resistance also expresses 10N or more. There are limits. Accordingly, it is necessary to develop a composite yarn for expressing cutting resistance in extreme environments.

The present invention was invented to solve the problems of the prior art as described above, and an object of the present invention is to provide a high-strength composite yarn with improved cut resistance by utilizing hard fibers and high-strength spun yarn having cut resistance.

Another object of the present invention is to provide a high-strength composite yarn with improved cut resistance with improved wearability by using a spun yarn with improved cut resistance including polyethylene fibers having high elongation.

The present invention relates to a high-strength composite yarn in which a hard fiber forms a core yarn and a high-strength spun yarn is formed on the outer periphery of the core yarn, wherein the high-strength spun yarn is formed of a polyethylene resin and the main repeating unit is ethylene. Including, wherein the polyethylene fiber has a melt index of 0.6 to 2 g / 10 min, is formed of a polyethylene resin having a molecular weight distribution index of 5 to 10, the degree of crystallinity of the polyethylene fiber is 75% or more, and the crystal size is 10 Å or more, High-strength composite yarn provides a high-strength composite yarn with improved cut resistance, characterized in that it satisfies the following formula (2).

Equation (2) 0 ≤ X ∠ A/2

X: the distance between the center point of the composite yarn and the center point of the core yarn

The center point of the composite yarn: the center of the circle with the shortest length (A) of the composite yarn as the diameter (M)

The center point of the core yarn: the center of the circle with the shortest length (a) of the core yarn as the diameter (m)

In addition, there is provided a high-strength composite yarn with improved cut resistance, characterized in that the polyethylene fiber has a strength of 12 to 16 g/d.

In addition, the polyethylene fiber, a melt index of 0.6 to 2 g / 10 min, a spinning step of melt-spinning a polyethylene resin having a molecular weight distribution index of 5 to 10 at 230 ~ 290 ℃ to form an undrawn yarn; a stretching step of stretching the undrawn yarn; And, it provides a high-strength composite yarn with improved cut resistance, characterized in that it is prepared including an aging step of aging the drawn polyethylene fibers at 90 ~ 130 ℃.

In addition, the spinning speed in the spinning step provides a high-strength composite yarn with improved cut resistance, characterized in that 120 ~ 160mpm.

In addition, the aging step provides a high-strength composite yarn with improved cut resistance, characterized in that aging for 5 to 20 seconds.

In addition, the manufacturing method provides a high-strength composite yarn with improved cut resistance, characterized in that it satisfies the following formula (1).

Equation (1) 210≤S+T≤290

However, S is an integer of the spinning speed (mpm) of the spinning step, and T is an integer of the aging temperature (℃) of the aging step.

In addition, the polyethylene fiber provides a high-strength composite yarn with improved cut resistance, characterized in that the fiber length is 20 to 100 mm.

In addition, the high-strength composite yarn with improved cut resistance provides a high-strength composite yarn with improved cut resistance, characterized in that the number of counts is 10 to 50.

In addition, the hard fiber provides a high-strength composite yarn with improved cut resistance, characterized in that the mineral fiber or metal fiber.

In addition, it provides an article comprising the high-strength composite yarn.

In addition, the article provides an article characterized in that the level (Level) according to the cut resistance standard is 5 or more.

In addition, the article provides an article, characterized in that the cutting force is 10N or more.

The high-strength composite yarn with improved cut resistance according to the present invention uses a hard fiber as a core yarn and a high-strength spun yarn having cut resistance is formed on the outer periphery of the core yarn, thereby improving cut resistance.

In addition, the present invention has the effect of improving wearability when manufactured into clothing with a spun yarn with improved cut resistance including polyethylene fibers having high elongation.

1 is a view showing a cross-section of a high-strength composite yarn according to the present invention.
2 is a process diagram showing a method of manufacturing a high-strength polyethylene fiber according to the present invention.
Figure 3 is a view briefly showing the aging step of the high-strength polyethylene fiber manufacturing process according to the present invention.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. First, it should be noted that in the drawings, the same components or parts are denoted by the same reference numerals whenever possible. In describing the present invention, detailed descriptions of related known functions or configurations are omitted so as not to obscure the gist of the present invention.

As used herein, the terms 'about', 'substantially' and the like are used in or close to the numerical value when manufacturing and material tolerances inherent in the stated meaning are presented, and provide an understanding of the present invention. To help, precise or absolute figures are used to prevent unfair use by unscrupulous infringers of the stated disclosure.

1 is a view showing a cross-section of a high-strength composite yarn according to the present invention, FIG. 2 is a process diagram showing a method of manufacturing a high-strength polyethylene fiber according to the present invention, and FIG. 3 is an aging step in the high-strength polyethylene fiber manufacturing process according to the present invention. It is a schematic view, and FIG. 4 is an SEM photograph of a high-strength composite yarn according to the present invention.

The present invention relates to a high-strength composite yarn with improved cut resistance in which hard fibers form a core yarn 10 and a high-strength spun yarn 20 is formed on the outer periphery of the core yarn as shown in FIG. 1 .

The core yarn 10 is formed of hard fibers and is a fiber with high strength and high surface hardness. In the present invention, mineral fibers such as glass fiber, glass wool, mineral wool, iron fiber, aluminum fiber, stainless fiber, tungsten fiber, etc. of metal fibers may be used.

In the present invention, it will be preferable to use economical glass fiber or stainless fiber.

The hard fiber as the core yarn is preferably a multifilament yarn, and preferably has a fineness of 50 to 100 denier.

The high-strength spun yarn is formed of polyethylene resin and includes polyethylene fibers whose main repeating unit is ethylene.

The polyethylene fiber has a melt index of 0.6 to 2 g/10 min, and is formed of a polyethylene resin having a molecular weight distribution index of 5 to 10, so that the polyethylene fiber has a crystallinity of 75% or more and a crystal size of 10 Å or more.

The present invention is an invention for improving the cut resistance of high-strength polyethylene fibers by controlling the degree of crystallinity and crystal size. Although the factors for expressing the cutting resistance have not been specifically identified, the paper J. Polym. Sci. Part B Polym. Phys., vol. 48, pp.1861-1872 (2010), Paper Mater. Sci. Eng. A, vol. Referring to Fibril Formation and Fracture Mechanism of crystallization of polyethylene in 500, 216-224 (2009), slippage of surface crystals from the point at which crystals are maximized as polyethylene multifilaments are stretched to express mechanical strength. Therefore, it can be estimated that the cut resistance is expressed.

The cut resistance measurement method is defined by calculating the number of repetitions when repeatedly cutting a woven or knitted fabric made of polyethylene by applying a constant load to a sharp circular blade, or a woven or knitted fabric made of polyethylene to a certain length by a straight blade. It can be defined as the load to be cut, and in the present invention, only the polyethylene fiber having a certain strength or more having a certain strength or more occurs crystal slippage due to an external force on the fiber surface by the blade when cutting, resulting in cut resistance It is estimated that , and it can be seen that there is a certain relationship between the degree of crystallinity and the crystal size on the cutting resistance.

The polyethylene fiber of the present invention preferably has a crystallinity of 75% or more and a crystal size of 10 Å or more, and it is more preferable that the crystallinity is 80% or more and a crystal size of 12 Å or more.

The polyethylene resin forming the high-strength polyethylene fiber of the present invention has a melt index of 0.6 to 2.0 g/10 min, preferably 0.8 to 1.4 g/10 min.

If the melt index is less than 0.6 g/10 min, the flowability of the melt of polyethylene resin in the extruder is not good, so that the spinning speed cannot be increased, and there may be problems that act as a cause of the nozzle surface during spinning. In addition, when the melt index exceeds 2.0 g/10 min, spinning workability is excellent, but flowability is not suitable at an appropriate spinning temperature, so it may be difficult to obtain high-strength polyethylene fibers after stretching.

In addition, the polyethylene resin used in the present invention may preferably have a weight average molecular weight (Mw) of 100,000 to 300,000, and a molecular weight distribution index (weight average molecular weight/number average molecular weight, Mw/Mn) of 5 to 10.

When the weight average molecular weight (Mw) is less than 100,000, spinning workability is improved during spinning, but there is a limit to expressing high strength, and when it exceeds 300,000, it affects the flowability of the resin inside the extruder during melt spinning, so that the spinning uniformity and Workability may be adversely affected.

When the molecular weight distribution index is less than 5, high magnification stretching of 10 times or more is required to express high strength, and the defects of the hair or the stretching roller are increased accordingly, so that the quality may be deteriorated as the number of stretching trimmings increases. In addition, when the molecular weight distribution index exceeds 10, a smooth stretching process cannot be performed because a large number of high molecular weight polyethylene and low molecular weight polyethylene are mixed in the polyethylene resin, and thus there is a limitation in expressing high strength.

As described above, the high-strength polyethylene fiber with improved cut resistance of the present invention is manufactured including a spinning step 100 , a stretching step 200 , and an aging step 300 as shown in FIG. 1 .

The high-strength polyethylene fiber with improved cut resistance of the present invention controls the crystallinity and crystal size of the polyethylene fiber through the spinning speed in the spinning step 100 and the aging step 300 carried out at a high temperature after stretching.

The spinning step 100 is a step of forming an undrawn yarn by performing the melt spinning. The polyethylene resin having the molecular weight distribution index and the melt index controlled is melted in an extruder, and an undrawn yarn can be prepared by installing a nozzle hot tube.

In controlling the crystallinity and crystal size of the polyethylene fiber, the spinning temperature in the spinning step is preferably 230 ~ 290 ℃, the spinning speed will preferably be 120 ~ 160mpm.

When spinning, the spinning nozzle having 60 to 400 holes can be used to manufacture high-strength polyethylene fibers with improved cut resistance of the present invention.

If the spinning speed is less than 120mpm in the spinning step, the manufacturing processability of the undrawn yarn is improved, but the stretchability is lowered in the drawing step, so it is difficult to control the fineness, and hair or loops of the fiber may occur.

In addition, if the spinning speed exceeds 160 mpm in the spinning step, the possibility of thread trimming on the nozzle face or the occurrence of thread trimming during cooling may increase, thereby reducing fairness. Therefore, it is preferable that the spinning speed be 120 to 160 mpm.

The spinning temperature and spinning speed are closely related to the orientation of high-strength polyethylene fibers, and in the case of polyethylene fibers with good fiber orientation, fairness during drawing is advantageous.

The stretching step 200 is a step of stretching the undrawn yarn prepared in the spinning step. The stretching step may be performed using a multi-stage stretching roller, and it is preferable to stretch in two or three stages at 60 to 120 ° C. will be.

In the drawing step, the overall draw ratio (DR) is preferably 6 to 10. If the overall draw ratio (DR) is lower than 6, the strength of the polyethylene fiber is lowered, and if it is higher than 10, the quality of the polyethylene fiber is severe due to the occurrence of yarn breakage during drawing. may be lowered.

The aging (Aging) step 300 is a step of aging (aging) the stretched polyethylene fibers by staying at 90 ~ 130 ℃.

In the aging step 300 , as shown in FIG. 2 , the polyethylene fiber drawn at a predetermined temperature may be aged using a plurality of aging rollers 330 in the heating chamber 310 .

The aging step does not use a heating roller that directly transfers heat to the roller in order to prevent defects of fibers due to the roller having a high temperature, and performs the aging step in a non-contact type using a heating chamber as in FIG. it would be preferable

3, when the aging step 300 is carried out through the heating chamber, the polyethylene fiber may sag due to the aging temperature in the heating chamber maintained at a constant high temperature on the roller surface. , it would be preferable to control a constant tension in the second guide rollers 210 and 230 and the tension roller 250 .

The heating chamber 310 maintains a constant heat received by the polyethylene fiber by controlling the ambient temperature in the chamber rather than the heating roller method.

Since the high-strength polyethylene fiber of the present invention has a fast crystallization rate and can form crystals in a short time and increase the crystal size, it is preferable to control the crystal aging time to pass through a plurality of aging rollers 330 .

The aging temperature is preferably in the range of 90 to 130 ℃, it will be preferable to control the speed of the roller with a draw ratio of 0.98 to 1.02.

If the aging temperature is less than 90 ℃, the tension in the aging roller 330 may increase and the fiber may be cut, thereby reducing fairness. If the aging temperature exceeds 130 ℃, the fibers may be fused to the roller surface or non-uniform. As a result, the physical properties of the polyethylene fiber may be reduced, and defects such as wool or loops may occur.

The aging step is preferably 5 to 20 seconds. When the aging time is less than 5 seconds, control over crystallinity and crystal size may be insignificant, and if it is 20 seconds or more, the polyethylene fiber is relaxed and the physical properties may be reduced.

The high-strength polyethylene fiber that has undergone the aging step 300 may be wound through a variable guide roller 410 .

As described above, in the high-strength polyethylene fiber with improved cut resistance according to the present invention, the degree of crystallinity and crystal size are controlled through the spinning speed in the spinning step and the aging temperature in the aging step. It would be desirable to satisfy (1).

Equation (1) 210≤S+T≤290

However, S is an integer of the spinning speed (mpm) of the spinning step, and T is an integer of the aging temperature (℃) of the aging step.

If the S+T is less than 210 or exceeds 290, the crystallinity and crystal size may be lowered, thereby reducing the effect of improving the cutting resistance.

The high-strength polyethylene fiber with improved cut resistance according to the present invention, which is manufactured including the spinning step 100, the stretching step 200, and the aging step 300 as described above, has the spinning step, the drawing step, and the aging step successively. It may be carried out as a one-step process, or it may be manufactured as a two-step process in which a stretching step and an aging step are continuously performed after the spinning step of manufacturing an undrawn yarn.

The polyethylene fiber of the present invention prepared as described above is manufactured as a multifilament, and is manufactured into a tow by rewinding, and then manufactured as a short fiber by a cutting process to be manufactured as a spun yarn.

The short fibers made of the polyethylene fibers can be adjusted in fiber length depending on the purpose of the spun yarn, but it is generally preferable to prepare short fibers having a fiber length of 20 to 100 mm to prepare the spun yarn.

The high-strength polyethylene spun yarn can be manufactured by a general spun yarn manufacturing method, and it may be manufactured by honta, somen/refined, soft, roving, and spinning processes.

The high-strength polyethylene spun yarn is preferably formed in 10 to 50 numbers, and when the high-strength polyethylene spun yarn is manufactured to exceed 50 numbers, the spun yarn thickness becomes thinner and the knitted fabric is excellent in wearing comfort, but the slip of short fibers during the softening process during the spun yarn process Due to the severe occurrence, each monofineness may become non-uniform, and strength and cutting resistance may become non-uniform, and fairness due to slip may be reduced. In addition, when the number of spun yarns is less than 10, the strength may be improved, but as the thickness of the spun yarns increases, the wearer's wearing comfort may be lowered.

The high-strength polyethylene fiber of the present invention exhibits high strength of 12 g/d or more, and has a crystallinity and crystallization size capable of expressing cut resistance, so that the spun yarn made of the high-strength polyethylene fiber can express cut resistance.

When the high-strength polyethylene fiber was less than 12 g/d, it was confirmed that the cut resistance was similarly lowered in the spun yarn, and even when the crystallinity was less than 75%, the cut resistance was lowered. This is thought to be possible because the polyethylene fiber constituting the spun yarn exhibits high strength, and the crystallinity and crystal size are within the range for maximizing the cutting resistance.

In addition, the high-strength polyethylene fiber of the present invention has an elongation of 7% or more, which improves wearability when manufactured into various clothes, and improves processability when manufactured with spun yarn.

After the high-strength polyethylene fiber is manufactured, post-processing such as crimping may be performed on the polyethylene fiber to improve the physical properties and wearability of the spun yarn before cutting into short fibers.

The core yarn and high-strength polyethylene spun yarn as described above can be formed into high-strength composite yarn with improved cut resistance according to the present invention by forming high-strength polyethylene spun yarn on the outer periphery of the core yarn through a general covering process or twisting process, and through the MVS spinning machine It will be possible to manufacture a composite yarn by simultaneously applying high-strength polyethylene yarn and covering.

The high-strength composite yarn with improved cut resistance according to the present invention has cut resistance due to the cutting resistance of the polyethylene spun yarn and the core yarn, and the cut resistance is greatly improved through the core yarn, which is a hard fiber, and the core yarn is located in the center of the polyethylene composite yarn. When positioned, the cut resistance is the best, but the actual cross-section of the composite yarn may have a circular or oval shape as shown in FIG. 1, and the core yarn may be biased toward one side than the center of the composite yarn.

When the core yarn is biased to one side and is dropped to the outside of the polyethylene spun yarn and exposed to the outside, the cut resistance may be reduced, and the touch and wearability may be deteriorated due to the hardness of the core yarn.

Therefore, the high-strength composite yarn with improved cut resistance according to the present invention will preferably satisfy the following formula (2).

Equation (2) 0 ≤ X ∠ A/2

X: the distance between the center point of the composite yarn and the center point of the core yarn

The center point of the composite yarn: the center of the circle with the shortest length (A) of the composite yarn as the diameter (M)

The center point of the core yarn: the center of the circle with the shortest length (a) of the core yarn as the diameter (m)

When the X value is 0, the center point of the composite yarn and the center point of the core yarn coincide, and the core yarn is located at the center of the composite yarn, so the cut resistance is improved, and when the X value is greater than 0 and lower than A/2, the core yarn is polyethylene It is prevented from being exposed to the outside of the spun yarn, so the cut resistance is not greatly reduced.

When the X value exceeds A/2, the core yarn may be exposed or exposed to the outside of the polyethylene spun yarn, thereby reducing cut resistance and physical properties of the composite yarn.

The X value can be controlled by the number of twists of the core yarn and the spun yarn, and when the number of twists between the core yarn and the spun yarn is 150 TM to 300 TM, the X value increases and the core yarn may be located at the center of the composite yarn. If the twist is less than 150TM, the density of the polyethylene yarn to be coated is lowered, so there is a limit to coating the core yarn, and the X value is lowered, thereby lowering the cutting resistance. In addition, when the number of twists exceeds 300TM, the probability of glass fiber breakage increases due to high twisting of the polyethylene yarn to be coated, which may cause a possibility of moving away from the center and lowering of the cutting resistance.

The high-strength composite yarn with improved cut resistance according to the present invention manufactured as described above has excellent cut resistance and has a cut resistance index of 21 or more when manufactured as a woven fabric or knitted fabric (Cut Level) 5 or more and an article having a cut resistance of 10N or more can be manufactured.

The high strength composite yarn with improved cut resistance may also be used in a wide variety of other types of articles.

Non-limiting examples include, for example, insulating materials for refrigeration units (eg, refrigerators, freezers, vending machines, etc.); automotive parts (eg front or rear seats, headrests, armrests, donor panels, rear shelf/package tray, steering wheel and interior trim, dashboard, etc.); building panels and components (eg roofs, wall cavities, underfloors, etc.); clothing (eg coats, shirts, pants, gloves, aprons, work clothes, shoes, boots, hats, sock liners, etc.); furniture and bedding (eg sleeping bags, duvets, etc.); fluid storage/transfer systems (eg, pipes or tanks of liquid/gas hydrocarbons, liquid nitrogen, oxygen, hydrogen, or crude oil); extreme environments (eg, underwater or in space); food and beverage products (eg cups, cup holders, plates, etc.); containers and bottles; etc.

In addition, high strength polyethylene fibers may be used in "garment", which is meant to include any article that has a shape that is generally tailored to a part of the body. Examples of such articles include, but are not limited to, apparel (eg, shirts, pants, jeans, slacks, skirts, coats, activewear, athletic wear, aerobics, and gym clothes, swimwear, cycling jerseys or shorts, swimwear/bathing suits) suit), lace suits, sweat suits, body suits, etc.); footwear (eg, shoes, socks, boots, etc.); Protective clothing (e.g. firefighter coats), clothing accessories (e.g. belts, bra straps, side panels, gloves, socks, leggings, orthopedic braces, etc.), underwear (e.g. underwear, t-shirts, etc.), compression garments, and draping clothing (eg, kilt loincloth, toga, poncho, cape, shawl, etc.).

Hereinafter, a high-strength polyethylene spun yarn with improved cut resistance was prepared as an example according to the present invention. The present invention is not limited to these examples.

Example 1 to 7, comparative example 1 to 4

Polyethylene resin having a melt index of 1.0 g/10min, a molecular weight distribution index of 7.0, and a weight average molecular weight of 120,000 g/mol is put into an extruder to extrude the molten polymer, cooled using a cooling device, and then spun using a spinning emulsifier. An oil agent was attached, and the undrawn yarn to which the oil agent was attached was wound up.

The undrawn yarn was drawn to a total draw ratio (DR) of 8.5 by two-stage drawing at about 70 to 90° C., and the drawn polyethylene fiber was subjected to an aging step using the same apparatus as in FIG. 3 . After that, the high-strength polyethylene fiber with improved cut resistance according to the present invention was prepared by winding it using an entangled device and a winder.

After the high-strength polyethylene fiber prepared above was cut to produce short 38 mm fibers, the high-strength polyethylene spun yarn with improved cut resistance of the present invention was prepared through a general spun yarn manufacturing process.

Melt index, weight average molecular weight, molecular weight distribution index and spinning temperature of polyethylene fiber, spinning speed, aging temperature and number of polyethylene spun yarns of the polyethylene resin used in each Example and Comparative Example are as the conditions in Tables 3 and 4 below. and other radiation conditions were the same

Comparative Example 5

A high-strength composite yarn was prepared in the same manner as in Example 1 using a 400 denier multifilament yarn, UHMWPE fiber (Dainima, Toyobo Corporation).

◈ How to measure

In Examples 1 to 7 and Comparative Examples 1 to 5, the strength, elongation, and cut resistance index and level of the polyethylene fiber and the high strength composite yarn, cut resistance, and the like were measured.

The cut-resistance index and level, and the cut-resistance were measured after manufacturing a knitted fabric with the high-strength composite yarns of Examples 1 to 6 and Comparative Examples 1 to 5.

The cut resistance evaluation was evaluated by covering the high-strength composite yarn using span yarn 100D for screening, and knitting the prepared covering yarn using a 13Guage L size glove knitting machine to knit the knitted fabric.

Examples of the cutting resistance level and cutting force are shown in Table 3, and the cutting resistance level and cutting strength of the comparative examples are shown in Table 4.

* Characteristics of polyethylene raw material: The weight average molecular weight and molecular weight distribution were measured using high-temperature GPC, and measured using Tosoh's HLC-8331 model. The measurement solvent was TCB+0.4% BHT, and the column temperature was measured at 160°C. . The sample concentration was 3 mg/mol, and Polystyrene was used as the standard sample, but the molecular weight of polyethylene was corrected by Mark-Houwink Equation to ensure smooth data.

* Melt index measurement: Measured in accordance with ASTM D1238, the measured temperature was 190℃, and the weight was defined as 2.16kg. During the measurement, preheating was performed for 5 minutes and free running for 3 minutes, and the values measured 10 times were defined as the average value. did.

* Crystallinity/Crystal Size: The degree of crystallinity and crystal size were measured using BRUKER's D8 DISCOVER.

* Strength/elongation measurement method: In accordance with ASTM D2256 standard, fiber strength and elongation were measured using Instron's Universal Testing Machine (UTM) under a measurement temperature of 20°C and a humidity of 65%.

* X value: The distance between the center point of the composite yarn and the center point of the core yarn. As shown in FIG. 4, the center (M) of the circle with the shortest axis (A) of the composite yarn as the diameter is the center point of the composite yarn, and the shortest axis (a) of the core yarn. After setting the center point of the core yarn with the center (m) of the circle having a diameter of , the distance between the center point of the composite yarn and the center point of the core yarn was measured, and 50 X values were measured and averaged.

* Cut-resistance index and level: Mesdan's glove cut tester, a device manufactured according to EN388 standard, was used for the cut-resistance evaluation method of knitted fabrics. The measurement was performed by attaching an aluminum foil wrapped with filter paper on a rubber support, placing the control sample and the test sample, measuring the control sample and the test sample before the test, measuring 5 times, and evaluated as follows to calculate the index.

<Cut resistance index>

Sequence C
control specimen T
test specimen C
control specimen I
Index One C ₁ T ₁ C _{2 i1} 2 C ₂ T ₂ C _{3 i2} 3 C ₃ T ₃ C _{4 i3} 4 C ₄ T ₄ C _{5 i4} 5 C ₅ T ₅ C _{6 i5}

[Cut resistance index (I) formula]

<Cut resistance level>

cut resistance index >1.2 >2.5 >5 >10 >20 Cut resistance level One 2 3 4 5

* Cutting resistance (N): The STM610 model manufactured by Satara, a device manufactured in accordance with ISO13997 standard, was used for the evaluation method of the cutting resistance of fabrics or knitted fabrics. Cutting is measured by the cutting resistance required to cut the material with a blade quality of 20 mm when the range of force is applied to the blade perpendicular to the sample surface. The measurement sequence is that a constant force is gradually applied between the sample and the blade, cutting within 5 seconds. and repeat the test with different forces until at least 15 records are obtained with cut lengths between 5 mm and 50 mm.

The cutting resistance is obtained in the range of 5mm to 15mm, 15mm to 30mm, and 30mm to 50mm, and the value obtained by multiplying the correction factor C by the cutting length is graphed to measure the strength when the cutting length is 20mm as the cutting resistance.

<Cutting resistance correction factor>

C = K/l

C is correction factor, l is 5.0N neoprene cutting operation length mm, K=20

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 melt index
(g/10min) 1.0 1.0 1.0 1.0 1.0 1.0 1.0 weight average
Molecular Weight (g/mol) 120,000 120,000 120,000 120,000 120,000 120,000 120,000 Molecular Weight Distribution Index 7.0 7.0 7.0 7.0 7.0 7.0 7.0 radiation temperature
(℃) 290 290 290 290 290 290 290 radial speed
(mpm) 160 160 160 160 160 160 160 aging temperature
(℃) 90 110 130 130 130 130 130 Crystallinity (%) 83.1 82.9 82.2 82.2 82.2 82.2 82.2 crystal size
(Å) 12.4 12.6 11.5 11.5 11.5 11.5 11.5 PE fiber strength
(g/d) 15.4 15.1 15 15 15 15 15 PE fiber elongation (%) 8.4 8.1 8 8 8 8 8 core yarn fiberglass fiberglass fiberglass fiberglass fiberglass stainless fiber tungsten
fiber composite yarn
Shortest axis (㎛) 72 72 68 86 68 68 68 X (μm) 20 18 20 14 18 12 12 yarn count 30 30 30 30 30 30 30 Cut Index 28.2 24.4 22.4 36.4 21.9 36.1 37 Cut Level 5 5 5 5 5 5 5 Cutting force (N) 10.6 10.4 10.4 11.2 10.2 15.6 15.4

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 melt index
(g/10min) 1.0 1.0 1.0 1.0 - weight average
Molecular Weight (g/mol) 120,000 120,000 120,000 120,000 - Molecular Weight Distribution Index 7.0 7.0 7.0 7.0 - radiation temperature
(℃) 290 290 290 290 - radial speed
(mpm) 160 160 120 160 - aging temperature
(℃) 130 130 40 135 - Crystallinity (%) 82.2 82.2 68.9 73.2 - crystal size
(Å) 11.5 11.5 8.3 9.2 - PE fiber strength
(g/d) 15 15 15.2 14.2 31.2 PE fiber elongation (%) 8 8 7.6 8.8 3.1 core yarn fiberglass fiberglass fiberglass fiberglass fiberglass composite yarn
Shortest axis (㎛) 68 86 86 90 72 X (μm) 36 46 46 50 20 yarn count 30 30 30 30 15 Cut Index 17.1 15.4 14 11.8 16.5 Cut Level 4 4 4 4 4 Cutting force (N) 8.5 8.5 4.5 8 9.1

As shown in Tables 3 and 4, in Examples 1 to 7 and Comparative Examples 1 to 4, polyethylene resins having a melt index of 1.0 g/10min, a molecular weight distribution index of 7.0, and a weight average molecular weight of 120,000 g/mol were used, Although spinning at a spinning temperature of 290°C, high-strength polyethylene fibers were prepared by varying the spinning speed and aging temperature.

All of the polyethylene fibers of Examples 1 to 7 and Comparative Examples 1 to 4 had an elongation of 7% or more, and Examples 1 to 5 had an elongation of 8% or more, which was more than twice as high as the UHMWPE fiber of Comparative Example 5. It will be more wearable than garments made from UHMWPE fibers.

The polyethylene fibers of Examples 1 to 7 were manufactured at a spinning speed of 160 mpm, an aging temperature of 90 to 130° C., and all had a crystallinity of 75% or more, a crystal size of 10 Å or more, and a strength of 12 g/d or more.

In addition, Examples 1 to 7 are high-strength composite yarns using hard fibers, and the distance (X value) between the center point of the composite yarn and the center point of the core yarn is not large, so that the cut resistance index (Cut Index) is 21 or more, the cut resistance level (Cut) Level) 5 and it can be seen that the cutting resistance is more than 10N.

The polyethylene fibers of Comparative Examples 1 to 4 had a spinning speed of 160 mpm, but the aging temperature was less than 90° C. or was carried out at a temperature exceeding 130° C., the crystallinity was less than 75%, and the crystal size was less than 10 Å. Also, it can be seen that there is a large difference in crystallinity and crystal size according to the aging temperature.

In addition, it can be seen that the composite yarns of Comparative Examples 1 and 2 used hard fibers for the core yarn, but the distance (X value) between the center point of the composite yarn and the center point of the core yarn was too far to lower the cut resistance, and Comparative Example 3 , 4 is the low crystallinity and crystal size of the polyethylene fiber, and the cut resistance of the polyethylene spun yarn is low, which is insufficient to express the cutting resistance of the composite yarn, and the composite yarn of Comparative Examples 1 to 4 has a cut resistance index (Cut Index) of 21 It can be seen that less than the cut resistance level (Cut Level) 4 and the cutting force is less than 10N, which has lower physical properties than Examples 1 to 7.

In addition, Comparative Example 5 is a high-strength composite yarn using UHMWPE fibers, and UHMWPE fibers are polyethylene fibers having a weight average molecular weight of 1 million or more and have high strength, but have high strength, but have low elongation and cut resistance of 10N or less. Wearability will not be excellent.

Claims (12)

In the high-strength composite yarn with improved cut resistance in which hard fibers form the core yarn and the high-strength spun yarn is formed on the outer periphery of the core yarn,
The high-strength spun yarn is formed of a polyethylene resin and includes a polyethylene fiber whose main repeating unit is ethylene,
The polyethylene fiber has a melt index of 0.6 to 2 g/10 min, and is formed of a polyethylene resin having a molecular weight distribution index of 5 to 10, and the polyethylene fiber has a crystallinity of 75% or more and a crystal size of 10 Å or more,
The high-strength composite yarn is a high-strength composite yarn with improved cut resistance, characterized in that it satisfies the following formula (2).
Equation (2) 0 ≤ X ∠ A/2
X: the distance between the center point of the composite yarn and the center point of the core yarn
The center point of the composite yarn: the center of the circle with the shortest length (A) of the composite yarn as the diameter (M)
The center point of the core yarn: the center of the circle with the shortest length (a) of the core yarn as the diameter (m) According to claim 1,
High-strength composite yarn with improved cut resistance, characterized in that the strength of the polyethylene fiber is 12 to 16 g/d. According to claim 1,
The polyethylene fiber,
A spinning step of melt-spinning a polyethylene resin having a melt index of 0.6 to 2 g/10min and a molecular weight distribution index of 5 to 10 at 230 to 290°C to form undrawn yarn;
a stretching step of stretching the undrawn yarn; and;
A high-strength composite yarn with improved cut resistance, characterized in that it is manufactured including an aging step of aging the drawn polyethylene fibers at 90 to 130°C. 4. The method of claim 3,
High-strength composite yarn with improved cut resistance, characterized in that the spinning speed is 120 to 160 mpm in the spinning step. 4. The method of claim 3,
The aging step is a high-strength composite yarn with improved cut resistance, characterized in that aging for 5 to 20 seconds. 4. The method of claim 3,
The manufacturing method is a high-strength composite yarn with improved cut resistance, characterized in that it satisfies the following formula (1).
Equation (1) 210≤S+T≤290
However, S is an integer of the spinning speed (mpm) of the spinning step, and T is an integer of the aging temperature (℃) of the aging step. According to claim 1,
The polyethylene fiber is a high-strength composite yarn with improved cut resistance, characterized in that the fiber length is 20 to 100 mm. According to claim 1,
The high-strength spun yarn is a high-strength composite yarn with improved cut resistance, characterized in that the number of counts is 10 to 50. According to claim 1,
The hard fiber is a high-strength composite yarn with improved cut resistance, characterized in that the mineral fiber or metal fiber. An article comprising the high-strength composite yarn of any one of claims 1 to 9. 11. The method of claim 10,
The article is an article, characterized in that the level (Level) according to the cut resistance standard is 5 or more. 11. The method of claim 10,
The article is an article, characterized in that the cutting force is 10.0N or more.

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