KR101353700B1 - Hybrid fiber and Method for manufacturing the same - Google Patents

Abstract

Disclosed are a mixed fiber and a method for producing the same, which have excellent mechanical properties while being manufactured at a relatively low cost. Mixed fibers of the present invention, the first filament; And a second filament different from the first filament, wherein the strength-elongation curve of the mixed fiber measured by the provisions of ASTM D 885 has at least one peak, wherein the strength-elongation curve is defined by two or more peaks. If present, the elongation difference between the first peak with the lowest elongation and the second peak with the highest elongation of the two or more peaks is 3% or less.

Description

Hybrid fiber and method for manufacturing the same

The present invention relates to a mixed fiber and a method for producing the same, and more particularly, to a mixed fiber and a method for producing the same having excellent mechanical properties while being manufactured at a relatively low cost.

When producing a product using fibers, it is less costly to produce the product using mixed fibers produced by mixing the expensive filaments with relatively inexpensive filaments rather than the expensive high performance fibers alone. It may be advantageous from the side.

However, if different filaments having different properties are mixed by conventional methods for the production of mixed fibers, the properties of the individual filaments are exerted individually so that no synergistic effect is exerted. For example, when an external force is applied to a mixed fiber of dissimilar filaments of different elongation, all the filaments do not resist the external force together, and the relatively low elongation filaments are first cut and then cut to a relatively high elongation. The filament is cut resistant.

As a result, such mixed fibers may be advantageous in terms of manufacturing cost, but have a problem in that they do not have physical properties that meet expectations.

Accordingly, the present invention relates to a mixed fiber and a method for producing the same, which can prevent problems caused by the above limitations and disadvantages of the related art.

One aspect of the present invention is to provide a mixed fiber having excellent mechanical properties while being manufactured at a relatively low cost.

Another aspect of the present invention is to provide methods for producing mixed fibers having excellent mechanical properties while being manufactured at a relatively low cost.

Further aspects of the invention will be described below, and in part will be apparent from such description. Alternatively, other aspects of the present invention may be learned through practice of the present invention. The objects of the present invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

In one aspect of the invention, a mixed fiber, the first filament; And a second filament different from the first filament, wherein the strength-elongation curve of the mixed fiber measured by the provisions of ASTM D 885 has at least one peak, wherein the strength-elongation curve is defined by two or more peaks. Wherein, the difference in elongation between the first peak with the lowest elongation and the second peak with the highest elongation of the two or more peaks is 3% or less.

In another aspect of the invention, preparing a first filament; Preparing a second filament having an elongation higher than that of the first filament; Applying tension to the second filament so that an elongation difference between the first and second filaments is 3% or less; And putting the first and second filaments together with an elongation difference of 3% or less.

In another aspect of the invention, preparing a first filament; Preparing a second filament having an elongation higher than that of the first filament; And weaving the first and second filaments, wherein the length of the first filament being spliced is longer than the length of the second filament being spun.

In another aspect of the invention, preparing a first filament; Preparing a second filament having an elongation higher than that of the first filament; Manufacturing a first lower twist yarn by rolling the first filament with a first twisted number; Manufacturing a second lower twist yarn by lowering the second filament with a second twist number smaller than the first twist number; And staging the first and second lower twist yarns.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the invention as claimed.

According to the present invention, a mixed fiber produced by mixing filaments having different properties may have new and improved properties that are completely different from the individual properties of the filaments.

Specifically, since the different types of filaments are mixed in a state of having a small elongation difference of 3% or less, the different types of filaments constituting the mixed fiber of the present invention may resist the external force applied to the mixed fiber together. As a result, the mixed fibers of the present invention can have improved tensile strength and elastic modulus.

In addition, according to the present invention, since a mixed fiber having excellent mechanical properties can be manufactured by using an inexpensive filament together with an expensive filament, a product manufactured by using the blended fiber itself as well as the price competitiveness For example, the price competitiveness of tire cords, hoses, belts, cables, body armor, ropes and composites can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
1 is a graph showing the strength-elongation curves of mixed fibers prepared by mixing nylon 66 filaments and aramid filaments in a conventional manner,
2 and 3 are graphs showing strength-elongation curves of mixed fibers produced by mixing nylon 66 filament and aramid filament according to embodiments of the present invention, respectively.

Hereinafter, the mixed fiber according to an embodiment of the present invention and a manufacturing method thereof will be described in detail.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Therefore, the present invention encompasses all changes and modifications that come within the scope of the invention as defined in the appended claims and equivalents thereof.

As used herein, the term 'mixed fiber' refers to a fiber made by fusing different kinds of filaments, and may be, for example, a fiber made by twisting nylon filaments and aramid filaments.

As used herein, 'lower lead' refers to twisting filaments, and 'lower twisted yarn' means a twisted product manufactured through the lower lead.

As used herein, "spinning yarn" refers to twisting two or more strands of the lower twisting yarn together, and "vertical twisting yarn" means a twisted product manufactured through the upper twisting yarn.

As used herein, 'twist number' means the number of twists per meter, and the unit is a twist per meter (TPM).

The mixed fibers of the present invention comprise different types of filaments. According to the present invention, the heterogeneous filaments are spun in a state of similar elongation. Therefore, the mixed fiber of the present invention has excellent tensile strength and elastic modulus.

The mixed fibers of the present invention may comprise aramid filaments and nylon66 filaments.

Aramid filaments are suitable for the production of tire cords because of their low shrinkage stress and good creep properties. In addition, since the elastic modulus of the aramid filament hardly changes even at high temperatures, there is an advantage that the risk of causing a flat spot phenomenon is significantly reduced when the tire cord is manufactured from the aramid filament.

However, since such aramid filaments are relatively expensive, they may be disadvantageous from an economic point of view when used as a general tire material.

Therefore, a method of preparing a mixed fiber by mixing nylon 66 filament having relatively good physical properties and a relatively low price with aramid filament and manufacturing a tire cord using the mixed fiber may be considered. However, there may be a problem that mixed fibers made using them because of the large difference in elongation between aramid filaments and nylon 66 filaments cannot have tensile strength and elastic modulus corresponding to expectations.

Specifically, if aramid filaments and nylon 66 filaments having a significant difference in elongation are simply mixed, the heterogeneous filaments cannot resist together against the external force applied to the mixed fiber, and the low elongation filaments first resist and then cut and then Elongated filaments are cut after resisting, and as a result, there may be a problem that the mechanical properties of the mixed fibers such as tensile strength and elastic modulus are inferior. In other words, one of the important reasons for the mechanical properties of the mixed fibers is less than expected, the heterogeneous filaments constituting the mixed fibers are individually resistant to external forces.

Based on the above problems and their causes, the present inventors have developed mixed fibers having mechanical properties that meet expectations and methods of manufacturing the same.

According to the present invention, since the filaments of the different types of filaments are similarly adjusted and then mixed, the filaments can resist together against the external force applied to the mixed fibers, resulting in a mixed fiber having excellent mechanical properties. Can be.

As a result, the mixed fiber of the present invention can be advantageously used in various fields because it can minimize the sacrifice of mechanical properties that were considered to be a disadvantage of the mixed fiber while maintaining the advantages of the mixed fiber of price competitiveness.

Various types of filaments may be used in producing the mixed fiber of the present invention. For example, the mixed fiber may be nylon filament, polyester filament, polyolefin filament, polyvinyl alcohol filament, acrylic filament, cellulose filament, urethane filament, all aromatic polyamide filament, all aromatic polyimide filament It may include, but is not limited to, fully aromatic polyester filament, xylon filament, carbon fiber, metal filament, ore filament, silicon filament, glass fiber and the like.

Hereinafter, with reference to the accompanying drawings will be described in more detail through an embodiment of the present invention.

1 depicts the strength-elongation curves of mixed fibers prepared by mixing nylon 66 and aramid filaments in a conventional manner.

As illustrated in FIG. 1, the strength-strength of a conventional mixed fiber obtained by simply using a tensile tester such as Instron (produced by simply combining a high-strength nylon 66 filament with a low-stretch aramid filament) ) Curve has two peaks. The first peak (a) located in the lower elongation region of the two peaks indicates the cleavage of the low elongation aramid filament, and the second peak (b) located in the high elongation region indicates the cleavage of the high elongation nylon 66 filament.

As can be seen from FIG. 1, in the case of the conventional mixed fiber, the distance between the peaks a and b, i.e., the elongation difference ΔS, is very large because the filaments are merged while maintaining their respective elongation. It becomes big. For example, a difference in elongation of 10% or more occurs in the case of a conventional mixed fiber composed of nylon 66 filament having 20% elongation and aramid filament having 4% elongation.

If the elongation difference is 3% or more, it can be considered that each filament separately resists synergistically against the external force applied to the mixed fiber, and the mechanical properties of such mixed fiber do not meet the expectations.

Figure 2 shows the strength-elongation curves of mixed fibers produced by mixing the filaments in a similarly controlled elongation of aramid filament and nylon 66 filament according to an embodiment of the present invention.

As shown in FIG. 2, it can be seen that the strength-elongation curve of the mixed fiber prepared by mixing the filaments with similar control of the elongation of different types of filaments has two peaks, but the elongation difference is not large. Can be. That is, the elongation difference which is the distance between the 1st peak (a) which is the cutting point of aramid filament and the 2nd peak (b) which is the cutting point of nylon 66 filament is 3% or less.

According to the present invention, since the filaments are mixed while the elongation difference between different types of filaments is made smaller than 3%, the filaments can resist together to some extent against the external force applied to the mixed fiber, and as a result The mixed fiber of the present invention has excellent mechanical properties.

FIG. 3 shows the strength-elongation curves of mixed fibers prepared by mixing the filaments after adjusting the elongation of the aramid filament and the nylon 66 filament to about the same.

As illustrated in FIG. 3, in the case of the mixed fiber produced by mixing the filaments under optimal conditions without the difference in elongation between the heterogeneous filaments constituting the mixed fiber, the filaments constituting the mixed fiber are together with respect to the external force. Resist and cut at the same time. Thus, the strength-elongation curve of such mixed fibers will have only one peak. The fact that an intensity-elongation curve with only one peak is obtained when measuring the elongation of the mixed fiber means that the mixed fiber most efficiently resists external forces and has maximum mechanical properties.

In summary, the strength-elongation curve of the inventive mixed fiber obtained by the provisions of ASTM D 885 has at least one peak, and if the strength-elongation curve has two or more peaks, then the lowest of the two or more peaks The difference in elongation between the first peak with elongation and the second peak with elongation is 3% or less.

Optionally, the strength-elongation curves of the mixed fibers of the present invention may have only one peak. Such mixed fibers can have better mechanical properties because their strength-elongation curves can more effectively resist external forces than mixed fibers having two or more peaks.

Optionally, the strength-elongation curve of the mixed fiber of the present invention has two or more peaks, and the difference in elongation between the first peak with the lowest elongation and the second peak with the highest elongation of the two or more peaks is 3 % Or less, and the first peak may have a greater intensity than the second peak. That is, among the filaments constituting the mixed fiber, a filament having a relatively high strength has a lower elongation than a filament having a relatively low strength. It may be advantageous for the filaments with high strength to have lower elongation than the filaments with low strength because the filaments with high strength can resist external forces more effectively than the filaments with low strength.

The mixed fiber of the present invention comprises different first and second filaments. As described above, the mixed fiber according to one embodiment of the present invention includes aramid filament as the first filament and nylon 66 filament as the second filament. Since aramid filaments have a low shrinkage stress and the modulus of elasticity of the aramid filaments hardly changes even at high temperatures, it may be advantageous to manufacture tire cords from aramid filaments in that the occurrence of flat spot phenomenon can be minimized. However, such aramid filaments may be disadvantageous from an economic point of view because they are relatively expensive.

Accordingly, according to one embodiment of the present invention, nylon 66 filaments having relatively good physical properties and relatively inexpensive prices are mixed with aramid filaments to produce mixed fibers, and the tire fibers, hoses, belts, cables, and body armor using the mixed fibers are used. A variety of products can be manufactured, including ropes and gloves.

According to one embodiment of the invention, the content of aramid filaments in the mixed fibers is 10 to 90% by weight. When the content of the aramid filament is less than 10% by weight, the mixed fibers may not have mechanical properties that meet expectations, and thus may not be applicable to various fields. On the other hand, if the content of the aramid filament exceeds 90% by weight can not take advantage of the unique advantages of the mixed fiber, such as manufacturing cost reduction.

The mixed fibers of the present invention may be twisted yarns. The blended fibers in the form of twisted yarns have improved tensile strength because the focusing force between the filaments constituting the blended fibers is improved.

According to an embodiment of the present invention, the first and second filaments constituting the mixed fiber are first and second primary twisted yarns, respectively, and the mixed fiber is the upper edge of the first and second lower twist yarns. Ply yarn obtained through secondary twisting. For example, in the case of a mixed fiber including aramid filament and nylon 66 filament, each of the aramid filament and nylon 55 filament may be lower twisted yarns twisted in the Z direction, and the mixed fiber may lead the lower twisted yarns in the S direction. It may be a twisted yarn manufactured by.

Such a twisted yarn-shaped mixed fiber not only has excellent mechanical properties because the heterogeneous filaments constituting it are strongly concentrated, but also has good adhesion to other materials such as resins due to its large specific surface area. Therefore, the mixed fibers of the present invention having these advantages can be used for various purposes such as the manufacture of tire cords.

Optionally, the first and second lower twist yarns may have different twist numbers. For example, the first lower twist yarn prepared by lowering the aramid filament may have a twist number of 600 TPM and the second lower twist yarn manufactured by lowering the nylon 66 filament may have a twist number of 200 TPM. That is, by stretching the different types of filaments by varying the number of twists according to the elongation of the filament, the elongation of the first and second lower twist yarns can be artificially similar, and thus the first and second elongation differences are reduced. The mixed fiber produced by staging together the second lower twisted yarns has excellent mechanical properties.

Optionally, the mixed fibers of the present invention may further comprise a resorcinol-formaldehyde-latex (RFL) adhesive. Mixed fibers further comprising such adhesives can be used as reinforcements for a variety of rubber products because they have excellent adhesion to rubber.

The mixed fiber of the present invention can be used to manufacture a variety of products such as tire cords, hoses, belts, cables, body armor, ropes, composites, bulletproof gloves, etc., depending on the purpose of the phenol resin, urethane resin, polyvinyl butyral resin Or ethylene vinyl acetate resin may be further optionally included.

Next, the manufacturing method of the mixed fiber which concerns on the 1st Example of this invention is demonstrated.

In the method of manufacturing a mixed fiber according to the first embodiment of the present invention, preparing a first filament, preparing a second filament having an elongation higher than the elongation of the first filament, the first and second filaments And applying tension to the second filament so that the difference in elongation of these materials is 3% or less, and putting together the first and second filaments having an elongation difference of 3% or less.

Specifically, the first and second filaments are wound on each creel and the first and second filaments are unwound.

Subsequently, tension is applied to the second filament so that the elongation difference between the first and second filaments is 3% or less. In this case, the first filament may be applied with a tension that is considerably smaller than the tension applied to the first filament, that is, the minimum tension to allow the operation.

For example, the first filament may be an aramid filament having an elongation of 4%, and the second filament may be a nylon 66 filament having an elongation of 20%. In order to make the elongation of the aramid filament and the nylon 66 filament the same or similar, a tension of 16% of the nylon 66 filament is applied to the nylon 66 filament, and the aramid filament has a minimum enough to enable operation. Only tension can be applied.

After the tensioned second filament is filamented with the first filament, the filamented first and second filaments may be lowered in the Z direction to manufacture lower twisted yarn. Then, the mixed fibers of the present invention can be completed by staging together two lower twisted yarns produced in this manner in the S direction. The step of fusing the first and second filaments may be performed using a guide roller, may be performed using an air entanglement nozzle, or may be performed using an adhesive, but is not limited thereto. Since the fineness of the mixed fibers required according to the use is different, the number of the lower twist yarns may be adjusted in consideration of this.

Optionally, before weaving the tensioned second filament with the first filament, the first and second filaments are respectively wound in the Z direction to produce lower twist yarns, and the yarn twisting process is performed by staging the lower twist yarns together in the S direction. It can also be done.

Next, the manufacturing method of the mixed fiber which concerns on 2nd Example of this invention is demonstrated.

In the method of manufacturing a mixed fiber according to a second embodiment of the present invention, preparing a first filament, preparing a second filament having an elongation higher than the elongation of the first filament, and the first and second Plying the filaments.

According to the second embodiment of the present invention, when the first and second filaments are spun together, the length of the first filament to be spliced is longer than the length of the second filament to be spun Feed more than the second filament.

For example, the first filament may be an aramid filament having an elongation of 4%, the second filament may be a nylon 66 filament having an elongation of 20%, and the length of the aramid filament being spun with the nylon 66 filament The aramid filament can be over fed to 15% longer than the length.

Optionally, prior to weaving the first and second filaments, the method may further include applying tension to the second filament. That is, in the above example, applying the tension of the nylon 66 filament 5% stretch to the nylon 66 filament, the length of the aramid filament to be braided 10% longer than the length of the tensioned nylon 66 filament Filament can be oversupply.

The lower filament yarn may be manufactured by incorporating a first filament having a longer length with the second filament and then lowering the spliced first and second filaments in the Z direction. Subsequently, the mixed fibers of the present invention can be completed by staging together a plurality of lower twist yarns produced in this manner in the S direction. Since the fineness of the mixed fibers required according to the use is different, the number of the lower twist yarns may be adjusted in consideration of this.

Optionally, prior to weaving the first filament having a longer length with the second filament, the first and second filaments are respectively lowered in the Z direction to produce lower twisted yarns, and the lower twisted yarns are wound together in the S direction, thereby A plunge process can also be performed.

Next, the manufacturing method of the mixed fiber which concerns on 3rd Example of this invention is demonstrated.

In the manufacturing method of the mixed fiber according to the third embodiment of the present invention, preparing a first filament, preparing a second filament having an elongation higher than the elongation of the first filament, the first filament Twisting with twisted number to produce a first twisted yarn, twisting the second filament with a second twisted number less than the first twisted number to produce a second twisted twisted yarn, and the first and second twisted twists Comprising the stages.

For example, the first filament may be an aramid filament having an elongation of 4%, the second filament may be a nylon 66 filament having an elongation of 20%, and the first lower twist yarn manufactured by lowering the aramid filament is 600 TPM The second twist yarn prepared by twisting nylon 66 filament with a twist number of may have a twist count of 200 TPM.

According to the third embodiment of the present invention, the elongation of the first and second lower twist yarns can be artificially similar by lowering the different types of filaments by varying the number of twists according to the elongation of the filaments, thus reducing The mixed fiber produced by staging together the first and second lower twisted yarns having different elongation has excellent mechanical properties.

Optionally, when manufacturing the second lower twisted yarn, the second filament may be lowered while applying tension to the second filament. In other words, in the above example, the aramid filament is unstretched in the unstretched state, while the nylon 66 filament can be stretched in the 15% stretched state.

The method for producing a mixed fiber of the present invention may further include the following process.

Resorcinol-formaldehyde-latex (RFL) adhesives can be imparted to the first and second filaments pulverized by the method of any one of the first to third embodiments of the invention described above.

The process of imparting the RFL adhesive may be performed by various methods. For example, the adhesive may be imparted to the spliced first and second filaments through a dipping process in which the spliced first and second filaments are immersed in a resorcinol-formaldehyde-latex (RFL) adhesive solution. have. At this time, one-bath dipping or two-bath dipping may be used. The RFL adhesive solution was 2.0 wt% resorcinol, 3.2 wt% formalin (37%), 1.1 wt% sodium hydroxide (10%), 43.9 wt% styrene / butadiene / vinylpyridine (15/70/15 ) Rubber (41%), and water.

After the adhesive is applied to the spliced first and second filaments, a heat treatment process may be performed. For the heat treatment, a first heat treatment process performed for 10 to 400 seconds at 105 to 200 ° C. and a second heat treatment process for 10 to 400 seconds at 105 to 300 ° C. may be performed sequentially.

The mixed fiber of the present invention prepared as described above can be used in various fields such as tire cords, hoses, belts, cables, body armor, ropes, composites, bulletproof gloves and the like.

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples. It should be noted, however, that the following examples are intended to assist the understanding of the present invention and should not limit the scope of the present invention thereby.

Example 1

Nylon 66 filament with 9 g / d tensile strength, 20% elongation and 1,000 denier fineness and para-aromatic polyamide filament with 23 g / d tensile strength, 4% elongation and 1,000 denier fineness Was incorporated. In this case, the nylon 66 filament was spun with para-aromatic polyamide filament in a 16% stretched state. The para-aromatic polyamide filaments were spun with the nylon 66 filaments in the unstretched state.

Subsequently, lower twist yarns were prepared by twisting the filaments with a twist of 285 TPM in the Z direction using a Ring type twister manufactured by Alma Co., Ltd.

Then, the mixed fibers were prepared by twisting the two strands of the twisted yarn with a twist of 300 TPM in the S direction. The content of para-aromatic polyamide filaments in the mixed fiber was 50%.

Examples 2 and 3

In Example 1 described above, mixed fibers were prepared in the same manner as in Example 1 except that the nylon 66 filaments were spliced with para-aromatic polyamide filaments in the state of being stretched at 15% and 17%, respectively.

Example 4

Nylon 66 filament with 9 g / d tensile strength, 20% elongation and 1,000 denier fineness and para-aromatic polyamide filament with 23 g / d tensile strength, 4% elongation and 1,000 denier fineness Was incorporated. At this time, the para-aromatic polyamide filament was oversupplyed such that the length of the para-aromatic polyamide filament to be spliced was 15% longer than that of the nylon 66 filament to be spun.

Subsequently, lower twist yarns were prepared by twisting the filaments with a twist of 285 TPM in the Z direction using a Ring type twister manufactured by Alma Co., Ltd.

Then, the mixed fibers were prepared by twisting the two strands of the twisted yarn with a twist of 300 TPM in the S direction.

Example 5

After stretching 15% of nylon 66 filament having a tensile strength of 9 g / d, 20% elongation, and 2,000 denier fineness, the Almasa Ring type twister was used. Nylon 66 low-twist yarn was prepared by twisting the stretched nylon 66 filament with a twist of 200 TPM in the Z direction.

In addition, a para-aromatic polyamide filament having a tensile strength of 23 g / d, an elongation of 4%, and a fineness of 2,000 deniers was used in the Z direction using an Alma Co. Ring type twister. Para-aromatic polyamide low-twist yarn was prepared by twisting with a twist of 400 TPM.

Subsequently, the mixed fibers were prepared by twisting the nylon 66 lower twisted yarn and the para-aromatic polyamide lower twisted yarn in the S direction with a twist of 300 TPM.

Examples 6 and 7

In Example 1 described above, the fineness of the nylon 66 filament and the para-aromatic polyamide filament was adjusted so that the content of the para-aromatic polyamide filament in the mixed fiber was 10 and 90% by weight, respectively. Mixed fibers were prepared in the same manner as in Example 1.

Comparative Example 1

In Example 1 described above, mixed fibers were prepared in the same manner as in Example 1 except that the nylon 66 filament was spun with para-aromatic polyamide filament in an unstretched state.

Comparative Example 2

In Example 1 described above, mixed fibers were prepared in the same manner as in Example 1 except that the nylon 66 filament was spliced with the para-aromatic polyamide filament in a 2% stretched state.

Tensile strength, elongation, and elongation difference of the mixed fibers obtained by the above examples and comparative examples were obtained by the following methods, respectively, and the results are shown in Table 1 below.

Tensile Strength (g / d) and Elongation (%) of Mixed Fibers

According to the ASTM D 885 test method, a 300 m / min tensile rate was applied for a sample length of 250 mm at 25 ° C. and 65% relative humidity using an Instron Engineering Corp. (Canton, Mass). By doing this, the tensile strength and elongation of the mixed fibers were measured.

Elongation Difference (△ S)

Using the elongation at the first peak (a ') and the elongation at the second peak (b') in the strength-elongation curve of the mixed fiber obtained when measuring the tensile strength and elongation of the mixed fiber according to the above-mentioned method The elongation difference (ΔS) of the mixed fibers was measured.

division Tensile strength (g / d) Shinto (%) Elongation Difference (△ S) Example 1 16.4 3.8 1.8 Example 2 16.0 4.1 1.9 Example 3 16.5 3.5 1.8 Example 4 15.1 3.6 2.2 Example 5 15.4 4.2 2.3 Example 6 20.2 3.4 0.5 Example 7 15.5 5.3 2.4 Comparative Example 1 11.5 15.4 12.8 Comparative Example 2 9.3 13.4 10.2

a: first peak a ′: elongation at first peak
b: second peak b ': elongation at second peak

Claims (20)

In the mixed fiber,
First filament; And
A second filament different from the first filament,
The strength-elongation curve of the mixed fiber measured by the provisions of ASTM D 885 has at least one peak,
If the intensity-elongation curve has two or more peaks, the difference in elongation between the first peak with the lowest elongation and the second peak with the highest elongation of the two or more peaks is 3% or less . The method of claim 1,
Said strength-elongation curve having one peak. The method of claim 1,
The intensity-elongation curve has two or more peaks,
Wherein said first peak has a greater strength than said second peak. The method of claim 1,
The first filament is an aramid filament,
The second filament is nylon 66 filament,
The mixed fiber, characterized in that the content of the aramid filament in the mixed fiber is 10 to 90% by weight. The method of claim 1,
Mixed fibers, characterized in that the twisted yarn (twisted yarn). The method of claim 1,
The first filament is a first twisted yarn,
The second filament is a second lower twist yarn,
Wherein said mixed fiber is a ply yarn obtained through secondary twisting of said first and second lower twisted yarns. The method according to claim 6,
And the first and second lower twist yarns have different twist numbers. The method of claim 1,
A mixed fiber, further comprising resorcinol-formaldehyde-latex adhesive. Preparing a first filament;
Preparing a second filament having an elongation higher than that of the first filament;
Applying tension to the second filament so that an elongation difference between the first and second filaments is 3% or less; And
And putting together the first and second filaments having an elongation difference of 3% or less. 10. The method of claim 9,
Further comprising the step of applying tension to the first filament,
The tension applied to the first filament is smaller than the tension applied to the second filament. 10. The method of claim 9,
The first filament is an aramid filament,
The second filament is nylon 66 filament manufacturing method, characterized in that the filament. 10. The method of claim 9,
Before twisting the first and second filaments, primary twisting the first and second filaments, respectively, to produce lower twist yarns,
Said pulverization is a method of producing mixed fibers, characterized in that it is carried out by secondary twisting the lower twist yarns. 10. The method of claim 9,
Producing lower twisted yarns by lowering the spliced first and second filaments; And
The method of producing a mixed fiber, characterized in that further comprising the step of the lower twist yarns. Preparing a first filament;
Preparing a second filament having an elongation higher than that of the first filament; And
Including the step of summing the first and second filaments,
The length of the first filament to be spliced is longer than the length of the second filament to be spliced. 15. The method of claim 14,
The length of the first filament to be spliced is longer than the length of the second filament to be spliced. 15. The method of claim 14,
And before tensioning the first and second filaments, tensioning the second filament. 15. The method of claim 14,
Prior to plying the first and second filaments, further comprising producing the lower twist yarns by lowering the first and second filaments, respectively,
Said pulverization is performed by staging said lower twist yarns. 15. The method of claim 14,
Producing lower twisted yarns by lowering the spliced first and second filaments; And
The method of producing a mixed fiber, characterized in that further comprising the step of the lower twist yarns. Preparing a first filament;
Preparing a second filament having an elongation higher than that of the first filament;
Manufacturing a first lower twist yarn by rolling the first filament with a first twisted number;
Manufacturing a second lower twist yarn by lowering the second filament with a second twist number smaller than the first twist number; And
And staging the first and second lower twist yarns. 20. The method of claim 19,
The second filament is lowered while the tension is applied to the second filament to produce the second lower twisted yarn.

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