KR101272692B1 - Method for producing cord of different fibers - Google Patents

Abstract

The present invention relates to a method for producing heterogeneous fiber cords, and more particularly, to a method for easily producing heterogeneous fiber cords used for tire cords. According to the present invention, a heterogeneous fiber yarn preparation step of preparing a first yarn and a second yarn having a greater elastic modulus than the first yarn; A tension imparting and twisting step of twisting the first yarn and the second yarn while imparting different tensions to the first yarn and the second yarn, respectively, the tension imparted to the first yarn in the tensioning and twisting step; Is provided with a heterogeneous fiber cord, characterized in that greater than the tension imparted to the second yarn.

Description

Manufacturing method of different fiber cord {METHOD FOR PRODUCING CORD OF DIFFERENT FIBERS}

The present invention relates to a method for producing heterogeneous fiber cords, and more particularly, to a method for easily producing heterogeneous fiber cords used for tire cords.

In recent years, tire performance has been continuously improved according to the improvement of the road environment and the performance of the vehicle, and in particular, it is recognized that safety is more important as a tire quality factor as the weight of the vehicle increases and the limit speed increases. In line with the demand for increasing tire safety, tire safety standards are also changing, and the tire industry is actively researching methods for providing tire safety.

In general, polyethylene terephthalate is commonly used as a carcass ply material of pneumatic radial tires, and more specifically, pneumatic radial tires having a flat ratio of 0.65 to 0.85. Rayon is relatively used as a carcass ply reinforcement material for high-speed pneumatic radial tires.

Recently, polyethylene naphthalate is partially used in such a high-speed, low-flat ratio radial tire, but polyethylene naphthalate has high temperature properties and shape stability compared to polyethylene terephthalate, but is limited in its application due to its high price. U. S. Patent No. 6,613,78 proposes a heterogeneous fiber cord manufactured by twisting each of the wound yarns of polyethylene terephthalate and polyethylene naphthalate. Polyethylene naphthalate fibers have a significantly higher modulus than polyethylene terephthalate fibers. Due to the difference in physical properties, when one yarn of each wound yarn of polyethylene terephthalate and polyethylene naphthalate is twisted, it causes a nonuniformity of tension of the raw cord. Due to this problem, the strong utilization rate during the continuous shooting and dipping occurs. In order to solve this problem, in recent years, a method of manufacturing heterogeneous fiber cords by giving different softening to yarns of high modulus and yarns of low modulus through at least two stages of twisting is used. However, this method of giving different types of training to two different yarns requires a two-step twisting process, which makes the manufacturing process complicated.

An object of the present invention is to provide a manufacturing method that can easily produce a heterogeneous fiber cord with improved strength utilization of the cord.

In order to achieve the above object, according to an aspect of the present invention,

Hetero fiber yarn preparation step of preparing a first yarn and a second yarn having a greater elastic modulus than the first yarn; A tension imparting and twisting step of twisting the first yarn and the second yarn while imparting different tensions to the first yarn and the second yarn, respectively, the tension imparted to the first yarn in the tensioning and twisting step; Is provided with a heterogeneous fiber cord, characterized in that greater than the tension imparted to the second yarn.

The elastic modulus of the second yarn may be at least 1.5 times greater than the elastic modulus of the first yarn.

The first yarn and the second yarn are nylon, polyester (polyester), polyethylene naphthalate (PEN), liquid crystal polyester, carbon fiber, polyimide, polyketone, cellulose fiber, glass fiber, aramid , Polyvinyl alcohol (PVA), acrylic fiber, polyolefin (Polyolefin), polyethylene (PE) and polypropylene (PP) may be selected from the group consisting of, in particular, the first yarn is a nylon (Nylon) yarn, 2 Yarn may be Aramid yarn.

According to the present invention, all of the objects of the present invention described above can be achieved. Specifically, it is possible to easily produce a heterogeneous fiber cord having improved strength utilization despite the same number of years by applying the yarn with different tension to the two fibers. In addition, it is possible to manufacture a variety of different fiber cords depending on the size of the tension given and the type of the two yarns.

1 is a flow chart illustrating a method of manufacturing a heterogeneous fiber cord according to an embodiment of the present invention.
Figure 2 schematically shows the structure of a tire for a passenger car manufactured by using a heterogeneous fiber cord in a carcass layer or belt reinforcement layer according to an embodiment of the present invention.

Hereinafter, the configuration and operation of an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, a method of manufacturing heterogeneous fiber cords includes preparing a heterogeneous fiber yarn (S10), a tensioning and weaving step (S20), a weaving step (S30), and a dipping step (S40).

In the heterogeneous fiber yarn preparation step (S10), the first yarn and the second yarn having different elastic modulus are prepared. In this embodiment, it will be described that the first yarn is a nylon yarn having a low modulus of 70 to 130 g / d, and the second yarn is an aramid yarn having a high modulus of 400 to 700 g / d. However, the present invention does not limit the first yarn and the second yarn to this kind. In addition, in the present invention, since the difference in length occurs depending on the presence or absence of tension, it is advantageous to use a yarn in which the difference in the elastic modulus of the yarn is obvious, so that the elastic modulus of the second yarn having the high modulus has a low modulus of elasticity. It is preferable that the elastic modulus of the yarn is at least 1.5 times larger.

In the tensioning and twisting step (S20), the twisting process is performed in a state in which a tension greater than that of the second yarn is applied to the first yarn. In this embodiment, it will be described that the tension given to the first yarn having a low modulus is 5 to 10 times the tension given to the second yarn having a high modulus. The tension value imparted to the first yarn having the low modulus described in the following description means a multiple of the tension imparted to the second yarn having the high modulus. In the present embodiment, the number of softening in the twisting step of the tensioning and the twisting step (S20) is preferably 19 to 20 TPM. Raw cords are manufactured by the twisting process. The raw cord thus produced is different in length even though the two yarns, which are different fibers, are the same soft water, so that the same effect as that of the heterogeneous fiber cord having different soft water used in the related art can be expressed.

In the weaving step (S30), the manufactured raw cord (Raw Cord) is woven by a weaving machine (weaving machine).

In the dipping step (S40), the fabric obtained in the weaving step (S30) is immersed in the dipping solution and cured to produce a 'Dip Cord' for a tire cord having a resin layer attached to the raw cord surface. Dipping in the manufacturing process according to the present invention refers to the impregnation of a resin layer called Resorcinol-Formaline-Latex (RFL) on the surface of the fiber. The dipping process is carried out to remedy the disadvantages of the fibers for tire cords that are less adhesive with rubber.

In the present invention, the adhesive solution for the adhesion of the heterogeneous fiber cord and the rubber can be prepared using the following method. 45.6 parts by weight of 29.4 wt% resorcinol; 255.5 parts by weight of distilled water; 20 parts by weight of 37% formalin; And 3.8 parts by weight of 10 wt% sodium hydroxide were prepared and reacted with stirring at 25 ° C. for 5 hours. Next, 300 parts by weight of 40 wt% VP-latex, 129 parts by weight of distilled water, and 23.8 parts by weight of 28% ammonia water were added and aged at 25 ° C. for 20 hours to maintain a solid concentration of 19.05%. After the heterogeneous fiber cord is dried, an adhesive solution is applied. In order to adjust the adhesion amount of the adhesive liquid, a stretch of 0 to 3% is required, and preferably 1 to 2% of stretching can be made. If the elongation ratio is too high, the adhesion amount of the adhesive liquid can be controlled but the elongation is reduced and consequently the fatigue resistance is reduced. On the other hand, if the elongation rate is too low, for example, if the elongation rate is lowered to less than 0%, a problem arises in that the dipping liquid penetrates into the cord, making it impossible to control the DPU.

The adhesive amount is preferably 4 to 6% by weight of the fiber based on the solid content. After passing through the adhesive liquid, the hetero fiber deep cord is dried at 120 to 150 ℃. 180 seconds to 220 seconds is dried, it is advantageous to dry in a state in which the heterogeneous fiber deep cord is stretched by 1 to 2% in the drying process. When the elongation ratio is low, the core and the elongation of the cord are increased, indicating physical properties that are difficult to apply to the tire cord. On the other hand, if the elongation rate is over 3%, the neutrophil level is appropriate but the body length is too small, which may reduce fatigue resistance.

After drying, heat treatment is carried out in a temperature range of 130 to 240 ℃. Elongation rate during the heat treatment is maintained between -1 to 0%, the heat treatment time is appropriate 50 seconds to 90 seconds. When the heat treatment is less than 50 seconds, the reaction time of the adhesive solution is insufficient, resulting in a low adhesive strength, when the heat treatment for 90 seconds or more may increase the hardness of the adhesive solution may reduce the fatigue resistance of the cord.

Table 1 shows examples of heterogeneous fiber cords prepared according to the present invention and the properties thereof.

division Low elasticity
Yarn High elasticity
Yarn Properties Power (kg) Doubt (%) Strong utilization rate (%) Shrinkage (%) Example Yarn Type nylon Aramid 35.8 13.2 74.1 1.6 Grant tension 10 One Comparative Example 1 Yarn Type nylon Aramid 33.0 8.5 68.2 1.6 Grant tension One One Comparative Example 2 Yarn Type nylon Aramid 35.1 5.4 71.9 1.6 Grant tension One 10

The heterogeneous fiber deep cord manufactured through such a process is applied to a carcass ply and cap fly and used for the production of a tire for a passenger car.

Figure 2 illustrates a structure of a tire for a passenger car, wherein the heterogeneous fiber deep cord according to the present invention is applied to a carcass ply or cap fly.

Referring to FIG. 2, the bead regions 35 of the tire 31 become annular bead cores 36 that are each non-extensible. Beadcore 36 is preferably made from a single or single filament steel wire wound continuously. In a preferred embodiment, the high strength steel wire having a diameter of 0.95 mm to 1.00 mm forms a 4 × 4 structure, resulting in a 4 × 5 structure.

In the embodiment of the tire cord according to the present invention, the bead region 35 may have a bead filler 37, the bead filler 37 should have a hardness of a predetermined level or more, preferably Shore A hardness 40 It may have a hardness of more than.

According to the present invention, the tire 31 may be reinforced with the crown portion by the belt structure 38 and the cap fly 39. The belt structure 38 comprises a cutting belt ply 40 consisting of two cords 41, 42, the cord 41 of the belt ply 40 having an angle of about 20 ° with respect to the circumferential center surface of the tire. Can be oriented as: One cord 41 of the belt ply 40 may be arranged in a direction opposite to the circumferential center surface of the tire, as opposed to the direction of the cord 42 of the other belt ply 40. However, the belt structure 38 may comprise any number of plies and may preferably be arranged in the range of 16 to 24 °. The belt structure 38 serves to provide lateral rigidity to minimize the rise of the tread 43 from the road surface during operation of the tire 31. The cords 41 and 42 of the belt structure 38 can be made of steel cords, and have a 2 + 2 structure, but can be made of any structure. The cap ply 39 and the edge ply 44 are reinforced on the upper portion of the belt structure 38. The cap ply cord 45 of the cap ply 39 is made of nylon and aramid yarns produced according to the method of the present invention. Can be prepared using a heterogeneous fiber cord. One layer of cap ply 39 and one layer of edge ply 44 may be used, preferably one or two layers of cap plies and one or two layers of edge plies.

Reference numerals 32 and 34 not described in FIG. 2 denote carcass layer 32 and fly turn-up 34. Reference numeral 33 denotes a carcass layer reinforcing cord 33.

In the above embodiment, the two yarns used in the production of the heterogeneous fiber cords were described as nylon yarns and aramid yarns, but the present invention is not limited thereto. In another embodiment, the two yarns used in the production of the heterogeneous fiber cords are nylon, polyester, polyethylene naphthalate (PEN), liquid crystalline polyester, carbon fiber, polyimide, polyketone, cellulose Fiber, glass fiber, aramid, polyvinyl alcohol (PVA), acrylic fiber, polyolefin (Polyolefin), polyethylene (PE) and polypropylene (PP).

Although the present invention has been described with reference to the above embodiments, the present invention is not limited thereto. The above embodiments may be modified or changed without departing from the spirit and scope of the present invention, and those skilled in the art will recognize that such modifications and changes also belong to the present invention.

31: tire 32: carcass layer
33: code for reinforcing the carcass layer 34: fly turn-up
35: bead area 36: bead core
37: Bead Filler 38: Belt Structure
39: cap fly 40: belt fly
41, 42: belt code 43: tread
44: edge fly 45: cap fly code

Claims (4)

Hetero fiber yarn preparation step of preparing a first yarn and a second yarn having a greater elastic modulus than the first yarn;
A tension imparting and twisting step of twisting the first yarn and the second yarn while imparting different tensions to the first yarn and the second yarn, respectively,
The tension applied to the first yarn in the tensioning and twisting step is a different fiber cord manufacturing method, characterized in that greater than the tension given to the second yarn. The method according to claim 1,
The elastic modulus of the second yarn is at least 1.5 times the elastic modulus of the first yarn. The method according to claim 1,
The first yarn and the second yarn is nylon, polyester (polyester), carbon fiber, polyimide (Polyimide), polyketone (Polyketone), cellulose fiber, glass fiber, aramid, polyvinyl alcohol (PVA), acrylic fiber, Polyolefin (Polyolefin), polyethylene (PE) and polypropylene (PP) method for producing a different fiber cord, characterized in that selected from the group consisting of The method according to claim 1,
The first yarn is a nylon (Nylon) yarn, the second yarn is aramid (Aramid) yarn, characterized in that the method for producing a different fiber cord.

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