JPH076143B2 - Polyester rope - Google Patents

Description

TECHNICAL FIELD The present invention relates to a high-strength polyester rope.

(Prior art) Since polyester fibers, especially fibers made of polyethylene terephthalate, have excellent wear resistance, cold heat resistance, and fatigue resistance, they are used as fishing materials such as stretch nets, seine nets, stationary nets, and ship materials such as mooring ropes. Although it is widely used for ropes such as other packaging materials, it has a drawback that it is inferior in strength as compared with nylon fibers and other high strength fibers.

Therefore, an attempt to increase the strength of polyester rope
This is done by increasing the strength of the raw yarn itself and by reducing the decrease in strength due to twisting yarn (increasing the strength utilization ratio during twisting). Specifically, as the former method, there is a method of increasing the intrinsic viscosity of the spun yarn and increasing the draw ratio, and as the latter method, the friction coefficient between the single fibers is lowered by improving the finishing oil agent. There is a way.

(Problems to be Solved by the Invention) However, there has been a limit to the enhancement of strength by these methods. That is, when the strength of the raw yarn is increased by the former method, the elongation decreases when it is brought close to 10 g / de, the tenacity utilization factor of the raw yarn due to twisting decreases, and the yarn breakage during spinning However, when the latter method is used, if the friction coefficient between the single fibers is reduced, the yarn converging property is reduced and the winding during winding occurs. There is a problem that collapse occurs, and it is not possible to improve the strong utilization rate.

An object of the present invention is to solve the above problems of the prior art and provide a polyester rope having high strength.

(Means for Solving Problems) As a result of various studies on the method of increasing the tenacity utilization ratio of the raw yarn in the twisted state, the present inventors replaced the conventionally used solid yarn with a hollow fiber. As a result, they have unexpectedly found that the strength of the rope is improved, and have reached the present invention. That is, the present invention is composed of polyester having an intrinsic viscosity of 0.8 or more having ethylene terephthalate as a main repeating unit, a breaking strength of 7 g / d or more, a breaking elongation of 10% or more and a hollow ratio of 5 to 20%.
Is a polyester rope obtained by twisting and twisting the hollow fiber.

The present invention is characterized in that a polyester hollow fiber is used as the rope fiber. By using hollow fibers, the tenacity factor of the raw yarn in the heated state is improved, so that it is not necessary to use very high tenacity yarn such as solid yarn.

The hollowness of the hollow fiber needs to be in the range of 5 to 20%.
When it is less than 5%, the strain absorbing function of the hollow fiber during twisting tends to be difficult to be sufficiently exerted. On the other hand, if it exceeds 20%, the hollow portion may be deformed in the yarn winding process due to the small wall thickness, and since the stiffness is small, most of the hollow portion is not formed at the initial stage during twisting. They tend to be deformed, and the strong holding function during twisting does not work sufficiently.

Deformation of the hollow part during twisting decreases the strength utilization factor when the deformation is completed at the initial stage of twisting, so to increase the resistance of the hollow part to deformation, the intrinsic viscosity of polyester (25 ℃, measured with oil chlorophenol solution) must be 0.8 or more. As the intrinsic viscosity increases, the strength of the polyester yarn itself also increases.

Also, the cutting strength of the polyester yarn is 7g in order to increase the strength of the polyester rope, especially the initial strength of the raw yarn.
Must be at least / de. Furthermore, in order to suppress the decrease in the strength utilization factor of the raw yarn due to twisting, the breaking elongation is required to be 10% or more.

The polyester rope in the present invention is obtained by plying a hollow fiber made of polyester having ethylene terephthalate as a main repeating unit, and the polyester includes polyethylene terephthalate. Further, it may be a copolyester in which the third component is copolymerized in the range of 15 mol% or less.

(Function) When a hollow fiber is used as a rope, the strength utilization factor of the raw yarn in a twisted state is improved. Although the details of this mechanism are not clear, it is thought that it works as follows.

A twisted yarn in which the hollow fiber absorbs strain due to deformation during twisting due to its own deformation, reduces stress unevenness between single yarns, and more effectively reflects the strength of the original yarn in the twisted rope. It is considered to form an aggregate structure.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.

Examples 1 to 5 Polyethylene terephthalate chips having an intrinsic viscosity of 0.98 were melted in an extruder, the polymer temperature was 305 ° C., and the number of holes was 250.
Spinning was carried out from a spinneret having a round hollow hole. A heating cylinder of 30 cm was attached below the spinneret through a spin block and a heat insulating plate, and the ambient temperature was 330 ° C. The spun yarn is solidified by cooling air in the cooling cylinder directly below the heating cylinder, is given an oiling agent by an oiling roller, is then drawn at a spinning speed of 850 m / min, is once wound, and is drawn under the conditions shown in Table 1. Heat treatment was applied. The hollow ratio was adjusted by changing the slit width of the round hollow holes and changing the cooling air volume to obtain the hollow ratio shown in Table 1.

Table 1 shows the physical properties of the drawn yarn obtained as described above. Ten of these drawn yarns are combined, and a lower twist of 170 times / m is applied. Then, three of these lower twisted yarns are combined, a middle twist of 200 times / m is applied, and three middle-twisted yarns are combined. Twisted and twisted 72 times / m to make a rope. Table 1 shows the strength and utilization rate of this rope.

In Table 1, the temperature of the first stage stretching is the temperature of the heating roller, the temperatures of the second stage stretching and the heat treatment are the temperatures of the air in the heated air bath, and the strength and elongation are the breaking strength and the breaking elongation, respectively. Indicates. The strong utilization rate was calculated by the following formula.

Comparative Examples 1 to 2 Spinning, drawing heat treatment, and rope preparation were performed in the same manner as in Example 1, except that the spinning die was changed to an ordinary round hole in Example 1 to obtain a solid yarn. The physical properties of the drawn yarn, the strength of the rope, and the strength utilization ratio are shown in Table 1.

As is clear from the results in Table 1, in the case of the ropes using the polyester hollow fibers (Examples 1 to 5), the strength is higher than that of the conventional ropes made of solid yarns (Comparative Examples 1 and 2). When the utilization rate is improved and the original yarn strength is at the same level, the rope strength is higher than that of the solid yarn rope.

(Effect of the Invention) According to the present invention, a polyester having a high tenacity utilization rate as compared with a conventional rope made of polyester solid yarn and having a tenacity of 10% or more when the original yarn tenacity is at the same level. Rope can be provided.

Claims (1)

[Claims] 1. A hollow fiber comprising a polyester having ethylene terephthalate as a main repeating unit and an intrinsic viscosity of 0.8 or more, a breaking strength of 7 g / d or more, a breaking elongation of 10% or more and a hollow ratio of 5 to 20%. A polyester rope made by twisting and twisting.