JPS63249730A - Core yarn - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a core yarn (hereinafter also referred to as covered yarn) that is highly strong and durable and has functions necessary for the industrial material field.

<Conventional technology> Traditionally, industrial material applications have used spun yarn or filaments (long fibers) depending on the purpose (specific application), but recently In order to take advantage of the characteristics of each individual yarn, composite materials such as twisting two or three types of yarn have come to be used. For example, in the case of ropes, spun yarn is more advantageous than filament for the surface layer of ropes in order to have good handling properties and less slippage, while on the other hand, in order for the ropes themselves to be highly strong and durable, Because filament yarns are more advantageous than spun yarns, so-called wrapped-twist ropes in which filament yarns are arranged in the center and spun yarns are wound around the surface layer are widely used. Furthermore, in the case of seaweed nets, threads are used that are made by intertwisting fibers that allow seaweed to grow well and fibers that have good durability.

On the other hand, in the case of a base fabric coated with thermoplastic resin such as polyvinyl chloride resin or rubber (natural or synthetic rubber), spun yarn is used to prevent peeling between the coating resin and the base fabric, that is, to improve adhesion. For the purpose of improving durability and shape stability, filament yarn is also used, and both of these are twisted yarns, which are used for weaving.

However, these are simply twisted yarns with two types of functionality, and the function of the composite yarn is determined only by the mixing ratio of the two types of yarns. In particular, in the case of intertwisted yarns, each yarn is heated, so the fibers that make up each yarn cannot be easily moved (in other words, it is impossible for both fibers to mix together) even if heated. , it is simply two types of threads that are in close contact with each other. In addition, simply twisting two types of yarns, A and 3, will result in
It is impossible for A (or B) to cover 8 (or A) at a mixing volume ratio of 8 and 8.

In other words, the surface of the twisted yarn is covered with each component yarn at a ratio equivalent to the mixing volume ratio, and the advantages of using two types of yarn are halved.

In order to prevent this, it is known that one fiber is placed in the center of the yarn and the other fiber is placed in a sheath that covers the center, which is a so-called covered yarn. It has been put into practical use. However, in the actual covered yarns, both the core and sheath fibers are short fibers (average fiber length of about 38 to 518) that are used for clothing, and in rare cases the core fibers are synthetic fibers. Fiber long fiber (
Even if the fiber is a filament, the short fiber that is the sheath fiber has the above-mentioned average fiber length, so it can hardly be used in the field of industrial materials that require high strength. If such coated yarn is used as an industrial material, it is not strong enough, and the average fiber length of the sheath fiber, which is the coated fiber, is short, so it has extremely low abrasion resistance and is easy to move, with a slight frictional force ( The sheath fibers may peel off or move due to friction with guides, travelers, sow collets, reeds, flat needles, etc. when processing coated yarns such as twisting, weaving, knitting, etc., and friction that the product receives during use. The core fibers will be exposed and the characteristics of the covered yarn will be lost.

<Problems to be solved by the invention> Ropes, etc., made by wrapping synthetic fiber filament yarns with spun yarn for the purpose of high strength and high durability, have filaments, which are strong-retaining components, concentrated and unevenly distributed in the cross section. Since the cutting elongation of the spun yarn and the filament are not necessarily the same, for example, the filament portion is not cut, but the surface layer of the spun yarn is gradually cut, resulting in a rope that is not strong. In addition, when a rope is subjected to repeated bending stress, the filament yarns, which are high-strength components, are concentrated, so the filament yarns rub against each other, leading to accelerated fatigue and poor bending resistance, resulting in a rope with no durability.

In addition, in the case of conventional seaweed nets, yarns made of fibers in which seaweed grows well and yarns made of fibers with good water fatigue resistance that support the seaweed net are twisted in pairs at a certain mixing volume ratio. The probability that fibers that allow the seaweed to grow well per unit area will appear on the surface of the seaweed net is approximately determined by the mixing volume ratio. The yield of seaweed per unit area of a seaweed net is determined by the ratio of fibers on the surface of the seaweed net that allow the seaweed to grow well. The yield will be affected.

Therefore, in order to increase the yield of seaweed while keeping the size of the seaweed net constant, it is possible to increase the mixed volume ratio of fibers in which seaweed grows well, but this poses the problem of decreasing water fatigue resistance. I will do it.

Also, in the case of base fabrics coated with resin or rubber, spun yarns are mixed and twisted to improve adhesion to the resin or rubber, and filaments are mixed and twisted to make the base fabric strong and stable. The adhesion force per unit area of the base fabric is determined by the mixing volume ratio with the base fabric, and adhesion force and strength/form stability are not compatible.

<Means for resolving the gap between points> As mentioned above, many composite threads with different functionality are used in the field of industrial materials.
Generally speaking, if the function of one of the composite materials is utilized, the function of the other will deteriorate, and the current situation is that the functions of the plurality of composite materials are not necessarily fully demonstrated.

The present invention solves the above-mentioned problems and provides a composite yarn having particularly high strength, high durability, and shape stability. The periphery is covered with a group of fibers constituting a sheath, and the single fibers constituting the sheath are covered yarns that are not substantially twisted with other single fibers constituting the sheath, and the following conditions ■ ~ ■ ■ Sheath The average fiber length of the fiber and core fiber is γO#, respectively.
The covered yarn is characterized by satisfying the following conditions: (1) The coverage ratio is (volume of core fiber) + (volume of sheath fiber) or more.

With this invention, it has become possible to provide the fibers constituting the sheath layer of the covered yarn with high strength and high durability as described above, and the functions required in each industrial material field. . Moreover, since the sheath layer does not move easily, the core is large and does not protrude outside, or the fibers that make up the core do not rub against each other violently, so the above-mentioned disadvantages do not occur. .

Table 1 outlines the functions required of materials used in the industrial materials field.

Table 1: Industrial materials and their required functions Among the functions required in the field of industrial materials, high strength is required across all fields. In order to achieve high strength, a synthetic fiber filament may be used as the core fiber of the covered yarn. However, industrial materials do not only need to be strong, but considering that they also require durability such as bending fatigue resistance, water fatigue resistance, and abrasion resistance, filaments are used as core fibers. It is not necessarily desirable to do so. In other words, when a filament is used as a core component of a covered yarn, since the filament is a continuous fiber, there are no fluffy fibers like in a spun yarn.
Since the surface is extremely smooth, even if short fibers are coated on the surface as sheath fibers, the sheath fibers and core fibers intermingle with each other and there is little improvement in entanglement. Separation is likely to occur, resulting in so-called peeling of the coated fibers, resulting in a coated yarn with unsatisfactory durability.

Therefore, in order to make a coated yarn without peeling of the core fiber and sheath fiber, it is desirable that both the core fiber and the sheath fiber are short fibers, but it is not possible to simply make the covered yarn with short fibers. ,
The high tenacity, which is the first necessary function as an industrial material, will be reduced, so by using coated yarn as described above, the decrease in tenacity is prevented as much as possible, and the durability is improved as mentioned above. be.

The single fiber denier of the fiber used in the core is 0.
A single fiber denier of 2 to 10 deniers is preferable for manufacturing purposes, and a single fiber denier of 1 to 15 deniers for the sheath portion corresponds to a denier of 0.2 to 10 deniers for the core portion for manufacturing purposes. And it is preferable from a functional point of view. That is, the smaller the denier of the fibers in the core compared to the fibers in the sheath, the better the coverage, and the larger the denier of the fibers in the sheath, the better the abrasion resistance and weather resistance, making them suitable as industrial materials. In addition, the total denier of the fibers that make up the core is 75 to 1000.
Denier is preferable in terms of tensile stress dispersibility and ease of manufacture. Core fiber materials include polyester, nylon, vinylon, rayon, acrylic, polypropylene,
Examples include polyethylene, aramid, and polyarylate.

These fibers may be a combination of a plurality of fibers.

Further, as the material used for the sheath fiber, materials selected from commonly used materials can be used depending on the purpose. Note that the sheath fiber may be a combination of multiple types of short fibers.

The covered yarn of the present invention must satisfy the following coverage ratio (%).

Coverage rate (%) ≧ Volume ratio of sheath fiber component in covered yarn (
%)xl,2 If the coverage ratio does not satisfy the above formula, it is necessary to increase the volume ratio of the sheath fibers in order to obtain the same coverage ratio, and the strength of the covered yarn will decrease.

In addition, in the covered yarn of the present invention, it is necessary that the single fibers constituting the sheath are not substantially twisted together with other single fibers constituting the sheath, and if the sheath fibers are heated and the single fibers are united together. When the sheath fiber becomes a yarn by itself,
Peeling from the core fiber is likely to occur, and the features of the covered yarn will be halved. To explain this in detail, the movement of the single fibers in the heated fiber bundle (yarn) is restricted by twisting (instead, they cannot move), so they intertwine with the core fibers. Therefore, since the core fibers and the sheath fibers constitute yarns separately, the sheath fibers tend to move easily.

If the sheath fibers are not substantially twisted together, the single fibers constituting the sheath fibers will intertwine with the core fibers, resulting in improved entanglement and a yarn with less peeling. In the field of industrial materials that are subject to stronger frictional forces, it is essential that there is less peeling. That is, the sheath fibers responsible for the surface properties of the yarn are peeled off, and the core fibers, which hardly contribute to the surface properties, are exposed on the yarn surface, making it unsuitable for the industrial materials field.

Moreover, it is preferable that the ratio of (volume of core fiber)/(volume of sheath fiber) in the covered yarn is 70/30 to 10/90.

If the volume ratio of the sheath component is less than 30%, the properties based on the sheath fiber, such as handleability, end processability, texture, fatigue resistance, etc. due to short fibers, cannot be fully exhibited, and the volume ratio is 90% or less. % or more, the strength will be insufficient and this is not preferable. More preferably, the volume ratio is 45 to 80%.

The volume of the core fiber and the volume of the sheath fiber are the total weight of the core fibers that make up a certain length of covered yarn divided by the density of the core fiber, and the total weight of the sheath fiber that makes up the covered yarn is the total weight of the sheath fiber that makes up the covered yarn. It is divided by the density.

In the present invention, it goes without saying that if the core fiber and sheath fiber are exactly the same, the yarn will not be a covered yarn. In other words, in order to make it a coated yarn, use a combination of fibers that differ in at least one of the following: fiber thickness, average fiber length, cross-sectional shape, surface properties (hydrophilicity, surface unevenness, etc.), material, etc. There is a need.

Next, an example of the method for manufacturing the covered yarn of the present invention is shown. First, the core component fiber and the sheath component fiber are separately made into slivers using a normal spinning process. The yarn is made and supplied to the spinning process. Generally, the process of converting fibers into slivers in the spinning process varies depending on the average fiber length used. For example, when the average fiber length is 38 to 80 m, it is converted into sliver by the carding process, and when the average fiber length is 80 to 300 m, it is Sliver can be obtained by conventional tow spinning processes (eg purlock or converter machines). However, these slivers still do not have good uniformity, so doubling and stretching are repeated multiple times in the filament process to obtain a sliver without unevenness. At the final stage of the filament process, the first
As shown in the figure, the sliver 2 as the core fiber is placed in the center and the sliver 1 as the sheath fiber is arranged at both ends, and the sliver is drawn and supplied to the spinning process as shown in Figure 2 (5 in Figure 1, i.e. Depending on the yarn count to be spun, the roving sliver may be fed to the roving process to produce 6° (q) of roving, and then this can be It not only fully satisfies the functionality required in the industrial materials field, but also
Because the average fiber length of the sheath component is long, it may be entangled with the core fiber)
When twisting covered yarn, weaving, or knitting, there is less scattering of fluff, which improves the environment, prevents deterioration of quality and quality due to fluff flying into the twisted yarn, and Process passability also improves. In addition, since the sheath fibers or the core fibers adhere well, the durability is improved when used as ropes, long lines, etc. that are subject to severe bending frictional forces.

The average fiber length of the sheath fibers must be 70 mm or more to achieve high strength.
It is necessary from the viewpoint of high durability and shape stability, and the longer the length, the better.However, on the other hand, the longer the tMM length, the larger the equipment for the spinning process. There is a limit to the extent, and especially considering both the peelability of the sheath fiber of the covered yarn and the scale of the equipment, it is 100 s to 15 s.
0# is the preferred average fiber length range.

In addition, the fiber length of the core fiber is 70. The above is necessary, and 300# or less is preferable in terms of equipment for the spinning process. Further, the average fiber length of the core fibers is preferably in the range of 90 to 110% of the average fiber length of the sheath fibers, even if it is the same as or different from the average fiber length of the sheath fibers.

The coverage ratio in the present invention is determined by the following method. Wrap the thread parallel to the panel, take a photo of the surface using a universal projector or microscope, place a piece of transparent paper on top of the photo, trace the outer circumference of the thread, and trace the exposed part of the core fiber. Fill in details. Thereafter, a piece of paper is cut along the outer periphery of the yarn, its weight is measured, and it is designated as Wo.Then, the portion where the core fiber is exposed is cut off, its weight is measured, and it is designated as old. The coverage rate is: Coverage rate (%) -70-'''xio.

W.

It is determined by

However, the sample length of the covered thread to be traced is that the twist of the thread is 100.
Refers to the length of the rotation.

That is, Trial length (inch > -100 Number of twists (t/in) I'm looking forward to it.

On the other hand, regarding the fact that the sheath fibers do not separate, which is one of the required performances of the covered yarn, we conducted a sensory test on the entanglement of the core-sheath fibers.As shown in Figure 3, the covered yarn was fixed to one side of a 300 m long frame. Then, apply a load of <5000) = a to the other end.

On the other hand, three round binders of 2 mφ were set up as shown in Fig. 4.5, and rotated at a traverse distance of 50 mm and a traverse speed of 1 ro/sec, and the exfoliation properties of the sheath fibers were sensory tested.

The measurement time was 15 minutes, the number of measurement samples was 10, and the results were evaluated as follows: ◎ Very good O Good △ Peeling × Very poor.

Next, the present invention will be explained with reference to Examples.

Example: The weight of the sliver to be used as the core fiber is selected according to the yarn count to be produced, and the average fiber length of the staple fiber to be used as the sheath fiber is specified by the usual worsted spinning method, parlock spinning method or converter spinning method. Sliver with a predetermined mixing ratio is produced using the equipment shown in Figure 1. If the yarn count is less than 10°3, the sliver is directly spun, and if it is 10°3 or more, roving is made from the sliver and then spun. A method was adopted in which the roving was spun using a device as shown in Figure 2. The main conditions of the spinning machine are as follows.

Count (fine count) 5/1 6.4/1
10/1 spindle rotation speed <r, D, m,)
5.500 5,500 10.000 Ring inner diameter (Mφ) 82.5 82.5
55 twists (ft/in) 5
．． 2 6. 1 10.2 The physical property values and performance of the core fiber, sheath fiber, and obtained covered yarn used in each example are shown in the table below.

[Brief explanation of drawings]

Figure 1 schematically shows an example of a filament mill that can produce the sliver necessary to make the covered yarn of the present invention, and Figure 2 shows how the sliver can be supplied directly or as a roving. This figure shows an example of a spinning machine that can produce covered yarn. Figures 3 to 5 show an apparatus for examining releasability. The numbers in FIGS. 1 and 2 represent the following, respectively. 1 Sliver serving as sheath fiber 2 Sliver serving as core fiber 3 Drawing zone 4 Trumpet 5 Composite sliver 6 Rough -・6° Sliver° 6°. 7 Stretching section 8 Snell wire 9 Spindle 10 Ring rail 11 Heating section In addition, in FIGS. 3 to 5, the numbers indicate the length (#).

Claims (1)

[Claims] 1. The core fiber bundle is surrounded by a group of fibers constituting a sheath, and the single fibers constituting the sheath are core yarns that are not substantially twisted with other single fibers constituting the sheath. and the following conditions (1) to (2) (1) The average fiber length of the sheath fibers and core fibers are each 70
nm to 300 mm, and (2) the coverage ratio is {(volume of sheath fiber)/[(volume of core fiber)+(volume of sheath fiber)]}×1.2 or more. A core yarn characterized by: 2. (Volume of core fiber) / (volume of sheath fiber) ratio is 70/3
The core yarn according to claim 1, wherein the core yarn has a molecular weight of 0 to 10/90. 3. (Volume of core fiber) / (volume of sheath fiber) ratio is 45/5
The core yarn according to claim 1, which has a molecular weight of 5 to 20/80.