JPH0797138A - Coreless package of carbon fiber - Google Patents

Abstract

PURPOSE:To provide releasing from an inner layer without collapsing a form by forming a cylindrical coreless package of carbon fiber so that virtual winding density obtains a specific range, and improving releaseability. CONSTITUTION:In a winder, a traverse guide 2, constituted of parallelly arranged two rotary rolls 3 with surface roughness 3S or more, is used to insert carbon fiber 4 to a clearance of the rolls rewound to a rewinding bobbin 7. Here is formed a winding core package into a cylindrical shape, to perform rewinding so that virtual winding density obtains 1.1 to 1.5g/cm<3> range. A friction coefficient of the carbon fiber is left as adjusted to at least 0.3 preferably 0.35 or more. Thus at conveying time or the like, even when an impact is received, collapsing a form is difficult, and releasing can be smoothly performed. Further, also fuzz of the released carbon fiber is decreased, and the coreless package of carbon fiber can be safely handled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbon fiber coreless package which is excellent in loosening property and can be loosened from an inner layer without losing its shape.

[0002]

2. Description of the Related Art Many carbon fibers are wound on a paper tube to form a package, which is then continuously released and processed into a higher-order product. Recently, however, carbon fiber coreless packages have been receiving attention due to demands for rationalization of transportation and cost reduction, and on the other hand, high-speed unraveling has been demanded for rationalization of processing steps. For responding to this request, for example,
In Japanese Examined Patent Publication No. 3-72547, the apparent winding density is 0.
There is disclosed a coreless package of carbon fiber which has a twist angle of ³ to 1.0 g / cm ^{3 and} which improves the peptization property.

[0003]

In this way, the practical application of the carbon fiber coreless package is progressing. However, the carbon fiber coreless package is easily deformed by a slight impact such as during transportation, The handling required extra caution. In addition, when the carbon fiber is pulled out from the inside of the package and unwound near the outermost layer, the outermost layer of the package loses its shape and there is a problem that untwisting is likely to occur. An object of the present invention is to solve the above problems, and to provide a carbon fiber coreless package that does not easily lose its shape and can be easily disassembled to the end.

[0004]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present inventor prototyped various carbon fiber coreless packages having different winding conditions, and produced a shape-defective, deflocculating and fluff generation. The evaluation was centered on the situation and appearance. As a result, it was found that the apparent winding density of the package and the coefficient of friction of the carbon fiber have a large correlation with the deformation of the package and the looseness. The carbon fiber coreless package has a cylindrical shape and an apparent winding density range of 1.1.
To 1.5 g / cm ³ to be suitable, furthermore, the friction if the coefficient is a carbon fiber of more than 0.3, onsets saw can be easily canceled hard to lose shape even when the non-core package, the Completed the invention.

[0005]

Actions and Examples of Embodiments The present invention will be specifically described with reference to examples of embodiments. The carbon fiber coreless package of the present invention has a cylindrical shape without a core and an apparent winding density of 1.1 to 1.5 g / cm ³ . If the apparent winding density is less than 1.1 g / cm ^{3, the} package is likely to lose its shape due to an impact received during transportation. On the other hand, in order to make it larger than 1.5 g / cm ³ , the tension at the time of winding must be set high, and under that condition, fluff occurs frequently on the carbon fibers and the carbon fibers in the package adhere to each other. This is not preferable because it becomes easy and a problem of unsolving occurs.

The friction coefficient of the carbon fibers should be adjusted to at least 0.3, preferably 0.35 or more. If the coefficient of friction is less than 0.3, slippage occurs between the carbon fibers, and the package tends to lose its shape during and after winding.

The method of measuring the friction coefficient of carbon fiber according to the present invention will be described with reference to the drawing (FIG. 3).
Carbon fiber yarn 1 unwound from carbon fiber package 11
2 through the guide roller 13 to the four fixed guides 14
led to a to d. The fixed guides 14a to 14d have a diameter of 10 m.
m and a surface roughness of 0.8 S (according to the measuring method described in JIS B0601) were attached in parallel to each other and in parallel to the guide roller 13 and the take-up roller 15. In the fixed guides 14a and 14d, the yarn paths are displaced by 45 degrees, and the fixed guides 14b and 14c are also moved.
In, the yarn path was displaced by 90 degrees, and the total angle θ of displacement was 270 degrees, that is, θ = 1.5π. The yarn coming out of the fixed guide 14d was taken up by the take-up roller 15 at a speed of 3 m / min, and the fixed guides 14a to 14d were rubbed with the carbon fiber 12. Tension T1 on the entry side of the fixed guide 14a
Was 0.02-0.15 g / denier. Tension T2 of the carbon fiber 12 on the exit side of the fixed guide 14d at that time
Was measured, and the numerical value calculated by the following formula from the measurement result was taken as the friction coefficient.

Friction coefficient (μ) = {ln (T ₂ / T ₁ )}
A carbon fiber having a friction coefficient of 0.3 or more is obtained by, for example, adhering a bisphenol / epoxy aqueous solution as a sizing agent to a carbon fiber obtained by firing an acrylonitrile filament obtained by a dry-wet spinning method, Dry in air for 1-2 minutes to reduce the amount of sizing agent deposited to 0.3-
It can be manufactured at 5%. Further, the adjustment of the friction coefficient can be achieved by changing the amount and composition of the sizing agent, but not limited to this.

A method for winding a fiber coreless package will be specifically described with reference to the drawings. FIG. 1 is a front view of a winding section showing an example of a winder used in the present invention. In the winder used in the present invention, a swaying guide 2 composed of two rotating rolls 3 arranged in parallel is used, and the carbon fiber 4 is passed through the gap between the swaying guide 2 and the winding bobbin 7.
The surface roughness of the rotating roll 3 is 3S or more. When the surface roughness is 3S or less, the friction coefficient with the carbon fiber 4 becomes large, fluffing is likely to occur, and the single fiber winding of the carbon fiber 4 around the rotating roll 3 easily occurs, which is preferable. Absent.

On the other hand, the outer diameter of the rotating roll 3 is 5 mm or more,
It is preferably 10 mm or more. The upper limit of the outer diameter of the rotating roll 3 is naturally limited by the conditions such as the yarn path, the maximum winding diameter, and the roller bale 5. When the outer diameter of the rotating roll 3 is smaller than 5 mm, the number of rotations increases, fluffing is likely to occur, and a single fiber of carbon fiber is easily wound, which is not preferable. The material of the surface of the rotary roll 3 is usually plated with metal and polished to a predetermined finish.
In principle, plastics having a surface roughness of at least 3S can be used.

Further, a roller bale 5 having a rotation axis parallel to the spindle 1 and rotating while being in contact with the side surface of the wound carbon fiber 6 (package) is mounted. It is preferable to wind up while applying a contact pressure of 0.2 kg / cm. Roller veil 5
It has the effect of increasing the apparent winding density of the package 6 and adjusting it. If the contact pressure is too small, it is necessary to increase the tension applied to the carbon fibers 4 in order to increase the apparent winding density of the package to 1.1 g / cm ³ or more, and fuzz tends to occur. If the contact pressure is too large, both end faces of the package 6 will bulge and the shape of the package 6 will deteriorate, which is not preferable.

The bobbin 7 set in the winder for winding the coreless carbon fiber package can remove the carbon fiber after winding the carbon fiber.
A split type bobbin or an air bag type bobbin is used. 8 is a guide roll (or tension roll).

The core carbon fiber package has a winding width of 1
00-300mm, inner diameter of package is 50-100m
m, and the outer diameter is preferably about 100 to 300 mm. If the winding width is small, if the winding amount is large, the winding diameter becomes large and it is difficult to handle. On the contrary, if the winding width is too long, the package is easily deformed when placed vertically. If the inner diameter of the package is too large, the whole becomes large, which is unfavorable for transportation, and if it is too small, the winding angle of the carbon fiber wound around the innermost layer of the package becomes large and the shape of the package tends to be deformed. The outer diameter of the package is not particularly limited, but it may be determined based on the ease of use in transportation and processing steps.

[0014]

[Examples and Comparative Examples]

Examples 1 to 10 and Comparative Examples 1 to 6 The effects of the carbon fiber coreless package of the present invention and the winding method thereof will be described with reference to Examples and Comparative Examples. A winder similar to that shown in Fig. 1 was used, and the outer diameter was 10 m.
m, a twirl guide roller in which two freely rotating rollers having a surface roughness of 10S are arranged in parallel, and a roller bale having a diameter of 30 mm, a length of 280 mm, and a surface hard chrome plated, are attached to the roller bale. By changing the contact pressure and winding tension of the carbon fiber, coreless packages of carbon fiber having different winding densities were made as prototypes, and the winding shape, pliability, and deformation were evaluated. The contact pressure of the roller bale was adjusted by pulling the support shaft of the spindle on which the bobbin is mounted toward the roller bale via a spring. To wind a coreless package, the number of filaments is 12000
Tape-shaped carbon fiber was used. Package winding width is 2
50 mm, outer diameter is 20 mm, package inner diameter is 85 mm after removing bobbin, winding speed is 10 m / min,
The winding amount per roll was 4 kg.

In order to change the friction coefficient of carbon fiber, carbon fiber obtained by firing dry-wet spinning and acrylonitrile filament produced by wet spinning is used, and bisphenol. An epoxy aqueous solution was applied to adjust the sizing adhesion amount. Examples 1 to 10 are shown in Table 1 and Comparative Examples 1 to 6 are shown in Table 2 including the conditions for adjusting the winding density of the package and the evaluation results.

[0016]

[Table 1]

[0017]

[Table 2]

[0018]

The carbon fiber coreless package of the present invention comprises:
It is difficult to lose its shape even if it receives an impact during transportation, and it can be released smoothly. In addition, since the fluff of the disentangled carbon fiber is small, the consumer can use the carbon fiber coreless package at ease. Such a package can be easily wound by using the winding method of the present invention.

[Brief description of drawings]

FIG. 1 is a front view of a winding unit of a winder used in the present invention.

FIG. 2 is a plan view of the winding unit of the winder.

FIG. 3 is a schematic diagram of a carbon fiber friction coefficient measuring device.

[Explanation of symbols]

1: Spindle 2: Twirl guide 3: Rotating roll 4: Carbon fiber 5: Roller bale 6: Rolled carbon fiber (package) 7: Bobbin 8: Guide roll

Claims (2)

[Claims] 1. A coreless carbon fiber package, which is cylindrical and has an apparent winding density range of 1.1 to 1.5 g / cm ³ . 2. The coreless carbon fiber package according to claim 1, wherein the carbon fiber has a friction coefficient of more than 0.3.