Carbon fiber package and carbon fiber packed member

Details Carbon fiber package and carbon fiber packed member Carbon fiber package and carbon fiber packed member

1998-08-28

2001-08-21

Walsh, Donald P. (Department: 3653)

Winding, tensioning, or guiding

Wound storage package

Particular winding

C242S175000, C242S176000, C242S178000

Reexamination Certificate

active

06276624

ABSTRACT:

TECHNICAL FIELD
The present invention relates to large packages and packed members of carbon fibers having particularly high fineness. Also, the present invention relates to packages of carbon fibers which are precisely formed into a desired shape with high winding density so as not to be easily broken, and to a method for producing the same.
BACKGROUND ART
There has been an increase in demand for the use of carbon fibers year by year, and the demand has been shifting from premium usage, such as for airplanes and sports equipment, to general industrial usage, such as for construction, civil engineering, and energy.
In general industrial usage, particularly in processes such as weaving, filament winding, pultrusion, and the like for forming large structural materials, a high fineness of approximately 100,000 deniers is required. Currently, in order to meet the demand described above, several yarns of approximately 7,000 to 20,000 deniers are combined to perform the formation.
Under the circumstances, if large packages having high fineness and heavy winding weight are obtained, the number of mountings of carbon fibers onto a higher processing apparatus will decrease and the creel unit will be more compact, and thus, great advantages are expected in the use of carbon fibers.
It is a first object of the present invention, in order to satisfy the demand described above, to provide a large package and a large packed member in which carbon fibers having particularly high fineness are wound so that the occurrence of trouble or inconvenience will be prevented during use.
On the other hand, with respect to the formation by combination, since there are distances between combination units, irregular impregnation of a resin may occur.
Also, since it is difficult to vertically layer fibers, fibers are horizontally combined, and thus, the thickness of the yarn will be the thickness of the combination unit, i.e., 7,000 to 20,000 deniers, and it is difficult to increase the thickness of the yarn. In particular, when a large and thick forming member is produced, the number of layers and the number of windings must be increased, resulting in disadvantage also in terms of formation time.
In other words, if a package of carbon fibers having a large number of filaments and large thickness is obtained, the number of mountings of carbon fibers onto a higher processing apparatus will decrease, formation time will be reduced, and the creel unit will be more compact, all of which are advantageous.
However, differing from general organic fibers, carbon fibers have significantly high Young's modulus and lack stretchability, and thereby, the range of windable tension is significantly small. If the tension is too low, trouble may easily occur, such as breaking at both sides of a roll, deformation due to external force, and slipping of a yarn layer out of a bobbin, and if the tension is too high, damage to yarns during winding, and deterioration of unwinding characteristics occur, and thus it has been technically difficult to set winding conditions with respect to cheese winding.
With regard to a carbon fiber package that does not easily break or does not have much fuzz during unwinding, a package has been disclosed in Japanese Patent Publication No. 62-46468, in which the package is a square-end type, and carbon fibers are taken up onto a bobbin with a given wind ratio, the wind angles of the fibers at the start of winding and at the end of winding are 10° to 30° and 4° to 12° respectively, and there is a shifting ratio of 50 to 150% of the average yarn width in relation to the already wound yarn, every 1 to 9 traverses. This package is a so-called “open-wind” package, in which, by minimizing the degree of overlapping of yarns, fuzz during unwinding and broken yarns are prevented. In the case of a bobbin having a given size, if the “open-wind” is used, as the yarns having a large number of yarns, that is, having high fineness, and having large thickness are wound, the spaces resulting from the overlap between yarns increase and the unevenness of the winding surface increases, and thus, the resultant package will be soft with low winding density, and both sides of the roll will easily bulge because the yarns are pushed out of the sides by means of winding tension and pressure on the winding surface (bearing pressure). Such a package may suffer broken winding during transportation, and because the bulge at both sides exceeds the length of a bobbin, the yarns may be damaged during the setup onto higher processing equipment.
It is the second object of the present invention, in view of the problems described above, to provide the most suitable shaped package with respect to winding of carbon fiber yarns having particularly high fineness, in which high winding density is obtained and breakage does not easily occur, by basically changing the form of winding.
DISCLOSURE OF INVENTION
A carbon fiber package as a first mode of the present invention includes a cheese winding package, in which a carbon fiber of
25
,
000
deniers or more is wound, and an outside diameter (D mm) of the package, a diameter of the bobbin (d mm), and a winding width (L mm) satisfy the following relationships:
d≧
50,
20≦(
D−d
)/2≦400,
and
0.05≦(
D−d
)/2
L≦
0.7
A carbon fiber package as a second mode of the present invention includes a coreless package, in which a carbon fiber having a fineness of 25,000 deniers or more is wound, and an outside diameter (D mm) of the package, an inside diameter (di mm) of the package, and a winding width (L mm) satisfy the following relationships:
di≧
50,
20≦(
D−di
)/2≦400,
and
0.05≦(
D−di
)/2
L≦
0.7
A carbon fiber package as a third mode of the present invention includes a square-end type package, in which a carbon fiber yarn having a fineness of 25,000 deniers or more is wound onto a bobbin such that a yarn width per fineness ranges from 0.15×10
×3
to 0.8×10
×3
mm/denier, wind angles at the start of winding and at the end of winding are in the ranges of 10° to 30° and 3° to 15°, respectively, and a fraction W
0
in a wind ratio W ranges from 0.12 to 0.88.
Also, in accordance with the present invention, a carbon fiber packed member is provided, in which a continuous carbon fiber having a fineness of 25,000 deniers or more is packed in a container with an average bulk density in a range of 0.03 to 1.2 g/cm
3
.
BEST MODE FOR CARRYING OUT THE INVENTION
In carbon fiber packages in accordance with the first and the second modes of the present invention, preferably a winding density ranges from 0.8 to 1.2 g/cm
3
. Herein, the winding density corresponds to “weight of wound carbon fiber/apparent volume of wound carbon fiber”. Since the cheese winding package and the coreless package generally have a winding configuration in the shape of a doughnut-like cylinder, in the case of a cheese winding package, the apparent volume of wound carbon fiber is calculated as &pgr;·L(D
2
−d
2
)/4, and in the case of an coreless package, it is calculated as &pgr;·L(D
2
−di
2
)/4.
Also, preferably, carbon fibers to be wound are substantially non-twisted. If carbon fibers are twisted, it is difficult to wind up with high winding density, and also slacks may occur on the bobbin owing to uneven tension, resulting in entanglement, which is disadvantageous during unwinding. Herein, “substantially non-twisted” means that the number of twists is one turn or less per 1 m.
In carbon fiber packed members, preferably the carbon fibers to be packed are also substantially non-twisted.
There is no limitation to the properties of carbon fibers in accordance with the present invention. For example, tensile stress may range from 200 to 700 kgf/mm
2
and tensile modulus may range from 15 to 50 tf/mm
2
.
In carbon fiber packages in accordance with the present invention, carbon fibers as described above are wound in the form of a cheese winding package or a coreless package, as a fiber bundle of thick carbon fibers having a fineness of 25,000 deniers or mor

Affiliated with

Also associated with

Rating

Carbon fiber package and carbon fiber packed member does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Carbon fiber package and carbon fiber packed member, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Carbon fiber package and carbon fiber packed member will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2472507