JP2539631Y2 - False twist disc - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a false twist disk for applying false twist to a yarn.

[0002]

2. Description of the Related Art Conventionally, a false twisting machine for imparting false twist to a yarn has been used. However, as shown in FIG.
Three rotating shafts 20 having a plurality of false twist disks 10
Each of the false twist disks 10 was arranged so as to partially overlap each other. When the yarn 30 is spirally provided so as to be in contact with each false twist disk 10 and the yarn 30 is run in the direction of the arrow while rotating each false twist disk 10, false twist can be applied to this yarn shape. Was.

Further, as a material of the false twist disk 10, a relatively soft material such as polyurethane or a ceramic excellent in abrasion resistance has been used. For example, a false twisted disk made of ceramics is disclosed in Japanese Patent Publication No. 53-10185.
In the publication, the average particle diameter is 10 to 40 μm, and the surface roughness is 1.0.
It is shown that alumina ceramics of up to 3.0 S are used. Japanese Patent Publication No. 53-27389 discloses that ceramics having an average particle diameter of 2 to 30 μm and a surface roughness of 1 to 6S are used.

[0004]

However, the false twisted disk 10 made of ceramics is formed by shaping a ceramic material into a predetermined shape, firing it, and then polishing the surface with a diamond whetstone or the like, thereby improving the dimensional accuracy and improving the dimensional accuracy. It had a predetermined surface roughness. Therefore, the crystal on the surface of the false twist disk 10 has a sharp edge, and there is a problem that a snow phenomenon occurs in which the yarn 30 to be false twisted is shaved to generate white powder. In particular, in recent years, a fine thread of about 25 to 75 denier has become mainstream, and in the case of such a fine thread, there was a risk of thread breakage.

[0005]

In view of the above, the present invention provides:
In the case of a ceramic false twist disk, the crystal grain size is 7
By re-firing the formed, fired and polished ceramic body so that the surface roughness (Ra) is 0.5 to 1.3 μm and the surface roughness (Ra) is 0.5 to 1.3 μm, the crystal on the surface is rounded and the crystal curvature radius is 2 μm or more Things.

In the present invention, the crystal radius of curvature of the surface means the cut surface in the vicinity of the ceramic surface, which is enlarged and photographed with an electron microscope, and based on this photograph, the sharpest crystal exposed on the surface is obtained. This is a value obtained by measuring the radius of curvature of the edge portion. That is, the false-twisted disk of the present invention has a smooth surface since the edge of the crystal on the surface is as large as a radius of curvature of 2 μm or more, and is unlikely to cause a snow phenomenon or a yarn breakage even with a fine yarn.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below.

As shown in a perspective view in FIG. 1 and a cross-sectional view in FIG. 2, the false twist disk 10 of the present invention is a disk made of alumina ceramics, and has a through hole at the center for attachment to a rotating shaft. 11 having an outer peripheral surface 1 in contact with the yarn 30
2 is a curved surface.

This false twist disk 10 is mounted on a rotating shaft 20 as shown in FIG. 5, and each false twist disk 10 is arranged so as to partially overlap each other.
If the yarn 30 is run while rotating 0, false twist can be applied to the yarn 30. At this time, the yarn 30 is
As shown in FIG. 2, twisting is performed by contact with the surface 12 of the false twist disk 10, but many twists are given,
In order to prevent a snow phenomenon, the state of the surface 12 is important.

In the false twist disk 10 of the present invention, FIG.
As shown in FIG. 3 which is a schematic diagram of an electron micrograph in which part A in FIG. 3 is magnified 1500 times, the ceramic crystal 13 forming the surface 12 has a rounded shape without sharp edges, and It has moderate unevenness as a whole. Therefore, many false twists can be provided without scraping the yarn 30.

In order to make the crystal 13 on the surface 12 of the false twist disk 10 round as described above, the ceramic body may be refired. That is, the manufacturing process of the false twist disk 10 of the present invention is as follows. First, a ceramic raw material powder is formed into a disk shape by press molding or the like, and then fired at a temperature of 1600 to 1700 ° C. Next, the surface of the obtained ceramic body is polished with a diamond grindstone or a barrel. By changing the size of the abrasive grains at this time, the surface roughness of the ceramic body can be freely changed. Finally, the ceramic body is refired, and the temperature at this time may be set to be equal to or higher than the firing temperature. Then, by re-firing in this manner, the crystals 13 on the surface 12 further grow to have a round shape without sharp edges.

For reference, FIG. 4 shows the state of the surface 12 (corresponding to the surface of a conventional ceramic disk) after polishing with a diamond grindstone during the above manufacturing process. As is clear from comparison with FIG. 3, it can be seen that by re-firing, the crystal on the surface can be rounded without changing the surface roughness and the average crystal particle diameter.

In the present invention, the radius of curvature of the crystal was measured in order to indicate the size of the roundness of the crystal on the surface of the ceramic body as described above. As shown in FIG. 3, an enlarged photograph of a cross section near the surface 12 of the false twist disk 10 is taken, and the curvature radius R of the sharpest edge of the crystal exposed on the surface is measured on this photograph. is there. Therefore, the larger the radius of curvature of the crystal is, the more the crystal is rounded.

Experimental Example Here, in the false twist disk of the present invention, as shown in Table 1, the average crystal grain diameter and the center line average roughness (R
a), prototypes having variously changed crystal radii of curvature were prototyped, and each was incorporated in a false twisting machine shown in FIG. 5 to perform a false twist test. As the material of the false twist disk, Al ₂ O ₃ 9
9.5% alumina ceramic, firing temperature 1
690 ° C. was used. The yarn to be false-twisted was made of polyester and had a thickness of 75 denier.
After the false twist test, the results of various evaluations are as shown in Table 2.

In Table 2, the number of twists is the number of twists per unit length, the strength is the strength per unit thickness, and the elongation is the elongation. The larger these values are, the better.

[0016]

[Table 1]

[0017]

[Table 2]

It is apparent from these results that 1 is
Since the surface roughness (Ra) was smaller than 0.3 μm and the average crystal particle diameter was smaller than 7 μm, the twist number was as low as 1800 T / m. In addition, No. In Nos. 2 to 4, since the re-baking temperature was low, the amount of white powder generated was large because the radius of curvature of the crystal was lower than 2 μm. In addition, No. In No. 5, since the surface roughness (Ra) was larger than 1.3 μm and the average crystal particle diameter was larger than 30 μm, the amount of white powder generated was large, and all were unsuitable as false twist disks.

Further, No. In No. 9, the surface roughness and the average crystal particle diameter were within the range of the present invention, but the crystal radius of curvature was smaller than 2 μm and the amount of white powder generated was large because rebaking was not performed. In addition, No. Numeral 10 is a urethane disk shown as a comparative example, which had an extremely large amount of disk wear and a short life as compared with a ceramic disk.

On the other hand, no. 6 to 8 have a surface roughness (Ra) of 0.5 to 1.3 μm, an average crystal particle diameter of 7 to 30 μm, and have moderate irregularities, so that the number of twists, strength and elongation are high. In addition, it can be seen that the amount of white powder generated can be reduced because the radius of curvature of the crystal is 2 μm or more after refiring.

[0021]

As described above, according to the present invention, in the false twisted ceramic disc, at least the portion that comes into contact with the yarn has a surface roughness (Ra) of 0.5 to 1.3 μm and an average crystal grain diameter of 7 to 7 μm. By setting it to 30 μm and re-baking to make the crystal radius of curvature of the surface 2 μm or more, the action of scraping the yarn becomes small while maintaining excellent false twisting characteristics, and it is possible to prevent snow phenomenon and yarn breakage. Also, since the false twist disk is made of ceramics, it has high wear resistance,
It is possible to obtain effects such as maintaining the initial false twisting characteristics over a long period of time.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a false twist disk of the present invention.

FIG. 2 is a sectional view taken along line XX in FIG.

FIG. 3 is a cross-sectional view of a portion A in FIG.

4 is an enlarged sectional view of a comparative example corresponding to FIG.

FIG. 5 is a side view showing a structure of a false twisting machine using a false twist disk.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... False twist disk 11 ... Through-hole 12 ... Surface 20 ... Rotation axis 30 ... Thread

Claims (1)

(57) [Scope of request for utility model registration] A ceramic disk for false twisting a yarn, wherein at least a portion in contact with the yarn is made of a ceramic having an average crystal grain diameter of 7 to 30 μm, and the ceramic constituting the disk is made of a ceramic. By refiring, the crystal at the contact portion with the yarn has a crystal curvature radius of 2 μm.
A false twist disk characterized by having the above roundness.