JP6708736B2 - Fiber guide - Google Patents

Description

The present disclosure relates to fiber guides.

In guiding fibers, fiber guides of various shapes called roller guides, oiling nozzles, rod guides and traverse guides are attached to and used in textile machines. The surface of the fiber guide that contacts the fiber (hereinafter referred to as the yarn contact surface) is required to be unlikely to cause damage such as scratches or frays on the fiber.

For example, Patent Document 1 proposes a fiber guide having a surface roughness Ra of 0.1 μm or less on the surface in contact with the conveyed fiber bundle.

JP-A-2000-73225

The yarn guide surface of the fiber guide of the present disclosure has a load length ratio Rmr20 of 15% or less at a cutting level of 20% obtained from a roughness curve, and a load length of 50% at a cutting level obtained from a roughness curve. The ratio Rmr50 is 60% or more.

It is a perspective view of a roller guide which shows an example of a fiber guide of this indication. It is a perspective view of an oiling nozzle which shows an example of a fiber guide of this indication. It is a perspective view of a rod guide which shows an example of a fiber guide of this indication. It is a perspective view of a traverse guide which shows an example of a fiber guide of this indication. It is an enlarged view which shows typically an example of the yarn contacting surface of the fiber guide of this indication. It is a schematic diagram of a sliding test device.

In recent years, in order to improve the production efficiency of fibers, the feeding speed of fibers has been extremely increased to 3000 to 10000 m/min. Since the fiber feeding speed is increased, the fibers are more likely to be damaged by the friction with the yarn contact surface. Therefore, there is a demand for a fiber guide having a low coefficient of friction on the yarn contact surface, which does not damage the fiber even when the fiber feeding speed is increased.

Since the fiber guide of the present disclosure has a low friction coefficient on the yarn contact surface, it is possible to suppress damage to the fiber when the fiber is guided. Hereinafter, the fiber guide of the present disclosure will be described in detail with reference to the drawings.

First, representative types of fiber guides will be described with reference to FIGS. First, the roller guide 10a shown in FIG. 1 guides the fiber 1 in the V groove portion while rotating. Next, the oiling nozzle 10b shown in FIG. 2 is used to attach oil to the sliding fiber 1. The rod guide 10c shown in FIG. 3 is used for converging or separating the fibers 1. Further, the traverse guide 10d shown in FIG. 4 is used for guiding when the fiber 1 is wound around the outer circumference of the cylindrical package. In the following description, the fiber guide will be described with reference numeral "10" unless a specific fiber guide is described.

In the fiber guide 10 of the present disclosure, the yarn contact surface with the fiber 1 has a cutting length of 20% determined from the roughness curve, a load length ratio Rmr20 of 15% or less, and a cutting level of 50% determined from the roughness curve. The load length ratio Rmr50 is 60% or more.

Since such a configuration is satisfied, the fiber guide 10 of the present disclosure has a low friction coefficient on the yarn contact surface, and can suppress damage to the fiber 1 when the fiber 1 is guided. Specifically, since the loaded length ratio Rmr20 is 15% or less on the yarn contact surface, the contact area between the fiber 1 and the yarn contact surface is small when guiding the fiber 1. Further, since the load length ratio Rmr50 is 60% or more, the fiber 1 is less likely to bite into the bottom of the valley portion in the yarn contact surface, and the fiber 1 can be slid smoothly. Therefore, the fiber guide 10 of the present disclosure has a low friction coefficient on the yarn contact surface.

The load length ratio Rmr obtained from the roughness curve is specified in JIS B 0601 (2013). The reference length is extracted from the roughness curve in the direction of the average line, and the roughness curve of the extracted portion is obtained. Is a ratio of the sum of cut lengths obtained when cut at a cutting level parallel to the crest line to the reference length, expressed as a percentage. Here, the cutting level is a ratio of the height to the maximum height (the sum of the maximum peak height and the maximum valley depth shown in JIS B 0601 (2013)) in the above reference length, which is expressed in percentage. Is. That is, the load length rate Rmr0 at the cutting level 0% is 0%, and the load length rate Rmr100 at the cutting level 100% is 100%.

Further, the yarn contact surface of the fiber guide 10 of the present disclosure may have a load length ratio Rmr50 of 75% or more. If such a configuration is satisfied, the fibers 1 are less likely to bite into the bottoms of the valleys on the yarn contact surface, and the fibers 1 can be slid smoothly.

Further, the yarn contacting surface of the fiber guide 10 of the present disclosure may have an average interval Rsm of irregularities obtained from a roughness curve of 5 μm or more and 25 μm or less. If such a configuration is satisfied, the contact area between the fiber 1 and the yarn contacting surface can be reduced, and at the time of guiding the fiber 1, the fiber 1 can be prevented from bouncing and the fiber 1 can be slid smoothly. be able to.

The average interval Rsm of irregularities obtained from the roughness curve is defined in JIS B 0601 (2013) and is the sum of the lengths of the center lines corresponding to one peak and one valley adjacent to it. Is an index showing the average value of the distance when the distance is between the mountain portion and the valley portion.

Further, the yarn contacting surface of the fiber guide 10 of the present disclosure may have a peak count Pc calculated from a roughness curve of 10 or more and 30 or less. If such a configuration is satisfied, the contact area between the fiber 1 and the yarn contacting surface can be further reduced, and when the fiber 1 is guided, the fiber 1 can be further suppressed from bouncing and the fiber 1 can be smoothly slid. Can be moved.

Here, the peak count Pc obtained from the roughness curve is defined in JIS B 0601 (2013), and when the average height of roughness is taken as the center line, peaks and peaks are formed with respect to the center line. It is an index showing the number of existing per unit length (10 mm) of the valley portion.

Here, the load length ratio Rmr20, the load length ratio Rmr50, the average interval Rsm of the unevenness and the peak count Pc on the yarn contact surface are measured by a surface roughness measuring machine (for example, SE-3400 manufactured by Kosaka Laboratory Ltd.). , SE-3500, SE-S500K, and other succeeding models of SE-3300 or later), the yarn contact surface may be measured and calculated based on JIS B 0601 (2013). As the measurement conditions, the reference length may be 0.8 mm, the cutoff value may be 1 mm, the tip radius of the stylus may be 2 μm, and the tip speed of the stylus may be 0.5 mm/sec. Then, it is sufficient to measure at least 5 or more points on the yarn contact surface and obtain the average value.

Further, the material of the yarn contacting surface of the fiber guide 10 of the present disclosure is not particularly limited. When the yarn contact surface is made of ceramics, the ceramics are superior in abrasion resistance and heat resistance as compared with metals and resins, so that the fiber 1 can be prevented from being damaged.

In particular, since aluminum oxide ceramics are inexpensive materials among ceramics, the cost can be suppressed by forming the yarn contact surface with aluminum oxide ceramics.

The yarn contact surface made of aluminum oxide ceramics may be manufactured by coating the surface of a member such as metal or resin with aluminum oxide ceramics, but the fiber guide 10 itself may be made of aluminum oxide ceramics. If it is, it will become more durable. Here, the aluminum oxide ceramics are those in which aluminum oxide accounts for 80% by mass or more of 100% by mass of all components constituting the ceramics.

The material of the yarn contact surface may be confirmed by the following method. First, the yarn contact surface is measured using an X-ray diffractometer (XRD), and identification is performed using a JCPDS card based on the value of 2θ (2θ is the diffraction angle) obtained. Next, the contained components are quantitatively analyzed using a fluorescent X-ray analyzer (XRF). Then, for example, if the presence of aluminum oxide is confirmed by the above identification, and the content converted from the content of Al measured by XRF to aluminum oxide (Al ₂ O ₃ ) is 80% by mass or more, the aluminum oxide ceramics Is.

When the yarn contact surface of the fiber guide 10 of the present disclosure is made of aluminum oxide ceramics, the average circularity of the aluminum oxide crystal particles 2 is 0.55 or more and 0.8 or less, as shown in FIG. May be. If such a structure is satisfied, the gap between the aluminum oxide crystal particles 2 is reduced while suppressing the shedding of the aluminum oxide crystal particles 2, so that the friction coefficient of the yarn contact surface can be made lower. it can. Note that the average circularity is an average value of circularity that is an index indicating the degree of circularity. Further, the circularity is 1 if it is a perfect circle, and shows a smaller value as the shape of the circle collapses.

Here, the average circularity of the aluminum oxide crystal particles 2 on the yarn contact surface may be calculated by the following method. First, surface analysis of the yarn contact surface is performed using an electron beam microanalyzer (EPMA). Particles in which titanium is not detected and aluminum and oxygen are simultaneously detected by the color mapping of the surface analysis are regarded as aluminum oxide crystal particles 2. Next, a photograph of the yarn contact surface is taken using a scanning electron microscope (SEM). It should be noted that FIG. 5 can also be said to schematically show a state in which the yarn contact surface is observed by SEM or the like, and the aluminum oxide crystal particles 2 exhibit a white color tone. Then, the crystal grains 2 of aluminum oxide are written on the tracing paper from the photograph of the yarn contact surface. Then, the tracing paper is read as image data, and the image analysis software “A image kun” (registered trademark, manufactured by Asahi Kasei Engineering Co., Ltd., when referred to as the image analysis software “A image kun” hereafter, Asahi Kasei Engineering The average circularity of the aluminum oxide crystal particles 2 can be obtained by performing image analysis by applying a method called particle analysis of "Image analysis software manufactured by Co., Ltd.". Here, as the analysis condition of the image analysis software “A image-kun”, the brightness of the crystal grains may be “bright”, the binarization method may be “automatic”, and the shading may be “present”. In the above measurement, when it is difficult to take a photograph of the yarn contact surface using SEM because the yarn contact surface is curved, the yarn contact surface is ground to a flat surface, and the polished surface is contacted. The measurement may be performed assuming that it is the same as the yarn surface.

Furthermore, the yarn contacting surface of the fiber guide 10 of the present disclosure may include crystal particles 3 of aluminum titanate, as shown in FIG. Here, the composition formula of aluminum titanate is represented as Al ₂ TiO ₅ , and its Young's modulus is extremely small as compared with aluminum oxide. Specifically, the Young's modulus of aluminum oxide is about 150-400 GPa, whereas the Young's modulus of aluminum titanate is about 4-6 GPa. Therefore, if such a configuration is satisfied, it is possible to prevent the fibers 1 from being damaged by elastic deformation of the crystal particles 3 of aluminum titanate that are in contact with the fibers 1 when the fibers 1 are guided. ..

Further, whether or not the aluminum titanate crystal particles 3 are present on the yarn contact surface can be confirmed by the following method. First, the surface analysis of the yarn contact surface is performed using EPMA. Then, the particles in which titanium, aluminum and oxygen are simultaneously detected by the color mapping of the surface analysis may be regarded as the aluminum titanate crystal particles 3. As shown in FIG. 5, the aluminum oxide crystal particles 2 have a white color tone, whereas the aluminum titanate crystal particles 3 have a black color tone, and thus can be visually identified. It is a thing.

Further, on the yarn contact surface of the fiber guide 10 of the present disclosure, the average crystal grain size of the aluminum titanate crystal grains 3 is 2 μm or more and 10 μm or less, and the area ratio occupied by the aluminum titanate crystal grains 3 is 1 area %. It may be 7 area% or less. If such a structure is satisfied, even if the fiber 1 is guided for a long period of time and the temperature of the yarn contacting surface rises, cracks due to the difference in thermal expansion coefficient between aluminum titanate and aluminum oxide will occur. The structure is difficult. Therefore, the fiber guide 10 of the present disclosure can keep the friction coefficient of the yarn contacting surface low, and can suppress the occurrence of damage to the fiber 1.

Here, the average crystal grain size of the crystal particles 3 of aluminum titanate and the area ratio occupied by the crystal grains 3 of aluminum titanate on the yarn contact surface may be calculated by the following method.

First, a photograph of the yarn contact surface is taken using an SEM. As described above, since the crystal particles 3 made of aluminum titanate have a black color tone, the method of particle analysis of the image analysis software “A image-kun” is applied using this photograph. Image analysis. Thereby, the average crystal grain size of the crystal particles 3 of aluminum titanate and the area ratio occupied by the crystal particles 3 of aluminum titanate can be obtained. As the analysis conditions of the image analysis software “A image-kun”, the lightness of the crystal grains may be “bright”, the binarization method may be “automatic”, and the shading may be “present”.

Next, a method of measuring the friction coefficient of the yarn contact surface will be described with reference to FIG. The sliding test apparatus shown in FIG. 6 includes a roller R1, a roller R2, a fiber guide 10, a roller R3 and a roller R4, and can guide the fiber 1 in this order. A tension detector (not shown) is connected to the rollers R2 and R3.

Then, the fiber 1 is guided by using this sliding test device, and the measured value of the tension T1 detected by the tension detector of the roller R2 and the measured value of the tension T2 detected by the tension detector of the roller R3 are measured. The friction coefficient (μ) can be obtained by using the equation (μ={ln(T2-T1)}/θ) of Amonton's law.

The friction coefficient changes depending on test conditions such as the type of the fiber 1, the shape of the fiber 1, the traveling speed of the fiber 1, the tension of the fiber 1, and θ. Therefore, it is necessary to compare the friction coefficients under the same test conditions.

Next, an example of the manufacturing method of the fiber guide of the present disclosure will be described. Here, among the fiber guides, an oiling nozzle will be described as an example.

First, aluminum oxide (Al ₂ O ₃ ) powder, which is a main raw material, is put into a mill together with a solvent and balls, and pulverized to a predetermined particle size to prepare a slurry.

Next, a binder is added to the obtained chiller, and then spray drying is performed using a spray dryer to produce granules.

Next, the granules, the thermoplastic resin, the wax and the like are put into a kneader and kneaded while heating to obtain a kneaded clay. Then, the obtained kneaded material is put into a pelletizer to obtain pellets as a raw material for injection molding (injection molding). Next, the pellets thus obtained are put into an injection molding machine (injection molding machine) and injection-molded to obtain a molding having an oiling nozzle shape.

As described above, in order to obtain a molded body having an oiling nozzle shape, a molding die having an oiling nozzle shape is prepared based on a general injection molding method, and the molding die is installed in an injection molding machine to perform injection molding. Good. Then, since the surface texture of the inner surface of this molding die is transferred to the surface of the molded body, the load length ratio Rmr20 is 15% or less and the load length ratio Rmr50 is 60% or more. In order to obtain the surface, a mold having a surface texture suitable for the surface may be used to produce the molded body. The same applies to the case of obtaining a yarn contact surface having a load length ratio Rmr50 of 75% or more, an average unevenness interval Rsm of 5 μm or more and 25 μm or less, and a peak count Pc of 10 or more and 30 or less.

Next, for example, in the case where aluminum oxide is the main raw material, the maximum temperature of the obtained oiling nozzle shaped molded body is set to 1500° C. or more and 1600° C. or less in the atmosphere, and the holding time at this maximum temperature is set. By firing for 2 hours or more and 5 hours or less, an oiling nozzle-shaped sintered body is obtained. The firing conditions such as the maximum temperature and the holding time vary depending on the shape and size of the product, and may be adjusted as necessary. Then, by finally washing and drying, the oiling nozzle of the present disclosure is obtained.

In addition, in order to obtain a yarn contact surface in which the average circularity of the aluminum oxide crystal particles is 0.55 or more and 0.8 or less, the standard deviation of the particle diameter of the aluminum oxide powder after milling with a mill is 0.05 μm. The above may be set to 0.2 μm or less. The particle size of the aluminum oxide powder is a value measured by a laser diffraction method.

Further, in order to obtain a yarn contacting surface on which aluminum titanate crystal particles are present, aluminum titanate (Al ₂ TiO ₅ ) powder may be added to aluminum oxide powder as a main raw material. Here, the average particle diameter of the aluminum titanate powder is 0.5 μm or more and 1.2 μm or less, and the proportion of the aluminum oxide powder and the aluminum titanate powder is 87 to 96 mass% of Al in terms of Al ₂ O ₃ , Al ₂ By adjusting so as to be 4% by mass or more and 13% by mass or less in terms of TiO ₅ , the average particle size of the aluminum titanate crystal particles is 2 μm or more and 10 μm or less, and the area occupied by the aluminum titanate crystal particles is A yarn contact surface having a ratio of 1 area% or more and 7 area% or less can be obtained. The average particle size of the aluminum titanate powder is a value measured by a laser diffraction method.

First, a slurry was prepared by putting aluminum oxide powder having a purity of 99.6% as a raw material powder together with water and balls as a solvent in a mill and pulverizing the powder.

Next, a binder was added to this slurry, and then spray drying was performed using a spray dryer to prepare granules. Then, a thermoplastic resin and a wax were added to the obtained granules, which were put into a kneader and kneaded while heating to obtain a kneaded material. Next, the obtained kneaded material was put into a pelletizer to obtain pellets as a raw material for injection molding. Then, the pellets were put into an injection molding machine to obtain a molding having an oiling nozzle shape.

Here, the surface texture of the inner surface of the molding die installed in the injection molding machine was set to the load length ratio Rmr20 and the load length ratio Rmr50 shown in Table 1.

Next, this oiling nozzle-shaped compact was fired at a maximum temperature of 1550° C. in the atmosphere for a holding time of 3 hours at this maximum temperature to obtain an oiling nozzle-shaped sintered body. Then, each sample was obtained by finally washing and drying.

Next, the load length ratio Rmr20 and the load length ratio Rmr50 of the yarn contact surface of each sample were measured using a surface roughness measuring machine (SE-3500 manufactured by Kosaka Laboratory Ltd.) according to JIS B 0601 (2013). It was calculated by measuring the yarn contact surface based on the above. As the measurement conditions, the reference length was 0.8 mm, the cutoff value was 1 mm, the tip radius of the stylus was 2 μm, and the tip speed of the stylus was 0.5 mm/sec. Then, the yarn contact surface was measured at 5 points, and the average value was calculated.

Next, each sample was set in the sliding test device shown in FIG. 6 and a sliding test was performed to determine the friction coefficient of each sample. The measurement conditions were as follows.
Fiber type: Nylon (75 denier)
Fiber running speed: 1000 m/min θ: 90°
Fiber tension: 50gf
Measurement frequency: 10 times (every 1 minute)
Friction coefficient: Each friction coefficient was obtained from the detected tension, and the average value of 10 times was used as the friction coefficient.

The results are shown in Table 1.

From the results shown in Table 1, the sample No. Sample Nos. 4 to 10 are sample Nos. The coefficient of friction was as low as 0.31 as compared with 1 to 3. From this, in the fiber contacting surface, the load length ratio Rmr20 is 15% or less, and the load length ratio Rmr50 is 60% or more. It was found that the fiber can be prevented from being damaged when being guided.

Next, a plurality of oiling nozzles having different load length ratios Rmr50 on the yarn contact surface were prepared. Then, a sliding test was conducted on these oiling nozzles to compare the friction coefficients of the yarn contact surfaces. As the manufacturing method, the sample No. 7 of Example 1 was manufactured except that the surface texture of the inner surface of the molding die installed in the injection molding machine was changed to the load length ratio Rmr50 shown in Table 2. Similar to the method, Sample No. 11 is the same sample as Sample No. 7 of Example 1.

Next, the load length ratio Rmr50 of the yarn contact surface of each sample was calculated by measuring in the same manner as in Example 1.

Further, the same sliding test as in Example 1 was performed to determine the friction coefficient of the yarn contact surface of each sample. The results are shown in Table 2.

From the results shown in Table 2, sample No. The friction coefficients of 12 and 13 were as low as 0.29. From this, it was found that a fiber guide having a load length ratio Rmr50 of 75% or more on the yarn contacting surface would have a lower friction coefficient on the yarn contacting surface.

Next, a plurality of oiling nozzles having different values of the average interval Rsm of irregularities on the yarn contact surface were produced. Then, a sliding test was conducted on these oiling nozzles to compare the friction coefficients of the yarn contact surfaces. As the manufacturing method, the sample No. 7 of Example 1 was manufactured except that the surface texture of the inner surface of the molding die installed in the injection molding machine was changed to have the average interval Rsm of the irregularities shown in Table 3. Similar to the method, Sample No. 14 is the same sample as Sample No. 7 of Example 1.

Next, the average interval Rsm of the concavities and convexities on the yarn contact surface of each sample was calculated by measuring in the same manner as in Example 1.

Further, the same sliding test as in Example 1 was performed to determine the friction coefficient of the yarn contact surface of each sample. The results are shown in Table 3.

From the results shown in Table 3, sample No. Nos. 15 to 17 had a low friction coefficient of 0.29. From this, it was found that the fiber guide having an average interval Rsm of irregularities of 5 μm or more and 25 μm or less on the yarn contact surface has a lower friction coefficient on the yarn contact surface.

Next, a plurality of oiling nozzles having different peak counts Pc on the yarn contact surface were prepared. Then, a sliding test was conducted on these oiling nozzles to compare the friction coefficients of the yarn contact surfaces. As the manufacturing method, the manufacturing method of Sample No. 7 of Example 1 was changed except that the surface texture of the inner surface of the molding die installed in the injection molding machine was changed to have the peak count Pc shown in Table 4. Similarly, sample No. 19 is the same sample as sample No. 7 of the first embodiment.

Next, the peak count Pc of the yarn contact surface of each sample was calculated by measuring in the same manner as in Example 1.

Further, the same sliding test as in Example 1 was performed to determine the friction coefficient of the yarn contact surface of each sample. The results are shown in Table 4.

From the results shown in Table 4, the sample No. 20 to 22 had a low friction coefficient of 0.29. From this, it was found that a fiber guide having a peak count Pc of 10 or more and 30 or less on the yarn contact surface has a lower friction coefficient on the yarn contact surface.

Next, a plurality of oiling nozzles each having a yarn contacting surface made of aluminum oxide ceramics and having different average circularity values of aluminum oxide crystal particles were produced. Then, a sliding test was conducted on these oiling nozzles to compare the friction coefficients of the yarn contact surfaces. The manufacturing method was the same as the manufacturing method of Sample No. 7 of Example 1 except that the standard deviation of the particle diameter of the aluminum oxide powder after milling was set to the value shown in Table 5. did.

Next, the average circularity of the aluminum oxide crystal particles on the yarn contact surface of each sample was calculated by the following method. First, surface analysis of the yarn contact surface was performed using EPMA. Particles in which titanium was not detected and aluminum and oxygen were simultaneously detected by color mapping of surface analysis were regarded as aluminum oxide crystal particles. Next, a photograph of the yarn contact surface was taken using an SEM, and the aluminum oxide crystal particles were written on the tracing paper from this photograph. Then, the tracing paper was read as image data, and image analysis was performed by applying a method called particle analysis of image analysis software "A image kun" to determine the average circularity of the aluminum oxide crystal particles. Here, as the analysis conditions of the image analysis software “A image-kun”, the brightness of the crystal grains was “bright”, the binarization method was “automatic”, and the shading was “present”.

Further, the same sliding test as in Example 1 was performed to determine the friction coefficient of the yarn contact surface of each sample. The results are shown in Table 5.

From the results shown in Table 5, the sample No. In Nos. 25 to 27, the friction coefficient was as low as 0.29. From this, it was found that a fiber guide in which the average circularity of the aluminum oxide crystal particles on the yarn contact surface is 0.55 or more and 0.8 or less has a lower friction coefficient on the yarn contact surface. ..

Next, an oiling nozzle having aluminum titanate crystal particles on the yarn contact surface was prepared. Here, a plurality of oiling nozzles in which the average crystal grain size of the aluminum titanate crystal grains and the area ratio occupied by the aluminum titanate crystal grains were made different were produced. Then, a sliding test was conducted on these oiling nozzles to compare the friction coefficients of the yarn contact surfaces. In addition, as a manufacturing method, a sample of Example 5 except that aluminum titanate powder having an average particle size shown in Table 6 was mixed with aluminum oxide powder in a ratio shown in Table 6 as a raw material powder The manufacturing method of No. 26 was the same.

Next, it was confirmed by the following method whether or not aluminum titanate crystal particles were present on the yarn contact surface of each sample. First, surface analysis of the yarn contact surface was performed using EPMA. Then, the particles in which titanium, aluminum and oxygen were simultaneously detected by the color mapping of the surface analysis were regarded as aluminum titanate crystal particles. As a result, the presence of aluminum titanate crystal particles was confirmed in all the samples.

Next, the average crystal grain size of the crystal grains of aluminum titanate and the area ratio occupied by the crystal grains of aluminum titanate on the yarn contact surface of each sample were calculated by the following method. First, a photograph of the yarn contact surface is taken using an SEM. Since the aluminum titanate crystal particles determined by the above measurement had a black color tone, the image analysis of this photograph was performed by applying the method of particle analysis of the image analysis software "A image-kun". By carrying out, the average crystal grain size of the aluminum titanate crystal grains and the area ratio occupied by the aluminum titanate crystal grains were determined. As the analysis conditions of the image analysis software “A image-kun”, the lightness of the crystal grains was “bright”, the binarization method was “automatic”, and the shading was “present”.

Next, the load length ratio Rmr20, the load length ratio Rmr50, the average interval Rsm of the irregularities, and the peak count Pc of the yarn contact surface of each sample were calculated by the same method as in Example 1. As a result, the load length ratio Rmr20, the load length ratio Rmr50, the average interval Rsm of the concavities and convexities, and the peak count Pc of each sample were the same values as those of the sample No. 26 of Example 5.

Further, the same sliding test as in Example 1 was performed to determine the friction coefficient of the yarn contact surface of each sample. The results are shown in Table 6.

From the results shown in Table 6, sample No. Nos. 29 to 41 are sample Nos. Compared with No. 26, the friction coefficient was as low as 0.28 or less. From this, it was found that the fiber guide having aluminum titanate crystal particles on the yarn contact surface has a lower friction coefficient on the yarn contact surface.

Then, the sample No. Sample No. 29 among Nos. 29-41. Since 30, 31, 33 to 36, and 38 to 40 have a friction coefficient of 0.27, the average crystal grain size of the aluminum titanate crystal grains is 2 μm or more and 10 μm or less, and the aluminum titanate crystal grains are It was found that the fiber guide having an area ratio of 1 area% or more and 7 area% or less has a further lower friction coefficient on the yarn contact surface.

1: Fiber 2: Crystal particles of aluminum oxide 3: Crystal particles of aluminum titanate 10a: Roller guide 10b: Oiling nozzle 10c: Rod guide 10d: Traverse guide 10: Fiber guides R1 to R4: Rollers

Claims (4)

The yarn contacting surface has a load length ratio Rmr20 of 20% for a cutting level determined from a roughness curve of 15% or less, and a load length ratio Rmr50 of 50% for a cutting level determined from a roughness curve of 60%. And above ,
The average interval Rsm of the irregularities obtained from the roughness curve on the yarn contact surface is 5 μm or more and 25 μm or less,
The peak count Pc obtained from the roughness curve on the yarn contact surface is 10 or more and 30 or less,
A fiber guide made of aluminum oxide ceramics, wherein the average circularity of the aluminum oxide crystal particles on the yarn contact surface is 0.55 or more and 0.8 or less . The fiber guide according to claim 1, wherein the yarn contact surface has the Rmr50 of 75% or more. The fiber guide according to claim 2 , wherein the yarn contact surface includes crystal particles of aluminum titanate. The fiber according to claim 3 , wherein the average crystal grain size of the aluminum titanate crystal grains is 2 μm or more and 10 μm or less, and the area ratio occupied by the aluminum titanate crystal grains is 1 area% or more and 7 area% or less. guide.

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