WO2010060357A1

WO2010060357A1 - Apparatus and method for preparation of yarn samples under different axial tensions for yarn cross section and packing density measurements

Info

Publication number: WO2010060357A1
Application number: PCT/CN2009/074925
Authority: WO
Inventors: Ying GUO; Xiaoming Tao; Bingang Xu; Tao HUA
Original assignee: The Hong Kong Research Institute Of Textiles And Apparel
Priority date: 2008-11-28
Filing date: 2009-11-16
Publication date: 2010-06-03
Also published as: CN102272366A; CN102272366B

Abstract

The present invention discloses the apparatus and method to prepare yarn samples for yarn cross section and packing density measurements by microscope under different yarn axial tensions. A method of preparing a yarn sample may include sealing one end of a tube having a yarn threaded therethrough, fixing the sealed end of the yarn with a first attachment member, applying a tension to the yarn, fixing the other end of the yarn with a second attachment member when maintaining the applied tension of the yarn, and filling the tube with a resin.

Description

APPARATUS AND METHOD FOR PREPARATION OF YARN SAMPLES

UNDER DIFFERENT AXIAL TENSIONS FOR YARN CROSS SECTION AND PACKING DENSITY MEASUREMENTS

BACKGROUND

[01] Longitudinal distribution of fibers in spun yarns is an important aspect of the yarn structures, yet it cannot provide enough information for a full understanding of fibers' configuration in the yarn of three-dimensional structures.

[02] Packing density is commonly used to represent fibers distribution in cross section of a yam to examine yarn structure more comprehensively. Many methods have been developed to calculate the packing density. In one example, the cross section of the yarn was divided into several annular zones with equal radial width or area. Packing fraction may then be defined as the ratio of the total cross-sectional area of the fibers in a given zone of a yarn cross section to the area of that zone. In another example, the packing density was studied by keeping the yarn lengths constant. However, these studies failed to account for the yarn packing fraction due to changes of applied tension.

[03] Given that yarn packing density may greatly change when different tensions are applied onto the yams, and that yams are not usually kept under a zero tension condition in practical applications, it may therefore be desirable to study yarn structures at different applied tensions. Unfortunately, preparing yarn samples for microtomy can be a time consuming exercise, and controlling the yarn samples under different applied tensions can be difficult. [04] It is therefore desirable to develop an improved and efficient apparatus and method of preparing yarn samples for cross-sectional measurements of the yarns under different axial tensions. BRIEF SUMMARY

[05] According to one aspect, a method of preparing a yarn sample may include sealing one end of a tube having a yarn threaded therethrough, fixing the sealed end of the tube to a first attachment member, applying a tension to the yarn, fixing the other end of the yarn with a second attachment member when maintaining the applied tension of the yarn, and filling the tube with a resin.

[06] According to another aspect, an apparatus for preparing a yarn sample may include the tube for threading the yarn, the first attachment member for fixing the sealed end of the tube, a tension gauge for applying and adjusting tension to the yarn, the second attachment member for fixing the other end of the yarn when maintaining the applied tension of the yarn. Other attachment members may be included for additional yarn samples. The apparatus may also include two fastening members for fastening a rotatable component of the apparatus at an upright position.

BRIEF DESCRIPTION OF THE DRAWINGS

[07] FIG. I depicts the schematic diagram for yarn sample preparation using the apparatus.

[08] FIG. 2 depicts the schematic diagram for yarn sample solidification using the apparatus. [09] FIG. 3 depicts a cross-sectional image of a 24Nm wool yarn prepared under 0 gram- force of tension.

[010] FIG. 4 depicts a cross-sectional image of a 24Nm wool yarn prepared under 3 gram- force of tension.

[011] FIG. 5 depicts a cross-sectional image of a 24Nm wool yarn prepared under 6 gram- force of tension.

[012] FIG. 6 depicts a cross-sectional image of a 24Nm wool yarn prepared under 8 gram- force of tension. [013] FIG. 7 depicts a graph of the relationship between fiber packing fraction and radial position of yarn.

DETAILED DESCRIPTION [014] Reference will now be made in detail to a particular embodiment of the invention, examples of which are also provided in the following description. Exemplary embodiments of the invention are described in detail, although it will be apparent to those skilled in the relevant art that some features that are not particularly important to an understanding of the invention may not be shown for the sake of clarity. [015] Furthermore, it should be understood that the invention is not limited to the precise embodiments described below, and that various changes and modifications thereof may be effected by one skilled in the art without departing from the spirit or scope of the invention. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of this disclosure and appended claims. In addition, improvements and modifications which may become apparent to persons of ordinary skill in the art after reading this disclosure, the drawings, and the appended claims are deemed within the spirit and scope of the present invention.

[016] A method of preparing a yarn sample may include sealing one end of a tube 2 having a yarn 3 threaded therethrough, fixing the sealed end of the tube 2 with a first attachment member 1, applying a tension to the yarn 3, maintaining the applied tension and fixing the other end of the yarn 3 with a second attachment member 4, and filling the tube 2 with a resin 6, as depicted in FIGs. 1 and 2.

[017] The first step may include sealing one end of the tube 2 having the yarn 3 threaded therethrough, as depicted in FIG. 1. The tube 2 may be of any shape that may allow the yarn 3 to be threaded through and allow resin 6 to be injected. The tube 2 may also be of any length and diameter according to the desired dimensions of the yarn sample to be prepared. Preferably, the tube 2 may be a plastic tube with circular cross section of length and diameter to be chosen according to the microtome. Any type of yarn of fiber material may be used. For example, filament yarn or staple yarn may be used. The tube 2 may be sealed by folding or any other methods known to one of ordinary skill in the art. Preferably, the yarn 3 should be positioned approximately at the centerline of the tube 2 when the tube 2 is sealed. [018] The second step may include fixing the sealed end of the tube 2 with the first attachment member 1. The first attachment member 1 may be a clamp, whereas other types of attachment means known to one of ordinary skill in the art may also be used.

[019] The third step may include applying a tension to the yarn 3. The tension may be applied and adjusted to a desired value using a tension gauge 5. For example, three, six, and eight gram- forces of tension may be applied to the yarn 3. Other types of equipment known to one of ordinary skill in the art to adjust the tension applied to the yarn may also be used.

[020] The fourth step may include maintaining the applied tension of the yarn 3 and fixing the other end of the yarn 3 with the second attachment member 4. Cautions should be paid to maintain a vertical position of the tube 2, and the yarn 3 should be placed close to the centerline of the tube 2. The second attachment member 4 may be a clamp, whereas other types of attachment means known to one of ordinary skill in the art may also be used.

[021] The above steps may be repeated to prepare more yarn samples at the same or different tension values. For example, six yarn samples may be prepared, as depicted in FIG. 1.

[022] The fifth step may include rotating a rotatable component of the apparatus upward and mounting the component to fastening members 7 and 8. For example, the rotatable component may be rotated 180 degrees upward. Preferably, the tube 2 in which yarn 3 has been fixed under the desired tension and closely positioned at the centerline of the tube 2 should be maintained at an upright position, as depicted in FIG. 2. The sealed and fastened end of the tube 2 should be facing downward. [023] The sixth step may include filling the tube 2 with the resin 6. Examples of the resin materials include Leica Historesin Embedding Kit. Other resin materials known to one of ordinary skill in the art may also be used.

[024] The seventh step may include solidifying the resin 6 to prepare samples for microtomy. The resin 6 may be solidified under room temperature ranging from 1 to 5 hours. The tube 2 may be removed from the yarn sample after solidification. The prepared yarn samples embedded in solidified resin may then be processed into desired lengths and diameters for test in microtomy or microscopy studies.

[025] An apparatus for preparing a yarn sample may include the tube 2 for threading the yarn 3, the first attachment member I for fixing the sealed end of the tube 2, the tension gauge 5 for applying and adjusting tension imposed on the yarn 3, the second attachment member 4 for fixing the other end of the yarn 3 when maintaining the tension applied to the yarn 3. Other attachment members may be included for additional yarn samples. The apparatus may also include two fastening members 7 and 8 for fastening a rotated component of the apparatus at an upright position.

[026] Having described embodiments of the present system with reference to the accompanying drawings, it is to be understood that the present system is not limited to the precise embodiments, and that various changes and modifications may be effected therein by one having ordinary skill in the art without departing from the scope or spirit as defined in the appended claims.

[027] Furthermore, it should be understood that the method and apparatus are not limited to the precise embodiments described below and that various changes and modifications thereof may be effected by one skilled in the art without departing from the spirit or scope of the invention. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of this disclosure and appended claims. EXAMPLES

Example 1 : Microtomy of the yarn samples under different tensions

[028] In the example, four 24 Nm woo! yam samples of different applied tensions were prepared using the apparatus and method as described above. The microtomy of yarn samples prepared under various tensions was investigated under a microscope. A cross-sectional image of a 24 Nm wool yarn sample prepared under 0 gram-force of tension is depicted in FIG. 3. A cross section of a 24 Nm wool yarn sample prepared under 3 gram- force of tension is depicted in FΪG. 4. A cross section of a 24 Nm wool yarn sample prepared under 6 gram-force of tension is depicted in FIG. 5. A cross section of a 24 Nm wool yarn sample prepared under 8 gram-force of tension is depicted m

[029] As shown in the FIG. 3, the wool fibers were loosely spread out across the image, when the yarn was prepared under 0 gram-force of tension. As shown in the FΪG, 4, the wool fibers more closely packed than in FIG. 3, when the yam was prepared under 3 gram-force of tension. As shown in the FΪG. 5, the wool fibers were more tightly bundled around the yam center than in both FIG. 3 and FICs, 4, when the yarn was prepared under 6 gram-force of tension. As shown in the F[G. 6, the wool fibers were more tightly bundled than all other FIGs, 3 to 5, when the yarn was prepared under 8 gram-force of tension.

[030] Therefore, these results have suggested that the yam structure tends to become more compact with the increase of tension.

[031] Tn this example, the relationship between the fiber packing fraction and radial position of yarn sample was evaluated. The wool yam samples at various tensions in Example 1 were used to measure the packing fraction and radial position. The results are plotted in FTG. 7. [032] As shown in FIG. 7, on one hand, fiber packing fraction varies along radial position of the yarn under tension. On the other hand, with increase of axial tension, the diameter of yarn decreases, and the packing fraction of fibers becomes greater, which suggests the yarn structure becomes more and more compact.

[033] While the apparatus and method have been described, it should be understood that the apparatus and method are not so limited, and modifications may be made. The scope of the method is defined by the appended claims, and all devices that come within the meaning of the claims, either literally or by equivalence, are intended to be embraced therein.

Claims

What is claimed is:

1. A method of preparing a yarn sample, comprising: sealing one end of a tube having a yarn threaded therethrough; fixing one end of said yarn with a first attachment member; applying a tension to said yarn; maintaining said applied tension and fixing the other end of said yarn with a second attachment member; and filling said tube with a resin.

2. The method of claim 1, further comprising rotating a rotatable component upward prior to filing said tube with said resin.

3. The method of claim 2, further comprising fastening said rotatable component using two fastening members to maintain the said component at an upright position.

4. The method of claim 1, further comprising solidifying said resin under room temperature after filling said tube with said resin.

5. The method of claim 5, further comprising removing said tube after solidifying said resin.

6. The method of claim 1, wherein said yarn comprises filament or staple yarn.

7. The method of claim 1, wherein said applying said tension comprises using a tension gauge.

8. The method of claim 1, wherein said resin comprises Leica Historesin Embedding Kit.

9. The method of claim 1, wherein said first attachment member comprises a clamp.

10. The method of claim 1, wherein said second attachment member comprises a clamp.

11. The method of claim 1 , wherein said tube comprises a plastic tube.

12. An apparatus for preparing a yarn sample, comprising: a tube for threading a yarn; a first attachment member for fixing one end of said tube with one end of said yarn; a tension gauge for applying and adjusting tension to said yarn; and a second attachment member for fixing the other end of said yarn when maintaining said applied tension of said yarn.

13. The apparatus of claim 12, further comprising a fastening member for fastening a rotatable component at an upright position.

14. A method of preparing a yarn sample, substantially as disclosed and described herein.

15. An apparatus for preparing a yam sample, substantially as disclosed and described herein.

16. Each and every novel feature herein disclosed.