A yarn twist tester

Abstract

The invention discloses a yarn twist tester, comprising a light source, a transparent stage, an objective lens, an eyepiece, a beam splitter, a plane mirror and a twist angle measuring device, wherein the light source generates parallel light, and the light source, the transparent stage, the objective lens and the eyepiece are placed in sequence, the transparent stage is located between one and two focal lengths of the objective lens, the eyepiece is located outside two focal lengths of the objective lens, and the distance between the axis of the eyepiece and the focus of the objective lens is the focal length of the eyepiece, the reflecting surface of the beam splitter forms an angle ε with the incident light, 0°<ε<90°, the plane mirror is located on one side of the beam splitter, the reflected light of the beam splitter is perpendicular to the mirror surface of the plane mirror, and the twist angle measuring device for measuring the angle is located opposite to the plane mirror. The yarn is enlarged by an optical device to facilitate the measurement of the twist angle, and the device has a simple structure and is easy to operate.

Description

Technical Field

[0001] The invention relates to a textile measuring device, in particular to a yarn twist tester, which is particularly suitable for measuring the twist angle of jet vortex yarn. The yarn is magnified by an optical device to directly obtain the yarn twist angle and the twist is obtained by calculation. Background Art

[0002] Yarn twist refers to the number of twists / 10cm along the axial direction of a yarn at a certain length, and is an important indicator for evaluating the grade of yarn. For the measurement of yarn twist, the commonly used method at home and abroad is the untwisting and twisting method. The untwisting and twisting method means that under the specified pre-tension, two adjustable distance clamps of the twist tester clamp the two ends of the yarn of known length, and one of the clamps rotates to drive one end of the sample to rotate, so that the yarn is first untwisted and then reversely twisted, and the yarn is twisted and stretched and twisted respectively. When the yarn returns to its initial length, the number of twists of the untwisting and twisting is twice the number of twists on the yarn of that length.

[0003] During the production process of air jet vortex yarn, the fiber bundle is output from the front roller jaws and enters the vortex chamber through the spiral guide surface of the nozzle. The front end of the fiber bundle enters the hollow tube (hollow spindle) under the action of the guide needle. The tail end of the fiber expands due to the centrifugal force and the airflow to form a free fiber (which can be called the tail end free end fiber). The tail end free end fiber rotates and twists into yarn under the action of the vortex formed by the airflow ejected from the tangential injection hole, and is led out from the hollow tube and wound into a cone yarn. In fact, not all fibers can fully expand to form fibers in a free state at the tail end, and a certain amount of fibers are still in the yarn core in an integral form. Therefore, vortex air jet yarn is a double-structured yarn. The yarn is basically composed of two very clear strands - core fibers and outer fibers. The core fibers of the yarn strip are arranged in parallel and basically have no twist. Compared with air jet yarn, vortex air jet yarn has more outer covering fibers and presents a more neat and clear strip-shaped spiral arrangement. The twist is accurately measured using the existing untwisting and twisting method. Under the specified tension (0.5±0.1cN / tex), clamp the two ends of a certain length of sample, rotate one end of the sample, and when the yarn elongation reaches the maximum, use a magnifying glass to observe the outer fiber, which is not completely untwisted. Continue to rotate the gripping jaws in the same direction under the microscope until the units are parallel. Because the core fiber begins to twist when the outer fiber begins to untwist, the maximum elongation of the yarn in the original method cannot be used to represent the complete untwisting of the yarn. Therefore, the untwisting and twisting method cannot be used to accurately measure its twist. For this reason, it is necessary to design a device that effectively characterizes the twist of the jet vortex yarn. Summary of the invention

[0004] In view of the above situation, the purpose of the present invention is to provide a yarn twist tester, which solves the problem that the existing testing method is difficult to measure the jet vortex yarn well and obtain yarn evaluation parameters such as twist angle and twist.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A yarn twist tester comprises a light source, a transparent stage, an objective lens, an eyepiece, a beam splitter, a plane mirror and a twist angle measuring device. The light source generates parallel light. The light source, the transparent stage, the objective lens and the eyepiece are placed in sequence. The transparent stage is located between one and two focal lengths of the objective lens. The eyepiece is located outside two focal lengths of the objective lens, and the distance between the eyepiece axis and the objective lens focus is the eyepiece focal length. The reflection surface of the beam splitter forms an angle ε with the incident light, 0°<ε<90°. The plane mirror is located on one side of the beam splitter, and the reflected light of the beam splitter is perpendicular to the mirror surface of the plane mirror. The twist angle measuring device for measuring the angle is located opposite to the plane mirror.

[0007] Furthermore, the twist tester also includes a twist conversion unit, which is based on the formula Convert twist angle to twist.

[0008] Furthermore, the twist tester also includes an aperture, which is located between the objective lens and the light source.

[0009] As an implementation manner, the twist measuring device includes glass and a universal angle ruler fixed on the glass.

[0010] As another embodiment, the twist measuring device includes glass, and angle lines are provided on the glass.

[0011] Preferably, the glass is frosted glass.

[0012] Furthermore, the twist tester also includes an objective lens rotating bracket, an eyepiece bracket and a bracket. Objective lenses of different magnifications are fixed on the objective lens rotating bracket. The objective lens rotating bracket is rotated to select an objective lens of appropriate magnification. The eyepiece is fixed on the eyepiece bracket. The bracket is arranged directly above the eyepiece bracket. A light hole is opened on the bracket corresponding to the eyepiece directly above the eyepiece. The beam splitter is fixed on the bracket at the light hole. The plane mirror is fixed on one side of the bracket. The twist angle measuring device is fixed on the other side of the bracket.

[0013] When in use, the light source, aperture, yarn, objective lens and eyepiece center are located on the same axis.

[0014] Compared with the prior art, the present invention magnifies the yarn through an optical device, which is convenient for measuring the twist angle, and the device has a simple structure and is easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the structure of the yarn twist tester in Example 1.

[0016] Figure 2 This is a partial imaging principle diagram of the yarn twist tester in Example 1.

[0017] Figure 3 This is a test photo of the yarn twist tester in Example 1.

[0018] Among them, 1-aperture, 2-objective lens, 3-objective lens rotating bracket, 4-eyepiece, 5-eyepiece bracket, 6-bracket, 7-plane mirror, 8-beam splitter, 9-twist angle measuring device. DETAILED DESCRIPTION

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and through specific embodiments. It should be understood that the following embodiments are used to illustrate the present invention rather than to limit its protection scope.

[0020] Example 1

[0021] like Figure 1 As shown, the twist angle tester involved in this embodiment includes a light source, a transparent stage, an objective lens 2, an eyepiece 4, a beam splitter 8, a plane mirror 7 and a twist angle measuring device 9, wherein the light source generates parallel light, and the light source, the transparent stage, the objective lens 2 and the eyepiece 4 are placed in sequence, the focal length of the objective lens is f, the focal length of the eyepiece is F, the transparent stage is located between one and two times the focal length of the objective lens 2, the eyepiece 4 is located outside two times the focal length of the objective lens 2, and the distance between the axis of the eyepiece 4 and the focus of the objective lens 2 is the eyepiece focal length F, the reflecting surface of the beam splitter 8 forms an angle ε with the incident light, 0°<ε<90°, the plane mirror 7 is located on one side of the beam splitter 8, the light reflected by the beam splitter is perpendicular to the mirror surface of the plane mirror, and the twist angle measuring device 9 for measuring the angle is located opposite the plane mirror.

[0022] Furthermore, the twist angle tester also includes an aperture 1, which is located between the objective lens 2 and the light source. By adjusting the size of the aperture 1, the intensity of the transmitted light is adjusted, and then the brightness and contrast of the yarn image in the plane mirror are adjusted to obtain an image with clear fiber texture.

[0023] As an implementation method, the twist angle measuring device includes glass and a universal angle ruler fixed on the glass. The virtual image of the yarn in the plane mirror can be seen through the glass, and the twist angle β of the yarn can be obtained by rotating the universal angle ruler.

[0024] As another embodiment, the twist angle measuring device includes glass with angle lines on the glass. Through the glass, a virtual image of the yarn in the plane mirror can be seen, and the glass is rotated to align the angle line with the yarn image to obtain the twist angle β of the yarn.

[0025] Preferably, the glass is frosted glass.

[0026] Furthermore, the twist angle tester also includes an objective lens rotating bracket 3, an eyepiece bracket 5 and a bracket 6. Objective lenses of different magnifications are fixed on the objective lens rotating bracket 3. The objective lens rotating bracket 3 is rotated to select an objective lens of appropriate magnification. The eyepiece 4 is fixed on the eyepiece bracket 5. During use, the eyepiece on the eyepiece bracket 5 with different magnifications can be replaced according to the selection. The bracket is arranged directly above the eyepiece bracket 5, and a light hole is opened on the bracket corresponding to the eyepiece directly above the eyepiece. The beam splitter 8 is fixed on the bracket at the light hole, the plane mirror 7 is fixed on one side of the bracket 6, and the twist angle measuring device 9 is fixed on the other side of the bracket 6.

[0027] And make the axis of the selected objective lens and the center of the aperture on the same axis

[0028] like Figure 2 As shown, the imaging principle of the twist angle tester involved in this embodiment is: put the yarn on the stage, and the parallel light emitted by the light source is irradiated on the yarn. The light source, yarn, objective lens 2 and eyepiece 4 are adjusted to be located on the same axis. Since the yarn is located between one and two focal lengths of the lens, through the objective lens, an inverted and enlarged virtual image is formed outside the double focal length of the objective lens. The eyepiece is placed outside the virtual image. The focal length of the eyepiece is equal to the distance between the focus of the objective lens and the axis of the eyepiece. After passing through the objective lens, the light is converted into parallel light and irradiated on the beam splitter. After being reflected by the beam splitter, an inverted and enlarged image appears on the plane mirror. The incident angle of the incident light of the beam splitter is θ, 0°<θ<90°. The larger the incident angle θ, the larger the image on the plane mirror. After passing through the objective lens, eyepiece and beam splitter, the yarn is magnified three times, with a magnification of 200-500 times. Each fiber ( Figure 3 ), the twist angle β can be easily obtained by the twist angle measuring device.

[0029] Specifically, Among them, α is the twist coefficient, also known as twist, β is the twist angle, and δ is the volume mass;

[0030]

[0031] Where, d is the yarn diameter, T t For fineness;

[0032] From formulas (1) and (2), we can get: Based on the above formula, the twist of the yarn can be directly calculated. For example, 32s polyester yarn is used, and the yarn diameter is tested 30 times, and the average value d = 0.1622mm is taken. The fineness of 32s polyester yarn Tt = 1.8443tex, and the twist angle is measured multiple times to take the average value β = 0.549, and α = 515.36 is calculated, which is a strong twist yarn.

Claims

1. A yarn twist tester, characterized in that: The invention comprises a light source, a transparent stage, an objective lens, an eyepiece, a beam splitter, a plane mirror, a twist angle measuring device, an objective lens rotating bracket, an eyepiece bracket and a bracket. The light source generates parallel light. The light source, the transparent stage, the objective lens and the eyepiece are placed in sequence. The transparent stage is located between one and two focal lengths of the objective lens. The eyepiece is located outside two focal lengths of the objective lens. The distance between the axis of the eyepiece and the focus of the objective lens is the focal length of the eyepiece. The reflecting surface of the beam splitter forms an angle ε with the incident light, 0°<ε<90°. The plane mirror is located between the beam splitter and the incident light. On one side of the mirror, the reflected light of the beam splitter is perpendicular to the mirror surface of the plane mirror, a twist angle measuring device for measuring angles is located opposite to the plane mirror, objective lenses of different magnifications are fixed on the objective lens rotating bracket, the objective lens rotating bracket is rotated to select an objective lens of appropriate magnification, the eyepiece is fixed on the eyepiece bracket, the bracket is located directly above the eyepiece bracket, a light hole is opened on the bracket corresponding to the eyepiece directly above the eyepiece, the beam splitter is fixed on the bracket at the light hole, the plane mirror is fixed on one side of the bracket, and the twist angle measuring device is fixed on the other side of the bracket; The twist tester also includes an aperture, which is located between the objective lens and the light source; The twist angle measuring device comprises glass and a universal angle ruler fixed on the glass, or the twist angle measuring device comprises glass, and angle lines are arranged on the glass; The twist tester also includes a twist conversion unit, which is based on the formula , where α is the twist coefficient, also known as twist, d is the yarn diameter, T t is the fineness, β is the twist angle, and the twist angle is converted into twist; The yarn is placed on the stage, and the parallel light emitted by the light source is irradiated on the yarn. The light source, yarn, objective lens and eyepiece center are adjusted to be on the same axis. Since the yarn is located between one and two focal lengths of the lens, an inverted and enlarged virtual image is formed outside the double focal length of the objective lens through the objective lens. The eyepiece is placed outside the virtual image. The focal length of the eyepiece is equal to the distance between the focus of the objective lens and the axis of the eyepiece. After passing through the objective lens, the light is converted into parallel light and irradiated on the beam splitter. After being reflected by the beam splitter, an inverted and enlarged image is formed on the plane mirror. The incident angle of the incident light of the beam splitter is θ, 0°<θ<90°. The larger the incident angle θ, the larger the image on the plane mirror. After passing through the objective lens, eyepiece and beam splitter, the yarn is magnified three times, and the magnification is 200-500 times. Each fiber can be clearly presented in the plane mirror, and the twist angle β is easily obtained through the twist angle measuring device.

2. The yarn twist tester according to claim 1, characterized in that: The glass is frosted glass.

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