Wear-resistant knitting needle manufacturing process

Abstract

The invention relates to the field of wear-resistant knitting manufacturing, in particular to a high-wear-resistance knitting needle manufacturing method. Comprising the following steps: (1) material selection; (2) precision machining; (3) heat treatment; (4) surface treatment; and (5) testing the wear resistance of the knitting needle. Wherein the step (2) comprises the following specific process steps: manufacturing a needle blank, processing a needle body and assembling the needle body. The specific process for manufacturing the needle blank comprises the three steps of blank punching, rolling and back planing. The needle body processing is to cut the rough surface between the curved surface of the needle blank and the needle tip at high speed to form a smooth surface. In the needle body assembly, a steel wire for manufacturing the latch is manufactured into the needle latch meeting the requirements in a mechanical extrusion, stamping, punching and shape cutting mode. And the step (3) specifically comprises the following process steps: cleaning, quenching and tempering. Cleaning refers to cleaning greasy dirt, impurities and the like on the surface of the knitting needle so as to guarantee the heat treatment quality. During quenching, Joule heat is used for heating the knitting needle, and argon protection and liquid nitrogen quenching are applied at the same time. Tempering means that the quenched knitting needle is heated to a certain temperature and then slowly cooled, so that residual stress in the knitting needle is eliminated, and the toughness and plasticity of the knitting needle are improved.

Description

Technical Field

[0001] The invention relates to a manufacturing process of wear-resistant knitting needles, belonging to the technical field of knitting needle manufacturing. Background Art

[0002] With the development of electronic technology, computerized flat knitting machine technology has been significantly improved, especially in the areas of electronic needle selection, electronic program control, and pattern preparation systems. These technological advances provide a technical foundation for precise needle control and convenient installation, but also place higher demands on needle wear resistance. Summary of the Invention

[0003] The present invention addresses the wear problem of knitting needles and provides a process for manufacturing wear-resistant knitting needles. This technological innovation not only improves the wear resistance of the knitting needles, but also reduces production costs and improves the quality of knitted fabrics. The present invention solves the above-mentioned technical problems with the following technical solutions: The process for manufacturing wear-resistant knitting needles includes (1) material selection; (2) precision machining; (3) heat treatment; (4) surface treatment; and (5) testing the wear resistance of the knitting needles.

[0004] On the basis of the above technical solution, the present invention can also be improved as follows.

[0005] Furthermore, the material selection in step (1) places high demands on the wear resistance of the knitting needle material. T9A steel is currently the most commonly used steel for knitting needle production. The higher the carbon content in the steel, the more supersaturated carbon atoms will dissolve when martensite forms during quenching, increasing lattice distortion and dislocation density, thereby significantly increasing the resistance to plastic deformation, that is, increasing the hardness and wear resistance of the knitting needle.

[0006] Furthermore, the composition of the T9A steel in step (1) is as follows: C 0.85-0.94%, Si ≤ 0.35%, Mn ≤ 0.40%, P ≤ 0.03%, S ≤ 0.02%. This steel has a relatively low inclusion content and is composed of acicular martensite with a small amount of retained austenite and carbide particles.

[0007] Furthermore, the specific process of precision machining in step (2) is: needle blank production, needle body processing and needle body assembly.

[0008] Furthermore, the specific process for producing the needle blank in step (2) includes three steps: punching, rolling, and planing. Punching is to use a die to apply pressure to the steel strip on a crank punch to separate it and form a needle shape. Rolling is to mechanically correct the side bend of the needle blank to obtain a straight needle blank. Planing is to improve the smoothness of the side surface of the needle blank by processing the rough part of the punched edge on the side of the needle blank with a planer.

[0009] Furthermore, the specific process of needle body processing in step (2) is to form a smooth surface by high-speed cutting on the rough surface between the curved surface of the needle blank and the needle tip, and to use the cold heading method to make the irregular needle tip from an ellipse into a circle, and at the same time use a milling cutter to mill out a circular arc at the needle body and needle belly to leave space for the installation of the needle tongue.

[0010] Furthermore, the specific process of needle body assembly in step (2) is to manufacture a needle tongue that meets the requirements by mechanically extruding, stamping, punching, and cutting the steel wire used for making the tongue, and install it at the needle belly position through a graduated transmission device. The alloy rods on both sides are squeezed in opposite directions to complete the positioning and making of the shaft, and the front needle tip is folded into a hook shape using a bending hook tool.

[0011] Furthermore, the process steps of the heat treatment in step (3) are cleaning, quenching and tempering. Cleaning refers to cleaning the oil, impurities and the like on the surface of the knitting needles to ensure the quality of the heat treatment. Quenching uses Joule heat to heat the knitting needles, while applying argon protection and liquid nitrogen quenching. During the entire heating and quenching process, argon is used as a protective gas to effectively prevent oxidation of the knitting needle surface. This helps to maintain the surface quality and dimensional accuracy of the knitting needles, indirectly affecting their final mechanical properties. Tempering refers to heating the quenched knitting needles to a certain temperature and then slowly cooling them to eliminate the residual stress inside the knitting needles and improve the toughness and plasticity of the knitting needles.

[0012] Furthermore, the surface treatment in step (4) mainly involves polishing the knitting needles. The knitting needles are polished using a polishing machine, and polishing liquid is sprayed onto the needle surface during the polishing process. Each liter of polishing liquid contains the following components: 50-150 mL of hydrogen peroxide solution, 6-30 g of ammonium bifluoride, 5-15 g of oxalic acid, and the balance is water.

[0013] Furthermore, the specific process flow of the needle wear resistance test in step (5) is installation, pressure setting and testing. Installation refers to installing the needle sample on the sample holder of the wear tester, such as the Martindale wear tester. Pressure setting refers to the sample being subjected to a specific pressure, usually 9 kPa or 12 kPa. Testing refers to rubbing the sample against a standard abrasive cloth or other sample for a specified number of cycles, and the test is carried out under controlled temperature and humidity conditions.

[0014] The beneficial effects of the present invention are: by optimizing the production process and accelerating the horizontal connection between each process, the production efficiency is greatly improved, the decentralized production chain is transformed into an aggregated production chain, the circulation process is shortened, the backlog of work-in-progress is reduced, the process accumulation is reduced, the number of waste needles during machine adjustment is reduced, the scrap rate is reduced, and the product completion rate is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and detailed embodiments.

[0016] Figure 1 This is a test chart of the wear resistance of knitting needles. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with specific embodiments, but these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. The technical solution of the present invention will be described in detail below, and the described embodiments are only part of the embodiments of the present invention, rather than all embodiments.

[0018] The manufacture of wear-resistant knitting needles mainly involves the following five steps: (1) material selection; (2) precision machining; (3) heat treatment; (4) surface treatment; and (5) needle wear resistance testing.

[0019] (1) The knitting needle material is T9A steel. The carbon content of T9A steel is between 0.85% and 0.94%. After proper heat treatment, it can obtain a higher hardness, generally reaching about HRC60, which is enough to meet the requirements of knitting needles resisting wear and deformation during the process of piercing the fabric. In addition, the surface of the steel is not easy to wear and is easy to keep smooth. The processing performance is relatively good, and it is easy to forge, roll and cut.

[0020] (2) Precision machining is mainly divided into three steps: needle blank production, needle body processing and needle body assembly. A die is used to apply pressure to the steel strip on a crank punch press to separate it and form a needle shape. The side bend of the needle blank is then mechanically corrected to obtain a straight needle blank. Finally, the rough part of the blank's side is processed on a planer to improve the surface finish of the needle blank. The rough surface between the curved surface of the needle blank and the needle tip is made smooth by high-speed cutting. The irregular needle tip is transformed from an elliptical shape to a circular shape using cold heading. At the same time, a milling cutter is used to mill a circular arc on the needle body and the needle belly to leave space for the needle tongue installation. The steel wire used for the tongue is mechanically extruded, stamped, punched, and cut to produce a needle tongue that meets the requirements. It is then installed at the needle belly position using a graduated conveyor. The extrusion shaft alloy rods on both sides are squeezed against each other to complete the positioning and shafting. The front needle tip is bent into a hook shape using a bending hook tool.

[0021] (3) After precision machining, the needle surface is first cleaned of oil, impurities, etc. to ensure the quality of heat treatment. The needle is then heated using Joule heat, while argon protection and liquid nitrogen quenching are applied. The quenched needle is heated to a certain temperature and then slowly cooled to eliminate the residual stress inside the needle.

[0022] (4) Polishing the knitting needles using a polishing machine, and spraying a polishing liquid onto the surface of the knitting needles during the polishing process. The polishing liquid used includes the following components: 50-150 mL of hydrogen peroxide solution, 6-30 g of ammonium bifluoride, 5-15 g of oxalic acid, and the balance is water.

[0023] (5) Install the finished knitting needle sample on the sample holder of the Martindale abrasion tester, set the sample pressure to 9 kPa, control the test temperature to usually around 20 ° C, and control the test relative humidity to around 65%, and rub the sample with the standard abrasive cloth or other samples 1000 times.

Claims

1. A process for manufacturing wear-resistant knitting needles, characterized in that: It includes (1) material selection; (2) precision machining; (3) heat treatment; (4) surface treatment; and (5) needle wear resistance test.

2. A wear-resistant knitting needle manufacturing process according to claim 1, characterized in that: The main material selected in the material selection in step (1) is T9A steel.

3. The process for manufacturing wear-resistant knitting needles according to claim 1, wherein: The process steps of precision machining in step (2) mainly include needle blank production, needle body processing and needle body assembly. The specific process of needle blank production includes three steps: punching, rolling and planing. Punching is to use a die to apply pressure to the steel strip on a crank punch to separate it and form a needle shape. Rolling is to obtain a straight needle blank by mechanically correcting the side bend of the needle blank. Planing is to improve the smoothness of the side surface of the needle blank by processing the rough part of the punching opening on the side of the needle blank through a planer. The needle body processing is to form a smooth surface by high-speed cutting the rough surface between the curved surface of the needle blank and the needle tip, and use the cold heading method to make the irregular needle tip from an ellipse into a circle. At the same time, a milling cutter is used to mill a circular arc on the needle body and the needle belly to leave space for the installation of the needle tongue. The needle body assembly is to manufacture the needle tongue that meets the requirements through mechanical extrusion, stamping, punching and cutting of the steel wire used for making the tongue, and then install it in the needle belly position through the indexing transmission device. The alloy rods on both sides are squeezed towards each other to complete the positioning and shaft making. The front needle tip is bent into a hook shape using a bending hook tool.

4. The process for manufacturing wear-resistant knitting needles according to claim 1, characterized in that: The specific process steps of heat treatment in step (3) are: cleaning, quenching and tempering. Cleaning refers to cleaning the oil, impurities, etc. on the surface of the knitting needles to ensure the quality of heat treatment. Quenching uses Joule heat to heat the knitting needles, and at the same time applies argon protection and liquid nitrogen quenching. During the entire heating and quenching process, argon is used as a protective gas to effectively prevent oxidation on the surface of the knitting needles. This helps to maintain the surface quality and dimensional accuracy of the knitting needles, and indirectly affects their final mechanical properties. Tempering refers to heating the quenched knitting needles to a certain temperature and then slowly cooling them to eliminate the residual stress inside the knitting needles and improve the toughness and plasticity of the knitting needles.

5. The process for manufacturing wear-resistant knitting needles according to claim 1, characterized in that: The surface treatment in step (4) mainly involves polishing the knitting needles. The knitting needles are polished using a polishing machine, and polishing liquid is sprayed on the surface of the knitting needles during the polishing process.

6. The process for manufacturing wear-resistant knitting needles according to claim 1, characterized in that: The specific process flow of the needle wear test in step (5) is installation, pressure setting, and testing. Installation refers to the installation of the needle sample on the sample holder of the wear tester, such as the Martindale abrader. Pressure setting refers to the sample being subjected to a specific pressure, usually 9kPa or 12kPa. Testing refers to rubbing the sample against a standard abrasive cloth or other sample for a specified number of cycles. The test is carried out under controlled temperature and humidity conditions.

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