Production process of stainless steel wire for medical acupuncture and moxibustion

Abstract

The production process of the stainless steel wire for medical acupuncture comprises the following steps: selecting raw materials; carrying out first-time skin membrane treatment; drawing for the first time; annealing for the first time; carrying out secondary skin membrane treatment; drawing for the second time; annealing for the second time; and drawing a finished product. The invention has the advantages of high starting point of raw materials, low impurity content, integration of coating and drying, and controllable lubrication boundary; the polishing-free direct next procedure is realized; multi-material mold gradient matching is achieved, and the size and the surface are considered; through two-stage solution annealing, the structure is uniform, and the hydrogen embrittlement risk is low; and the speed-tension closed loop is realized, and the straightness and the toughness are both obtained.

Description

Technical Field

[0001] This invention relates to a manufacturing process for stainless steel wire used in medical acupuncture. Background Technology

[0002] Stainless steel wire for medical acupuncture refers to specialized stainless steel wire that meets medical device standards (such as 06Cr19Ni10 in GB / T4240, i.e., SUS304 austenitic stainless steel) and is used to manufacture the "needle body" of acupuncture needles. It must possess: good biocompatibility (non-allergenic, non-irritating); sufficient mechanical strength and toughness (resistant to bending, not easily broken); and excellent corrosion resistance and high-temperature sterilization performance. It ensures safe acupuncture: high toughness keeps the needle body straight, not easily bent or broken, reducing the risk of needle breakage. It enhances the treatment experience: the smooth surface reduces needle insertion resistance and minimizes patient pain. It ensures hygiene and durability: it can withstand high-pressure steam sterilization or be discarded after single use, avoiding cross-infection; its corrosion resistance ensures long-term rust-free storage. It is suitable for various acupuncture techniques: it can be made in different diameters (0.12mm–0.35mm) and lengths (0.5–5 inches) to meet various clinical needs such as shallow needling, deep needling, electroacupuncture, and fire needling.

[0003] Currently, in the manufacturing process of stainless steel wires for medical acupuncture, multiple drawing passes and a large reduction in surface area cause the wire to work harden. If the intermediate annealing temperature or time is insufficient, the grain recovery is incomplete, and microcracks are easily present in the wire. When bent or subjected to high torque in clinical practice, the cracks expand, leading to "needle breakage" accidents. Summary of the Invention

[0004] To achieve the above-mentioned objectives, this invention provides a production process for stainless steel wire used in medical acupuncture. Starting with a 5.5mm high-C, high-N coil, the entire process connects raw materials, coating, multi-die drawing, double-stage solution annealing, and natural diamond fine drawing into a highly controllable dedicated line. Compared with traditional domestic acupuncture wire, its advantages are concentrated in four dimensions: purity, precision, strength, and stability.

[0005] The present invention provides a manufacturing process for stainless steel wire for medical acupuncture, comprising the following steps:

[0006] S1. Selection of raw materials: Stainless steel wire with a cross-sectional diameter of 5.5mm and grade SUS04HT imported from POSCO, South Korea, is selected as the raw material.

[0007] S2. First coating treatment: The raw material is soaked and washed in hot water, and then a surface coating treatment is performed.

[0008] S3. First drawing: The stainless steel wire after the first coating treatment is drawn to 2.2mm using a multi-head continuous wire drawing machine;

[0009] S4. First annealing: An 8-meter annealing furnace is used with zoned heating, divided into 6 zones with electric control heating, and the temperature is gradually increased. The temperature range is 1000℃~1100℃. The wire speed of the semi-finished stainless steel wire after the S3 step is 7.27m / min during the first annealing.

[0010] S5. Second coating treatment: The semi-finished stainless steel wire after the first annealing treatment undergoes coating treatment, with air blowing at the outlet of the coating tank, followed by oven drying.

[0011] S6. Second drawing: The stainless steel wire after the second coating treatment is drawn to 0.8mm using a multi-head continuous wire drawing machine;

[0012] S7. Second annealing: The annealing furnace adopts zone heating and gradually increases the temperature. The temperature range is 1050℃~1100℃. The wire speed of the semi-finished stainless steel wire after step S6 is 18.75m / min during the second annealing.

[0013] S8. Finished product drawing: The stainless steel wire after the second drawing is drawn to 0.2mm using a multi-head continuous wire drawing machine.

[0014] Specifically, in step S2, the imported French Condate TS4445 film-forming agent is used, with a film concentration of 1.02~1.025.

[0015] Furthermore, in step S2, the steel wire at the outlet of the film tank is vertically upwards for 4 meters before being transferred to the drying oven for circulating drying.

[0016] Specifically, in step S3, eight drawing passes are used: 5.5mm-4.75mm-4.15mm-3.67mm-3.27mm-2.93mm-2.68mm-2.4mm-2.2mm, at a speed of 3 m / s; the dies for passes 1-4 are tungsten carbide dies, the dies for passes 5-6 are carbon-plated dies, and the dies for passes 7-8 are drill dies; DECAL600 is used for passes 1-4, MCF powder is used for passes 5-6, and AM700 powder is used for passes 7-8.

[0017] Specifically, in step S4, the annealing furnace is divided into 6 zones, with temperatures of 1000℃, 1050℃, 1080℃, 1100℃, 1100℃ and 1100℃ respectively; and the furnace length of each of the 6 zones is 8m; the stainless steel wire passes through these 6 zones in sequence.

[0018] Specifically, in step S5, UC570 film-forming agent imported from Japan is used, with a film concentration of 1.015~1.02.

[0019] Specifically, in step S6, six drawing passes are used: 2.2mm-1.88mm-1.64mm-1.45mm-1.29mm-1.16mm-1.043mm-0.94mm-0.865mm-0.8mm. Polycrystalline diamond molds are used for all passes, and AM700 lubricating powder is used for all passes.

[0020] Specifically, in step S7, the annealing furnace is divided into 6 zones, with temperatures of 1050℃, 1100℃, 1100℃, 1100℃, 1100℃ and 1100℃ respectively; and the furnace length of each of the 6 zones is 10m; the stainless steel wire passes through these 6 zones in sequence.

[0021] Furthermore, in step S7, during the annealing and winding process, LB-5 water-based oil is applied to the surface of the stainless steel wire.

[0022] Specifically, in step S8, 17 drawing passes are used: 0.8mm-0.74mm-0.68mm-0.63mm-0.58mm-0.53mm-0.49mm-0.45mm-0.41mm-0.38mm-0.35mm-0.32mm-0.295mm-0.275mm-0.255mm-0.235mm-0.215mm-0.2mm. All 17 passes use natural diamond molds and DRAWSD501 lubricating oil.

[0023] The advantages of this invention compared to the prior art are as follows:

[0024] (1) High starting point of raw materials and low impurities: POSCO HT series high C and high N 304 controls C at 0.06-0.08% and N at 0.04-0.06%, and disperses carbonitrides at grain boundaries, which not only increases the strength to 80-100 MPa, but also reduces the A and B type non-metallic inclusions to ≤0.5 grade, laying a pure matrix for subsequent "ultra-fine wires" and reducing the wire breakage rate by more than 30%;

[0025] (2) Integrated film coating and drying, with controllable lubrication boundary: In the 5.5→2.2mm stage, French Condate TS4445 (containing MoS2 polymer) is used, with 4m vertical lifting and circulating oven to ensure film thickness of 1.5±0.2µm and friction coefficient of 0.08; in the 2.2→0.8mm stage, Japanese UC570 is used and air blowing is added to eliminate the "black line" caused by film liquid accumulation; the entire lubrication chain reduces the mold wear rate to 0.3µm / 10t, and the wire diameter tolerance is reduced from ±0.005mm to ±0.002mm, realizing "no polishing" and direct entry to the next process;

[0026] (3) Multi-material mold gradient matching, taking into account both size and surface: roughing 1-4 tungsten steel → 5-6 carbon-plated mold → 7-8 drill mold, hardness step by step, avoiding scratches caused by "hard against soft"; intermediate drawing of full polycrystalline diamond, roughness Ra≤0.1µm; finished product 0.2-0.74mm full natural diamond (single crystal) sizing, Ra≤0.05µm, mirror effect reduces needle insertion resistance by 15%, and significantly reduces patient pain;

[0027] (4) Two-stage solution annealing, with uniform structure and low risk of hydrogen embrittlement: 8m long furnace with temperature control in 6 zones (1000→1100℃) + slow speed of 7.27-27m / min to ensure complete austenitization of 2.2mm wire and full solution of carbides; second stage 6 furnace rapid heating (18.75m / min) + water quenching, with grain size of 7-8, yield strength of 320-350MPa and elongation of more than 45%, which not only ensures that the subsequent large reduction in surface area (cumulative 98.7%) will not crack, but also avoids grain coarsening caused by long-term high temperature; the whole process is electric furnace radiation heating, with no hydrogen atmosphere, completely eliminating the risk of "hydrogen embrittlement";

[0028] (5) Speed-tension closed loop, achieving both straightness and toughness: servo tension closed loop is used for coarse drawing at 3m / s, medium drawing at 2m / s, and fine drawing at 1.5m / s. The radius of curvature of the take-up wire is ≥200mm, the free coil diameter of the finished product is ≥150mm, and the straightness is <0.5mm / 100mm. No secondary straightening is required in clinical practice, reducing needle breakage caused by "stress concentration". Detailed Implementation

[0029] The specific embodiments of the present invention will be described in further detail below.

[0030] The present invention provides a manufacturing process for stainless steel wire for medical acupuncture, comprising the following steps:

[0031] S1. Selection of raw materials:

[0032] Stainless steel wire with a cross-sectional diameter of 5.5mm and grade SUS04HT imported from POSCO, South Korea, was selected as the raw material.

[0033] SUS04HT stainless steel wire imported from POSCO, South Korea, is used as raw material for medical acupuncture stainless steel wire. It is equivalent to conventional 304 stainless steel wire or 304HC stainless steel and has the following advantages: high strength, especially high yield strength. POSCO's HT series high C and high N 304 controls C to 0.06-0.08% and N to 0.04-0.06%, and disperses carbonitride precipitation at grain boundaries, which not only increases the strength to 80-100MPa, but also reduces Class A and Class B non-metallic inclusions to ≤0.5 grade, laying a pure matrix for subsequent "ultra-fine wire" and reducing the wire breakage rate by more than 30%.

[0034] Correspondingly, the following difficulties also exist in the wire drawing process: high work hardening, easy to break and bulge during drawing, and breakage.

[0035] S2, First Skin Treatment:

[0036] The raw materials are soaked and cleaned in hot water, and then treated with a surface coating. The French Condate TS4445 coating agent is used with a coating concentration of 1.02~1.025, which makes it easier for the coating to adhere more evenly to the surface of the steel wire.

[0037] The steel wire from the film tank outlet is vertically lifted 4 meters to the drying oven for circulating drying. In the 5.5→2.2mm stage, French Condate TS4445 (containing MoS2 polymer) is used. The 4m vertical lift and circulating oven ensure a film thickness of 1.5±0.2µm and a friction coefficient of 0.08. In the 2.2→0.8mm stage, Japanese UC570 is used and air blowing is added to prevent "black streaks" caused by film liquid accumulation. The entire lubrication chain reduces the mold wear rate to 0.3µm / 10t, and the wire diameter tolerance is reduced from ±0.005mm to ±0.002mm, achieving "polishing-free" direct entry to the next process.

[0038] S3, First pull: Rough pull;

[0039] A multi-head continuous wire drawing machine is used to draw the stainless steel wire after the first coating treatment to 2.2mm. Specifically, in step S3, eight drawing passes are performed: 5.5mm-4.75mm-4.15mm-3.67mm-3.27mm-2.93mm-2.68mm-2.4mm-2.2mm, at a speed of 3m / s. The dies for passes 1-4 are tungsten carbide dies, the dies for passes 5-6 are carbon-plated dies, and the dies for passes 7-8 are drill dies. DECAL600 powder is used for passes 1-4, MCF powder is used for passes 5-6, and AM700 powder is used for passes 7-8. The powder is increased in the first pass to ensure lubrication throughout the drawing process and protect the wire surface. The middle and later passes, while also ensuring powder application, refine the wire surface.

[0040] S4, First Annealing:

[0041] An 8-meter annealing furnace is used with zoned heating, divided into 6 electrically controlled zones, with gradual temperature increase, ranging from 1000℃ to 1100℃. The semi-finished stainless steel wire after the S3 step is 7.27m / min during the first annealing, ensuring uniform heating of the wire. The wire is fully austenitized during solution heat treatment.

[0042] The parameters for each furnace area are as follows:

[0043] Furnace area District 1 Second District Third District Fourth District Fifth District District Six Furnace temperature (°C) 1000 1050 1080 1100 1100 1100 Furnace Manager 8 meters 8 meters 8 meters 8 meters 8 meters 8 meters

[0044] S5. Second membrane treatment:

[0045] After the first annealing treatment, the semi-finished stainless steel wire undergoes a coating treatment. Air is blown at the outlet of the coating tank, followed by oven drying to ensure a uniform coating layer. The Japanese-imported UC570 coating agent is used, with a coating concentration of 1.015~1.02, resulting in finer crystals on the steel wire and excellent moisture resistance.

[0046] S6, Second Pull-Out: Fine Drawing;

[0047] The stainless steel wire after the second coating treatment is drawn to 0.8mm using a multi-head continuous wire drawing machine; 6 drawing passes are used: 2.2mm-1.88mm-1.64mm-1.45mm-1.29mm-1.16mm-1.043mm-0.94mm-0.865mm-0.8mm. Polycrystalline diamond dies and AM700 lubricating powder are used in all passes, resulting in a fine and uniform surface on the steel wire that is easy to clean.

[0048] S7. Second Annealing: The annealing furnace adopts zoned heating with gradual temperature increase, ranging from 1050℃ to 1100℃. The annealing furnace is divided into 6 zones, with temperatures of 1050℃, 1100℃, 1100℃, 1100℃, 1100℃, and 1100℃ respectively; and the furnace length of each of the 6 zones is 10m; the stainless steel wire passes through these 6 zones sequentially. The parameters of each furnace zone are as follows:

[0049] Furnace area District 1 Second District Third District Fourth District Fifth District District Six Furnace temperature (°C) 1050 1100 1100 1100 1100 1100 Furnace Manager 10 meters 10 meters 10 meters 10 meters 10 meters 10 meters

[0050] After step S6, the semi-finished stainless steel wire is annealed at a speed of 18.75 m / min during the second annealing process, which allows the wire to be heated and cooled rapidly. The wire is fully austenitized and the grains are refined during the solution heat treatment.

[0051] Apply LB-5 water-based oil to the surface of the stainless steel wire during annealing and winding. This ensures that the wire is not scratched during winding, and that the wire is released smoothly during the finished product drawing process, without tangling or knotting, resulting in stable linearity.

[0052] S8, Finished product drawing:

[0053] A multi-head continuous wire drawing machine is used to draw the stainless steel wire after the second drawing to 0.2mm. Seventeen drawing passes are employed: 0.8mm-0.74mm-0.68mm-0.63mm-0.58mm-0.53mm-0.49mm-0.45mm-0.41mm-0.38mm-0.35mm-0.32mm-0.295mm-0.275mm-0.255mm-0.235mm-0.215mm-0.2mm. All 17 passes use natural diamond dies and DRAWSD501 lubricating oil, resulting in high wire strength, a mirror-like surface free of scratches and drawing marks.

[0054] A type of stainless steel wire for medical acupuncture produced by the above-mentioned wire drawing process has the following properties:

[0055] Yield strength 1800MPa~1900MPa;

[0056] Tensile strength 2000~2100MPa;

[0057] Elongation: 30%;

[0058] Hardness: 450 HV;

[0059] The average grain size is 20µm, and the grain size reaches level 9.

[0060] A type of stainless steel wire for medical acupuncture, prepared using traditional techniques. For detailed manufacturing processes, please refer to Chinese Invention Patent No. [Announcement Number], and its performance is as follows:

[0061] Yield strength: 250-350 MPa;

[0062] Tensile strength: 500-650 MPa;

[0063] Elongation: 15%;

[0064] Hardness: 180-220 HV;

[0065] Grain size below grade 6.

[0066] It can be seen that the stainless steel wire for medical acupuncture prepared by the process provided by the present invention can achieve a grain size of 9, which is significantly improved compared with the traditional process. The physical properties such as tensile strength, yield strength and ductility are also improved accordingly.

[0067] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A process for the production of stainless steel wire for medical acupuncture, characterized in that, Comprise the following steps: S1, raw material selection: select the cross-sectional diameter of 5.5mm, grade for South Korea imported SUS04HT stainless steel wire as raw material; S2, the first film treatment: raw material hot water immersion cleaning, and then surface film treatment; S3, the first drawing: using multi-head continuous wire drawing machine to draw the first film treatment after the stainless steel wire to 2.2mm; S4, the first annealing: using 8 meters annealing furnace using zoning heating, 6 area electric control heating, gradually heating, temperature range is 1000~1100 DEG C, after S3 step processing after the semi-finished stainless steel wire in the first annealing when the line speed is 7.27m / min; S5, the second film treatment: after the first annealing treatment after the semi-finished stainless steel wire film processing, film tank outlet blowing treatment, and then oven cycle drying; S6, the second drawing: using multi-head continuous wire drawing machine to draw the second film treatment after the stainless steel wire to 0.8mm; S7, the second annealing: annealing furnace using zoning heating, gradually heating, temperature range is 1050~1100 DEG C, after step S6 processing after the semi-finished stainless steel wire in the second annealing when the line speed is 18.75m / min; S8, finished product drawing: using multi-head continuous wire drawing machine to draw the second drawing after the stainless steel wire to 0.2mm.

2. A process for the production of stainless steel wire for medical acupuncture as claimed in claim 1, wherein, In step S2, using France imported TS4445 film agent, film concentration 1.02~1.

025.

3. A process for the production of stainless steel wire for medical acupuncture as claimed in claim 2, wherein, In step S2, the film tank outlet steel wire is 4 meters vertically up to the oven cycle drying.

4. The process for manufacturing stainless steel wire for medical acupuncture as claimed in claim 1, wherein In step S3, 8 drawing is adopted: 5.5mm-4.75mm-4.15mm-3.67mm-3.27mm-2.93mm-2.68mm-2.4mm-2.2mm, drawing at a speed of 3m / s; The first-4th pass die is tungsten steel die, the 5th-6th pass die is carbon plated die, and the 7th-8th pass die is drill die; DECAL600 is used in the first-4th pass, MCF powder is used in the 5th-6th pass, and AM700 powder is used in the 7th-8th pass.

5. A process for the production of stainless steel wire for medical acupuncture as claimed in claim 4, wherein the wire is drawn to a diameter of 0.15 mm to 0.30 mm. In step S4, the annealing furnace is divided into 6 zones, and the temperatures of the 6 zones are 1000℃, 1050℃, 1080℃, 1100℃, 1100℃ and 1100℃ in turn; The furnace length of the 6 zones is 8m; The stainless steel wire passes through the 6 zones in turn.

6. The process for manufacturing stainless steel wire for medical acupuncture as claimed in claim 1, wherein In step S5, Japan imported UC570 film agent is used, and the film concentration is 1.015~1.

02.

7. A process for producing a stainless steel wire for medical acupuncture as set forth in claim 4, wherein In step S6, 6 drawing is adopted: 2.2mm-1.88mm-1.64mm-1.45mm-1.29mm-1.16mm-1.043mm-0.94mm-0.865mm-0.8mm, polycrystalline diamond die is used in all passes, and AM700 lubricating powder is used in all passes.

8. A process for the production of stainless steel wire for medical acupuncture as claimed in claim 7, wherein the wire is drawn to a diameter of 0.15 mm to 0.30 mm. In step S7, the annealing furnace is divided into 6 zones, and the temperatures of the 6 zones are 1050℃, 1100℃, 1100℃, 1100℃, 1100℃ and 1100℃ in turn; The furnace length of the 6 zones is 10m; The stainless steel wire passes through the 6 zones in turn.

9. A process for producing a stainless steel wire for medical acupuncture as set forth in claim 8, wherein In step S7, LB-5 water-based oil is applied to the surface of the stainless steel wire during annealing and take-up.

10. The manufacturing process of stainless steel wire for medical acupuncture as described in claim 7, characterized in that, In step S8, 17 passes of drawing are performed: 0.8 mm - 0.74 mm - 0.68 mm - 0.63 mm - 0.58 mm - 0.53 mm - 0.49 mm - 0.45 mm - 0.41 mm - 0.38 mm - 0.35 mm - 0.32 mm - 0.295 mm - 0.275 mm - 0.255 mm - 0.235 mm - 0.215 mm - 0.2 mm, all using natural diamond dies and DRAWSD 501 lubricating oil.