Acupuncture Needle Tip Strength and Sharpness Testing Guide

Acupuncture Needle Tip Strength and Sharpness Testing Guide

Provided by Shanghai Yingle Instrument Co., Ltd.

1. Scope of Application

This guide is based on the GB2024-2016 "Acupuncture Needles" standard and applies to the testing of tip strength and sharpness of acupuncture needles, ensuring compliance with clinical safety and performance requirements.

2. Test Equipment Requirements

Tip Strength Tester: Equipped with a high-precision force sensor (accuracy ±0.5%), a loading rate control module (≤10mm/s), and a steel block fixture (hardness ≥HRC60, surface smooth and free of rust).

Tip Sharpness Tester: Uses an aluminum foil fixture (foil thickness 0.05mm±0.002mm, purity ≥99.5%), a transmission system (vertical loading accuracy ±0.1N), and a data acquisition module (sampling frequency ≥1kHz).

Auxiliary Tools: 5x magnifying glass, absorbent cotton, optical glass plate (used for the rolling method).

3. Tip Strength Test Procedure

Tip Strength Test

1. Sample Installation: Securely clamp the test acupuncture needle in the needle holder, ensuring the exposed tip length is ≥5mm to guarantee accurate force application during testing.

2. Loading Test: Apply the needle tip vertically onto the steel block, gradually loading to the force value specified in clause 4.3 at the speed specified in B.2.2. The loading process must be smooth and even, avoiding any impact force that could affect test results. After loading, hold for 5s–10s, then remove the load.

3. Result Observation: Carefully examine the needle tip using a 5x magnifying glass. The tip must not show any hooking or bending. Alternatively, drag the needle tip across absorbent cotton. If no fibers are pulled out, the tip strength meets the requirements.

Tip Sharpness Test

1. Foil Preparation: Select an appropriately sized piece of aluminum foil and clamp it flat in the foil fixture. Do not apply any noticeable tensile or compressive force to the foil, so as not to affect its original strength.

2. Puncture Test: Clamp the acupuncture needle (which has already undergone the strength test) in the needle holder. Press the control switch to activate the transmission system, which applies a gradually increasing vertical force from the needle tip onto the aluminum foil. When the force applied by the needle tip exceeds the foil's strength, the tip punctures through the foil and the instrument automatically stops loading. At this point, record the value indicated by the pointer on the pendulum arm (or the value displayed on the instrument). This is the puncture force of the acupuncture needle tip.

3. Instrument Reset: Press the operation control switch button to reset the pendulum arm and pointer (or instrument display) to zero, preparing for the next test.

4. Foil Adjustment: Loosen the foil fixture and reposition the foil inside, ensuring that the distance between each puncture point is greater than 3 times the diameter of the test sample, to prevent adjacent puncture holes from affecting each other.

5. Repeat Testing: Repeat steps 1–4 above for a total of 3 tests. Take the arithmetic mean of the 3 test results. This average value is the sharpness puncture force of the tested acupuncture needle.

4. Precautions

Environment Control: Test environment temperature should be 20–25°C, humidity ≤60%, to prevent moisture from affecting the aluminum foil results.

Equipment Calibration: Calibrate the force sensor and loading rate daily before use to ensure data accuracy.

Sample Handling: Clean the needle tip after testing to avoid residual aluminum foil fragments interfering with subsequent tests.

Data Recording: Fully preserve test curves, raw data, and judgment results to ensure traceability.

This guide provides a scientific basis for acupuncture needle quality control through standardized operating procedures and quantitative judgment methods, helping the industry improve product safety and clinical effectiveness.