The pneumatic yarn strength tester is mainly used to test the breaking strength and elongation of the yarn. The operation must be rigorous to ensure the accuracy of the data. The following are detailed instructions and precautions:

I. Operation steps

1. Preparation

Equipment inspection: Confirm that the air pressure source is stable (usually 0.4-0.6 MPa is required), there is no leakage in the air pipe connections, and the clamps are not worn.

Calibration: Use standard weights or calibrators to calibrate the force sensor and elongation device (recommended to be performed before starting the machine every day).

Yarn sampling: Cut a yarn sample of a specified length (usually 500mm) according to the standard (such as GB/T 3916) to avoid twisting or damage.

2. Clamping the sample

Clamp selection: Choose a flat clamp or a capstan clamp according to the thickness of the yarn to prevent slippage or clamping.

Clamping method:

(1) Place both ends of the yarn vertically into the upper and lower clamps to ensure that there is no slack or pre-tension.

(2) After clamping, check whether the yarn is centered to avoid deflection affecting the test results.

Pre-tension: The elastic yarn needs to be subjected to initial tension (such as 0.5cN/tex), which can be set with a tension clamp or software.

3. Parameter setting

Test mode: Select "constant speed stretching" (usually 100-500mm/min) or "constant elongation".

Test conditions: Set the gauge length (usually 250mm or 500mm), stretching speed, and number of tests (≥10 times, taking the average).

Air source adjustment: Adjust the air pressure to the required range of the equipment (such as 0.5MPa) through the pressure reducing valve.

4. Start the test

Click the "Start" button, and the device automatically stretches the yarn until it breaks.

Observe the yarn breaking process in real time. If there is slippage or abnormal fixture, pause and reload the sample immediately.

5. Data recording

The instrument automatically records the breaking strength (cN or N), breaking elongation (%), time-strength curve, etc.

Indicate the test conditions (temperature and humidity, stretching speed, etc.) when exporting data.

6. End cleaning

Turn off the air source and release the residual air pressure.

Clean the fixture to prevent fiber residue from affecting the next test.

II. Precautions

1. Safe operation

Do not touch moving parts during testing to prevent pinching.

The equipment will stop when there is a sudden gas failure and needs to be reset manually.

2. Data accuracy

Test the same sample at least 10 times and eliminate abnormal values (such as ±20% deviation from the mean).

Laboratory temperature and humidity must meet the standards (such as 20±2℃, 65±3%RH).

3. Maintenance points

Check the aging of the air pipe every week and lubricate the guide rail regularly.

The sensor should avoid overload shock and the calibration cycle should not exceed 3 months.

III. Common Problem Solving

Yarn slippage: Replace the anti-slip clamp or increase the clamping area.

Results fluctuate greatly: Check the yarn uniformity or clamp alignment.

The device does not respond: Confirm whether the air pressure meets the standard and restart the control system.

Through standardized operation and regular maintenance, the test results can be ensured to be reliable. The details of different models may vary slightly, it is recommended to refer to the specific equipment manual.

Email: hello@utstesters.com

Direct: + 86 152 6060 5085

Tel: +86-596-7686689

Web: www.utstesters.com