VIT 420 – Portable Single Yarn Strength Tester

Testing Method

Yarn strength, also known as yarn fastness, is a critical quality indicator. During production, yarn must withstand various tensions and loads, so adequate strength ensures smooth knitting and manufacturing processes. Yarn strength is categorized into:

• Absolute Strength: Also called breaking strength, the external force needed to break the yarn, expressed in CN/tex.
• Relative Strength: The ratio of absolute strength to yarn fineness, indicating the yarn’s overall quality.

What is the Portable Single Yarn Strength Tester? This portable electronic instrument tests the breaking strength of yarn both in the field and in the lab. It is crucial for evaluating yarn performance, identifying joint strength, and ensuring uniformity in yarn strength. Controlled by a microcomputer, it automates data processing and can send results directly to a printer. The tester is known for its ease of setup, speed, and accuracy.

Test Procedure

1. Place the tester on a stable, horizontal surface and power it on. Set test parameters such as number of tests, yarn type, and print intervals.
2. Mount the ring bobbin onto the axis and hitch the yarn. Adjust the strength device as needed.
3. Hold the yarn’s end with the right hand and press the “clamp/stretch” button. As the right gripper rotates, gradually release the yarn until it breaks. Remove the sample from the gripper.
4. Repeat steps 2 and 3 until all tests are completed. The tester will display and print the results.