LH-485 EST


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Lawson Hemphill Inc. Machines and Instruments to Test and Measure Fabrics and Yarns
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1658 G.A.R Highway, Suite 5

Swansea, MA 02777, USA

Tel:+1 (508) 679-5364

Fax: +1 (508) 679-5396

Email: Information@lawsonhemphill.com

Entanglement Strength Tester

The Entanglement Strength Tester analyzes the yarn to simultaneously measure the number of entanglements per meter and length of the entanglement skips. The system uses a two zone transport system, first to remove the entanglements and second to provide constant tension for optimum entanglement count measurement.

The transport system uses state of the art control system to ensure the yarn is under precise elongation % that is desired by end user requirements in Zone 1, which is also known as Draw Zone.

As the yarn passes through the Draw Zone, the high resolution Tension device measures the tension developed on the yarn as the entanglement are being removed. Depending on the strength of the entanglement, this tension value can be high or low for strong or soft entangled yarns respectively.

As soon as the yarn leaves the Draw Zone, it enters the Entanglement Measurement Zone under controlled tension. In this zone, a CCD camera collects the yarn diameter information with precision of 3.5 micron. The diameter data is used to identify and count the entanglements and entanglement skips in the running yarn.

The complete EST test routine will include running the yarn at a reference condition, normally at 0% elongation and this test result will be used as the baseline for Entanglement Strength (ES%) calculations. After the reference step is finished, the EST will start drawing the yarn, up to 20 steps per test and will collect the entanglement data at each step. The Entanglement Strength will be calculated as the % entanglements remaining in the elongated yarn after it is subjected to the desired draw conditions.

A full statistical report for each bobbin is available at the end of each test.

This dual zone approach to measuring the entanglement strength automates the manual method, thus providing a highly efficient, repeatable, precise procedure that is free from the influence of human error.

Entanglement Testing System for running and applying up to 20 Elongation steps to the yarn under test

Dual Zone transport with Draw Zone and Measurement Zone tension monitoring

Draw selectable in 0.5% Elongation steps

Selectable testing speed 50 to 400m/min

Draw Zone Accuracy ± 0.1% elongation

Draw Tension measurement 0 to 1000 grams

Pretension adjustable 5 to 45 grams

CCD camera, capable of measuring every 0.5 mm of yarn with precision of 3.5 micron

Self contained yarn waste bin