Tensile Tester

Universal Textile Tensile Testing Machines (UTM) 

CRE Principle & Servo‑Drive Precision 

Why Tensile Testing Matters

In the textile universe, tensile testing is the backbone of quality assurance of textile materials, including apparel, upholstery, geotextiles, and industrial fabrics. Lab managers, quality control engineers, and procurement officers always rely on tensile testers to ensure compliance with ASTM and ISO standards, verify supplier claims, and maintain ISO 17025 accreditatio,n which is the main requirement of each and every textile industry.

Unlike legacy Constant Rate of Traverse (CRT) pendulum testers, which suffer from inertial errors, modern Constant Rate of Extension (CRE) systems help to get reproducible, standard‑compliant results. DaRong’s YG Series Universal Testing Machines (UTM) are engineered to meet all the required demands with the latest technology, such as servo‑drive precision and advanced gripping solutions.

In the modern era competitive textile industry, reproducibility is not optional but essential. Buyers from anywhere always demand fabrics that meet strict performance criteria, and auditors require data that withstands scrutiny. A tensile tester is not just a machine but the backbone of credibility in a laboratory.

Engineering Foundation CRE vs CRT 

The Physics of Accuracy 

1. CRT testers are pendulum-based and their speed varies with the stiffness of the fabric, which leading to inertial errors
2. CRE tester having servo motors, which always maintain a constant elongation speed regardless of the testing specimen

Why CRE Principle Matters

1. CRE meets the strict velocity requirements as required in both ISO 13934-1 and ASTM D5034
2. It’s always eliminates the variability which sis caused by the stiffness of the testing specimen
3. It ensures the reproducibility of ISO 17025 audits

Case Study Example

A European testing lab switched from CRT to CRE testing systems and found 25% decrease in the failed audits. The improvement was attributed to the elimination of the speed variation, which clearly highlights why CRE technology has become the global standard.

 Extended Technical Note 

The constant rate of extension (CRE) principle ensures that the elongation speed of a testing specimen remains steady, even when the the testing material stiffens or begins to neck during testing. This consistency is always achieved through the advanced servo-motor feedback systems, which continuously monitor the resistance and adjust the torque in real time to maintain the uniform strain rates. In contrast, the CRT tester always depends on pendulum mechanics. These mechanical systems usually naturally accelerate or decelerate, totally depending on how the testing specimen responds, which introduces variability into the test. As a result, CRT usually produces inconsistent strain rates and unreliable data, but on the other hand, CRE always ensures accuracy and repeatability.

Mechanical Precision — Servo Drive & Ball Screw Systems 

Closed‑Loop Control

DaRong testers use Panasonic AC Servo Motors with closed‑loop feedback, which always ensures precise speed control from 0.01 – 1000 mm/min.

Ball Screw Drive vs Belt Drive

1. Ball screw drive having zero backlash, high rigidity, and long service life
2. Belt drive has functions such as being prone to slippage and reduced accuracy

Data Integrity 

1. The sampling rate is 1000Hz+ for detailed stress-strain curves
2. The load cell hysteresis compensation provides guarantees of repeatability across hundreds of testing
3. The accuracy class is class 0.5, which meets the ISO calibration standards

Extended Technical Note 

Ball screws are machined to C5 precision grade, which helps a lot in ensuring minimal deflection under load. Combined with linear guide rails, this architecture maintains alignment even under 50kN forces, which is critical for geotextile testing.

Case Study

A US automotive textile supplier adopted DaRong’s servo‑drive systems and reported a 30% improvement in repeatability compared to belt‑driven testers. This improvement directly contributed to passing supplier audits from major OEMs.

Advanced Gripping Solutions — Eliminating Slippage & Jaw Breaks 

The Problem 

“Jaw Breaks” (failures at the clamp line) and slippage are the #1 pain points in tensile testing, invalidating results and frustrating lab managers.

The DaRong Solution

1. Pneumatic Side Action Grips: It helps to ensure constant clamping pressure and auto-adjusts as sample necks
2. Capstan (Bollard) Grips: It distributes the stress evenly for high tenacity yarns required as per ISO 2062 testing
3. Manual Wedge Grips: The are for a self-tightening design, especially for heavy canvas.
4. Jaw Faces: Having rubber (silks), serrated (cottons and wave pattern (synthetics)

Example in Practice 

A US denim manufacturer reduced invalid Grab Test results by 40% after adopting pneumatic grips, saving thousands in wasted samples and audit delays.

Extended Technical Note

Pneumatic grips working as using compressed air to maintain constant pressure across the testing specimen. As the fabric necks under load, the grip automatically adjusts, which helps a lot in preventing slippage. Manual grips, by contrast, rely on operator tightening, which can vary between tests and introduce inconsistency.

Standards Compatibility Matrix

Extended Note

This matrix is not just a reference; it is a compliance roadmap. By aligning test methods with recommended fixtures, DaRong testers ensure labs can quickly configure machines to meet specific standards and requirements without guesswork.

Geo‑Targeting & Technical Specifications 

Voltage Compatibility

1. Configurable for 110V/60Hz (for USA and Canada)
2. 220v/50Hz (for Europe and Asia)
3. Available for universal wide voltage systems

Force Capacity Options

1. 5kN for apparel fabrics
2. 10kN for upholstery and composites
3. 30kN and 50kN for geotextiles and industrial fabrics

Software Connectivity

1. Bi-directional PC control via USB/RS232
2. Can export reports to Excel and PDF formats
3. Highly compatible with LIMS systems

 Frame & Travel

1. High-rigidity alloy frames work as anti-vibration
2. Excellent crosshead travels up to 1200mm for wide-width geotextiles

Procurement Note 

US buyers usually hesitate to purchase Asian equipment specially due to voltage concerns. By explicitly offering 110V/60Hz compatibility, DaRong removes this barrier too. EU buyers benefit from CE compliance and 220V/50Hz options.

Compliance & Accreditation

DaRong testers are designed to support ISO 17025 compliance by:

1. Providing the reproducible stress-strain data
2. Can meet the class 0.5 accuracy requirements
3. Offering calibration traceability

Accreditation Example

A Canadian lab achieved ISO 17025 certification in half of the expected time because DaRong’s CRE systems provided both audit‑ready velocity and accuracy documentation.

 FAQ 

What is the difference between Grab Test (ASTM D5034) and Strip Test (ISO 13934‑1)?

The Strip Test is performed to evaluate the full width of a raveled fabric strip, measuring true yarn strength. The Grab Test clamps only the center of the fabric, simulating seam stress. You can perform both tests with the help of DaRong tester’s interchangeable jaws.

Why is a CRE tester better than a CRT tester? 

CRE testers use servo motors to maintain a constant elongation speed, which is the main requirement of ISO 13934. CRT pendulum testers vary in speed depending on stiffness, resulting in less accurate results.

Can this machine test Geotextiles? 

Yes. DaRong’s Heavy‑Duty Series (up to 50kN) with 200mm Wide‑Width Clamps complies with ASTM D4595 and ISO 10319.

What accuracy class is required for ISO 17025 textile labs? 

Class 0.5 accuracy is required for ISO 17025. DaRong testers meet this with calibrated load cells and closed‑loop servo control.

Can tensile testers integrate with LIMS systems? 

Yes. DaRong software exports to Excel and PDF formats and integrates with LIMS via RS232/USB protocols.