Sock Stretch Tester

Product Overview

The Sock Stretch Tester is a precision instrument designed to evaluate the elongation and elastic recovery of hosiery, swimwear, pantyhose, knitted pants, and other stretchable garments. It measures both longitudinal (vertical) and transverse (horizontal) stretch, providing accurate data on tensile behavior, plastic deformation, and elastic recovery. The system combines a Siemens PLC control unit with ergonomic design and adjustable parameters for reliable, repeatable testing.

Application

The tester is widely used in:

(1) Hosiery and sock manufacturing: evaluating elongation and elasticity performance

(2) Swimwear and activewear production: testing tensile and stretch properties

(3) Knitted garment industry: assessing pantyhose, leggings, and belly pants

(4) Textile R&D: developing new fabrics with desired elasticity and recovery

(5) Quality control laboratories: verifying compliance with garment stretch standards

(6) Third-party testing and certification laboratories: product performance validation

Standards

Chinese Standards:

FZ/T 70006: Hosiery tensile performance

FZ/T 73001: Knitted fabrics – General tensile test

FZ/T 73011: Knitted pants – Stretch and recovery test

FZ/T 73013: Swimwear – Stretch and elongation evaluation

FZ/T 73029: Pantyhose – Tensile properties

FZ/T 73030: Hosiery – Elastic recovery test

International Standards:

ISO 20932-1: Textiles – Determination of elastic recovery of knitted fabrics – Part 1: Strip method

ISO 13934-1: Textiles – Tensile properties of fabrics – Part 1: Strip method

ASTM D4964: Standard Test Method for Stretch and Recovery of Knitted Fabrics

ASTM D2594: Standard Test Method for Elastic Properties of Yarn and Fabric

EN 14704: Textiles – Knitted fabrics – Determination of elastic elongation and recovery

BS 3049: Hosiery – Test methods for elongation, stretch, and recovery

Product Features

Ergonomic design: Control panel located at ~100 cm height for comfortable operation

Vertical stretching structure: Facilitates sample installation and testing with small horizontal footprint

Siemens PLC control system: Ensures precise, stable, and reliable testing

Multiple test modes: Constant tensile, fixed elongation, constant elongation rate, and timed elongation

Integrated measurement: Records elongation force, elastic recovery, and plastic deformation

Pre-tensioning and manual fixture: Ensures consistent sample setup for accurate testing

Real-time display: LCD screen shows tensile speed, force, elongation, and test conditions

Technical Specifications

Test Procedures / Maintenance

Install the sample on the vertical stretching frame using the manual fixture and pre-tensioning weights.

Set the test mode (constant tensile, fixed elongation, etc.) via the LCD controller.

Adjust tensile speed, rated tension, and stretch holding time as required.

Start the test; the system records elongation, elastic recovery, and plastic deformation in real time.

After testing, remove the sample and clean the fixture to avoid residue buildup.

Periodically inspect the tensile system, weights, and controller for accuracy and calibration.