Industrial Manufacturing News

Also known as the Elmendorf test, the tearing test has been performed in the textile industry for more than a half-century in order to measure the mean internal resistance of textiles to the propagation of a deliberately initiated tear. It enables rapid determination of the dynamic resistance of materials designed to be subjected to strong shearing loads (e.g. suitcases, industrial fabrics) or liable to be damaged by sharp or heavy objects (e.g. seatbelts, outerwear, protective clothing).

Subsequently, the test was naturally adopted for all materials in the form of cloth, knitted fabrics, nylons, industrial fabrics, non-woven fabrics, etc. for which the service requirements are required to sustain high tolerance.

Principle:
The test is carried out on a specimen composed of one or more samples of standard dimensions, usually with a distance of 43mm (1.7") remaining to be torn after initiating the tear. The energy of a pendulum of suitable weight is used to completely tear the specimen. The difference in the angle from the vertical of the center of gravity of the pendulum between the downswing and the upswing is a measure of the energy absorbed in tearing the sample. This angular movement is measured with a digital encoder and is immediately converted to the mean tearing force for a single sheet by the microprocessor incorporated in the apparatus.

New Features:
• Repeatability: The mechanical-pneumatic specimen gripping system guarantees sufficient clamping pressure to avoid all slipping phenomena, thus ensuring perfect reproducibility of the experimental conditions.

• Safety: As soon as the safety hood preventing access of the operator to the swinging pendulum zone is closed, the specimen is pre-notched automatically by a pneumatically driven shear.

• User-friendliness: The mean tearing force is indicated on an easy-to-read alphanumerical liquid crystal display and can also be transferred to a computer, either for additional statistical treatment or for record keeping purposes.

• Ergonomics: When the apparatus is equipped with an automatic pendulum raising device, after each test, the pendulum raising device, after each test, the pendulum is immediately reset in its starting position.

Some important features of this tester include:
• Automatic specimen notching
• Safety Hood
• Mechanical-pneumatic clamping avoids sample slippage to ensure repeatable results
• Automatic pendulum reset with lifting device.
• Tearing force displayed digitally
• RS-232 data output

Applications in textiles, linens, cotton, outerwear, industrial fabrics, home goods, upholstery, non woven's and outdoor coverings and materials. Meets TAPPI 414, APPITA P 400, ASTM D 689, NEN 1760, BS 4468, SCAN P 11, UNI 6444, CSA D9, ISO 1974- 1974, NF T.54.141, ISO 6383/2, ASTM D 1922, NF G.07.149, ASTM D 1424B

About Lawson-Hemphill
Lawson-Hemphill is recognized worldwide as an industry leader in supplying innovative solutions to textile quality assurance. To every corner of the world, Lawson-Hemphill is providing testing equipment as well as turnkey quality control systems to new and expanding manufacturing facilities, from global giants to specialty producers.

In October 2005, Lawson Hemphill became a member of the TMI Group of Companies. This exciting event significantly strengthens Lawson-Hemphill's ability to serve our global customer base with our new offices in Canada, The United Kingdom, The Netherlands and France. For more information on Testing Machines Inc., please visit our website at www.testingmachines.com

For more information contact:
Worldwide Headquarters:
Lawson-Hemphill
1658 G A R Highway
Swansea, MA 02777 USA
Phone: 508 679-5364
Fax: 508 679-5396