Glove material strength and stretch are important factors in a glove’s quality and performance. Medical and cleanroom gloves undergo testing according to ASTM D412 to meet International standards. This ensures you get a glove that is not prone to tear or fail, and has adequate stretch.
ASTM D412 is one of over 12,000 standards that operate globally under ASTM International. The current version of the standard is D412-06a(2013) Tensile Properties of Vulcanized Rubber and Thermoplastic Elastomers – Tension.
In this standard, glove material is measure for tensile stress (or tension,) tensile strength, yield point and ultimate elongation.
Test Method A
- Cut a die from the glove sample to form a dumbell shape
- Set the test sample onto the grips tightly and ensure no slippage
- Run the test by stretching from either end by an ASTM D412 standardized tensile machine at a constant speed
- Once the sample breaks, its data will be calculate and record
- The test is repeated on samples that have been put through the accelerated aging process in heating chambers according to ASTM D573. This test simulates the glove’s physical properties at the end of its shelf life. This is a “worst case” scenario. Many gloves that have been store properly, in a cool, dry place away from sunlight, heat and humidity, will have better strength and elongation than the “after aging” test results.
While high tensile strength is preferred, the “highest” number does not necessarily mean “best” performance. Glove manufacturers must carefully balance strength with stretch and comfort. Too high tensile strength will make a glove stiff or difficult to don.
Elongation is important to the performance of the glove. High elongation helps the glove material stretch instead of tear when snagged. A glove with good elongation will stretch and conform to your hand, improving comfort and performance.
The use of tensile test is always require in different industries including the factory serving medical industries. Thus, it is important get the technique and equipment right for it. Victor provides the Universal Testing Machine that is comply with the test standard of ASTM D412.