ISO 3341 Tensile Textile Glass Yarn Test Equipment

Glass yarn is yarn made from many interwoven glass fibers. This standard defines testing to determine breaking force, breaking strength and lengthening. The breaking force is the maximum force registered (or reached) during a breaking test on the test piece, carried out on a tensile testing machine with constant rate of traverse of the moving element. That constant rate is 200mm/min. The breaking force values given in the tables of glass yarn specifications are only valid when this type of testing machine is used.

The key challenge in testing glass yarn is gripping the material in a way that does not significantly reduce the strength of the material. Almost all grips will cause a stress concentration on glass yarn material because they must squeeze the sample enough to avoid slippage during loading. 2 gripping strategies have proven effective:

1. The use of capstan bollard grips, where the material is wound around a cylinder with friction and then gripped. This reduces the tensile force at the edge of the grip jaws which encourages the material to break between the capstan cylinders at a force that is very close to the true tensile strength of the specimen material. A problem with capstan grips is that it is hard to determine the true gauge length of the material because some of the material along the capstan cylinder lengthens during the test.
2. The use of potted tabs at both ends of the glass yarn material. We can recommend PMMA epoxy potting material. Use form that create tabs at both ends of the material. The shape of the tabs should be such that a vice grip can grab them well. The problem with this gripping strategy is the test preparation time is typically at least 24 hours for the epoxy curing time.

Equipment Required

Universal testing machine capable of a constant rate of extension of 200 mm/min +- 20 mm/min. The machine shall be capable of stressing the sample until failure occurs. If the test machine has a pre-tensioning capability, a pre-tension force of 5 mN/tex +- 22.5 mN/tex shall be applied to the specimen. By means of our testing expertise and modular product design, we will help find the solution that is right for you. Give our test engineers a call today for help configuring the best test machine and accessories according to your standard.

Recommended Test Machines

100 Series Universal Test Machines

Forces up to 10 kN (2,250 lbf)
Low force tabletop systems
Modular series of five frame options with adjustable test space
Affordable testing option for tension, compression, bend, peel and much more

200 Series Electromechanical Universal Test Machines

Forces up to 5 kN (1,125 lbf)
Low force tabletop systems
Tests at speeds up to 2,500 mm/min (100 in/min)
Best for high travel or high elongation test requirements

300 Series Electromechanical Universal Test Machines

Force range of 5 kN to 600 kN (1,125 lbf to 135,000 lbf)
Adjustable test space
The most popular choice for static tension and compression tests
These dual column testers are available in both tabletop and floor standing models

Recommended Accessories

Capstan Bollard Grips

Force range of 0.2 kN to 250 kN (45 lbf to 55 kip)
Adjustable air pressure

Mechanical Vice Grips

Force range of 1 kN to 300 kN (225 lbf to 67,500 lbf)
Interchangeable jaws
Specimen centering tool
Optional pneumatic cylinders