Q: Which method do you recommend for elastane content fabrics?
A: I would definitely not recommend the Elmendorf test. If the fabric contains elastane, when you tear fabric, the distance of 43mm will change with fabric that will stretch considerably, thus the tear force calculation will be incorrect. One of the methods ISO 13937 parts 2 or 3 might be more appropriate, probably part 2 will be best for this application.
The CRE tester such as Titan can probably accommodate stretch without any problems because it doesn’t use a particular distance in its calculation of the tearing force.
Q: We want to test how badly damaged the elastane in a denim is, is there a method suitable for this?
A: If assessing damage in elastane, maybe a stretch and recovery test would be better than tear strength, this way you can get a sample of fabric before and after the damage treatment, and you could evaluate the stretching and recovering and calculate the percentage change from before to after.
Q: Can we perform calibration before each test to check the load cell?
A: You can verify the readings are correct by using a set of verification weights which connect to the load cell. You can check the reading of each one and can see the correct weight is recorded. You can use this as a method to check for drift to see if the weight recorded is changing etc.
Q: Does tear depend on fabric GSM?
A: In general yes it does. A fabric with higher weight will typically have a higher tear strength than a lighter weight fabric.

Q: In the case of fabric with elastane, which is the right way to put the sample for burst testing?
A: Insert the specimen between the top & bottom clamp ensuring that the specimen is free from creases and folds. This is the same method as non-stretch fabrics. The small dome would be used with stretch fabrics.

Q: For legging products, what are the benefit(s) using the ball burst test method (ASTM D6797)?
A: For stretch fabrics, the diaphragm method is limited by the height of the test dome (bell). When using the ball burst method, the length travelled of the ball is usually much greater than the height of the dome allowing the fabric to be tested to burst, rather than reaching the maximum capacity of the dome. Results from D3786 and D6797 are NOT comparable. 

Q: Are there noticeable differences in test results when testing is performed using hydraulic and pneumatic systems?
A: There is no significant difference in the bursting strength results achieved using pneumatic or hydraulic burst testers, for pressures up to 800kPa. This pressure range covers the majority of performance levels expected for general apparel (see ISO 13938-2). Some hydraulic burst testers include pressures exceeding 800kPa.

Q: What is the required pressure for the bursting machine?
A: Maximum pressure: 10 bar (145psi) regulatedMinimum pressure: 6 bar.The use of an air compressor expands the upper limit of available pressure from typical factory airlines to 1000kPa/145psi and are supplied with a filter and regulator.

Q: In which direction the sample must have tension, all directions or only in courses?
A: When testing is performed in TruBurst, the whole fabric is stretched multiaxial.