Fabric sampling for testing and sampling instrument

Fabric sampling for testing 

• Fabrics are made from both natural and manufactured fibres that are extensively used for clothing, decoration, and industrial applications. 
• The physical and mechanical properties of these fabrics are affected by the fibre type, yarn construction, and fabric structure, as well as any treatment that may have been applied to the materials. 
• A range of fabric performance parameters is assessed for different end-use applications. These can be only estimated by testing and ultimately testing is carried out by proper sampling.
• Unlike other homogeneous materials, fabrics are heterogeneous materials so the test results differ when a fabric specimen is tested in different directions. 
• I.e. - warp or weft for direction specimen for woven fabric, course or wale for knit fabric. 
• (While different test standards are applied to different types of fabric tests, it is important to note that the three important factors for any test are the sampling protocol, the conditions of measurement, and the instrumentation and measurement procedure.)

Fabric sample instrument

Fabric sample cutter

Fabric sample cutter

The fabric sample cutter is a simple circular cutter that cuts the fabric for testing.

To cut out the circular sample, the fabric is placed under the instrument, and the top portion of it is rotated by the technician. 

By rotation of a top portion of the instrument, a shred blade moves on its circumference at the base of the instrument that circularly cut the fabric.

This is applicable for all materials including woven, nonwoven, and knitted textiles, carpet, felts, and foam which comes for testing.

Individual circular cutters in various diameters are available for different test methods or applications like 100 cm∧2 (5 or 10 mm depth), 10 cm∧2, 50 cm∧2, 38 cm∧2, and 140 cm∧2 areas. 

Hydraulic sample press atom

Hydraulic sample press atom

In this instrument, a swing arm cutting press is used to prepare sample Rubber and soft plastic before testing. 

Depending on resilience, several thicknesses can be cut at once with a cutting force of 20 tons. 

Control push buttons with a time delay to ensure complete operator safety. Maximum cutting area 18" (450mm) x 36" (900mm). Cutting dies of any shape and size can be supplied. 

 

Cut-pro sample shredder

Cut-pro sample shredder

The CutPro instrument is used for cutting samples into small pieces that are suitable for chemical testing like colourfastness, dye penetration, percentage of size, or another finish coating. 

This machine speeds up the cutting process so that it decreases the time-consuming labour of using scissors to cut up samples. 

It quickly and safely cuts samples into appropriate size pieces for chemical tests for formaldehyde, heavy metals, and AZO dyes, among others. 

The machine has a static elimination system and a built-in compressor with a hose for cleaning between sample cuts to eliminate cross-sample contamination. This Sample is  cut within two passes and takes less than 20
seconds.

It has Blade that self-sharpening feature and a powerful motor that can handle all textiles as well as
leather up to 4 mm thick.

• According to British Standard,  theoretically correct methods of fabric sampling from lengths or rolls of fabric require that laboratory samples be taken at intervals along the length of the fabric. 

• However practically, rolls of fabric can be very long, and there are economic and practical handling difficulties in applying the above standard method. 

• In most cases, fabrics cannot be cut, except at the ends of the fabric piece, and therefore sampling cannot be carried out across the whole population. 

• If a particular fabric property is known to vary along the length of the roll, then tests carried out only at the ends of the roll will not be representative of the whole length of the fabric. 

• In special cases, for example, where faults or changes in a property along the length of the fabric are to be examined, samples may need to be taken at intervals along the whole length of the roll. In this case, the number and arrangement of samples depend on the specific requirement and are agreed upon between the parties. 

• The number of cases (containers, etc.) and the number of rolls to be inspected are specified in the British Standard.

•  In practice, samples from the selected rolls are taken by cutting, not tearing, at a distance of 1 m from the end of the roll. 

• The size of the sample taken is sufficient to carry out the required tests. Any visible irregularities, damage, or colour differences are avoided. Furthermore, check that not two specimens should contain the same set of threads line of warp or weft.

Questions -

1. How sampling is done for fabric?
2. How fabric sampler works?
3. What is a hydraulic sample press atom?
4. What is a cut-pro sample shredder and how does it work?

References

Booth, J. E. :. (n.d.). Principles of textile testing an introduction to physical methods of testing textile fibres, yarns, and fabrics. London: National Trade Press Ltd,1961. from https://www.abebooks.co.uk/Principles-Textile-Testing-Introduction-Physical-Methods/19989810376/bd

Cenote, M. (2015). Google Books. In The SAGE Guide to Key Issues in Mass Media Ethics and Law (pp. 847–858). SAGE Publications, Inc.

Ferreiro López-Riobóo, J. I. (2015). Long-term (2001–2012) study of a proficiency testing scheme for textiles. Accreditation and Quality Assurance, 20(4), 239–245. https://doi.org/10.1007/s00769-015-1128-1

TEXTILE VALUE CHAIN. (2020, May 5). Textile Testing and quality control. TEXTILE VALUE CHAIN. https://textilevaluechain.in/in-depth-analysis/articles/textile-articles/textile-testing-and-quality-control/

Writer - DSPAT Team