The fabrics and textiles industry is one of the oldest in the world, and with modern innovations and the advent of fibre reinforced polymers (FRP) offering lightweight potentials for innovative techniques, the verification of manufacturing quality is paramount as it directly impacts the mechanical properties of the materials and the structural behaviour of its constituents.
Common faults include: uneven linear density, count variation, slubs, neps and end breaks during spinning. In addition many materials, such as paper, are coated with a finishing product like china clay and the consistency of this requires inspection, and quality assurance.
Quality assessment of materials constructed with FRP's is critical, particularly for the verification of fibre orientations post manufacture, there are numerous inspection methods of which X-ray analysis is advantageous. Computer tomography, CT, is employed to assess fracture modes after mechanical testing under both tensile, compressive and torques loads and inner pressure loading. Damage detection in braided composite pipes is commonly carried out via acoustic emissions.
In production line assessment of more traditional textile products (clothing, carpeting, medical dressings etc) is important to detect error in human inspection as a result of fatigue. Optical devices are used to detect pick density and locate fabric flaws where lasers bounce light off the yarn and a one-dimensional image is fed back to computer software where the defects can be imaged.
Alternatively samples can be taken and further studied and analyzed macroscopically, for faults and consistency in production, using a stereomicroscope, or microscopically, using an incident light microscope, in the laboratory.