Filament analyses

Every yarn needs to comply to certain specifications depending on your application and your specifications. At Senbis we are specialized in measuring the properties of yarns for both quality control and R&D. We do so according to renowned standards like ISO, ASTM and BISFA. A large amount of properties can be measured in our dedicated polymer laboratory.

For the mechanical analyses of filaments, please go to the submenu mechanical analyses. Other typical yarn analyses include cross section analysi...Read more

Every yarn needs to comply to certain specifications depending on your application and your specifications. At Senbis we are specialized in measuring the properties of yarns for both quality control and R&D. We do so according to renowned standards like ISO, ASTM and BISFA. A large amount of properties can be measured in our dedicated polymer laboratory.

For the mechanical analyses of filaments, please go to the submenu mechanical analyses. Other typical yarn analyses include cross section analysis, entanglement tests, hot air shrinkage and yarn evenness measurements

Physical structure analysis on yarn can help to improve your product and process!

A general rule of thumb is that orientation of polymeric chains increases strength in a yarn.  The amount of orientation can be determined in detail by a combination of 5 analysis; density, ubbelohde viscometry, birefringence, pulse propagation method and x-ray diffraction.

  • The overall density of a yarn is determined with a davenport gradient column. This information is later used in calculations.
  • Ubbelohde viscometry is used to determine the molecular weight of the polymer of interest and is also used in later calculations.
  • Birefringence, determined by means of a microscope using polarized light, gives information about the average amount of orientation originating from both the crystalline and amorphous phases.
  • The pulse propagation method (PPM) determines the maximum amount of orientation in the yarn, composed of crystalline domains and the amorphous phase. As a soundwave is send through a yarn the propagation speed is measured. The first and fastest wave is most important, because sound travels fastest through orientated materials. The maximum orientation can be mathematically determined.
  • X-ray diffraction is a method to measure the size, orientation and density of crystalline domains in the yarn using x-rays. The density of the crystalline fraction is most important in order to determine the total amount of crystalline material in a yarn. By subtracting the x‑ray diffraction results from the pulse propagation method results, the maximum orientation in the amorphous phase is determined.

This is a perfect example of how multiple analysis can be combined to determine the structure of a yarn. The molecular weight, viscosity, density, percentage of crystalline domains, density of crystalline domains, amount of orientation in the amorphous phase of a yarn is known after doing 5 analysis and mathematics. By doing these analysis we can understand the polymer and relate its physical structure to process settings and predict properties. Process optimization can be done and steered into a specific direction suiting your needs.