Rieter

De-blending

Index

The spinner aims to distribute the different fibers evenly in the yarn. For this purpose, he must firstly produce a good blend at some stage of the process, and secondly be able to maintain the blend up to the stage of binding into the yarn. It is a well-known fact that meeting the first of these requirements is not always easy; sometimes the second is harder still. Fibers of different length, surface structure, crimp, etc., also behave differently during movements as individuals. A “de-blending” effect can very often arise. During rolling of fibers in hoppers (bale openers, hopper feeders), migration of the components occurs where the fibers have different structures (e.g. cotton and man-made fibers). A similar effect is found during drawing in drafting arrangements. Fibers with large differences in length or surface form (smooth/rough, dyed/undyed, etc.) do not exhibit the same cohesive contact with each other.

When a drafting force is applied, they move differently – this leads to clumping of fibers into clusters and finally to de-blending. Pneumatic transport can also cause de-blending.