fiber covering, has a variety of applications. The aim of using core spun yarns is to take advantages of the different properties of these two components. However, a common problem with core spun yarns made on a ring spinning frame is the slippage of the staple fibers relative to the filament. An effective method for resolving this problem was proposed as spreading mutifilament yarns into mono filaments by using electrostatic field. In this research we describe a new method of producing composite yarn called cluster-spun yarn that is spun with cotton fibers and polyester multifilament spread by slotted roller. Slotted roller, with fine grooves divides the multifilament into two or three (even four) substrands and produce clustered spun yarn, the principles that was used in manufacturing of solospun yarns. For this purpose, core spun and cluster spun yarns were produced at different twist levels and then these yarns and relevant fabrics were tested for a range of properties, i.e . tenacity, elongation, evenness and abration resistance of fabrics. Structural characteristics of core and cluster spun yarns have been studied by SEM as well. Microtomy method and image processing techniques were used to study the distribution of fibers in the cross section of sample yarns.
