By: Chidambaram Rameshkumar & Dr. N. Anbumani

Department of Textile Technology, Bannari Amman Institute of Technology
Sathyamangalam. Email :crktex@gmail.com

Department of Textile Technology, PSG College of Technology
Sathyamangalam

1.0 Introduction

Definition:
Core-spinning is a process by which fibres are twisted around an existing yarn, either filament or staple spun yarn, to produce a sheath� core structure in which the already formed yarn is the core.

Core-spun yarns are two-component structure with Core and sheath. Generally continuous filament yarn is used as core and the staple fibres used as sheath covering. The core-spun yarn used to enhance functional properties of the fabrics such as strength, durability and stretch comfort.

2.0 Methods for production of Core spun yarns

The production of Core-spun yarns done successfully by many spinning systems. Each system has its own features .The conventional ring spinning is simple and economy but the core positioning in the centre is difficult and major strip back problem may arise during subsequent process and the core filaments get twisted. In Dref III the core positioning can be set accurately and used to produce the industrial and conductive yarns. Probable methods of core-spun yarn production are discussed below.

1. Conventional core spinning attachment with ring spinning systems
2. S.R.R.C Core wrap spinning method
3. A.R.S. Patterned Spinning system
4. Core-twin spinning system
5. Composite electrostatic spinning system
6. Rotor spinning system
7. Friction spinning system and
8. Air jet spinning system

2.1 Conventional Core spinning attachment in Ring frame

A core spinning attachment in ring spinning is shown in Fig.1. The attachment consists of metal plate (Bracket) bent to a shape. One end of the device is fitted on the roving traverse guide bar such that the relative position of the roving and the core filament may be kept constant all the time. There is a provision to vary the position of the device if required. The other end of the plate is fitted with a porcelain guide that feed the core filament at a precise position behind the front drafting rollers. This devise is fitted with a pre-tensioner and is kept in a horizontal plane. Varying the number of tension discs may vary the input tension of the core filament. The package containing core filament material is suspended from a bar such that they could rotate easily, thus avoiding any tendency to stretch the filament before it is fed to the tensioning device.