Functions and Objectives Of Simplex Machine/Roving Frame/Speed Frame

Simplex Machine

A simplex machine or speed frame or roving frame is situated after the comber in the yarn manufacturing process. However, the sliver which is produced from the comber is thicker and it is not suitable to feed into the ring frame directly to produce yarn. For this reason, the drawn sliver is treated before entering into the ring frame. An intermediate process is done before the ring frame. This intermediate process is done by a simplex machine or speed frame. Moreover, this roving frame converted the thickly drawn sliver into a thin sliver with a low twist and produce fine roving which is suitable to produce yarn by feeding into the ring or others. Followings are the principle of the roving frame.

Working Principle of Simplex Mchine:

The Roving frame or simplex machine or speed frame works as the following flow chart. They are-

Drawn sliver→ Speed frame/Roving frame/Simplex →   Roving

Roving →        Ring frame →    Yarn

In this process drawn sliver is input and fine roving is output. This roving is fed into a ring frame for yarn production. It is noted that simplex is essential for the production of cotton yarn in the case of ring spinning by ring spinning system.

Objectives Of Simplex Machine/Roving Frame/Speed Frame

The following are the main objects of the simplex machine. They are-

  • Firstly, drafting uses to attenuation of drawn sliver to form roving of the required count.
  • Secondly, a small amount of twist inserts gives the required strength to roving.
  • Thirdly, to wind the twisted roving onto the bobbin.
  • Lastly, to build the roving in the full length of the bobbin in such a form that will facilitate handling, transfer, and feeding to the ring frame for yarn production.
Roving Frame
Simplex Machine/Roving Frame/Speed Frame

Image Source:

Functions Of Simplex Machine/Roving Frame/Speed Frame

Various types of objectives are achieved by the simplex frame like carding or combing action. Followings are the main functions of simplex or roving or speed frame.


Creeling is the first objective of simplex frame arrangement. By the creeling, a small amount of draft is applied to the drawn sliver.


Attenuation of drawn sliver to produce the required amount of roving by drafting. Thickly drawn sliver is converted into thin roving by the drafting system.


A small amount of twist is inserted in the drafted stand of fibers by the twisting. The amount of twists is very low.


Build the roving onto the bobbin in such a form that will facilitate unwinding handling and transfer to the next process.


Produced or twisted roving is wound on the bobbin by the winding process. This bobbin is fed to the ring frame and this bobbin accelerates the next process. So, it is important.


It is the optional function of the speed frame. Doffing could be done manually or automatically.

So, the simplex machine plays an important role in the spinning process. Consequently, various types of yarn faults could appear for the wrong drafting or twisting. For this reason, the operator should be careful during the process. Hence, machine parameters should be set properly for producing specific count yarn.

In sum, proper roving can give better yarn properties. So, we should be care full about the selection of simplex or speed frame, or roving frame.

Leave a Comment