Auto Doffing System | Roving

Doffing: After the required length is wound on to the package, the fully wound package is replaced by empty package by doffing operation. Doffing is the process where the wounding device like bobbin will change after fully wounded by yarn.

Types:

1. Stationary systems integrated in each ring spinning machine
2. Mobile systems which can serve several machines.

When new machines are equipped with automatic doffing systems, these are almost always stationary systems. Mobile systems are used, if at all, almost exclusively in existing ring spinning mills. Whereas with stationary systems all cops on a machine are doffed simultaneously, mobile systems usually feature individual doffing, often also doffing in groups. A stationary system is described below as an example for many other options.

Automatic doffing: Automatic doffing enables labor requirements and doffing times to be drastically reduced. The fully automated Rieter F 35 roving frame performs doffing in less than 2 minutes. This has been made possible by separate actuation of bobbin rail and doffer rail by two independent frequency converters.

Doffing sequence-

1. Doffing sequence: 1– The bobbin rail (1) moves out and at the same time the footboard is set up.  The doffer beam with the empty tubes is lowered between the full bobbins (2).
2. Doffing sequence: 2 – The empty bobbin pegs of the doffer beam grasp the full bobbins. (All the bobbin pegs are now occupied). The doffer beam moves up to reversing position.
3. Doffing sequence: 3 – The conveyor belt in the doffer beam moves into intermediate position.
4. Doffing sequence: 4 – The doffer beam puts the empty tubes onto the spindles.
5. Doffing sequence: 5 – The doffer beam moves into top position with the full bobbins. The slide moves in and the footboard is lowered at the same time. The safety zone is free again.
6. Doffing sequence: 6 – The bobbin rail (1) is raised to spinning start-up position. The full bobbins (2) are transported to the transfer station. The roving frame starts up automatically.

The doffing sequence of the f35 roving frame is shown by following Figure.

  

Conclusion: Auto doffing is very important for more production. It has added a new change in doffing system. It is safe and quick doffing system which is needed for modern technology.