Abstract
A string wound cartridge can be produced on a Random or Precision winding system. Both of them have certain disadvantages, making them unsuitable for applications like dyeing and filtration. Winders designed to operate on the step precision principle could be a solution to the above mentioned issues.
Commercial winders working on step precision winding principles are available in the market. They are recommended by manufacturers when packages for dyeing are to be produced but commercial, electronically controlled filter winders on dual principle are rare to find. It was thought of applying step precision winding principles to produce wound cartridges for filtration end uses with the intention of improving their performance. This paper describes improvement in the existing electronic filter winder so that it can be operated on dual principle. This system allows programmable selection of traverse/wind ratio so that it gets changed automatically step wise. Compared to mechanical systems, it is less complicated, there is ease of changeover, is more flexible, and also offers choice of operating mode. Beside this, it was possible to produce graded cartridges successfully showing better filtration efficiency and lower pressure drop.