The high production in the spinning process to save time leads to the reduction in yarn quality. The technological changes that have occurred today are remarkable. Modern machines reach the production rate of 60 – 100 kilograms/hour which is remarkable when compared to only 5 – 10 kilograms/hour which was possible until 1970. Great advantages have brought us new machinery, as they reduce production time and less physical effort.

Today spinning equipment is fed by rolls directly, the operator, according to the type of machines will be in charge of a section and that section will be constituted from four to eight teams. The fundamental operations applied by the card are stretching and continuous cleaning for the case of natural fibers.

The cotton card differs from the bar in that the latter is larger because of the physical characteristics of the wool, another type of card is the one used for the production of non-wovens that serves to manufacture disposable cleaning materials, mouth covers, layers of diapers etc.

In the conventional spinning processes there is the tendency to omit the flap due to the accommodation or adaptation of continuous production processes, by direct feeding mainly in medium to higher quality fibers, groups of feeders, loaders are used and mixers coupled and in sequence with the card. Although the flap is also still applied in lower quality fibers, for thick articles, for cleaning materials and in opening of short, artificial and synthetic fibers.