To optimize the cleaning of cotton in a spinning milk, there is entered into a control original data concerning fiber characteristics and proportions of different types of contamination inherent to the origin of fiber cotton bales. Also there is entered into the control a desired degree of cleaning and a throughput quantity of the carded fiber sliver. The control delivers predetermined control signals based upon the entered original data, the throughput quantity of the carded sliver and the desired degree of cleaning. These control signals set adjustable operating members governing the rate of opening of the cotton bales by bale opening machines, the degree of cleaning of the cotton fibers by cleaning machines and the rate of processing of the cotton fibers by at least one carding machine.

Method for producing a card sliver and carding machine therefor. The flexible bend of a card is set automatically by the machine control by means of a controllable actuator system on the basis of a wear characteristic, this characteristic representing the wear as a function of the production of a given material.

A throttle valve is provided within a discharge air duct located adjacent a fiber duct receiving a fiber laden air stream. The throttle valve cooperates with a stop in a lowered position to form a gap to allow a minimal air flow therethrough. In addition, a weight is provided on an arm attached to the throttle valve for pivoting therewith. The weight is disposed to counterbalance a substantial portion of the weight of the flap valve in the raised position of the valve so that the air flow maintains the valve in the open condition.

Method for producing a card sliver and carding machine therefor. The flexible bend of a card is set automatically by the machine control by means of a controllable actuator system on the basis of a wear characteristic, this characteristic representing the wear as a function of the production of a given material.

A sliver-delivering machine such as a card and a sliver coiler are each provided with an independent drive including a frequency-controlled free-phase motor. In addition, a frequency converter is connected in common to the motor of each drive for supplying power to each. The motors of the sliver-delivering machine and the coiler have a load-dependent speed characteristic, for example, each is an asynchronous motor with a maximum slip of 3% over a delivery speed range of up to 300 m/min.