Wearing Coating for Delivery Rollers of a Drawing Roller Frame

A roller drafting apparatus for a spinning machine that defines a drafting field for fibers having a known average staple length, comprising:

• a pressure roller and opposed lower cylinder at the output of the drafting field, the pressure roller having an inner layer fastened around a core of the pressure roller;
• a deflection rail;
• an endless apron that travels in a running path over the pressure roller and the deflection rail, the apron formed as an outer layer that loosely surrounds the inner layer and is thinner and harder than the inner layer fastened around the pressure roller;
• and
• wherein the deflection rail comprises a cross-sectional circumference that is greater than the known average staple length of the fibers drawn on the roller drafting apparatus.

An endless apron for use in a roller drafting apparatus for a spinning machine that defines a drafting field for fibers having a known average staple length, the drafting apparatus having a pressure roller and opposed lower cylinder at the output of the drafting field, the pressure roller having an inner layer fastened around a core of the pressure roller, wherein the endless apron travels in a running path over the pressure roller and a deflection rail, the apron formed as an outer layer that loosely surrounds the inner layer, the apron further comprising:

• a first yarn insert having yarns wound in a first direction;
• a second yarn insert having yarns wound in a second opposing direction against the yarns of the first yarn insert;
• and
• wherein the opposed yarn inserts provide the apron with a low expansion in the running direction of the apron and prevent asymmetrical running of the apron over the deflection rail.