Enhancing Performance

Cot Centering and Mounting

The pneumatically operated vertical mounting machine is recommended for mounting alu cots for ring frame and roving frame.

The spring-loaded centering pin is essential for guiding the cot onto the roller with proper alignment. This aids perfect mounting without any damage to the core

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Precision Grinding

Cot is supplied as a semi finished product. After mounting it should be ground to ordered dia. which is usually referred as FOD. Accuracy and precision is important so that the cot surface is free from eccentricity.

Initial grinding of 0.3 to 0.5 mm is essential to get a eccentricity free surface. Subsequent regrinding can be in the order of 0.15 to 0.2 mm or depending on the extent of wear on the cot surface. Roll shop should be equipped with an eccentricity tester and precise values must be attained as per machinery manufacturers recommendations.

Roughness Measurement

After grinding, the cot must have a smooth fine surface. This can be tested by using Perthometer.

The device measures surface finish in microns (Ra–average surface roughness).

For ideal working Ra should be in the range of 0.8 to 1.0 mic.

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Grinding Wheel Quality

The grinding wheel must be dressed by using a Diamond tipped dressing tool.

This should be done periodically in order to get a good surface finish on cots.

Ideally it can be done after grinding 1200 to 1500 ring frame top rollers.

Roving Traverse Mechanism

The proper functioning of a roving traverse mechanism is important to get the most out of aprons and cots.

The width of a roving traverse should be adjusted to 8-10 mm (depending on width of cot) in conventional spinning system. The movement of traverse should be continuous and smooth and the dwelling time (time taken at reversal point) should be very less.

Typically, there is a cam-and-follower system in the ring frame to convert rotary movement to linear movement. In case there is any wear out in these components, the linear movement will not be continuous and smooth. This will result in groove formation in aprons/cots.

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