# GATE (TF) Textile 2013 Question Paper Solution | GATE/2013/TF/13

###### Question 13 (Textile Engineering & Fibre Science)

Increase in the ratio of the length of crank to the of connecting rod leads to

Option A

### What is meant by sley eccentricity ratio?

Sley eccentricity in weaving refers to the amount of variation or deviation in the position of the sley relative to its normal or central position during the weaving process. The sley is a component in a weaving machine that controls the insertion of the weft yarn into the warp shed, forming the fabric.
In a weaving machine, the sley is typically moved back and forth in a reciprocating motion to create the shed, which is the opening between the warp yarns through which the weft yarn is inserted. The sley may have a fixed position or be designed to move with varying degrees of eccentricity, meaning it deviates from its central position during its reciprocating motion.
Sley eccentricity can be caused by various factors, such as manufacturing tolerances, wear and tear of machine parts, or intentional design for specific fabric requirements. Sley eccentricity can affect the uniformity of the fabric being produced, as it can result in variations in warp tension, warp crimp, fabric width, and selvage quality. Therefore, controlling sley eccentricity and maintaining it within acceptable limits is important for producing high-quality woven fabrics with consistent properties.
Sley eccentricity can be measured and quantified, and the sley eccentricity ratio is often used as a parameter to describe the amount of sley eccentricity in a weaving machine. The sley eccentricity ratio is calculated by dividing the difference between the maximum and minimum sley eccentricity values by the sum of the maximum and minimum values, and it provides an indication of the magnitude of sley motion during weaving. By controlling sley eccentricity and maintaining a low sley eccentricity ratio, weavers can produce fabrics with more consistent properties and better quality.
The formula for sley eccentricity ratio in weaving textiles is as follows:

Sley eccentricity=r/l =Radius of crank/length of connecting rod

and

Sley Eccentricity Ratio = (Max Sley Eccentricity – Min Sley Eccentricity) / (Max Sley Eccentricity + Min Sley Eccentricity)
where:
Max Sley Eccentricity: The maximum value of sley eccentricity, which represents the farthest deviation of the sley from its central position during its reciprocating motion.
Min Sley Eccentricity: The minimum value of sley eccentricity, which represents the closest deviation of the sley to its central position during its reciprocating motion.
The sley eccentricity ratio is calculated by taking the difference between the maximum and minimum sley eccentricity values, and dividing it by the sum of the maximum and minimum values. The resulting ratio provides an indication of the magnitude of sley motion during weaving, with a higher ratio indicating larger deviations of the sley from its central position.
Sley eccentricity is an important parameter in weaving as it can affect the uniformity of the fabric being produced. By controlling sley eccentricity and maintaining it within acceptable limits, weavers can produce fabrics with consistent properties and higher quality.