Prediction of Stitch length from the QAP (Quality Adjusting Pulley) setting for the large diameter single jersey circular weft knitting machine of AUST laboratory
CHAPTER-1
INTRODUCTION
1|Page
1.1. INTRODUCTION:
The production of high quality fabric is gaining importance because of increasing consumer consciousness and tough competition in the global market. On circular weft knitting machines yarn feeding devices play a major role in controlling the size and the regularity of the stitches formed. In fact the yarn- feeding device has become one of the most important elements of a modern multi-feeder circular knitting machine as it draws yarn from the package and delivers it to the needle to form stitches during a defined interval. Currently in Circular weft knitting machines, positive feeding is generally used and the stitch length is altered by manually adjusting the diameter of the quality pulley, sometimes termed as QAP (Quality
Adjusting Pulley) or VDQ (Variable Diameter Quality) pulley or Quality wheel. QAP is adjusted to match the drive belt speed to the required yarn delivery rate. Even if the
QAP diameter is adjusted to the correct speed, stitch length on the fabric may be quite different.
As the knitter has to work with quick production process of present days he should have the knowledge to adjust the VDQ pulley to get the required stitch length value in a short time. In this project work such an attempt has been taken to establish a relation between the QAP diameter and stitch length of the fabric produced on the large diameter single jersey circular weft knitting machine of AUST laboratory.
2|Page
1.2. Objective:
To discover the maximum and minimum limits for QAP diameter settings in the circular weft knitting machine of AUST laboratory.
To find out the range for stitch length that can be achieved practically on the produced fabric in the mentioned machine.
To calculate the amount of deviation between calculated and actual course length during different stages of knitting.
To establish a relation between VDQ pulley diameter and fabric stitch length for common
INTRODUCTION
1|Page
1.1. INTRODUCTION:
The production of high quality fabric is gaining importance because of increasing consumer consciousness and tough competition in the global market. On circular weft knitting machines yarn feeding devices play a major role in controlling the size and the regularity of the stitches formed. In fact the yarn- feeding device has become one of the most important elements of a modern multi-feeder circular knitting machine as it draws yarn from the package and delivers it to the needle to form stitches during a defined interval. Currently in Circular weft knitting machines, positive feeding is generally used and the stitch length is altered by manually adjusting the diameter of the quality pulley, sometimes termed as QAP (Quality
Adjusting Pulley) or VDQ (Variable Diameter Quality) pulley or Quality wheel. QAP is adjusted to match the drive belt speed to the required yarn delivery rate. Even if the
QAP diameter is adjusted to the correct speed, stitch length on the fabric may be quite different.
As the knitter has to work with quick production process of present days he should have the knowledge to adjust the VDQ pulley to get the required stitch length value in a short time. In this project work such an attempt has been taken to establish a relation between the QAP diameter and stitch length of the fabric produced on the large diameter single jersey circular weft knitting machine of AUST laboratory.
2|Page
1.2. Objective:
To discover the maximum and minimum limits for QAP diameter settings in the circular weft knitting machine of AUST laboratory.
To find out the range for stitch length that can be achieved practically on the produced fabric in the mentioned machine.
To calculate the amount of deviation between calculated and actual course length during different stages of knitting.
To establish a relation between VDQ pulley diameter and fabric stitch length for common