knitting production and quality control
DESCRIPTION
A brief description about knitting hall requirementsTRANSCRIPT
Knitting Technology Part 2 Elaboration of different controlling parameters having significant impact on knitting technology Dr Muhammad Mushtaq Mangat www.mushtaqmangat.org
Process control in weft knitting
Fabric elasticity depends upon: Type of fibers
Number of wales per inch Stitch length
Relaxation/finishing route Yarn linear density Planner weight
Tightness Factor
L is stitch length, K ranges from 1.29-1.6 [1]
Quality control in weft knitting
Off machine by using HATRA course length tester and Shirley crimp tester.
On machine by yarn speed and length meter
Issues:
Variation in tensions
Variation in yarn thickness
Production Calculation Gauge of machine= 20
Diameter of machine=30
Number of feeders= 90
Stitch length 4mm
Total number of needles=20*30*3.14=1884
RPM= 20
Yarn count= 20s
Production day (20 hr) *.85 (efficiency)=
=((((1884*90*20*60*20*4*.85)/1000)*1.0936)/(840*20))/ 2.2046=408 Kgs per day
Knitting Hal Requirements Controlled environment in knitting hall (moisture and temperature)
Machine maintenance,
Quality of compressed air
Skill of workers
Yarn storage place and methods
Fabric storage
Lubricants quality
Quality of needles and sinkers
Fluff level in the environment
Knitting hall temperature and moisture
Mayer and Cie, one of the largest and most aggressive knitting machine manufactures recommends maintaining 20 C° temperature and 65 % RH humidity in knitting hall.
It is expected that 20-25% production of the knitting mill can be improved by putting an air conditioning plant.
In addition to that 50% less faults and 50% less consumption (breakage) of needles and sinkers is expected.
A healthy environment to workers, which keeps them healthy.
And finally we have a neat, clean, free from fly and healthy environment, which definitely improver our productivity.
Cont… No tripping of electronic parts, which is quite common
at high temperature
Less breakage of needles due to low temperature
Satisfied operator since environment is neat and clean along with suitable temperature and humidity
Better knitted fabric quality due to less yarn breakage and low machine stoppage frequency
Better health of workers
Less yarn wastage
Conducive environment for creativity
Moisture Free Compressed Air
Cool and moisture free compressed air for knitting is required
We can have following advantages of cool, free from contaminant in and dry air:
Helps reduction in needle breakage
Avoiding rust on machine
Smooth running of machine
Reduction in accidents
References
[1] Anand, S.C., Technical fabric structures – 2. Knitted fabrics, in Handbook of Technical Textiles A.R. Horrocks, Anand, S. C., Editor 2000, Woodhead Publishing Ltd Cambridge.