warp preparation for rope dyeing-1

Warp Preparation Requirements for Rope Dyeing

Ball Warping: Equipment required to form the rope of yarn. It involves creeling multiple ends of yarn ( Between 350-500 ends) and collecting them into an untwisted rope for dyeing. the rope is wound onto a long cylinder called a log on a machine called as a ball warper.

Some Notes

1. Packages of yarn are preconditioned before ball warping
2. Packages are loaded into the creel ( larger lots- magine transefer creeL0 and smaller lots- swing gate or truck creel
3. Packages are placed on adapters. An adapter support the package of yarn and ensure that the package remains aligned to the tensioning devices. Wooden plug type adapter are most effective as they require least amount of exertion to remove the empty package.

Next Step is threading the tensioner located at each yarn package

1. Post and Disk tensioner. It has two posts mounted onto a flat base. two round disk are placed onto each post. The yarn is threaded between the disk and wrapped around the post. One of the parts is movable so that the angle of wrap can be varied. More tension can be added to the yarn by adding round weights onto the top disk.

Advantages are 1. Inexpnsive 2. does Marginally adequate job of maintaining yarn tension 3. Simple to thread up 4. Low maintenance requirements.

Disadvantages are 1. Yarn has a tendency to jump out from between the disks at the rear of the creel. 2. It is labour intensive- when different tension levels are required. 3. There is more frequency of cleaning up 4. It doesnt control tension well at higher speed.

2. The driven disk tensioner

It also uses twin disk arrangement, however the disks are supported from below- there are no posts. Tension is applied from above- there are weights or spring loaded.
A gear under each pair of disks is matched to another gear mounted on a continuous shaft which runs the length of the vertical tension post. This shaft is connected to a 4 rpm motor which rotates the disk.

Advantage of disk rotation are 1. Thread cutting prevention 2. Dampens out variation due to ballooning action of yarn. There is mor uniform tension 4. Less effor required to change tension levels.

Disadvantages are 1. It is more difficult to thread up, there is more maintenance due to electric motor used and at high speed the tension control is not well.

loom shed

Process Control in Loom shed

It consists of two parts:
1. Increasing machine productivity
2. Improving quality or reducing defects

Control of the productivity can be done with

1. controlling nominal loom speed close to currently set standards.
2. Ensuring that loss of speed through belt slippage is minimum
3. Control of loss of loom efficiency by minimising:
a. Loom stoppage rate through correct maintenance
b. Control of down time of loom through corrective action on the basis of data collected by snap reading.

1.
2.

3. Factors effecting Loom efficiency

Various factors that affect the loom shed efficency are

1. Technical
2. Human ( Related to weaver skill and work methods)
3. Organisational

Relating the three factors

The technical and human (weaver related) factors have a very basic relationship with loom efficiency. The relationship is

P = NEX
= NE at

or E = P/ Nat
Where P= operative efficiency
N= number of machines per operative
E= Machine efficiency

X= Service factor, and it is equal to the average time taken to clear the stops in unit running time of a machine and equals at.
a= average no of stops per unit running time of a machine
t= average time to clear a stop including walking time

Thus if during an hour, the operator spends on an average 30 minutes in clearing stops, 15 min in ancillary durites like bringing raw materials etc and 15 min on rest and relaxation then
operative efficiency = (30 x 100)/60 = 50%
Work load = (30+15)x100/60 = 75%

Thus to maximise loom efficiency
- The stoppage rate should be low
- the weaver should be trained so that he takes the minimum possible time for clearing a stop.
- the operative efficiency should not fall below the optimum level
- loom allocation should be optimum

Costing in Drawing-in

Costing in Drawing-in

Drawers and reachers are paid their basic wages on piece rate system. The rates are related to the type of cloth to be woven. the basis of allocation of expenses to the different types of cloths are

1. Basic Wages of drawers and Reachers= Rate per 1000 ends x total production in 1000 ends.
2. DA to drawers and reachers and all other expenses = total production/production per shift

Cost of Drawing-in

Unit costs of this process as cost per 1000 ends. The cost of this process is calculated as shown below:

Cost of drawing-in per piece lengtrh = (cost per 1000 ends x total no of ends x tape length)/ weaver's beam length

Reed Calculations

Reed Calculations

Reeds are generally counted using STOCKPORT system, which is based on the number of ends in two inches.
Ex. A 72s stockport reed means 72 dents on 2 inches or 36 dents per inch.

Particulars of reed while ordering

100s ST, 18 G., 44"x 5" blue

- Stockport reed of
- 100 count
- using dents of 18s wire gauge
- Reed is 44" long
- 5" deep
- there will be blue paper on baulk of the reed.

Ex. What will be the number of ends/inch in a reed of 3/80s stockport

80s stockport= 80 dents per 2 inches
= 40 dents per inch

Therefore no of ends per inch = 3 x 40 = 120

Plain Set

When a set contains 4 shafts, it is called a plain set.

The number of heald eyes per inch across the healds in a set expresses the count of the heald.

Ex: 60s count for a plain set means 60 heald eyes on 4 shafts per inch i.e. 15 eyes per inch per shaft. For a 6 shaft set, it becomes 60 heald eyes on 6 shafts per inch i.e. 10 eyes per inch per shaft.

Ex. Find the count of healds that will be required for weaving a 6 shaft satin fabric using 72s stockport reed, drawn 3 ends per dent.

No. of ends per inch in the reed = (3x72)/2 = 108 ends
Therefore no of healds /inch = 108/6= 18 healds per inch.

Thus we require 72s count of reeds in a plain set.