Silk Reeling is simply the unwinding of filaments from a group of cocoons in hot water bath on to a reel.
There are two methods of reeling a) Direct Reeling method on standard reels and b) Indirect method which includes preliminary reeling on small sized reels and transferring the reeled silk directly from the reels to standard sized reels on re-reeling machines.
Before reeling, cocoons have to pass various stages and production of quality silk depends upon various factors:
Purchase of Cocoons :
Selection of cocoons must be done carefully as any carelessness is this respect would spell serious losses to the reeling enterprise. Selective purchase of cocoons in an open market is extremely difficult, and becomes imperfect particularly in the absence of determined standards of quality for cocoons, and standard methods of testing for classifying cocoons into quality grades.
Cocoons should not be too flossy. Floss merely adds to the weight of cocoons when yielding silk for reeling. Cocoons should have well-rounded and firm ends and must not have too pronounced points. Well pointed ends are easy to detect because of their shape; thin ends can be detected by the lighter shade of colour at the end which when pressed yields readily, when floss is peeled off the cocoons, the surface must be fine grained and not deeply wrinkled.
Transporting Techniques :
The selected cocoons must be transported safely in perforated bamboo baskets or in loosely packed plastic crates, and must be transported during the cool hours. Packing the cocoons tightly and transporting them in the hot sun must always be avoided.
COCOON STIFLING & PRESERVATION
COCOON STIFLING:
Cocoons in their fresh condition with the pupae alive in them cannot be stored for a long time as the living pupae are soon transformed into moths. They are useless for reeling raw silk because the continuity of the bave in them is broken. Reeling cocoons, therefore, have to be subjected to a process of stifling with the object of killing the pupae inside without in anyway interfering with the structure of the silk shell around it. Cocoons can be stifled
by several methods but the popular methods in reeling industry are sun drying, steam stifling and hot air conditioning.
PRESERVATION:
Storage of cocoons is an important problem especially when the stiled cocoons have to be stored for a very long period. Complete desiccation of cocoons is a fairly satisfactory solution to the problem but even fully desiccated cocoons are liable to mould damage if the storage room is kept dry.
The other source of damage to cocoons in storage comes from the beetle pest, Dermestes lardarius. The following measures have to be followed for preservation of cocoons.
· Complete desiccation of cocoons before storing should be ensured.
· All care should be taken to see that the relative humidity in the store room does not rise above 70%.
· The store room must have good ventilation.
· Cocoons should be given regular and frequent turnings during the period
of storage and on no account should they be allowed to become damp.
· When fumigants are used care should be taken to keep the doors and windows open until all the traces of fumigants are removed
REELING & RE-REELING TECHNIQUES
Silk Reeling is simply the unwinding of filaments from a group of cocoons in hot water bath on to a reel.
There are two methods of reeling a) Direct Reeling method on standard reels and b) Indirect method which includes preliminary reeling on small sized reels and transferring the reeled silk directly from the reels to standard sized reels on re-reeling machines.
Systems of Reeling
There are two systems of reeling cocoons :
( i ) Floating System
( ii ) Sunken System
Floating System of Reeling
In floating system, the cocoons are cooked only to the extent the shell becomes wet, but is still impervious to water, so that they float in water when the cooked cocoons are put into the reeling basin. Floating system is associated with
1. Reeling of cooked cocoons which float in reeling basin.
2. High speed reeling.
3. High basin temperature.
4. Less number of reeling ends.
Sunken System of Reeling
In this system, the cooked cocoons sink in water at the time of reeling. In this system, not only the shell is cooked but in the process, the cocoon also gets filled with water inside to the extent of 97 to 98%, with the result, the cocoon becomes heavy and sinks in the reeling water. This system of reeling is associated with :
1. Reeling of cooked cocoons which sink under water in reeling basin.
2. Slow speed reeling.
3. Low basin temperature reeling.
4. Large number of reeling ends.
This system is suitable for superior quality cocoons like bivoltine. RE – REELING
Re – reeling is done to transfer the raw silk into standard sized hanks. The grant reeling helps in finding of broken ends of the thread and also its knotting. In grant reeling the hank is divided into several parts which can be kept separately by means of lacing. The ratio of the bevels determine the width of the diamond. For finer denier silk, more number of teeth have to be used. Re – reeling speed is almost double the reeling speed. So one end re-reeling will be enough to take the input of two end reeling. 13/24 bevel combination will produce 13 diamonds.
SKEINING
The standard size hanks from the swift are carefully examined for defects if any,it is laced and folded upon itself to form a skein with the help of skeining machine. The weight of the skeins varies from 50 g. to more that 100 g.
The skeins of raw silk are then made into books and bales are marketed later.
DIFFERENT SILK REELING DEVICES WITH ECONOMICS Reeling Devices:
There are three distinct reeling devices in mulberry sector namely
(a) Charka : It is a crude system of reeling. It is a simple hand driven device consists of a large cooking cum reeling pan where boiling water is kept.
(b)Cottage Basin System : It is improved over charka. It consists of separate cooking and reeling basin, where temperature is at boiling point only in the cooking basin, but reeling basin temperature is hardly 40 C.
(c) Multiend Basin System : It is a further improved version over the Cottage Basin and it is power driven. Boilers are installed and steam is used for cooking and reeling purpose and also for cocoon stifling in the special steam chambers.
BYE – PRODUCTS USES
During the process of mulberry silk reeling, the different qualities of mulberry silk waste obtained as bye-products:
a) Waste from cocoons:Floss or Blaze, Spelaia (Italian) or Keba (Japan) Discarded cocoons, pierced, double, stained etc.,
Floss or Blaze: Floss silk or blaze also known as borra is the first part of the bave extruded by the worm for the frame work of the cocoon. Most of it is removed from the cocoons during their collection and rest while sorting. This can be used for noil spinning.
Discarded cocoons : This includes all cocoons found to be unreelable during sorting like :
Double Cocoons: which are jointly formed by the combination of two worms in the same shell and which due to the the interlocking of the continuous filaments cannot be reeled alongwith good cocoons. These cocoons are also employed for reeling ‘dupion silk’
Inferior Cocoons:The improperly built cocoons and those deformed in shape and also melted cocoons and other cocoons which become unfit for reeling due to some reason or the other.
b) Reeling waste :It may be filature, Cottage basin or charka silk waste
c) Winding waste: Re-reeling, winding or throwster’s waste, Weaving waste (Hard waste)
