| Sell BACKWASHING |
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| Detailed Trade Lead Description |
Backwashing is used to scour and dry wool,acrylic or polyester tops after dyeing.During backwashing three different operations are executed.These are:
-Scouring to eliminate dye particles and other unfixed dyeing auxiliaries
-Even application of additives(lubricant,softener,antistat etc)
-Drying
Many manufacturers of modern dyeing machines claim that backwashing is not required.They argue that the scouring efficiency in the dye vessel is sufficient to remove all traces of impurity after dyeing.However,the very nature of the design of the vessel suggests that it is impossible to remove all impurity at the end of the dyeing cycle.The wool pack acts as a sponge and retains liquor and therefore it is necessary to complete many rinsing operations to remove as much residue as possible.This ties up the dyeing vessel for longer than necessary and uses large amounts of water.After dyeing the wool has to be dried and it is beneficial to carry out this operation after backwashing during which the lowest possible temperatures may be employed because residual moisture content is low and evenly distributed.
The scouring action must be uniform.CMT Overworld backwashers use suction drums having very efficient bath circulation,forcing the liquor through the slivers toensure rapid and complete removal of residues.An impeller located inside the drum ensures that liquor is forced through the slivers.Electronic control of the speeds of the backwash bowls permits the use of very low sliver tension in the tops which further aids the flow of liquor through the slivers.
Impurties are readily removed from the fibre and carried away to the drain.Each fibre of each sliver from start to finish is treated uniformly.
To further ensure uniformity CMT Overworld Machinery Company Limited has incorporated many features that assist the operator to maximise quality and productivity.These include:
-Anti-lapping devices on each roller and drum with acoustic and visual alarms
-Automatic speed reduction in the event of a lap
-Sliver support devices for slivers exiting each bowl
-High efficiency squeezing
-Manual or automatic operation
-Easy to use electronic synoptic panel with touch screen operation
The benefits for the spinner are easy to realise:
-Better yield in spinning with reduction in CV
-Uniform frictional characteristics
-Reduced fibre breakage
-Nocoloured dust
Drying is uniform again thandks to the use of suction drum technology.The drums are superimposed to maximise the amount of fibre in contact with the drying surface giving rise to greaterproduction efficiencies.
To ensure the accurate and uniform applicationof additives,each backwashing plant is supplied with a Dosamatik chemical station.This permits theaccurate addition of chemicals to the bath in proportion to the speed of production.The feed is controlledelectronically according to the production rate.
Production rates depend on a variety of factors such as sliver weight,composition,colour,numberof bowls and number of drums in the dryer.The following are typical:
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