The heating equipment is necessary when dyeing and printing factories are doing fabric processing. The process of fabric treatment is actual chemical reaction and how to control the reaction temperature is very important.
This article mainly discusses the printing factories dryers.
There are two common dryers, one is steam heating dryer,and another is hot air dryer. The IR dryer is rarely used due to itslow efficiency.The advantages of steam heating dryer is small space occupied and fast dry speed.
The defect is hard to control the humidity so normally it is used on last procedurewhen chemical treatment on fabrics has already finished.
During cropping stage, when color paste just print on the fabric and dyestuff has not yet reaction with fibers the drying process has big influence for color developing. If cropping is too dry, the shade will be dull and color fixationmight be insufficient.If cropping is too wet,the fabric accumulated in cloth box it could occur the color overlapping andnot able to remove color overlapping in any procedure.
Therefore,printing machines normally use air cushion hot air dryer to maintain same temperature on front and back from left and right parts of drying chamber. It is suitable for all types fabrics if it required non-touch drying and normally carries fabric with polyester mesh.
To ensure hot efficiency and qualified printing fabrics, factories will clean drying chamber regularly, remove the rubbish, dyestuff and fibers.
Hot air stenter is the necessary device for everyfactory. It could reduce fabric’s shrink,adjust hand feeling and make the fabrics looks more beautiful.Moreover,it could eliminate static and improve the fabric quality.
There are two types of heating methods,open coalgas (natural gas) flame heating(Openrecirculating airfirstly then ignite) and closed type heat exchanger(steam or high temperature oil cycle).
The fabrics carry out first dry on polyester guide band,the hot air jet goesup and down to avoid fabrics moves up and down.During second dry,hot air jetsfrom down to up and the fabrics presson the polyester guide band.
The dryer diagrammatic sketch is as below; hope it could help us to understand the operation equipment.
Rotary printing machine
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Hot air mesh dryer
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IR dryer
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Internal structure of IR dryer
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Drying cylinder dryer
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Hot air Stenter
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Stenter internal operation
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Stenter section
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