These versatile dryers have the ability to dry typically ‘slow’ pine oil and water miscible inks using a combination of Infra Red radiation with Hot Air and ambient or refrigerated air cooling from above and below.
Natgraph manufacture a range of Air Force IR Glass Dryers that has been developed from years of experience gained in the production of 100’s of IR High Temperature Conveyorised Systems, that are in world-wide daily use. These versatile dryers have the ability to dry typically ‘slow’ pine oil and water miscible inks using a combination of Infra Red radiation with Hot Air and ambient or refrigerated air cooling from above and below.
These dryers have been designed, developed and manufactured for drying surface coatings applied to glass products from 0.6mm through to 24mm thick and up to 3m wide. This glass is used in the automotive, architectural, domestic appliance, solar energy, electronic display and furniture industries. Whatever the requirement for drying ceramic inks onto glass, Natgraph have a solution.
With 5 standard belt widths, Touch Screen PLC Control System, 4 layouts, combined Hot Air/IR lamp systems, double sided cooling, special transport systems and modular design, this range of dryers is extremely adaptable, versatile and efficient.
The Natgraph range of Air Force IR Glass Dryers is available in 5 belt widths from 70cm through to 260cm, with a comprehensive selection of module types available depending upon the production line requirements. A combination of IR/Hot Air, with extra Hot Air, Extraction, Ambient Cooling or Refrigerated Cooling Modules, make these dryers extremely adaptable.
Features
- Touch Screen, PLC Control System
- High temperature operation, optionally up to 200°C
- 16 medium wave IR lamps per 2m module
- High efficiency vented stainless steel reflectors
- Gas filled lifting arms on the hood
- Steel bar or P.T.F.E coated fibre glass mesh transport systems
- Modular construction
- Castors & jacking feet
- Colour coded to industry standards
- Optional recirculation filters
- Variable output of IR lamps
- Optional inlet filter
- Available in 5 sizes
Optimum Dryer Design
The solvents contained in ceramic inks are commonly pine oil based and so, very slow to force dry. Also the glass can be up to 24mm thick, thus forming a massive ‘heat sink’ below the ink, absorbing the energy that is needed to accelerate the evaporation of solvents. When Natgraph configures the specification of a glass dryer, the considerations are:
- Ink type
- Ink layer thickness
- Line speed
- Maximum glass thickness
- Maximum & minimum glass sizes
- Glass exit temperature
Taking these factors into account, the dryer is specified utilising a combination of the following modules:
IR Hot Air Modules: The construction of these High Temperature Dryers is completely different from standard units, with extra insulation layers and air gaps required to keep the external surfaces cool, even though it can be over 200°C inside the dryer. The air recirculation system uses a different principle, as the hot air needs to be retained in a specially insulated, inner ducting system that has additional insulation layers.
Extraction Modules: To ensure safe and efficient operation, all gases emitted from the ink during the drying process are extracted from the dryer, internal extraction ducting is provided within the heating modules, or alternatively a separate evaporation/extraction module can be included.
Cooling Modules: The required exit temperature of the glass determines the type and number of cooling modules needed. Natgraph’s unique, double sided cooling system uses either ambient or refrigerated air. The refrigerated air modules recirculate the air through an internal cooling coil (with air filter), that is connected to an external chiller plant by flexible pipework. Water is cooled by the chiller plant as required to maintain a controlled air temperature within the module. The chiller plant requires a separate electrical power supply, but is controlled from the dryers PLC system.
Transport Systems: Flat glass to be screenprinted can typically vary in thickness from 0.6mm to 24mm, with sizes from 10cm to 3m wide, weighing up to 500kgs per piece, therefore the transportation for each application may require a specific conveyor system. Variable speed, P.T.F.E. coated, fibre glass mesh belts are the most common and economical solution. If very large, heavy glass is to be reliably transported, a driven chain/bar system or driven rollers will be required, the choice of which will depend upon the minimum glass size. These systems support the glass with the minimum of contact to maintain the dryer’s efficiency of heating and cooling. In the case of refrigerated cooling, the transport system is assembled in 2 sections, split in the 1m Extraction Module, this separates the hot conveyor from the refrigerated one thereby increasing the efficiency of the dryer.
Options
Inlet Filters
An optional Inlet Filter stack can be fitted to each dedicated air inlet s ensure that the air being drawn into the dryer is free of dirt and dust. This freestanding filter stack has a replaceable, slide in unit, with a filter rating of EU4 (4 microns) and has been designed to maintain air efficiency for the dryer, whilst preventing contamination.
Variable Output of IR Lamps
An optional system can be fitted to control the output (power level), of the Infra Red lamps on a percentage basis, this system can be very useful when the effects of the IR can be critical, or are unknown. This system is controlled by the Touch Screen PLC Control System with a digital output.
Inverter Drives for Fan Motors
An optional Inverter Drive can be fitted to control the air speed at the glass surface. This can be useful when very thin, or metallic inks are to be dried at high speed in the same dryer to be used for thicker, conventional ceramic inks.
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