FlexAir Dryer Systems can be broken down into the dryer itself, and the electrical systems that power and control the dryer. Except for the larger Coater and Tunnel Dryers , our drying systems are similar in construction and operation.
Our Dryers
   
   
   
FlexAir’s patent pending air bars are the heart of each dryer system, and in a sense are individual dryers themselves because functionally they each receive, heat, and disperse the compressed air at the web. This, along with having a very small profile, allows us tremendous flexibility in our dryer designs.

The dryer enclosure is constructed from stainless steel, and provides a barrier between the air bars and the surrounding environment. This creates an atmosphere within the dryer that intensifies the effect of the hot “dry” air and in turn further improves evaporation rates. The enclosure also minimizes the amount of hot air that can escape to the surrounding environment. The escaping air, more commonly known as fugitive air, can have adverse affects on other areas of the press such as with the inking systems.

Depending on the type of application, dryers may include:

  • Idle Rolls - to support the web as it passes through the dryer
  • Access Doors - for maintenance and web thread up
  • Web Slot Gates - to minimize air entering and leaving the dryer enclosure as the web passes through the dryer
  • Exhaust Port(s) - for removing the saturated air from the dryer
  • Chain Web Up – for threading the web through the dryer
  • Mounting Brackets - In most cases our dryer mounting brackets will use in existing holes in the press frames

The dryers can be designed for both water-based and solvent-based applications and web widths in excess of 100 inches.

Controls & Electrical Systems
The operator controls and electrical systems are simple, robust systems that are designed using common off-the-shelf components.

Operator controls typically include a power On/Off/Auto switch, a temperature controller, and an air regulator & gage. Depending on the space available and the application, operator controls may be housed in the dryer itself or in a separate enclosure that can be mounted remotely from the dryer. When our dryer systems are purchased as a standard option on a new press, some or all of the operator controls may be incorporated directly into the press controls.

Our temperature controller contains a programmable microprocessor that acts as the brains of electrical system. A thermocouple mounted on one of the air bars provides a temperature feedback to the microprocessor. The microprocessor then uses this information to pulsate power on and off to the heating elements.

This temperature circuit, in combination with the robust heating elements allows the dryers to be powered up and maintain operating temperature without consuming compressed air. In application, the compressed air is linked to the press run signal, where a solenoid valve is used to automatically turn the compressed air on and off when the press starts and stops.

The dryer systems can be designed to work with any of the standard voltages in the industry.

Coater & Tunnel Dryer
This group of dryers is primarily designed for applications that require higher levels of drying. The dryers are designed to provide customers with tremendous flexibility even after the dryer has been purchased and installed.

The dryers can be designed to fit virtually any web path. Low friction idler rolls are use to support the web as it passes through the dryer. The air bars are positioned opposite idlers to eliminate scratching of the web and to help control registration. Additional locations are typically available in the housing to add more air bars and idler rolls if additional drying is required in the future. Air bars cane be move to empty locations to change the dryer gradient.

These dryers are designed with multiple sets of operator controls, where each set of controls is designed to independently control a series of air bars within the dryer. This provides the operator an option to create different drying zones within the dryer.

In many cases adequate drying will require the web to cure at an elevated temperature for a prolonged period of time. In order to make the most out of the dwell time in the dryer, it becomes very important to bring the web up to temperature as quickly as possible.

In any dryer system, temperature rise of the web only occurs under the nozzle or heat source. In the case of forced hot air dryer systems, the nozzles must be evenly spaced throughout the dryer to avoid issues with balancing airflows. FlexAir air bars are not only much more efficient at transferring heat into the web, but they can be placed side-by-side as the web enters the dryer. This results in the ability to raise the temperature of the web much more quickly.

In the case of a 15-foot forced hot air tunnel dryer, it may take the first six feet of dwell time in the dryer to bring the web up to temperature, whereas in a compressed air dryer it may only take three feet of dwell time. This effectively adds three feet of dwell time to the web at the elevated temperature. The increase in dwell time at the elevated temperature from 8 feet to 11 feet represents a 37% increase the curing capacity.