A global manufacturer of fiber-cement building products needed to spray a proprietary resin coating on siding boards to aid the drying process. The previous spray system, which lacked a controller, resulted in inconsistent coating and messy overspray. With boards being produced at speeds that varied up to 65% the system’s inability to automatically adjust flow rate based on line speed was also problematic.
The company required a spray solution that would precisely apply the coating with minimal overspray and waste. This would reduce maintenance, cleanup, scrap material and associated man-hours. Achieving these objectives while, at the same time, being able to make on-the-fly changes to line speeds and production schedules without switching out spray nozzles also was paramount.
The AutoJet® resin coating sytem
The company purchased our AutoJet® resin coating system. This includes the AutoJet E1850+ Spray System, an enclosed PulsaJet® header equipped with six PulsaJet®AA10000AUH-104210 electrically actuated spray nozzles and UniJet® PWMD tips. Prior to entering the drying oven, siding boards are conveyed under the 1676 mm spray header and sprayed with the resin coating from a 216 mm spray height. We use a flow rate range of 1.5 to 7.5 liters/hour per nozzle.
The AutoJet® system provides Precision Spray Control (PSC) to ensure accurate, uniform placement of the resin coating. All of this is achieved with minimal waste – even with line speeds ranging from 90 to 150 meters/minute. The ability to produce a wide range of flow rates eliminates the need to change the spray settings during production.
The AutoJet® E1850+ Spray System provided significant cost benefits over the first four months of operation. It reduced consumption of the expensive resin coating and cleanup of messy overspray. Furthermore, the improved quality consistency led to less scrap being created and eliminated the need to haul it away. In addition PSC set the flow rate concerns to rest.
The system’s success led the fiber-cement manufacturer to project an annual savings of € 80,000. This translated to a payback period of less than three months on the investment. It also resulted in the company approving the capital expenditure for 12 additional systems for similar use in other plants.