Phoseon develops LED curing with a low sound threshold

WhisperCool uses proprietary and patented Phoseon innovations to maximum UV output while keeping the sound level to a minimum. This involves utilizing a holistic, system architecture approach combining more than a decade of semiconductor light matrix (SLM) LED array experience, advanced thermal management, computational fluid dynamic (CFD), and electronic control.

Phoseon sees LED curing being installed on many digital inkjet presses, in addition to enjoying rapid growth in both coating and adhesive applications. Collaboration between light source providers, materials companies and machine builders have advanced LED curing capability to deliver three primary benefits: advanced capabilities, low operating economics and environmental advantages.

And according to Phoseon, air-cooled LED light sources have grown in popularity due to their simple design and lower overall system prices, with no need for a cooler or chiller, no water maintenance and no risk of condensation. To keep the LEDs operating at maximum efficiency, air-cooled systems use fans to move ambient air across heat-sinks to remove any heat generated by the diodes.

For Phoseon to provide increasingly powerful air-cooled lamps, more air flow is required to remove the heat generated by LEDs. The amount of air flow is measured in cubic feet per minute (CFM). CFM is typically improved with either larger fans or increasing the speed at which the fans rotate. A fast rotating fan typically equates to increased sound as the fan’s blades must turn at a higher RPM.

Sound is measured in decibels (dBA) on a logarithmic scale. The human ear has a large dynamic range and is sensitive to both actual sound as well as pitch and/or tone. Due to the logarithmic scale, most humans perceive a doubling in sound with a 5-10dBA increase in sound. There are workplace safety regulations in place that specify machinery must operate at or below a safe threshold. For example, European directive EU 2003/10/EC states machinery must operate under 80dBA to be considered safe and above 85dBA ear protection is required. OSHA standards in the US are 85dBA and 90dBA respectively.

An additional challenge is product size, as while a large, slowly rotating fan is ideal, it is not a practical alternative given the physical size constraints users demand from their LED curing systems. Additionally, if a 300mm long unit measures 75dBA, then two 300mm units would measure 78dBA. Each equivalent addition of a similar product size increases the output by 3dBA.

Phoseon said a reduced sound level allows equipment operators to work in a safer, more productive environment, leading to improved productivity.

‘[We] developed WhisperCool to address the sound level as LED light sources become more powerful,’ said Joe Becker, product marketing manager at Phoseon Technology. ‘This is the second innovation, after TargetCure, that Phoseon is bringing to the market in 2016 to improve customer's curing capabilities.’