Think you can't push your production speeds? This speed boost equation says you can!

It is probably safe to say that everyone in the digital printing industry considers the demand for increased production speed an ever-present challenge. In order to remain competitive, printer manufacturers must continually balance the desire for increased speed with the need to avoid raising equipment and ambient temperatures to levels that negatively impact operations. Excessive heat in production printing can cause equipment malfunctions or failures and degrade product quality, ultimately causing lost production cycles, increased supply waste and lower ROI.  No material is exempt -- the challenge to balance speed and heat is found in digital printing on all types of substrates: paper, tiles, carpet, textiles, even glass.  

Inkjet manufacturers most often encounter thermal management challenges in drying equipment and ink roller systems. In many instances, short- or mid-wavelength IR lamps are used in drying systems and emit a significant amount of heat. When drying ink, whether oil- or water-based, heat from IR lamps or other drying equipment must be carefully controlled to ensure it is neither too high – which can damage substrates, or too low – which can cause ink to smear and impact product quality. While the goal is to complete the drying process as quickly as possible, it cannot be rushed. Inks need to be completely dried, cured or fixated before the end-products can move to the next processing step.

Both air- and water-cooled ink roller systems are also subject to thermal management challenges. Rolls must maintain an ideal temperature to ensure the desired end quality. Water-cooled systems achieve this by changing the temperature of the roll starting from the inside. This approach requires the entire roll to reach the desired temperature in order to control the surface, where the ink properties are determined. It can take several minutes for the optimal temperature to be reached, and during that time manufacturers do not have adequate control over ink viscosity and thus print quality. This delay significantly impacts production speed.

Air cooling systems take less time to achieve the optimal temperature because only the immediate surface must change temperature, but nonetheless, there is a time lag. And, since conditions change, especially as speeds increase, the roll does require periodic re-establishment of temperature.

As a first step to overcoming these thermal management challenges, manufacturers can employ IR sensors. However, if they wish to increase production speed while also maintaining product quality, IR sensing alone may not be adequate. Speed increases require very precise temperature measurements, which can only be achieved by accounting for the difference between the surface temperature of a material (which can be directly measured) and the bulk material temperature (which must be indirectly measured). There is only one methodology in the world today that can provide that measurement and that can help manufacturers reach the speed increases they desire. It's known as the Speed Boost Equation™, and is based on a mathematical formula developed by Dr. Francesco Pompei, the CEO of Exergen, a leader in industrial and medical temperature technology.

The Speed Boost Equation, which employs a novel application of the LaPlace Transform method, uses the data from a material's surface temperature, combined with other non-contact temperature data, to derive the internal temperature of a material. By employing the simple result from a complex mathematical model, the bulk temperature can be estimated from surface temperatures, ambient temperatures, material properties, and speed. The Speed Boost Equation can be directly employed with appropriate IR sensors to increase production speeds while maintaining material temperature characteristics.

The Speed Boost System consists of Exergen's IRt/c™ non-contact infrared sensors for precision thermal measurement and control, a controller/data acquisition signal processing module, certified accurate D Series hand-held surface sensors for calibration, and SnakeEye sensors for temperature measurement.

When applied, for instance, to a printer drum roll, IR sensors used in conjunction with the Speed Boost Equation correctly adjust the flow of heat to maintain a consistent balance into and out of the roll surface. With this balance, temperature control is maintained accurately, and speed may be increased to the maximum values allowed by the press without loss of quality. HP Indigo has employed the Speed Boost Equation in their complete digital printing line of machines and achieved amazing results.

Bart van Liempd of Exergen Global will be explaining how the use of their technology can help boost production speeds across many printing applications at the IMI Europe Digital Printing Conference in Amsterdam, 30 Nov-1 Dec.