A commercial printer in the height of summer. At 6:30 a.m., a prepress operator arrives and begins making plates for a four-color brochure for a local furniture store. Suddenly the plant’s air conditioning system acts up. The temperature at the plant starts rising. Halfway through the print run, a plate gets damaged. At 11am, the pressroom requests a replacement. But the prepress room is now 5°C hotter than when the original plates were made.
What happens next?
The operator makes a new plate and it’s sent to the pressroom. But because the aluminum has expanded in the heat, the image on the plate is the wrong size and the plate can’t be used. Another complete set of plates has to be made, wasting precious time and materials both in prepress and on press.
The prepress operator makes the new plate, which matches the damaged plate exactly, despite the heat. The run continues with no issues. He pours himself a refreshing drink.
Aluminum, like many materials, expands and shrinks with changes in temperature. So plates, especially remakes, made at different times under typical shop conditions can end up being imaged at different sizes, which leads to subsequent on-press registration and color shift problems. A 5°C change in plate temperature can cause dots to shift by ½ rosette. Automatic Temperature Compensation, a feature of SQUARESPOT Imaging Technology, enables accurate registration even with variations in ambient temperature. Two sensors in the engine measure the temperature, and firmware in the imaging engine makes adjustments and places the pixel in an adjusted location to compensate for the aluminum expansion of the plate. Repeatability on one KODAK Platesetter is 0.00508 mm for the entire environmental operating temperature range of the machine. The accuracy between plates made on different machines is within 0.02032 mm.
A printer has a 10-year-old CTP device that it was planning to replace this year. An unexpected expense in another area of the business means the budget for the replacement CTP has been cut, and it needs to last another year. The imaging head is reaching the end of its projected life, and a laser dies.
So what happens next?
The CTP device stops imaging properly. The team calls a technician, who tells them he can keep the device going with reduced performance until the laser is replaced – if it’s on the edge of the swath. But if it’s in the middle, they must replace it before the device can be used at all, and productivity will take a hit.
The CTP device continues performing normally and no one even notices the problem.
As any CTP device ages, the laser is wearing out. In a KODAK CTP Device, if one of the 19 emitters dies, the system continues and automatically compensates as each emitter exposes the full laser swath feeding into the light valve without impact to plate throughput. Even if multiple emitters die, the system continues to work. Towards the end of the life of the laser, an easy check by Kodak’s remote team can predict the life of the head before it requires replacement.
A large newspaper running multiple CTP devices wants to fully automate its operation.
What happens next?
Plates have to be kept with other plates made on the same CTP device, so the newspaper has to design a system where each line has its own separate stacking and sorting equipment. The operation becomes bigger, more expensive and more complex.
The newspaper designs its operation with all CTP devices feeding plates into one system, which sorts the plates to optimize productivity. The operation works like a dream, because the plates can be made on any CTP device and still match all the others.
Every KODAK Platesetter with SQUARESPOT Imaging Technology is calibrated at the factory to provide stability in imaging, even across different KODAK Platesetters. This means printers can maintain registration while imaging a job on multiple CTP devices. Printers can also remake a plate without having to track which device made the original set. This Geometric Compensation feature provides stability in imaging by correcting asymmetries and aligning the imaging grid to the plate edge.
A busy print shop runs an average of [TBD] m² of plates through its plate processor each month. Processors need cleaning, which takes time, as does changing the chemistry when it ages. It’s been about 2 weeks since the chemistry has been changed.
What happens next?
The operator finds the print isn’t meeting the required color standards and grey balance – because the dots on the plates are changing size and getting more and more out of spec. The team wastes time adjusting the press and plates to maintain print quality. To keep in spec without as many adjustments, the prepress operators will have to change the chemistry more often, wasting precious time and expensive chemicals.
The print shop gets maximum life out of its chemistry, cleaning the processor once a month (according to the recommended standard for their plate).
All CTP lasers expose dots according to a grid of pixels, typically of about 2,400 per inch. Laser systems found on many platesetters use a laser spot with an effective diameter of about 1500 dpi. More importantly, the laser energy tapers off towards the outer diameter in what is called a Gaussian (soft/fuzzy) profile.
Conventional Gaussian laser energy profile.
GLV laser energy profile
SQUAREspot Technology laser energy profile
The Gaussian profile creates an area of uncertainty in the laser imaging spot that is highly sensitive to variation. Although more precise on one dimension, grating light valve (GLV) technology produces a similar area of uncertainty on the other dimension. As the developer ages, more and more of these fuzzy areas are developed on the plate, resulting in larger halftone dots and introducing inconsistencies that need to be addressed on press. High-resolution, 10,000 dpi SQUARESPOT Technology substantially reduces the Gaussian effect, delivering halftone dots with greater immunity to normal process variations in prepress.