What are you doing to introduce printers to quality control?
BATISTATOS: We look at it as a two-step process. Make sure we understand customers’ needs—stamping, roller identification, packaging or any other special kind of job instructions. Constantly reviewing this with the customer makes sure it is meeting their needs.
A second way we introduce quality control is to help the customers to understand each other’s engraving measurement systems. Correlation between scopes makes sure we’re all on the same page, as far as calibration and providing the engraving exactly how the customer needs it for their tolerance.
HARVEY: Apex is incorporating a customer portal that gives customers access to live data related to the order status and position in the production process. We also provided a QCA document, standardized around the world, itemizing tolerances and customer service procedures with a unique QR code. This QR code requests the QCR record and a digital download option gives the production data and images related to the order. This is a robust automatic document that is exempt from manual amendments. The image and the volumes are automatically applied to the document, once the final inspection has been checked and saved.
In addition, Apex has conducted extensive tests and validation of the leading digital microscopes, including seismic analysis of the environment, to ensure the consistency is as controlled as possible.
Apex has records and data from 17 devices going back over the last two years on a daily basis. Therefore, the device production capabilities are fully understood. Measurements are stored on an independent global server. All readings are captured in a single database/dashboard that is color coded to control the device consistency. A floating device that is kept at the OEM (MicroDynamics) is always in perfect showroom condition—when one of the 17 devices drops out of the tolerance, we immediately activate the “floating device” to be dispatched, while the device is sent back for repair/calibration.
WOODARD: We perform endless roller audits and provide care and handling seminars in the field to help educate our customers as to the condition and effectiveness of their rollers. This often leads to some customers purchasing their own analysis equipment for routine monitoring.
POULSON: We have ongoing raw material testing. This is our coupon testing for ceramic raw materials. This goes out to a third-party lab to quantify that our raw materials, as well as our functional practices, are being reproduced and maintained. We are the first anilox supplier to be ISO certified. We also have come up with a new geometry that has shown an increased print quality, as well as other enhancements that were unexpected going into this geometry shift.
RASTETTER: There’s an outstanding amount of information that is available through consultation with our technical team. We would be pleased to have a detailed, personalized conversation on any of these subjects, and many others, far beyond the scope of what we can put into print.
BEESON: Sandon is working with printers to encourage them to measure and record data, so they can see trends in wear and damage. If you cannot measure it, you cannot control it. Flexography is a process. Lock down the variables and the outcome can always be repeated.
Measuring cleaning alone is one area. Let’s say the operational cost to your business is $350 per hour. If you lose one hour every day because the anilox rollers are not clean, and you cannot achieve the color, and this happens over six days a week, for 48 weeks, you could have lost $100,800 that year. Quality control is a big deal, and we are working with customer to overcome these challenges.
If every supplier engraved an anilox to a specific lpi, volume and engraving type, would it be the same? If not, why?
BATISTATOS: It would not be the same. Troika did a study several years ago where a banded roll with multiple engravings was sent to 13 different anilox companies for measurement. The readings, on the same engravings, varied drastically. The study showed that every company has different measurement techniques and devices. We still see this today. Not only do companies have different scopes, but their frequency and accuracy of calibration varies, which also cause different readings.
HARVEY: Understand that the three elements stated are by no way definitive related to the anilox performance.
First, lpi. This is the number of cells in a linear inch along the angle of engraving (60 degree). It is calculated from the center of the cell to the center of the next cell. Therefore, a 300 lpi anilox that has an 85-micron opening plus wall distance, can be made from a 20-micron cell opening with 65-micron walls; or an 80-micron opening and 5-micron walls. Both will measure 300 lpi, but both will perform completely differently.
Second, volume or bcm. This is simply a measurement of space and how much liquid can fit inside the engraving—not what will be transferred! A closed cell with thick cell walls will require a deeper engraving to achieve the same volume as an open engraving.
Therefore, to answer the question, lpi and bcm are not sufficient to judge a comparison in anilox performance. It is too simplistic to look at just the numbers. If utilizing the same method of ceramic application, the cell shape, cell depth, cell opening, cell wall, cell volume (measured with the same device), surface polish; then the results will be very similar.
WOODARD: No. We’ve seen this time and time again. What measurement equipment does one supplier use versus another? What software version of that equipment is being used? How is the equipment calibrated and, of course, what laser-engraving technology is being used?
POULSON: There are variations between suppliers. This may be due to scope technology being used, as well as engraving quality and how each company calibrates scopes. We have many interferometers running—all calibrated to a universal scope. We have many 3DQCs and we make sure they all read the same. There are theoretical vs. interferometry which will show a variance. The differences can be drastic. Basically, if you understand what you run and those volume requirements, you will have sufficient control of your inventory.
Consistency with rollers of the same bcm is what you need to look out for. Standardization will make that happen. If you have 10 1,000-linscreen rollers at 2.0 bcm, they should all deliver the same volume and solid ink density.
Out of linescreen, engraving angle, cell depth, cell width and volume, volume is the most important. This accommodates the graphic requirements. It also controls ink film thickness, dot gain and solid ink density. After we know what volume is needed, you can move on to linescreen and geometry, but it’s all about the volume going onto substrate. Depending on what the ink chemistry is and its function, then we talk about geometry, linescreen and cell opening. It also matters what volume is used in every linescreen chosen. If you follow the Harper volume chart, it will lead you in the right direction.
MIDDLETON: Simply put—No! Understanding the differences in how volume is measured is a key factor. What tolerances are acceptable from each engraver? To answer that, we would need a universal standard of measurement.
BEESON: “No” is the short answer. Taking into consideration some of the following, is the reason why they will never be the same.
- Different ceramic—not all ceramic is made equally
- Porosity level
- There is no standard for volumetric measurement; devices and settings differ
- Operators
- Not every cell is engraved equally—methods differ, equipment levels differ and operator skill differs
- Historic measurement calculations—Are they correct?
- How the anilox is micro finished—by hand, by machine or not at all?
All these have an impact on the anilox roller’s ability to print. This is why no two suppliers are the same. Sandon Global can offer a “calibrated standard” to customers that use the same volume checking equipment, whether using a Troika Ani-cam, MicroDynamics or Voltec ink drawdown system.