NASHVILLE, TN—Taking the stage to welcome attendees to Tuesday morning’s Forum 2015 sessions, cochairs Jessica Harrell and Jennye Scott said that, in reviewing comments from last year’s event, there was a common refrain: “Bring it back to the basics.” Listening to those calls, they kicked off Toolbox Tuesday, a four part session delivering grounded and proven advice, strategies, tips and words of caution to a full room of attendees.
Part I of Toolbox Tuesday, subtitled “Optimizing Flexo: The Decoders Guide to Process Control,” was chaired by Alexander James, of Harper GraphicSolutions, and Bob Hannum, of DuPont Packaging Graphics.
Alix Guyot, Anderson & Vreeland began by discussing process control, outlining three steps to follow:
- Define the quality control checkpoints in the plate room
- Record the data from checkpoints
- Use and review the data to monitor the plates and make changes when needed
She then touched on best practices for a number of areas of the flexographic workflow, providing the audience with an all encompassing guide of what to do and what not to do.
Categories of best practices:
- Room environment
- Cleanliness
- Temperature and humidity control
- Equipment consistency
- Imaging
- Exposure
- Processing
- Processing solvent
- Processing water
- Thermal
- Drying
- Post/detack
- Raw materials
- Acclimating the material
- Raw sheet material gauge
Guyot urged attendees to compile daily, weekly and semiannual checklist reviews to ensure these categories and steps are being followed, as well as having at least one preventative maintenance per year—ideally two.
Graphs the data collected from these checks, she said, helps to visualize the numbers and measurements that can be harder to decipher in a spreadsheet.
Cori Devlin, from DuPont Packaging Graphics, came next, with a presentation on dot geometries and how to optimize your prepress workflow to take advantage of them. She gave a quick overview of analog and digital dots and reminded attendees why new dot geometries are developed: to deliver the highest quality.
She then hit a number of image preparation steps and told printers to “be realistic about printing conditions” and to prepare images to align with what is feasible. “A well done 120 lpi screen is preferable to a poorly done 150,” she noted.
She continued by providing printers with other useful tips and things to consider (or avoid):
- Dirty printing: “Pick your process and optimize it”
- Prepress guidelines
- Selecting the proper minimum dot: “The right minimum dot is the smallest correctly formed dot that can stand up to the pressure of printing”
- Creating curves: “Make sure the curve is smooth and is always rising”
- Managing tonal transitions in images and vignettes
- Quality control targets
- Relief: Follow Flexographic Image Reproduction Specifications & Tolerances (FIRST) standards with 0.018-in. to 0.022-in.
Devlin brought it back home and reminded the audience that “higher quality requires process control.”
Part I wrapped up with a talk from Tetra Pak’s Pranab Singh, who delivered a truth: Quality control is, too often, a reactive measure. He followed that with a sobering statistic that further supported the need to implement process control: At his company, the total amount of defective production from its 32 factories is equal to an entire factory’s output.
He also said that historically, Tetra Pak has measured quality by customer claims and complaints, and that the improvements made to process control have reduced those claims by 75 percent in the last 15 years.
Singh outlined two quality matrices, for quality assurance (QA) and quality maintenance (QM). Speaking to a QA matrix, he gave three basic steps to help in its creation:
- Identify required quality
- Detail steps in a process map
- Establish a relationship rating between process parameters
In a QM, the method used to control each parameter is defined, as well as the control’s physical location. Singh then displayed a photo of himself next to a QM, with the document consisting of 82 process parameters and stretching nearly twice his height.
“Process control needs to add value,” he made sure to note.