The rapid growth of security printing creates new challenges for reel inspection, also on difficult substrates. A contribution for in-line video inspection in the print and converting stage. By John Cusack, Product Manager, QuadTech, Inc.
Over the past decade, brands have used increasingly sophisticated substrates and print enhancements for their product packaging and labeling. At the same time, higher security items like credit cards, gift certificates, vouchers, tickets and common financial documents include security features like holograms, UV-inks and foil stamping.
The challenge is for these products and features to be inspected. Foils, metalized substrates, holograms and other print enhancements can create a serious challenge for camera-based systems. However, most applications can be successfully inspected with the right system, but it needs careful consideration and the flexibility to meet unique characteristics of any job.
Printers and converters who can offer web inspection that identifies these faults and save their customers time and money can be at once more competitive and profitable.
Fortunately, QuadTech offers custom made solutions that integrate best with a customer’s workflow and the products produced, to achieve product security, integrity and print quality.
The system characteristics. The QuadTech® Inspection System with SpectralCam™ offers a flexible platform that can be configured on a press or finishing line, but the earlier the fault is identified, the greater the savings. SpectralCam calculates L*a*b, Delta-E, Density and Delta-Density at full press speeds, offering the assurance of high-quality, defect-free print, while saving time and reducing waste. It is suitable for a wide range of roll-fed applications including commercial print, flexible packaging, folding carton and labels, and can be configured for use with transparent and translucent substrates.
For jobs like hologram or foil inspection, QuadTech uses proprietary LEDs to provide optimum illumination. A top light focuses a narrow beam on the web to inspect normal print, adjusted dependent on the conditions needed for the substrate.
Special lights producing a lower intensity and diffuse light are used for inspecting metallic foils or UV varnishes, while a “back light” can be used to inspect translucent and transparent materials. The system will ensure that a hologram has been correctly applied, verify its registration and orientation on the document, and check that it is without folds or wrinkles.
