Coating Master Class Involves Stepping Out of Comfort Zones
- Published: November 17, 2025
The VCM coater — shown with with multiple processing stations — can be custom configured for pilot or the production coating of products as diverse as packaging, medical devices and disposables; automotive, electronics, security and products requiring precision. Photo courtesy of RK PrintCoat Instruments Ltd.
By Tom Kerchiss, Chairman of RK Print Coat Instruments Ltd
There are times, when tasked with processing the unfamiliar it can feel as though you are in the middle of a master class. As one hurdle or process variable is resolved another inconsistency pops up to demand the team’s attention.
While packaging may be the mainstay for many a converter, the reality of processing and remaining competitive may involve the converter and coating operative stepping outside of their comfort zone: toe-dipping into areas such as printable electronics, building and construction, and OLED and flat screen technology.
Complicating matters is that many of the substrates and consumables that the converter have become adept at using over time may not for much longer be justifiable to process or even available as legislative measures bite, and as eco-acceptable materials become ever more prevalent. The falling out of favor of many multi-web materials and the introduction of an increasing range of mono web and bio-based, bio-compostable materials, synthetics and nano-technology will undoubtedly make for interesting times. All of the aforementioned together with the banning of single-use plastics necessitate fresh processing approaches.
A VCML pilot coater custom configured with three dryer. The VCML coater enables product developers and converters engaged in trialing or determining product feasibility and commercial viability to coat, print or undertake wet or dry laminating. Hot air, infrared and UV curing are an option. Photo courtesy of RK PrintCoat Instruments Ltd.
The challenge for the converter and those engaged in coating and come to that laminating as well is that there is little in way of point of reference, so the processing, the coating of these new materials and applications necessitate a degree of flexibility, trialing and care. Partnering with industry professional; the chemists and formulators; research educators and institutes is a must. Input from AI sources is assured.
Coating can be a complex task; failure in one area can lead to poor quality and high levels of waste. With this is a real possibility of delaying additional converting processes or missing customer delivery deadlines altogether. Process inconsistencies may arise for a number of reasons, which is why it is important to trouble-shoot and consider problems from every angle. Drying conditions, for example, are a case in point. If not thermally controlled correctly, serious defects appear on a product surface.
Drying defects can occur if the temperature exceeds that of the dryer temperature. Distortion, variation in flatness and changes in form, function and appearance are often symptomatic of poor heat management and ineffective dryers. Water-borne inks and coatings can be challenging to dry and may require additional drying units.
The FlexiProof UV LED can be used for flexographic color matching and for determining how inks and substrates interact over time. Typically the lamps supplied offer a tailored output either at the important 385 or 395 nm wavelength and are ozone-free. Photo courtesy of RK PrintCoat Instruments Ltd.
Coating practitioners and other converters, those tasked with making a concept a reality, need to obtain as much information on the substrate and product end use. Will the product suffer periods of repeated flexing or deformation? Will the product be subjected to extreme temperature changes? The customer and converter must gather information on the robustness of the coating solution over the anticipated life of the product. The economics, the cost involved in bringing the coated product to market, the environmental implications such as recyclability and/or ease of disposal and much more must be considered.
Coating uniformity, the desired coat weight and the methods to achieve this are vital, one of the reasons being that no one wants to waste expensive materials. More importantly uniformity and pinhole-free deposition of a coating flow is essential for providing an effective barrier resistance for flexible packaging, medical and wound care applications.
Controlling a high-speed moving web, particularly when ultra-thin coating weights are involved, can be a challenge. A differential heated gravure-offset head for the application of laminating adhesives at coat weights evenly, and as low as 0.5 gsm-wet, has been developed and is one of many selectable coating technologies available for pilot machine.
The K Control Coater enables users to quickly produce accurate and repeatable samples that can be used for quality and presentation purposes, for R & D, for computer color matching, etc. Photo courtesy of RK PrintCoat Instruments Ltd.
Pilot coating systems are often ideal for engaging in suitability and feasibility studies prior to commitment to commercial production. Production line coating machines are not ideal for trialing purposes as the scope for running different materials and coating technologies and drying/curing methods is limited. Pilot coating systems custom configured and offering short-run capability provide the means whereby users can determine the most cost-efficient and process-viable method for bringing a product to market.
For the product developer and the converter, a key requirement is to have in place the most suitable equipment for trialing, monitoring and research and development. In electronics, security/anti-counterfeiting, medical and many other applications, it is essential that accredited standards, including those established by food agencies are followed and documentation is available and verifiable.
ABOUT THE AUTHOR
Tom Kerchiss is the chairman of sample preparation system and
print/coat/laminating technology specialist RK PrintCoat Instruments Ltd. The company, which won an Innovator in Pre-Press Award for the FlexiProof 100, supplies printing ink manufacturers, both large and small, as well as printers, converters and other businesses with color communication devices for all of the major print disciplines.
