Web Coating

Cartridge coaters are a new coating hardware concept that permits rapid change of coating methods in any coater, without a long costly set-up time.  As a result, the optimum coating method for any products can be used without requiring a very long time to change methods. The basis for the need to rapidly change coating methods is that there is a growing requirement for manufacturing coating lines to coating a wide variety of products with a wide range of coating variables, viscosity, wet coating weights, line speed, uniformity etc.

However; there is no single coating method that can coat all possible ranges of properties at optimum quality and uniformity. Each coating method has an optimum coatability window in which good product is made. However, when the coating variables move outside this window; quality, reproducibility, and uniformity deteriorates.  Therefore, the coating method should be selected that has the optimum coatability window that is consistent with the product variables. To do this, several coating methods are required.

The difficulty with using many coating methods is that typically the majority of Pilot and Production coating stations are designed for one only coating method and new methods cannot be easily added. The previous approach to do this was to disassemble a significant part of the coating station and to add new hardware configuration to the coating station to accommodate a new method.  This approach is time consuming and will result in loss of production material. Also, the precision and accuracy of the coating station variables may not be adequate. In addition if a third method is needed a third configuration is needed. Also, the cost of the additional configurations can be prohibitive, which will minimize alternate configurations. These difficulties have limited the use of multiple coating methods on Production Coaters.

Cartridge coaters were developed to avoid the above difficulties by designing a new concept coating station where each of the methods are in a separate cartridge and be can be rapidly withdrawn and inserted in several minutes versus hours. Another benefit is that if cleaning is needed the cartridge can be removed, cleaned off-line and another cartridge inserted. This saves production coater time.

Typical cartridge coaters are shown at the bottom of the blog. They are courtesy of New Era Converting Machinery, Inc.

The cartridges can accommodate multiple application methods such as direct gravure, offset gravure, differential gravure, reverse roll, four- and five-roll, kiss, Mayer rod, slot die, and knife coating. The services needed are in each cartridge and are easily interfaced with coater utilities. Systems with computer control, remote gap settings are available.

The cartridge system can be used in new coaters or retrofitted to old machines.