From slot die and UV coating to hot melt and pressure sensitive adhesives and silicones, when the word coating comes to mind, the thought of giant 50" to 60" equipment is a first vision. But among the multitude of wide web coating equipment manufacturers, only a few are involved in the production of narrow web coating equipment.
Used for various applications, from testing laboratories and R&D departments, to converters for numerous specialty niche applications, such as medical and health care, narrow web coating equipment is a growing and improving segment of the industry.
"Coating of pressure sensitive adhesives and silicones is done mostly at wider widths and higher speeds, and then the material is slit down to size," explains Matthew Tielkemeier, vice president, Dri-Tec Inc., Milwaukee, Wis. "Narrow web coating applications for pressure sensitive or silicones are used by pilot facilities for testing out new processes and by converters for specialty medical applications," he adds.
"Narrow web coaters are purchased by converters looking to do more unique applications. Everyone wants to do something different," says Gary Faulkner, president of Advanced Coating, Nashville, Tenn. Advanced Coating is a representative for Independent Machine Company, Fairfield, N.J.
Narrow web coating can be accomplished off-line and in-line. "In-line narrow web coaters are used in-line with printing presses and other types of equipment, and off-line coaters are used generally in laboratories or R&D departments to test materials and coatweights," says Scott Seymour, vice president and CFO of Euclid Tool & Machine Co., Bay City, Mich.
"The problem with coating in-line," explains Faulkner, "is that if the press has to stop for any reason, the web may have void areas with no coating. That's why most people prefer off-line coating."
As for a list of various applications, industry coating professionals name pressure sensitive labels, packaging, price marking labels, tapes, medical and healthcare, specialty labels and laminations. "End users are constantly coming up with innovative ideas. As a result, the industry is constantly moving forward," says Steven Manno, president of Greystone Manufacturing, Cooperstown, N.Y.
Although many different types of coating processes exist, four stand out in the crowd. Faulkner of Advanced Coating provides an overview.
Extrusion coating, he says, is used in many slot-die applications. The coating is applied like a thick film and is used in most cases as a moisture barrier.
In roll coating, the coating is placed on the material with a cylinder. This type of application provides lower coatweights, but is slightly more expensive.
Spray coating is used for hot melt applications. In this process the coating is heated and interjected with hot air to achieve different spray patterns.
With an intermittent lay-down coater, the coating experiences less contact with the web to achieve void places of adhesive. This process produces less coating waste and is able to achieve excellent patterns.
As with all equipment involved in the narrow web converting industry, faster speeds are always on demand. "Customers are asking for faster machines, equipment that coats thinner adhesives to reduce cost, and improved performance," says Ted Loranz, site manager at Acumeter, Holliston, Mass. Acumeter is involved in the manufacture of coating equipment for slot die coating of hot melt adhesives, with testing facilities available for evaluation of substrates and coatings. "Hot melt is an area that people go to from solvent adhesives to get a certain performance at a value," says Loranz.
One of the trends in this market, says Loranz, is an interest from customers in UV curable liquid coatings. "Many adhesive companies have come up with new formulations. The area of focus is to get the cost down, but the performance is there," he says.
Another trend is the coating of film to accept digital printing. "The digital printing niche is definitely growing, as well as many applications for the flexible packaging industry. They are all creating new ideas for coating," says Manno of Greystone Manufacturing. He says the coating of film prior to digital printing requires the use of different equipment. "The coating of a film for digital printing may not be used to put on heavy adhesives," he explains. Greystone Manufacturing is involved in retrofitting coating units with modular unwind/rewind units. "Customers have the opportunity to use any coating manufacturer and interline our modular unwind/rewind units," says Manno.
The move into an integral process control, with one station touch screens is another major trend for coating equipment.
Tielkemeier of Dri-Tec says this feature permits modern production equipment to be adaptable for future process requirements and changing production needs. "The system reduces operator finesse requirements by simplifying complex equipment," he says. "On-line help screens provide operators with a level of comfort, and help maximize run times," he adds.
Other advantages to this Windows-based system include statistical process control on Excel, where valuable production information can be constantly monitored. "The system centralizes control and makes it easier to operate at a glance," says Tielkemeier.
Security, provided by log-in rights, is another plus. Passwords are assigned to individual operators, allowing management to track output and identify problem areas so pressmen can be properly trained, says Tielkemeier. "Maintenance is assigned a higher level of access for sophisticated servo diagnostics and input/output troubleshooting, and is allowed to make program changes to extend operating parameters." Finally, says Tielkemeier, upper management is allowed to make changes to log-in rights.
On the market
In the narrow web market, a few coating equipment manufacturers stand out in the crowd, with the latest in technological developments. Euclid Tool & Machine, manufacturers of direct gravure, offset gravure and blade coating machines, has been making strides with its patented pneumatic blade assembly.
By varying the amount of air pressure applied to this assembly in conjunction with variable roll speed and variable roll pressure, users are able to obtain any desired coating weight onto paper, film and foil, says Seymour of Euclid Tool & Machine. "Our lab coaters are significantly more accurate than wire-wound rod methods as well as various other types of coating systems," he adds, "and our coaters provide a 100 percent uniform, consistent, and repeatable coating weight ranging as low as one-tenth of one micron to as high as five mils, all for a wide variety of different coatings including silicones, adhesives, inks, UV coatings, paper coatings, resins, polymers, overcoat varnishes, etc."
Euclid Tool & Machine offers its multiple system lab coater at 18" wide. This unit has a bottom roll driven with a variable speed motor and controller, and an optional additional second motor for independent drive of the center roll with the FOR/REV controller for the center roll. Both the top and center rolls are air regulated for applying downward pressure, and a vertical height adjustment allows the user to set a gap between the rolls for varying substrate thicknesses, or allow the rolls to make complete contact.
Acumeter is marketing the LH-3 laboratory hot melt coater-laminator with widths up to 8". The unit features integrated microprocessor temperature and drive control, web speeds to 300 fpm, a precision gear pump for accurate application, manual tension control, benchtop size footprint, and is easy to use and maintain.
Independent Machine Company is offering its 20" hot melt coater/laminating system for use on a range of materials. This system features both extrusion slot die coating and fiberizing spray coating capabilities, providing the user with a versatile lab or production system. The unit has a speed range to 750 fpm and includes auto edge guided primary and secondary unwinds, closed loop tension control and auto edge guiding. Other features include 16" diameter driven chill roll, Allen-Bradley PLC with touchscreen operator controls, and a multi-drive DC system.
Dri-Tec features its integrated machine control as a standard feature on all products. With this pre-programmed system, set-up information, diagnostics, and maintenance specifications are all stored in one environment.