For manufacturers that utilize flat-rolled steel, aluminum and other metals to fabricate parts or products, the ability to bond decorative foils and laminate films to the substrate provides an opportunity to deliver attractive finishes for a competitive edge. However, the process of laminating to metals is fraught with potential complications. If the wrong adhesive is utilized, if the curing process is not precisely controlled or a variety of other variables are not managed, the result can be a high scrap rate or parts that fail in the field.
When this occurs, OEMs and even the coil processors that supply them with bare or B-stage (pre-applied adhesive) coil turn to custom formulators for unique solutions to production issues. In many cases, the proper adhesive formulation can have significant benefits such as speeding production, eliminating scrap, reducing the amount of material required and even improving corrosion, UV and antimicrobial resistance.
Options for applying laminate
The use of laminated flat-rolled metal to fabricate parts or products is widespread throughout manufacturing. Some of the more common applications including appliances (refrigerators and freezers, washing machines, dishwashers, microwaves, range or fume hoods), construction products (insulated wall panels, garage doors, roofing products) and the mobile and manufactured home markets (walls, door panels). The processing of adhering laminates to coiled rolls or sheets occurs in several different ways. Manufacturers can employ in-house personnel, but this process is slow, requires manual labor and quality can also be an issue.
Laminated metals are available with a wide range of coatings. Photo: Unichem
“Application of adhesives in the final manufacturing facility can lead to significant amounts of scrap, higher per piece labor costs, and can expose the manufacturer to significant environmental costs and scrutiny,” says Eric Fossen, managing director of Spencer Ridge Consulting of Ontario, Canada. “So they often are looking for a more efficient solution that gives them a more consistent [laminate] performance.”
Adhesives applied in a coil coating operation offer the advantage of a high degree of consistency in both film thickness and cure conditions, which can provide a stronger and more durable adhesive bond. High quality application allows the final product to be post-lamination formed into many severe bends and shapes without affecting the integrity of the bond between adhesive and film. Although coil processors control the application process much more tightly, the quality of the bond ultimately depends on the type of adhesive used
When off-the-shelf solutions don’t meet their needs, coil processors and even OEMs turn to the few adhesive formulators with the expertise and experience in coil processing to come up with unique solutions to solve difficult problems.
Case in point – Door Panels
For Elixir Door Company, manufacturing entrance doors for manufactured homes involved vinyl-coated steel that was stamped and formed before being filled with urethane foam for insulation and structural strength. Approximately 2-3 years ago, however, the company began to experience significant adhesion problems leading to a high scrap rate. “The vinyl was coming off in major proportions – not just a ‘spot here’ or a ‘spot there,’ but in many places. It was very inconsistent,” explains general manager Archie Brown.
Unable to identify the reason, Brown says he called in a custom adhesives and coating formulator, Universal Chemicals & Coatings (Unichem). The company specializes in coil processing and can create custom adhesives and also coatings.
Photo: Elixir Door
The solution involved an adjustment to the temperature parameters of the curing oven as well as a custom-formulated adhesive designed to cure within a broader temperature range. “We analyzed our entire process and came up with some corrective actions,” says Brown. “We adjusted everything and have had no problems since.”
According to Brown, Elixir Door subsequently decided to outsource the entire process. Now the coil processor delivers a finished, vinyl-coated part using the custom adhesive formulation that is already sized and stamped into shape. “We were paying [the coil processor] to apply adhesive, then paying to apply the vinyl in house. Now they do it all in one operation at their facility,” says Brown. “So our cost is much less and we don’t have to worry about scrap because it’s on them, not us anymore.”
For more information on laminated coatings, visit www.unicheminc.com
Photo: Elixir Door
Filed Under: Materials • advanced
