For ''Friendly'' Adhesives and Coatings, You Must Prioritize

Published: September 01, 2000, By David J. Bentley Jr., RBS Technologies

People working with adhesives and coatings for the converting industry constantly hear the terms "environmentally friendly" and "user friendly." These people hope that any product they use also will be "friendly" to their pocketbook. Is it an oxymoron to describe an adhesive or coating as friendly to the environment, the user, and the user's pocketbook? Let's hope not.

When the words "environmentally friendly" are used to describe an adhesive or coating, it means the material will not harm the environment. This lack of harm must cover many factors. Raw materials used in the product must not deplete any naturally occurring material. The method or process that combines the raw materials must not harm the environment by releasing any harmful by-products or other unwanted materials. Packaging for the adhesive or coating should also reflect a concern for the environment by not using excessive material that requires disposal or any material that will not degrade in a reasonable time. (Returnable containers are obviously highly environmentally friendly.)

Adhesives and coatings that are environmentally friendly must also display this characteristic during their use by the converter. This again requires that they do not create undesirable emission products or items that need disposal.

The final step in the cycle of environmental friendliness for adhesives and coatings used in converting covers the actual use of the converted product, i.e., laminate or coated item, in its intended use as a package. The primary concern here is disposal of the packaging material as waste and the biodegradation time necessary for this waste.

And, when this environmentally friendly adhesive or coating must also be user friendly, it complicates the situation further. "User friendly" means that the material in question must not place any new or additional demands on the user.

In the 1970s, when environmental concerns began in earnest, many people in the converting industry that used adhesives and coatings made a conscious decision to use aqueous products, high solids materials, and similar approaches. Although there was sometimes a relatively steep learning curve involved in the switch, some converters, especially those using absorbative substrates such as paper, were able to use the same equipment, or at least the same equipment with some slight modifications, and the same or similar processing. Those converters could often switch from an adhesive or coating in solvent to one that was in compliance with few changes in coating weight, line speed, drying conditions, final properties, etc. This certainly represented optimum user friendliness.

If one adds economics as a third requirement, the restrictions become very demanding. When trying to make an adhesive or coating that is economical, environmentally friendly, and user friendly, the supplier will have severe limitations on which raw materials are possible.

For example, an expensive additive might be exactly the solution for a deficiency in an environmentally and user friendly material, but its cost takes it out of consideration.

What is the best way to solve this dilemma? Prioritization will usually provide the best of all worlds. When working with the supplier of an adhesive or coating, a converter should rank the importance of each of the "friendly" characteristics. In most cases, environmental friendliness will have the most importance due to regulations; making something environmentally friendly is not merely desirable—it's the law! Therefore, converters can gain a competitive advantage by allowing their suppliers latitude in the areas of user friendliness and economics.

If you are willing to be creative and consider changes in application technique, structure, operating conditions, etc., you could incur some additional costs but you might be able to enhance certain final package properties.

An example would be a curing agent that would add 5 cents to the raw material cost and require a 3% lower line speed but offer 100% improvement in chemical resistance for a laminate.

So figure out what is most important to you. Prioritize the characteristics of environmental friendliness, user friendliness, and economics. The willingness to sacrifice in one area in order to enhance another can offer an aggressive converter significant advantages that will translate into a competitive edge.