Tech Briefs

Adhesives using 100 percent solids coating act fast, without need for solvents.

In the medical industry, adhesives play a crucial role in applications ranging from diagnostics and device assembly to transdermal and wound care. There are varying methods by which an adhesive can be coated onto a substrate, but solvent coating has dominated in the medical industry for many years. Solvent-coated silicone, acrylic, and rubber-based adhesives are widely used as medical adhesive solutions. Despite their popularity, solvent-coated adhesives are far from a perfect answer to the medical market’s needs. Solvents may contain volatile organic compounds (VOCs) and even carcinogens that can be dangerous to humans. There are also major concerns regarding outgassing or leaching from solvent- coated adhesives in medical settings. As a process, solvent coating is not especially efficient with adhesives requiring drying, which can limit speed and cost-effectiveness of processing.

Fig. 1 – More inert adhesives have less potential for skin irritation.
Other options do exist for medical manufacturers when it comes to medical-grade adhesive production due, in large part, to substantial investments by select adhesives companies with extensive formulation expertise in 100 percent solids technology. Considered to be one of the most exciting innovations of the past two decades for the adhesives industry, 100 percent solids coating allows for the use of 100 percent neat adhesive components in coatings: no solvents or water are required. Via this coating process, adhesives can be applied at, or slightly above, room temperature, and require no slow, messy drying. This equates to significantly faster processing speeds and diminished costs for manufacturers, as well as numerous other advantages over competing technologies.


While processing efficiency and decreased cost are major incentives to adopt 100 percent solids adhesive coating, there are other practical reasons to consider this form of processing. First, 100 percent solids have a major advantage over water-coated or emulsion adhesives as emulsions typically do not meet the latex-free requirements of many medical industry applications. As previously stated, they also have an advantage over solvent-coated adhesives by avoiding some of the outgassing and migration risks that come from the solvents themselves, due to the absence of residue monomers, inhibitors, and stabilizers in 100 percent solids-coated adhesives. As a result, 100 percent solids adhesives have less potential for irritation, making them more inert and skin friendly.

Additionally, 100 percent solids adhesives have adhesion properties that are equivalent to adhesives coated via other means. They also often have the advantage of better property retention after sterilization. Adhesives coated via 100 percent solids processing also create less environmental impact than alternative processes, as the VOCs associated with solvents are avoided and minimal amounts of energy are consumed.

Notable Applications

Many medical applications benefit from 100 percent solids adhesive coating. Examples of prominent areas for use include:

• Diagnostics equipment: For in vitro diagnostic testing, where inertness, low-outgassing, low-fluorescence, pHresistance, and UV-resistance properties are crucial to avoid interference with reagent assays, 100 percent solids acrylic adhesives excel.

• IV dressings: The low costs, performance properties, and biocompatibility of 100 percent solids-coated acrylic adhesives make them attractive for use in IV dressing applications. A skinfriendly option with excellent breathability, it typically endures for up to 10 days. (See Figure 1)

• Self-adhering bandages/surgical drapes: For applications that require reliable adhesion to skin, comfortable removability, and skin-friendly properties, 100 percent solids rubber adhesives are beneficial.

• Medical equipment: When it comes to bonding parts in medical settings, from tools to robots, 100 percent solids rubber adhesives provide the best adhesion properties and can be used safely, effectively, and inexpensively with many substrates.

Capitalizing on 100 Percent Solids

If you are wondering why 100 percent solids coating is not more common within the industry given the obvious benefits of this technology, the answer lies in the level of investment required for 100 percent solvent processing. Adhesives companies must make a substantial investment in infrastructure, human capital, and knowledge to offer 100 percent solids adhesive coatings. There are a few adhesives companies that have mastered the technology, possessing the necessary equipment, many years of experience with 100 percent solids processing, as well as extensive formulation and compounding knowledge. If you are seeking to differentiate your products from competitors, seek out these companies for expertly tailored, safe, affordable 100 percent solids-coated solutions that will be of the greatest advantage to both your operations and your customers.

Especially when governmental regulatory bodies are taking a closer look at solvent usage, and there is considerable pressure to reduce the cost of patient care, 100 percent solids adhesive coating will become increasingly important within the medical industry. Investigate how this technology might benefit you most to maintain an edge in the marketplace moving forward.

This article was written by Steve Schroff, Senior Development Chemist, MACtac, part of the Bemis Company, Stow, OH. For more information, visit

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