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Hot Melt Adhesives_New Routes to Safety

Hot Melt Adhesives: New Routes to Safety

Posted 29 Apr 2022 by Inaki Sigler, Global Product Marketing Manager

Forbes reports that 41% of workers have left workplaces because of unsafe conditions. With the great resignation moving into the future, organizations must address the environments people work in to keep valuable workers and spare the expense of training new employees.

Challenges in Hot Melt Technology

Worker safety is always a top priority, and there is a renewed focus from governments and business to improve workplace conditions. In line with these developments, many adhesive manufacturers are focusing on low free isocyanate monomer, a family of highly reactive, low weight chemicals used to formulate reactive hot melts (RHM).

RHMs generally include certain hazardous components, such as monomeric diisocyanates. Additional training can effectively reduce potential harm to workers, but traditional RHMs do require extra time and expense to train operators properly and safely, which challenges manufacturers to balance expenses and time management more proactively.

Today’s process for achieving a low monomer (<0.1%) adhesive formula poses multiple challenges, including:

  • Expensive and energy intensive processes;
  • Reliance on single-sourced raw materials;
  • Slower and longer cure time;
  • Reduced space for formulation;
  • Higher cost.

Real Risks of Traditional RHMs

The risks of using traditional RHMs are high. For example, sensitization (an allergic reaction that causes major lung and respiratory problems) may permanently affect workers' health. This syndrome happens by both contact on the skin and inhaling airborne particles when the molten form of adhesive is near.

Labeling traditional RHM instead of standard free monomer shows its hazard potential. A high risk rating means the adhesive requires more stringent labeling and indicates a higher degree of harm. Here, a low free isocyanate monomer formulation would solve much of the potential risks to workers who handle this class of adhesives and have less severe safety risk labeling.

H.B. Fuller Steps up

H.B. Fuller has developed a simple and new way to create low monomer RHMs. The new route for creating this energy-efficient, high-performing, and easier-to-produce RHM increases formulation space and qualifies for label-free packaging in the European Union (EU).

The optimized reaction temperature, reaction time, and NCO/OH ratio enable tuning properties for a wide range of applications. Many grades are possible, and low viscosity, sprayable, high green strength far surpass traditional standard monomer hot melts. These innovations use readily available raw materials, and no new manufacturing equipment is required.

Some of the benefits of our new low monomer RHM include:

  • Similar or slightly higher viscosity;
  • Better green strength;
  • Better application stability;
  • Similar or slightly higher cost;
  • No hazard labeling.

Low-hazard, high-performing RHMs available in the EU now should be available for the global market soon. Formulations in development will serve the automotive, durable assembly, and electronics markets with lower exposure-related risks.

Safer Products Now

H.B. Fuller’s Rakoll adhesive solutions have low monomer content and deliver excellent performance for woodworking applications that bond to a wide variety of materials. This line maximizes business efficiencies and are made of more sustainable chemical components. Our patented, low monomer RHM allows flexible formulations of adhesives that combine different green strengths, viscosities and open time.

Recognition of Adhesive Technology

H.B. Fuller is thrilled to announce that our Low Monomer/Emission Reactive Hot Melt Adhesive has been recognized by The Adhesive and Sealant Council (ASC) as 1st Runner Up for the 2022 Best Innovations Award. Our team – including Sudipto Das, research scientist and manager for Woodworking, and João Magalhães, global director for Wood & Composites, were present at the event to receive the award. This is an exciting journey for our woodworking team, and we are looking forward to further demonstrating how we’re helping create a safe and sustainable future for polyurethane products.

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We think our new hot melt formula is unlike anything on the market. Contact us to learn more about the latest products offered by H.B. Fuller.

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