A Look at Common Adhesive Chemistries

How to select the right adhesive for your packaging needs.

Machines and production both run faster than ever before. Packaging is becoming more complex, requiring adhesives that work on a wide variety of substrates. Companies are continually developing ways to improve how they produce and package products, reduce downtime, lower energy, increase line speed, and lower maintenance costs.

Ethylene Vinyl Acetate (EVA) and Metallocene Catalyzed Polyolefin Polymer (mPO) are two common synthetic adhesive formulations used to describe a packaging adhesive’s chemistry. EVA and mPO refer to the polymer properties of the adhesive that contribute to an adhesive’s toughness, elasticity, and resistance to stresses such as shear or high temperatures . 

What’s a Polymer?

Polymers are natural or synthetic compound chains made of repeating monomers that gain specific properties through a reaction process called polymerization. Example polymers include a wide range of acrylics, nylons and styrenes, condensation polymers and epoxies, phenolics, and silicones.

In today’s market, many manufacturers are developing alternatives to single-source ingredients. That’s why you’ll see products marketed as proprietary, hybrid, or high polymer.

Everything About EVA

Although EVA adhesives were first developed in the mid-1900s, nearly half of all packaging adhesives sold today are considered EVA. They have proved to be a mainstay of adhesive production for decades. They offer excellent performance and value, but typically have lower thermal stability, which can require a more diligent maintenance routine. Benefits to EVAs include: 

  • Superior strong bonds 
  • Formulation versatility
  • Performance can be tailored for a narrow operating window for high or low end
  • Handles more difficult substrates 

What to Know About mPO

Newer to the market, mPO adhesives were developed in the 1990s. They are a good choice if you seek very clean machining and performance, with a slightly higher cost. Metallocene adhesives are more thermally stable in equipment, which can result in lower maintenance costs and reduced downtime.

  • More well rounded
  • Products are typically light in color or water-white
  • Increased thermal stability which can lead to less performance drift and longer maintenance intervals
  • Offers lower density and efficiency, adhesives are purchased by weight and dispensed by volume 
  • Less odor with better machine hygiene/machine cleanliness; clean cut-off prevents adhesive dripping or stringing buildup
  • “Set it and forget it” mentality. Requires less babying of equipment/application 

Equipment Can Be a Decision Maker 

Selecting the proper adhesive is essential but it is just as important to choose the right equipment solution for the job.  For instance, lower-cost EVA technology may be used with the Graco® InvisiPac ® due to its tankless design and true melt-on-demand design. APPLIED offers one-stop access to all technologies, allowing you to use the correct equipment for the job.   

Want a Simplified Solution?

Although chemical composition is important, there’s more to choosing an adhesive than the polymer used within. It’s important to look at cost, performance, and more. That’s why APPLIED Adhesives works with you to:

  • Identify and evaluate all performance criteria used in your packaging process
  • Understand baseline application and performance
  • Make product, as well as process and equipment solution recommendations
  • Continue to check in on adhesive performance

Contact us for a holistic and thoughtful discussion about the right adhesive option(s) for your packaging needs.

For more about selecting the right adhesive view this video: https://www.youtube.com/watch?v=QBIIIErTKyw