Hot Melt Adhesives – growing demand for polyolefin elastomer-based HMAs
Hot melt adhesives (HMAs) are 100% solid thermoplastic polymer-based formulations. They are typically are applied hot at their softening temperature and allowed to solidify by cooling to room temperature to provide necessary adhesion between two different materials. Once applied and brought in contact with the second surface, they solidify to a physical state that possesses structural integrity and function as adhesives.
Some of the key benefits of HMAs include rapid bond formation, flexible application, ability to bond with porous as well as non-porous surfaces, bond moisture sensitivity, longer shelf life, and absence of harmful volatile organic compounds.
Globally, HMA demand growth is driven by their use in solar panels, textile, and home applications, although packaging sector continues to be the biggest sector. HMAs have also been steadily driven by the growing healthcare industry, where they are used in applications such as electrodes, toupee tapes, wound dressing, surgical drapes, insulin pump attachment, and ostomy appliances. They are also used in sanitary products such as baby diapers, sanitary diapers, pet sheets, etc. In North America, certain POE-based HMAs have even received U.S. Food and Drug Administration approval. Exhibit 1 shows the key demand sectors for HMAs.
Exhibit 1. Key applications for hot melt adhesives and their relative market share, 2018
Key components of HMAs are a high-molecular weight polymer that acts as the primary adhesive, a tackifier or resin that provides more adhesion and wetting properties, and a plasticizer (wax or oil) that controls the viscosity and the ability for small machinery to easily dispense it. Different methods of application include extrusion, rolling, or spraying and joining, which are carried out immediately after application or after reheating the solidified layer. HMAs are produced using a variety of polymers such as ethyl vinyl acetate (EVAs), styrene block copolymers (SBCs), thermoplastic polyurethanes (TPUs), polyolefin elastomers (POEs), and other polymers such polyamides (PAs) and amorphous polyolefins (APAOs).
EVA- and TPU-based HMAs dominate the market today, while growth is driven by POE- and EVA-based HMAs. Demand for TPU-based HMAs is expected to remain moderate for the foreseeable future while SBC-based HMAs show mild growth.
POE-based HMAs are cleaner and well-suited for carton and tray sealing applications. Their key benefits include higher temperature windows than EVA-based HMAs, no stringing while applying, no char or gel build up in tanks or nozzles, faster set time, low to no odor, extreme cold or heat resistance, and high operational life due to thermal stability. These properties make them suitable for hygiene and healthcare applications such as diapers for babies.
With overall economic growth, North America is expected to implement more POE-based HMAs. The cost of POE-HMAs versus EVA-HMAs has not deterred U.S. consumers due to their performance.
ADI Chemical Market Resources has extensively researched the global HMA markets including size and segmentation by region and base polymer type, key applications, players and their competitive positions, growth opportunities, and strategic implications. Contact us at info@adi-cmr.com or +1 281 506 8234 to learn more.
By Panuswee Dwivedi and Uday Turaga