Printing, packaging, manufacturing, textiles. The list of industries relying on hot melt adhesives (HMAs) goes on and on. Offering high coverage, reversible bonds, and numerous application options, HMAs serve as versatile, reliable fastening solutions.
Not all HMAs are created equal, however. Depending on the work volume, common substrates, and specific environment in question, manufacturers have a wide range of options regarding the tools, systems, and types of adhesive used to get the job done.
Understanding Hot Melt Adhesives
A form of polymer-based thermoplastic, hot melt adhesive is among the most popular and widely used industrial adhesive solutions. Extremely versatile, HMA has a long shelf life and ensures reversible bonds that set quickly and easily. When using these materials, it’s critical to apply the right amount of heat; no water, solvents, or additional chemical treatments are required.
Common Hot Melts
HMAs are formulated in a variety of different compounds to suit unique application needs. Some of the most common types include:
- EVA, or ethylene vinyl acetate, most common in the packaging industry and prized for its versatility
- PE, or polyethylene, an older hot melt technology with limited adhesion capabilities
- PSA, a pressure-sensitive HMA with a tacky film
- Metallocene, a metal-catalyzed polyethylene adhesive with industry-leading thermal stability
- Polyamide, a high-strength, flexible, and oil-resistant adhesive offering excellent heat resistance but poor heat stability
- Rubber, a higher-performing solution than EVA
- PUR, or polyurethane, providing superior heat and cold resistance but without the remeltable quality of traditional hot melt materials
Hot Melt Adhesive Systems
Allowing for easy application in a wide range of industries, HMA materials are very popular in large-scale manufacturing facilities with high-volume systems. Gap-filling, fast-setting HMAs are environmentally friendly and readily bond impervious surfaces while ensuring optimal safety. If efficient fastening, quick work, and overall cost efficiency are essential to your operations, a hot melt adhesive system may be the answer.
Depending on the volume, scale, and style of system demanded by a particular application, the adhesive material itself can come in different forms. These solid thermoplastic materials are readily stored and transported by drum, pail, and even railcar, and are most commonly found in:
- Pellets (in bags or pails)
- Slats or blabs
- Wrapped bricks or cakes
Certain setups are optimized to handle particular adhesive styles. For example, newer, tank-free hot melt systems don’t hold preheated adhesive in a tank; this reduces charring, shortens startup times, limits opportunities for contamination, and generally minimizes nozzle plugging. In order to operate so efficiently, this equipment utilizes a vacuum system to draw fast-melting adhesive pellets quickly into its dispensers, on demand. Adhesive waste and overheating problems are eliminated, and the equipment maintains a regulated, continuous application.
HMA Processing Methods
Beginning with the original, straightforward glue gun, various hot melt adhesive dispensing solutions have been developed over the years to serve specific application needs. Most large-scale hot melt systems apply the material using an applicator approach such as one of these:
- Slot die
- Spiral spray
- Melt blower
By equipping a hot melt adhesive setup with vacuum conveyance, melt reservoirs, and systematized unloading, clients in various industries — including packaging, hygiene, labeling, product assembly, and textiles — can process goods in high volumes with optimal precision.
Notable HMA Manufacturers
An advanced hot melt dispensing system can be a major asset for production managers and employees; these tools reduce downtime, improve workplace safety, enhance operational efficiency, and reduce bottom-line costs. Plus, some systems are equipped with intelligent monitoring capabilities, making it possible to track material usage and expenses for long-term recordkeeping purposes and process control.
Some of the most well-known OEM hot melt manufacturers include:
- Valco Melton
- ITW Dynatec
- Union Tool
Hot Melt Dispensing Systems: Maximum Production, Minimal Glue
Allowing for increased production value and reduced material use, hot melt adhesive systems are popular for a reason. Optimized for high-speed manufacturing, these tools allow jobs to be completed at faster rates, with great bonding versatility, simple setting, minimal shrinkage, and effective gap filling capabilities.
Whether working in labeling, construction, or automotive assembly, hot melt adhesive systems help to quite literally hold our world together.
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