A Hot-Melt Trilogy – Parts II and III: Functionality of Melt-on-demand Systems Expands

Posted on 2/20/2015 2:28:37 PM By Hallie Forcinio

Last month, we talked about how melt-on-demand (MOD) hot-melt technology has been available since the late sixties and the advent of tank-less systems. This month provides an overview of today’s MOD equipment, as well as ancillary systems that help ensure good seals and optimize hot-melt consumption.

Today’s MOD Systems

Sophisticated controls track operation of MOD hot-melt systems and can provide alerts and real-time data about faults. With this operational data in hand, end users “have good understanding of what’s happening in the business,” says John Ferguson, strategic sales manager-Packaging at Graco. Armed with this information, root causes of problems can be identified and eliminated.

Graco’s Invisipac melter, the product of more than two years of development work, consists of a cylindrical unit with a heater core in the middle. It maintains about 500 ml of adhesive in a molten state and “does the same work of as systems with 4-, 7- or 10-L tanks,” says Ferguson.

Winner of the Bronze Stevie in 2014 for New Product or Service of the Year in the Industrial Products and Services category of the American Business Awards competition, the Invisipac tank-free hot-melt delivery system works with any EVA or metallocene hot melt as long it’s vacuum-feedable and in pellet form. The Invisipac system also earned recognition at EastPack 2013 in Philadelphia when it won the Gold Visionary Award in a competition organized by UBM Canon’s Packaging Group.

Its latest Invisipac model, the HM50 melter, offers a 50 pound-per-hour capacity, double the capacity of the HM25 model, introduced in 2012. Both models accommodate up to six hoses.

Also new from Graco is an advanced feed system and the air-on/air-off GM100 gun, which incorporates a fourth filtration point right before nozzle.

Nordson’s first tank-less product—the Freedom® system—launched in 2012 and was followed by the ProBlue Liberty™ system in 2014. According to Nordson, both models provide on-demand melting in a smaller footprint than older MOD architectures. At PACX EXPO International (Nov. 2-5, 2104, Chicago) and PACK EXPO East (Feb. 16-18, 2015, Philadelphia), Nordson’s tank-less hot-melt systems were seen integrated with packaging machines. A number of OEMs currently offer equipment with tank-less hot melt systems from Nordson including Thiele, Wexxar BEL, ADCO, Marq, PMI, Combi Packaging, Switchback, Brenton Engineering, Massman Automation and Nuspark.

Nordson’s Freedom system provides packagers with tank-less melting and easy-to-use touch-screen controls. There’s also an onboard EcoBead™ pattern generator to optimize adhesive patterns.

The ProBlue Liberty system, Nordson’s mid-tier tank-less offering, occupies the same physical footprint as its standard ProBlue® melter, simplifying retrofit. Both systems offer automatic filling, as well as the patented, self-cleaning MiniBlue® II Surebead® applicator for maximum line efficiency. 

Other MOD systems on the market include the Kube model from Valco Melton and the Dynamelt product line from ITW Dynatec. An enclosed system with integrated autofeeder on the Kube unit prevents dirt and debris from getting in the melt tank.

The Dynamelt S Series was released toward the end of 2012 and accommodates a wide range of adhesives. It features 15 times more filtration area to further prevent particulate matter from obstructing adhesive flow and a new nano-ceramic hopper coating, which is five times more durable than competitive PTFE coatings. An intuitive, easy-to-read operator interface can be moved between the front and the side of the machine and displays all system parameters at a glance. Designed to reduce operating costs, the model consumes up to 20% less energy and significantly less air than similar competitive units. A standard 7-Day Scheduler and adhesive level sensor simplify daily operation. Automatic fillers are an option.

Ancillary Equipment

Another new product from Graco, a pattern controller, can be used with its machines, as well as with other brands. When used with Graco machines, an icon-based display shows what the pattern will look like, allowing the operator to input the percentage of glue used, while recording product count and adhesive consumption per product. Performance data can be downloaded via a USB port or via Graco’s wireless Line Sight option. The wireless communication is particularly well-suited to operations with multiple hot-melt systems because it streamlines data gathering and analysis and remote access.

PackChek™, an automated packaging inspection system from Valco Melton’s ClearVision Technologies, Inc, is installed at the discharge of a machine to capture a thermal and visible image of every package and confirm hot melt has been applied to the correct locations. Positioning at the discharge overcomes issues with traditional hot-melt sensors, which can be difficult to retrofit on packaging machines due to space constraints.

Although market share for MOD systems is low, it’s growing. In fact, industry leaders predict tank-free systems will supplant tank-equipped systems for certain applications as on-demand systems work very well for packaging.

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