Common Hot-Melt Adhesive Uses and Applications

Hot-melt adhesives (HMA) are as numerous as they are versatile.  In general, hot melts are applied by extruding, rolling or spraying, and the high melt viscosity makes them ideal for porous and permeable substrates.  HMAs are capable of bonding an array of different substrates including paper, rubbers, ceramics, metals, plastics, glass, wood and more.

 

Today, hot melt adhesives are available in a variety of different types, allowing for use in a wide range of applications across several industries. For use in industrial processes, HMA adhesive is supplied in larger sticks and glue guns with higher melting rates. Aside from hot melt sticks, HMA can be delivered in other formats such at granular or power hot melt blocks for bulk melt processors.  Larger applications of HMA traditionally use pneumatic systems to supply adhesive.

Some common examples of industries where HMA is used include:

  • Closing the flaps of corrugated boxes and paperboard cartons in the packaging industry
  • Spine gluing in the bookbinding industry
  • Profile-wrapping, product assembly and laminating applications in the woodworking industry
  • Disposable diapers are constructed through the use of HMA, bonding the non-woven material to both the backsheet and the elastics
  • Many electronic device manufacturers may also use an HMA to affix parts and wires. or to secure, insulate, and protect the device’s components

And here are some general terms used for HMA’s:

  • Open time: the working time to make a bond, where the surface still retains sufficient tack, can range from seconds for fast-setting HMAs to infinity for pressure-sensitive adhesives
  • Set time: time to form a bond of acceptable strength
  • Tack: the degree of surface stickiness of the adhesive; influences the strength of the bond between wetted surfaces.
  • Surface energy: which influences wetting of different kind of surfaces.

Are you looking for a standard or custom hot-melt adhesive solution for your industrial, manufacturing, or packaging process?  Feel free to contact us and/or request a sample.

Hot Melt Adhesives Market Expected to Grow 6% Annually Through 2024

 

According to a Q4, 2017 report from Global Market Insights, the global hot melt adhesives market is forecasted to record an annual growth rate of more than 6% through 2024.

Hot Melt Adhesive (HMA) is gaining considerable traction with the growing need for high standard performance adhesives across various industries. Also known as hot glue, provides optimal hold & superior manufacturing flexibility. In industrial applications, HMA provide several advantages over waterborne or solvent based adhesives.

Other benefits offered by HMA include:

  • Longer shelf life
  • Quick drying
  • Increase throughput in production
  • Easy disposal

Each of the above have significantly driven the product demand. A $5.5 billion market in 2015, hot melt adhesives are projected to surpass $10 billion by 2024.

For more information on the report, check out Market Insider.

To access the full report from GMI, click here.

To learn more about hot melt adhesives from Evans Adhesive, contact us and request a free sample today.

 

An up-close look at a new Metallocene option: ReliaSeal

ReliaSealPrevious posts described the problems inherent with char-prone EVA-based adhesives, and outlined the benefits of using a metallocene-based adhesive instead.

Choosing to make the switch from traditional EVA-based hot-melt to metallocene-based hot-melt is a simple, straightforward, and cost-effective solution to eliminate the high cost of lost production time, and reduce the risk of packaging failure in your company’s packaging operations.

ReliaSeal is Evans Adhesives’ newest metallocene-based adhesive, specifically designed for the challenges of packaging. Due to its lower density, ReliaSeal makes it possible to use up to 40% less adhesive, providing significant cost savings in your packaging operation.

Learn more about ReliaSeal here.

(Excerpted from “No More Char”, a recent issue of Evans Adhesive Solution Advisor. Download entire issue here.)

A Range of Metallocene Hot-Melt Options Available

Metallocene-based hot-melt adhesives not only offer superior performance properties, but also provide manufacturers with a range of product options and capabilities:

Mettalocene

  • High-melt metallocene: Applied at 350 degrees Fahrenheit, this gives production operators a smooth-flowing, consistent, and trouble-free adhesive solution for a wide variety of product operating requirements;
  • Low-melt metallocene: Applied at 250 degrees Fahrenheit, this melts to a lower viscosity, so the same amount can be applied at lower pressure, increasing mileage. Low-melt also offers machine operators the added safety feature of working with adhesive at a safer, lower application temperature
  • Packaging-specific metallocene: Formulated for a wide variety of specialized box, carton, tray, and packaging materials, including corrugated plain and inked, coated and uncoated stocks, paper bag stocks, trays, frozen food and ready-made meals packages, and other packaging stocks and configurations.

Next Time: A new Metallocene option

(Excerpted from “No More Char”, a recent issue of Evans Adhesive Solution Advisor. Download entire issue here.)

Comparing Costs: Metallocene vs. EVA Hot Melt Adhesive

Previous posts outlined the advantages of metallocene-based adhesives compared to traditional EVA-based hot-melt adhesives.

But what about cost?

Metallocene-based hot-melt adhesive may initially cost more than EVA-based hot melt adhesive. However, the costs associated with problems from char-prone EVA can erase any initial cost savings you may have received.

Costs from problems with char buildup can include:

  • Production downtime expense: Usually the highest cost, which can be calculated from hundreds to thousands of dollars per hour, depending on the operator’s production environment
  • Product defect costs: Packaging defects due to poor carton adhesion, which lead to pop-opens and other package failures throughout the distribution chain, can be a significant ongoing expense, leading to additional negative impacts from lost and damaged products, negative effects on customer goodwill, and potential liability cost

Replacement adhesive applicator parts and service cost: When charring conditions reach the point where the adhesive application system can no longer be cleared, hoses, nozzles, and other affected parts of the system must be replaced, usually at a significant cost in new applicator components and additional costs per hour of service expense.

CharvsClear

Next Time: Choosing the right Metallocene

(Excerpted from “No More Char”, a recent issue of Evans Adhesive Solution Advisor. Download entire issue here.)

Key Benefits of Metallocene-Based Adhesives (Part 2)

The previous post covered several key advantages of metallocene-based adhesives compared to traditional EVA-based hot-melt adhesives.

Metallocene Benefits 2

Here are several more metallocene advantages:

  • Can be used with a wide variety of coated and uncoated package stocks: The superior adhesion performance of metallocene-based hot melt makes it versatile for application to a wide variety of coated and uncoated paper packaging and corrugated stock. Because of this versatility, metallocene is especially suited for application to coated stock used in frozen food products.
  • Better penetration over heavy ink surfaces: Compared to EVA-based adhesive, metallocene adhesive provides deeper penetration of packaging surfaces which have heavy ink coverage. This deeper adhesive penetration provides greater package and carton sealing assurance and reliability.

Next Time:  Cost Advantages of Metallocene

 

Excerpted from “No More Char”, a recent issue of Evans Adhesive Solution Advisor. Download entire issue here.)

Key Benefits of Metallocene-Based Adhesives (Part 1)

Metallocene-based hot melt adhesives offer several key advantages compared to traditional EVA-based hot-melt Metallocene Benefits 1adhesives:

  • Improved mileage: Because metallocene-based adhesives have a lower density than EVA-based adhesives, they can be applied at lower flow rates, often yielding up to 40% reduction in adhesive use compared to EVA.
  • Precision application: Since viscosity of metallocene hot-melt does not increase during its pot life, it gives operators more precise control over flow, bead size, and bead quality, so adhesive application can be continuously optimized for maximum economy.
  • High and low-temperature performance: Metallocene-based adhesive provides superior bonding strength across a wide range of temperature variations, offering resistance to both high temperatures and freezing cold. This performance makes metallocene a strong choice for frozen food packaging applications, as well as for many packaging, carton, and box applications requiring resistance to wide temperature fluctuations

Next Time:  More Key Benefits of Metallocene-based Adhesives.

(Excerpted from “No More Char”, a recent issue of Evans Adhesive Solution Advisor. Download entire issue here.)

One Solution to the Problem Of Char: Metallocene-Based Adhesives

Clear with MetalloceneIn the past few years metallocene-based polymer hot-melt adhesives have become more widely available in the marketplace, and more affordable for use in the packaging field.

Metallocene-based hot melt offers superior performance and char-free operation, because the chemical composition means they are not subject to carbon buildup, gelling, or any other changes over extended high temperature storage and use.

As a result, metallocene-based adhesives can be stored indefinitely in glue tanks at high temperatures. The glue will flow clearly at all times through the application cycle, without char buildup or any other material change. Also, unlike EVA-based adhesive, metallocene-based adhesives won’t cause poor or blocked adhesive flow through pumps, hoses, or nozzles.

Next Time: Key Benefits of Metallocene-based Adhesives.

(Excerpted from “No More Char”, a recent issue of Evans Adhesive Solution Advisor. Download entire issue here.)

Preventive Maintenance Can’t Solve Char Buildup

Preventive maintenance, which involves systematic monitoring and periodic flushing of the adhesive application system, can substantially reduce the incidence of charring and gelling and extend the life of applicator hoses and extrusion nozzles.

However, the unfortunate fact is that charring is an inherent problem with EVA-based adhesives (see previous posts). No matter how diligent the preventive maintenance program, charring will eventually occur in any hot melt system using EVA-based adhesive kept at an operating temperature above 350º for prolonged periods. Since prolonged high temperature operation naturally occurs in any production environment, char resulting from EVA will eventually pose a problem, regardless of the steps taken to prevent it. (Read more about the impact of char.)

In some cases, the maintenance required when using EVA is considered part of the cost of choosing this type of adhesive. However, in other cases, finding an alternate adhesive may address some of the drawbacks inherent with EVA-based adhesive.

Next Time:  One Solution to the Problem of Char.

(Excerpted from “No More Char”, a recent issue of Evans Adhesive Solution Advisor. Download entire issue here.)

The Problem of Char: Negative Effects

Before char is apparent oChar Clogs Hoses and Nozzlesr clogging occurs, char creates a thermal barrier in hose linings. This lowers the optimal operating temperature of the adhesive, causing poor flow performance. When your system applies more heat to compensate, even more char build up results.

When char buildup occurs, pieces break loose in your application system. These pieces clog applicator hoses and nozzles, causing uneven adhesive application and eventually, production stoppages. (Read more about Common Causes of Char.)

Even when charring isn’t immediately visible, hidden char deposits contribute to poor adhesive application due to clogged or char-degraded tanks, hoses, or nozzles. This leads to improperly and insufficiently glued packages, plus unsightly char deposits on packaged products.

Next Time:  Can char build-up be prevented?.

(Excerpted from “No More Char”, a recent issue of Evans Adhesive Solution Advisor. Download entire issue here.)

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