Polyurethane Reactive (PUR) hot melts are an excellent adhesive to use for many different applications because they have a stronger and longer-lasting bond than more traditional hot melts. They can also be adapted for different uses as well as many other key benefits. Its ease of use and fast curing time means a more rapid production which leads to lower labor costs for the end-user, so long as the integrity of the product is kept. stronger
PUR hot melts are used in many different industries for many applications. These adhesives are used in a variety of ways including in food packaging, product assembly, toys, automotive and more!
The Challenge
A large adhesives manufacturer offers a wide range of industrial-strength adhesives used under various conditions and applications. Their Polyurethane adhesives are packaged as reactive hot melt adhesives, meaning the adhesive goes into the drum hot. A Reactive hot melt means the main component cures in reaction with ambient moisture, this can cause many problems for the end-user due to the sensitivity to moisture and the atmosphere.
If the adhesives come in contact with too much moisture or the atmosphere, it can cause the adhesive to start curing and a layer of crust can form on top. During their processing, if there are crust particles in the adhesive, that crust could cause damage to their pipes, meaning that they would need to shut down production and clean (sometimes) miles of lines! This is why Barrier foil liners are important, the adhesive will set as it cools down but as long as it does not come into contact with moisture it does not cure.
The Solution
We supply them with our heat-resistant round bottom drum liners (3D723/4) for them to package their adhesives. This material is heat-resistant up to 302℉, but it also has the lowest oxygen and moisture transmission rates of any known flexible packaging. They gas-flush the headspace of the liner when sealing to ensure there is no residual oxygen in the liner and send the drums to the end-user. These packages are called “silver bullets”.
The Result
The end-user takes the slugs or “silver bullets” and melts down the PUR hot melt for the automotive industry, gluing the internal panels to car doors and dashboards. It also includes any leather, Alcantara (a synthetic material used in car interiors) and carbon fiber panels.
Hot melt adhesives are important for the automotive industry. They offer ideal bonds that need flexibility for movements like contraction and expansion. These adhesives don’t just have great flexibility to retain the form of the vehicle but also allow for the lifespan to be extended. Parts like the carpet and the headliner (the liner on the roof of the car) are held in place with PUR hot melt adhesives due to their durability. These parts of the car are subject to high temperatures and constant contact from passengers, so they need to stay intact.