EVA Adhesives

EVA (ethylene-vinyl acetate) is the backbone polymer and most important component for many of our hot melt adhesives. EVA hot melts are used for packaging, assembly, wood bonding and labeling. EVA can range from 20-60% of the hot melt formula, being a viscous, rubber like material will add flexibility and adhesion to the formula. EVA is compounded with resin tackifiers, waxes, plasticizers and thermal stabilizers to achieve a wide range of properties for example, EVA hot melts can bond porous and non-porous materials even some with specialty surface coatings. We have learned how best to custom formulate EVA hot melts for a wide range of service temperatures (freezer to hot transit trucks), to provide quick set time, green strength and hot tack or alternatively we can make them slower setting for hand assembly situations.

Metallocene

Metallocene hot melt is compounded with a new technology Dow resin plus hydrogenated tackifiers that result in much improved hot melt adhesive. For example clear color, better heat stability, less odor and improved resistance to oxidation may be realized.

So the adhesive consumer can see less char forming inside the melter helping to avoid a common operational problem of plugged nozzles. Metallocene hot melt can fit well in most traditional applications served with EVA and HMPSA formulas.

So if you would predict metallocene to be significantly more expensive with all these benefits, in fact it can go further reducing costs to be closer to traditional hot melts. One weakness of metallocene hot melt comes from less crystallinity so it may not hold up as well in hot weather or hot truck transit..

Rubber Based Adhesives

HMPSA’s are custom compounded hot melt adhesives based on styrene-butadiene or styrene-isoprene rubber, EVA, resin tackifiers, plasticizers and mineral oil. They are applied hot and may remain tacky after cooling. They can be used for palletizing, pre-applied labels, baler bag closures, coated cartons and other applications where a long assembly time, permanent, semi-permanent or removable adhesive is needed. Often HMPSA can be used where a conventional hot melt containing wax will fail to penetrate and bond well.

Water Based

Water Based adhesives are normally 40-50% solids, viscous emulsions of PVA (polyvinyl acetate) or EVA (ethylene vinyl acetate) in water. These are compounded adhesives with plasticizers, tackifiers and fillers that can then bond both porous and non-porous materials such as wood, paper, non-wovens and coated labels. They all set up by drying while clamped.

The main advantages of water based adhesives is that their application equipment is simpler, they can be cheaper and can provide very long open time for assembly and laminating. The final bond is durable, water and heat resistant. Sometimes Water based adhesives are used together with hot melt adhesives that clamp the “wet” bond until dried. Water based acrylic adhesives are available too as tacky and pressure sensitive adhesives when needed for special situations such as bonding very difficult materials.