Aspects of hot melt adhesive that affect performance

2021/06/18

Adhesion

    Adhesiveness is one of the most important properties of hot melt adhesives, and it has the most influencing factors. First of all, EVA is the main determinant of the bonding performance of hot melt adhesives. As mentioned earlier, when the VA content in EVA increases, the adhesion of the hot melt adhesive is greatly improved.

 

Viscosity and fluidity

     The viscosity and fluidity of hot melt adhesives are closely related to sizing performance. Choose EVA with a large MI, and a tackifying resin with a small melt viscosity can reduce the viscosity of the hot melt adhesive. You can also choose EVA with different MI levels to adjust the construction viscosity of the hot melt adhesive.

 

Glass transition temperature Tg

     The Tg of hot melt adhesive is directly related to the low temperature performance of the adhesive. Below Tg, the adhesive is brittle and easily breaks when it is impacted or bent. The Tg of EVA in hot melt adhesives is lower, but the Tg of tackifying resins and waxes are generally higher.