The ethylene-vinyl acetate (Eva) hot-melt adhesive is the most widely used hot-melt adhesive at present. This kind of hot-melt adhesive has the characteristics of excellent adhesion, flexibility, heating fluidity and cold resistance. Widely used in paper boxes, books bonding, wood laminated board production and woodworking edge, non-woven fabric production.

Eva type hot melt adhesive in the role of wax mainly reflected in these aspects:

1. Adhesiveness

Adhesion is one of the most important properties of hot melt adhesive, and many factors affect it. The lower the viscosity, the more easily the hot melt adhesive infiltration porous substrate, thus forming mechanical bonding. The wax surface energy is low, when the wax quantity increases, the hot melt adhesive wettability enhancement, may increase the adhesion. The adhesion caused by valence bond force can be improved by using microcrystalline wax instead of paraffin. This is because of the low modulus and long setting time of microcrystalline wax hot melt adhesive. 

For polar substrates, the use of wax with polar groups (such as hydroxyl wax or natural wax) can improve the adhesion. The adhesion of hot melt adhesive is affected by the compatibility of the whole adhesive system. For polar substrates, the use of wax with polar groups (such as hydroxyl wax or natural wax) can improve the adhesion. The adhesion of hot melt adhesive is affected by the compatibility of the whole adhesive system. Taking wax and Eva as example, Eva with 18%-28% VA content has the best compatibility, easy to form co-crystallization, adhesion is very good, but when VA content is less than 9% , Eva crystallizes before wax, become wax filler, adhesive adhesion is very poor. 

Qingdao Sainuo Eva wax

 2. Viscosity and fluidity

The viscosity and fluidity of hot melt adhesive are closely related to its sizing performance. Wax is the biggest impact in this, because wax is the hot melt adhesive viscosity of the smallest component, increase the amount of wax, can reduce viscosity, increase liquidity.

3. Tensile strength and modulus

The wax with good compatibility with Eva can increase the tensile strength and modulus of the hot melt adhesive, but the incompatible wax will increase the rigidity of the adhesive, which is not beneficial to the improvement of tensile strength. The tensile strength and modulus of hot melt adhesive can be improved by using high crystalline wax or high melting point wax with high content of n-alkanes.

4. Flexibility

Wax also has a great impact on the flexibility of hot melt adhesive. The flexibility of the hot melt adhesive can be increased by using microcrystalline wax instead of paraffin, or by using synthetic wax with narrow distribution instead of ordinary synthetic wax, because microcrystalline wax is more flexible than paraffin, however, the narrow distribution wax was more compatible with the ethylene segment in Eva.

5. In other ways

The glass transition temperature (TG) of wax is directly related to the low temperature properties of the adhesive. The opening time of hot melt adhesive can be shortened by increasing the amount of wax, and the setting time can be adjusted by using different waxes.

It has good dispersion effect on carbon black and pigment, with good light dispersion and high coloring intensity.

Qingdao Sainuo Chemical Co.,Ltd. We are manufacturer for PE wax, PP wax, OPE wax, EVA wax, PEMA, EBS, Zinc/Calcium Stearate…. Our products have passed the REACH, ROHS, PAHS, FDA testing. 

Sainuo rest assured wax, welcome your inquiry!

Website：https://www.sainuowax.com

E-mail：sales@qdsainuo.com

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