EVA Hot Melting Glue Formula

1. Adhesion

Adhesion is one of the most important properties of hot melting glue. Adhesion of hot melting glue is most affected by EVA, tackifying resin and wax. The more VA (the more tackifying resin or the less wax) is contained, the greater polarity and the higher adhesion the glue will have to polar materials.

2. Viscosity and fluidity

Viscosity and fluidity are mainly supplied by wax and tackifying resin. Their melting viscosity is pretty low. Therefore, the more wax or tackigying resin is added, the lower melting viscosity the glue will have. On the other hand, wax cannot be added above certain amount, normally within 10-20%. otherwise, the viscosity of hot melting glue will be apparently decreased.

3. Softening point

Softening point is determined by EVA, tackifying resin and wax together. Lower VA content brings about higher EVA softening point. The softening point of paraffin wax is low while that of PE wax is high. And the point of tackifying resin depends on the variety. EVA, tackifying resin and wax with close softening point should be selected to prepare appropriate EVA hot melting glue.

4. Solidifying time

Softening point and crystallization rate of EVA hot melting glue lie in the softening point and crystallization rate of EVA and wax. If the softening point and crystallization rate of the both are pretty high, the solidifying time of hot melting glue will increase. In addition, heightening softening point of tackifying resin will improve solidifying speed of hot melting glue.

5. Glass transition temperature (Tg)

Glass transition temperature is one of the indexes to measure hot melting glue’s resistance to low temperature. Wax and tackifying resin can both increase Tg obviously. The lower Tg is, the better resistance to low temperature the material will have, such as PDMS. On the other hand, the material with higher Tg has better resistance to high temperature. One example is PMMA, also named acrylic or organic glass. It is always hard, crispy and plastic under certain temperature. Common pressure-sensitive glue has low Tg and can function under normal temperature.

Application of hot melting glue

The EVA hot melting glue sealing is normally used for the carton sealing , to take the place of tuck in closing. Especially for the cosmetic , personal care and food industry.

We have matched a lot for the cartoning machine with the hot melt glue spraying, if you also need the glue sealing closing for the box, please contact us for more.