Hot-melt adhesive production from natural rubber

Abstract

The purpose of this research was to study hot-melt adhesives from natural rubber (Standard Thai Rubber 20, STR 20). In order to improve the adhesion and melting properties of hot-melt adhesive to get the best glue formula from STR 20, the ethylene vinyl acetate content (EVA), paraffin wax (Wax) and petroleum resin (Resin) were varied from 25, 50, 100, 125 and 150 phr (Part Per Hundred Rubber). It was found that the best adhesive formulas consisted of 100 phr of STR 20, 25 phr of wax, 150 phr of EVA and 150 phr of resin. For preparing hot-melt adhesive, first, the wax was heated and maintained at 160-170 ºC, then cut the STR 20 into small pieces and slowly added the rubber into the melted wax until the rubber was completely melted. And then added resin and EVA and cooled to room temperature, finally, the results show that hot-melt adhesive was dark brown, hard and odorless, smooth texture and easy to melt with 514±14 centipoises of Viscosity at 150 ºC, 82.49±1.4 lbf/in2 of shear strength and 2.06±0.02 kN/m of cleavage peel strength.