Preparation and Investigation of Laser-Assisted Hot Melt Adhesives Based on Polypropylene (PP)/Ethylene-Vinyl Acetate (EVA)

Abstract

In recent years, with the advancement of laser equipment and technology, several papers have documented the utilization of laser technology in the domain of plate edge sealing. However, there is currently a lack of research on suitable materials for laser edge sealing. Therefore, in our research described in this paper we mainly explored the use of a functional layer of a kind of edge sealing material used in laser edge sealing technology, namely a laser hot melt adhesive material. In this study we used polypropylene (PP) and ethylene-vinyl acetate (EVA) as matrix materials to prepare laser hot melt adhesive materials which can be activated by a 1065 nm near-infrared laser. Compared with the traditional edge sealing technology, our operation process is simpler, the beauty of the product is better and all its performances meet the relevant standards. The thermogravimetric analysis (TGA) and other thermal analysis methods demonstrated that the laser adhesive can undergo melting upon laser activation, provided an appropriate amount of inorganic laser-sensitive agent is added, without undergoing any thermal decomposition. The influence of the elastomeric EVA resin on the crystallinity of the PP was investigated using X-ray diffraction (XRD) and differential scanning calorimetry (DSC), demonstrating a significant impact on the resulting blend properties. X-ray photoelectron spectroscopy (XPS) shows a partial reduction of Cu2+ to Cu+ within the laser sensitizer after activation of the adhesive by the laser. The optimal mass ratio of PP and EVA in the laser adhesive was investigated through experimental analysis. The morphological changes of the laser adhesive before and after laser activation were observed using scanning electron microscopy (SEM). We believe the research conducted by our team has significantly advanced the progress of laser edge banding technology and expedited its application in the field of furniture manufacturing.