Most hot melt adhesive users prefer clear or transparent hot melt. Below are two approaches to achieve this aesthetic goal.

1.To produce a transparent EVA-based HMA, one should first select EVAs and tackifiers possessing similar solubility parameters. In other words, the selected tackifiers should be very compatible with the soft VA (Vinyl Acetate) segment of the EVA. Natural tackifiers such as rosin and Terpene derivatives are more polar material and therefore are more compatible with VA. Disregarding the color, it is normally easier to make a transparent EVA-based HMA with natural tackifiers. Among various types of synthetic hydrocarbon tackifiers, C5 (aliphatic)/C9 (aromatic) or C10 (DCPD, di-cyclo-penta-diene)/C9 co-tackifiers are more compatible to VA and can be easier to make transparent EVA-based HMAs.

2.The production procedure is also critical to obtain transparent HMAs. During mixing, adhesive blends are normally transparent at elevated temperatures beyond the cloud point of the blends. When finished adhesive blends are suddenly chilled… Read Article>>

Clear EVA-based Hot Melt Adhesives
- by Pierce Covert, Glue Machinery Corporation