Plastic adhesives are one-part adhesives that don’t need to be mixed. Dry to the touch and faster and easier to apply than two-part adhesives, they’re best for use on automated assembly lines. Often used to join solar cells in solar panels, these adhesives make instant electrical connections without flux at lower temperatures than soldering. Since they attach to solar cells with heat and slight pressure, they limit stress cracks that can form when soldering. These adhesives can also be used as a bridge between multiple solar panels.