A variety of high-tech equipment is available to dispense two-part adhesives.
Dispensing a one-part adhesive is easy. You only have to worry about the viscosity of the material, the flow rate, and how you want the material to be applied to the part.
Dispensing a two-part adhesive is another kettle of fish. Now you have two viscosities and two flow rates to think about, and you also have to be concerned with how easily the two materials will blend. You have to make sure the resin and the catalyst are metered in the correct ratio. And, you must ensure they are adequately mixed.