Lab Rod FAQ's

How do I choose the correct wire size?

Use the size selection chart to find an appropriate starting point. Perform a test with that size (in the lab preferably) and measure the actual film thickness. Use the actual transfer rate (wire size to film thickness) to refine your size selection.

Should the rod be allowed to roll when performing a hand drawdown?

No, the rod should not be allowed to rotate during a drawdown. Hold the rod steady and pull the coating down the sheet with consistent speed and even pressure.

Does RDS offer rods for my coater/drawdown machine?

RDS can provide rods for nearly any coater or drawdown machine. Simply request a quote and specify the coater/machine make and model.

What effect does rod diameter have on coating thickness?

None, the coating thickness is determined by the wire (or groove) size.

What are the benefits of formed rods?

The U-shaped groove of a formed rod cleans up easier than its wire wound counterpart. 

Why is the film thickness different for a wire wound
versus a formed rod?

The cavity between wire windings is a V-shape while the formed rod has a U-shaped groove. Coating flows through the shapes differently so the actual transfer rate depends largely on coating rheology.