Frequently Asked Questions

What are the benefits of Mayer rod coating?

Rod coating provides excellent accuracy and uniformity through a wide range of speeds at a low cost that is simple to setup and change over. Mayer rod coating has been and still is in the top three most popular coating methods.

Should the rod be driven?

Yes, rotating the rod will prevent uneven wear. Rotating the rod will also present a relatively clean rod surface to the substrate.

Which direction should the rod rotate?

Normally the rod rotates against the web. However, rotating the rod with the web may result in a better finish for some coatings.

What speed should the rod rotate?

25 to 50 rpm is a good starting point. Rotate the rod faster to see if the coating finish improves.

What is the best wrap angle?

Every application is different but most coaters operate with 5 to 15 degrees of wrap. The most flexible coaters will be able to adjust the wrap angle for different applications.

Should I realign the drive motor when changing wire sizes?

Yes, if the size change is significant enough to prevent the rod from laying flat on the rod bed. (Note that with a 60 degree V-groove rod bed, any increase in diameter will cause an equal increase in rod height).

What are the benefits of formed rods?

The U-shaped groove of a formed rod cleans up easier than its wire wound counterpart. Unlike wire wound rods, the diameter of a formed rod increases very little from a small groove size to a larger one. Formed rods are generally less expensive at high volumes.

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.

What effect does rod diameter have on coating thickness?

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

What other factors should be considered when choosing rod diameter?

Since rods are generally made of solid stainless steel, the rod diameter will have a drastic affect on rod price. The need for a rod holder depends upon rod diameter (and several other factors).

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?

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

Is there a minimum order amount?

There is no minimum for wire wound rods. There is a 5 rod minimum per size for formed rods (or a $35 setup charge per size).

What is the standard lead time for custom coating rods?

Our standard lead time is 1 to 2 weeks after receipt of order. We offer stocking programs for higher volume users. If you need an order sooner please contact us about expediting.

Does RDS accept credit cards?

Yes, RDS accepts Visa, MasterCard and American Express.