A common problem in dip coating is “pooling” or the “edge effect”. Gravity pulls excess liquid to the bottom edge of your part, making the film too thick there. This thick edge can crack or cure poorly. Here is how to fix it without just relying on a constant pulling speed.
1. Why Constant Speed Fails
Standard dip coaters pull the part out at one steady speed. But as the part leaves the liquid, surface tension grabs extra liquid and drags it down. Gravity then turns this into a thick pool at the bottom.
2. The Fix: Variable Speed (Linear Withdrawal)
The best way to stop pooling is to change the speed right at the end. By speeding up or slowing down just as the part exits the liquid, you control the surface tension. This lets the extra liquid flow smoothly back into the tank.
3. SDI’s Linear Dip Coater
Our Linear Dip Coater lets you program these speed changes easily. Whether you are coating flat plates or complex 3D shapes, you can set a custom speed profile. This guarantees an even coat from top to bottom, which is much better than manual touch-offs.
Summary
You don’t have to accept thick bottom edges. Upgrading to a variable speed (linear) system is the best way to get a perfectly even coat, especially for thick liquids or precise electronic parts.
▼ Specialized in Variable Speed Withdrawal! Learn more about Linear Dip Coater (LD1304S2)
https://www.sdicompany.com/en/dipcoater/ld1304s2.php