Lip Plates

Lip plates are critical precision components in slot-die coating heads that form the narrow gap through which coating fluids are extruded onto substrates. They consist of two parallel plates (upper and lower) that create a precisely controlled slot opening, typically ranging from 50 to 500 microns. The plates feature precisely machined surfaces and edges that determine coating bead stability, wet film thickness uniformity, and coating width control. Lip plates work in conjunction with the coating die body and manifold to distribute coating fluid evenly across the entire coating width.

Lip plates operate by creating a precisely controlled gap between two parallel surfaces through which coating fluid is extruded. The upper and lower plates form a slot that meters the coating material onto moving substrates. Fluid pressure from the manifold forces coating material through the slot, where the gap height determines the wet film thickness. The plates' edge geometry and surface finish control the coating bead formation and stability, while the slot width determines the coating application width. Precise alignment and parallelism between the plates ensure uniform coating distribution across the entire substrate width.