The manifold is a critical internal component of a slot-die coating head responsible for receiving coating fluid from the inlet and distributing it uniformly across the entire width of the die slot. It ensures consistent flow rates and pressure to achieve uniform coating thickness on the substrate. The manifold's internal geometry, often featuring a tapered or specially designed flow channel, gradually expands to distribute the fluid across the width. It maintains laminar flow and minimizes pressure variations to deliver a consistent fluid curtain through the die slot. This component is available in materials such as stainless steel 316L, aluminum alloy, and PTFE-coated steel, each selected based on the chemical compatibility and wear resistance required for the specific coating fluid. Key parameters include operating pressure (1.0–1.6 MPa), flow rate (0.5–5.0 L/min), temperature range (-10–80 °C), internal volume (0.5–2.0 L), surface roughness (Ra 0.2–0.4 µm, ISO 4287), material grade (316L, ASTM A240), weight (15–30 kg), die width (300–2000 mm), pressure drop (0.1–0.3 MPa), and leakage rate (0.01–0.05 mL/min). These values are reference ranges and must be verified for the specific model and application. The manifold is designed for use in slot-die coating systems, where uniform distribution is essential for coating quality. Proper selection requires consideration of the coating fluid's viscosity, temperature sensitivity, and required flow rate. Verification of the manifold's performance should include checks for pressure drop, flow uniformity, and leakage under rated conditions. Maintenance signals include increased pressure drop, uneven coating thickness, or visible wear on internal surfaces. Failure boundaries include operating outside the specified pressure or temperature ranges, which can lead to inadequate sealing or material degradation. Always consult the legal manufacturer or supplier to confirm model-specific values and standards.
Coating fluid enters the manifold through a central or side inlet. The internal geometry of the manifold (often with a tapered or specially designed flow channel) gradually expands to distribute the fluid across the width. It maintains laminar flow and minimizes pressure variations to deliver a consistent fluid curtain through the die slot.
