Process and related apparatus for block coating
The present invention discloses an apparatus for block type extrusion coating, and a process for forming block coating or grid-type coating on a substrate. The present invention uses a die set composed of an upper mold, a lower mold and a shim therebetween, which can be used to form a plurality of coated stripes. The present invention further uses several control valves, pumps and a controller to intermittently extrude a coating solution from the die set, so that the stripe coating is converted to a block coating. The block coated substrate can be rotated 90 degrees, followed by a stripe coating process to form a grid-type coating on the substrate.
1. An apparatus for block type extrusion coatings comprising a die set and a control device, wherein
the die set comprises an upper mold, a lower mold and a comb-shaped shim having a plurality of vacant regions, a first groove being formed on a lower surface of the upper mold, so that a plurality of channels for permitting a coating solution to flow from the first groove to a slit between a die lip of the upper mold to a die lip of the lower mold are formed between the upper mold and the lower mold, when the shim is disposed between the upper mold and the lower mold, wherein the upper mold further comprises a feed hole connected to the first groove, a first extraction hole connected to the first groove, and a second extraction hole connected to the first groove; and
the control device comprising a first pump, a second pump, a first valve, a second valve, a third valve, and a controller, wherein the first pump and the first valve are placed at a feed pipe connected to the feed hole; the second pump and the third valve are placed at an extraction pipe connected to the second extraction hole; the second valve is placed at a release pipe connected to the first extraction hole; the first pump, the second pump, the first valve, the second valve, and the third valve being all electrically connected to the controller, so that the first pump, the second pump, the first valve, the second valve, and the third valve are capable of being controlled by a signal received from the controller.
2. The apparatus as claimed in claim 1 , wherein the controller controls the first pump, the second pump, the first valve, the second valve, and the third valve to be on/off or opened/closed according to following method: at a time t0, turning on the first pump and opening the first valve, and simultaneously closing the second valve and the third valve; at a time t1, simultaneously closing the first valve, and opening the second valve and the third valve, and turning on the second pump; and at a time t2, closing the third valve.
3. The apparatus as claimed in claim 2 , wherein the lower mold has a second groove corresponding to the first groove.
4. The apparatus as claimed in claim 2 , wherein the first pump and the second pump are screw pumps, and the first pump and the second pump are controlled according to following method: at a time t0, turning on the first pump until a coating process is finished; and at a time t1, turning on the second pump until the coatings are finished.
5. The apparatus as claimed in claim 1 , wherein the lower mold has a second groove corresponding to the first groove.
6. The apparatus as claimed in claim 1 , wherein the shim has a thickness between 30-200 μm.