Systems and methods for dispensing a fluid
A fluid dispensing system may include a first die portion having a first face defining a first edge and a second die portion spaced from the first die portion and having a second face facing the first face and defining a second edge, wherein the first edge and the second edge define a fluid outlet opening. The fluid dispensing system may also include a fluid inlet for introducing fluid to a region between the first face and the second face, and a cavity in flow communication with the fluid inlet, wherein the cavity opens to the region between the first face and the second face. The fluid dispensing system may further include a shim disposed between the first die portion and the second die portion to maintain the spaced positioning of the first and second die portions, wherein the shim defines a plurality of channels bounded by the first and second faces and extending from the cavity in a direction toward the fluid outlet.
1. A fluid dispensing system, comprising:
a first die portion having a first face defining a first edge;
a second die portion spaced from the first die portion and having a second face facing the first face and defining a second edge, wherein the first edge and the second edge define a fluid outlet opening;
a fluid inlet for introducing fluid to a region between the first face and the second face;
a cavity in flow communication with the fluid inlet, wherein the cavity opens to the region between the first face and the second face; and
a shim disposed between the first die portion and the second die portion to maintain the spaced positioning of the first and second die portions, wherein the shim comprises a plurality of fingers, each finger having different tapered cross-sectional regions provided stepwise or in a stepwise fashion, each cross-sectional region being uniform and defining a plurality of channels bounded by the first and second faces and extending from the cavity in a direction toward the fluid outlet.
2. The system of claim 1 , wherein the channels are in direct flow communication with the cavity.
3. The system of claim 1 , wherein the channels extend in a direction of fluid flow from the fluid outlet during fluid dispensing.
4. The system of claim 1 , wherein the channels extend over the cavity.
5. The system of claim 1 , wherein the channels terminate in a plurality of fluid expansion zones within the region between the first and second die portions.
6. The system of claim 1 , wherein the channels are configured to prevent cross-flow of fluid flowing in the region between the first and second faces at least at a location of the channels.
7. The system of claim 1 , wherein the channels span a width of the region between the first and second faces.
8. The system of claim 1 , wherein the channels are configured to provide a substantially uniform fluid flow rate under ultra-low flow conditions.
9. The system of claim 1 , wherein the fingers extend from a base portion of the shim and overlap at least partially with the cavity.
10. The system of claim 1 , wherein the fingers have tapered transition regions between the differing cross-sectional regions.
11. The system of claim 1 , wherein the differing cross-sectional regions sequentially decrease in size toward a free end of each finger.
12. The system of claim 1 , wherein the fingers have two differing cross-sectional regions.
13. The system of claim 1 , wherein the fingers have three differing cross-sectional regions.
14. The system of claim 1 , wherein the fingers are substantially identical in shape.