Nozzle assembly for applying a liquid to a substrate
View Patent ↗The aim of the invention is to achieve a rapid, homogeneous application of a liquid with as little force as possible to a substrate. To achieve this, the invention provides a nozzle assembly ( 22 ) for applying a liquid to a substrate, said assembly having a nozzle body ( 26 ) comprising a plurality of nozzles ( 36 ) that are substantially arranged in a line and a guide plate ( 28 ) that extends essentially in a vertical direction with a straight lower edge. According to the invention, the nozzles ( 36 ) above the lower edge are directed towards the guide plate ( 28 ) in such a way that a film of liquid forms on the guide plate ( 28 ) and flows over the lower edge ( 64 ).
1. A nozzle assembly for applying a liquid to a substrate, wherein the nozzle assembly comprises a nozzle body incorporating a plurality of nozzles located substantially in a line and a substantially vertically extending guide plate having a flat surface and a straight lower edge wherein the nozzles are directed towards the flat surface of the guide plate above the lower edge so that a liquid film forms on the guide plate and flows off over the lower edge, wherein a downwardly widening gap is formed between the nozzle body and the guide plate, said widening gap being formed by a flat surface of the nozzle body and the flat surface of the guide plate which are arranged at an acute angle (α) of between 0.5 and 4° relative to one another, and wherein the planes of the flat surfaces cross above the nozzles in the area of the nozzle body.
2. A nozzle assembly in accordance with claim 1 , wherein the acute angle (α) is adjustable.
3. A nozzle assembly in accordance with claim 1 , wherein the acute angle (α) lies between 1° and 3°, and more preferably between 1.5° and 2.5°.
4. A nozzle assembly in accordance with claim 1 , wherein the flat surface of the guide plate extends downwardly over the entire flat surface of the nozzle body.
5. A nozzle assembly in accordance with claim 1 , wherein the guide plate is attached directly to the nozzle body, or wherein the guide plate is attached to the nozzle body above the nozzles.
6. A nozzle assembly in accordance with claim 1 , wherein a seal is located above the nozzles between the nozzle body and the guide plate.
7. A nozzle assembly in accordance with claim 6 , wherein a recess is provided in the nozzle body for accommodating the seal.
8. A nozzle assembly in accordance with claim 7 , wherein the inlet ends of the nozzles flow into a common distributor line which has a substantially larger cross section than the respective nozzles.
9. A nozzle assembly in accordance with claim 8 , wherein the inlet ends of the nozzles lie at or in the proximity of a highest point of the distributor line.
10. A nozzle assembly in accordance with claims 8 , wherein a supply line is located below the distributor line and is connected by a plurality of feeder lines to the distributor line.
11. A nozzle assembly in accordance with claim 10 wherein the feeder lines are evenly spaced over the entire length of the distributor line.
12. A nozzle assembly in accordance with claim 6 , wherein the seal has a round cross section.
13. A nozzle assembly in accordance with claim 1 , wherein the nozzles are formed by straight passages in the nozzle body and whereby, in terms of height, an inlet end of the passage lies below an outlet end.
14. A nozzle assembly in accordance with claim 1 , wherein at least one surface of the guide plate directed toward the nozzles consists of a hydrophilic layer.
15. A nozzle assembly in accordance with claim 1 , wherein a mechanism is provided for producing a relative movement between the substrate ( 2 ) and the nozzle assembly.
16. A nozzle assembly in accordance with claim 15 , wherein the mechanism comprises a unit for moving the nozzle assembly substantially parallel to the surface of the substrate, or a linear-movement unit for moving the substrate and/or the nozzle assembly.
17. A nozzle assembly in accordance with claim 16 , wherein the nozzle body and the guide plate are attached to a pivotal arm.
18. A nozzle assembly in accordance with claim 1 , wherein the guide plate is wider than the substrate.
19. A nozzle assembly in accordance with claim 1 , wherein the outermost nozzles along the line are spaced by a distance which is greater than the width of the substrate.
20. A nozzle assembly in accordance with claim 1 , wherein a mechanism is provided for adjusting the spacing between the lower edge of the guide plate and the substrate.
21. A nozzle assembly in accordance with claim 1 , wherein the lower edge of the guide plate is a sharp edge.
22. A nozzle assembly in accordance with claim 1 , wherein a mechanism is provided for opening and closing pre-determined nozzles.
23. A nozzle assembly in accordance with claim 22 , wherein said mechanism is provided for opening and closing outermost ones of the nozzles.
24. A nozzle assembly in accordance with claim 1 , wherein an angle within the range of 90° to 94°, and preferably between 90.5° and 93° is formed between the nozzles and the guide plate and more preferably between 90.5 and 92.