Abstract
A method for manufacturing an spray device includes assembling at least one spray nozzle plate into a thermoplastic holder, while controlling the temperature of the spray nozzle plate and/or the holder and as a result at least locally plastically deforming the holder permanently. After the thermoplastic deformation of a seat of the holder, a diameter of the seat of the holder upstream of the spray nozzle plate exceeds a diameter of the seat of the holder downstream of the nozzle plate. The thermoplastic holder may have a tapered seat, where the smallest cross section of the tapered seat is smaller than the spray nozzle plate, where a widest side of the tapered seat is pointing towards a supply side of the liquid.
Claims
1. A spray device comprising: a nozzle plate having an spray nozzle orifice, and a holder having a seat, the seat holding the nozzle plate, wherein the holder is made of a thermoplastic material and wherein the seat comprises a first rim, the first rim being formed of the thermoplastic material and being an integral part of the holder, the first rim sealingly engaging a downstream surface of the nozzle plate and extending along a circumferential edge of the downstream surface of the nozzle plate.
2. The spray device according to claim 1, wherein a width of the first rim in a direction parallel to the downstream surface of the nozzle plate is at least 25% of a thickness of the nozzle plate.
3. The spray device according to claim 1, wherein, in a direction perpendicular to the downstream surface of the nozzle plate, the first rim has a thickness of minimum 50% and maximum 250% of a thickness of the nozzle plate.
4. The spray device according to claim 1, further comprising an adapter having an inner surface that fittingly holds an outer surface of the holder, preferably a stiffness of the adapter exceeding a stiffness of the holder.
5. The spray device according to claim 4, wherein the adapter comprises an adapter rim extending at a downstream side of the holder and substantially parallel to the downstream surface of the nozzle plate so as to support the first rim of the holder during operation.
6. The spray device according to claim 5, wherein a width of the adapter rim as seen in a direction along the downstream surface of the nozzle plate is between 50% and 200% of a width of the first rim of the holder.
7. The spray device according to claim 5, wherein in a direction perpendicular to the downstream surface of the nozzle plate, the adapter rim has a thickness between 50% and 200% of the holder rim.
8. The spray device according to claim 4, wherein the outer surface of the holder and the inner surface of the adapter both have a tapering section that tapers positive in a downstream direction, preferably a tapering angle being between 5° and 45°.
9. The spray device according to claim 1, wherein the seat tapers in a downstream direction from a cross section which is larger than the nozzle plate to the thermoplastic material that sealingly engages the nozzle plate.
10. The spray device according to claim 1, further comprising a prefilter plate, the prefilter plate being placed in the holder at a distance from the nozzle plate and at an upstream side of the nozzle plate, the holder comprising a second rim, the second rim extending along and fitting along a circumferential edge of a downstream surface of the prefilter plate in between the nozzle and the prefilter plate.
11. The spray device according to claim 10, wherein in a direction perpendicular to the downstream surface of the nozzle plate, the second rim has a thickness of at least 50% and maximum 250% of a thickness of the prefilter plate, in particular with a thickness of minimum 100 and maximum 500 micrometer.
12. The spray device according to claim 10, wherein the holder, at an upstream side of the prefilter plate comprises a fixation rim to fixate the prefilter plate in the holder.
13. The spray device according to claim 10, wherein at least one of the nozzle plate and the prefilter is provided with a coating having molecules with endgroups that have a strong interaction with molecules of the holder.
14. The spray device according to claim 10, wherein the at least one of the nozzle plate and the prefilter plate is provided with anisotropic locking features on the downstream or upstream surface thereof, the anisotropic locking features to mechanically anchor the at least one of the nozzle plate and the prefilter plate in the holder, preferably the anisotropic locking features having a width between 2 and 20 micrometer and a depth/width aspect ratio of at least 2, more preferably at least 5.
15. The spray device according to claim 10, wherein the prefilter plate has a pore size less than 450 nanometer, in particular 220 nanometer, or in particular 100 nanometer.
16. The spray device according to claim 1, wherein the spray nozzle unit has at least one track and trace feature.
17. The spray device according to claim 1, comprising an identification feature having a dimension between 0.01 and 10 microns, the identification feature being identifyable with microscopy or fluorescence methods.
18. The spray device according to claim 17, further comprising a prefilter plate, the prefilter plate being placed in the holder at a distance from the nozzle plate and at an upstream side of the nozzle plate, the holder comprising a second rim, the second rim extending along and fitting along a circumferential edge of a downstream surface of the prefilter plate in between the nozzle and the prefilter plate, wherein the prefilter comprises a plurality of pores, wherein at least one of the pores of the prefilter has a different size than the remaining pores, preferably about 10-50 nanometer smaller or larger than the other pores, a location of the at least one of the pore having the different size providing the identification feature.
19. The spray device according to claim 1, wherein the components are assembled in the holder with a thermoplastic deformation process.
20. A method for manufacturing a spray device, the method comprising: providing a nozzle plate and a thermoplastic holder having a tapered seat, wherein a smallest cross section of the tapered seat is smaller than the nozzle plate, the method comprising: heating the nozzle plate; pressing the nozzle plate into the tapered seat of the holder by bringing the nozzle plate towards a smallest side of the tapered seat, thereby thermoplastically deforming a wall of the tapered seat; and forming a spray device from an assembly of the nozzle plate and the thermoplastic holder, whereas a widest side of the tapered seat is pointing towards a supply side of the liquid.
21. The method for manufacturing a spray device according to claim 20, featuring two or more nozzle plates, wherein a first one of the nozzle plates has a smaller surface area than a second one of the nozzle plates, the method comprising: placing the first one of the nozzle plates in a seat of the thermoplastic holder, and placing the second one of the nozzle plates under controlled temperature in the seat of the thermoplastic holder, the thermoplastic holder thereby being locally thermoplastically deformed into a flange, thereby fixating the first one of the nozzle plates.
22. The method of manufacturing a spray device according to claim 20, wherein the thermoplastic holder is heated before assembling the nozzle plate(s) and cooled again after assembly, to improve the sealing around the nozzle plate(s).
23. The method of manufacturing a spray device according to claim 22, wherein a rivet like flange or rim is created by heating and deforming the wider end of the tapered seat of the thermoplastic holder, in order to fixate the position of the nozzle chip.
24. The method of manufacturing a spray device according to claim 23, wherein the described rivet-like flange or rim is created by temperature controlled placement of an object other than an nozzle plate, e.g. such as a metal ring, which stays in the assembled spray device.
25: The method of manufacturing a spray device according claim 21, using 3 or more nozzle plates in the spray device assembly, thus forming a balanced functional stack, e.g. a stack of a prefilter, a last chance filter and a spray nozzle.
26. The method of manufacturing a spray device according to claim 25, whereas an antimicrobial agent is present in one of the cavities in the assembled spray device.
27. The method of manufacturing a spray device according to claim 21, wherein at least one of the nozzle plates is coated. Such a coating may be applied on wafer scale.
28. The method of manufacturing a spray device according to claim 26, wherein the agent is an antimicrobial coating.
29. The method of manufacturing a spray device according to claim 20, wherein the at least one nozzle plate has tapered sides or has local protrusions for anchoring purposes.
30. The method of manufacturing a spray device according to claim 20, the method comprising: providing an nozzle plate having a diameter; providing a thermoplastic holder having a seat, wherein the diameter of the nozzle plate exceeds a diameter of the seat at an intended position of the nozzle plate in the seat, heating at least one of the nozzle plate and the thermoplastic holder; placing the nozzle plate into the seat of the holder at the intended position, thereby providing a thermoplastic deformation of at least a part of the seat, and forming a spray nozzle unit from an assembly of the nozzle plate and the thermoplastic holder.
31. The method according to claim 29, wherein the nozzle plate is placed into the holder in a direction of movement of the nozzle plate relative to the holder, which corresponds to a flow direction relative to the holder, the flow direction of liquid from which the spray is to be generated in use of the spray device
32. The method according to claim 29, wherein after the thermoplastic deformation of the seat, a diameter of the seat upstream of the nozzle plate exceeds a diameter of the seat of the holder downstream of the nozzle plate.
33. A spray device manufactured according to the method claimed in of claim 20.
34. A spray device for generating a spray from a medicinal fluid manufactured according to the method claimed in claim 20.
35. A liquid administration device for spraying a liquid, the administration device comprising: a container for holding the liquid, the spray device according to claim 1, and a pressurizing device for propagating the liquid under pressure from the container to the spray device.
36. The administration device according to claim 35, wherein the liquid comprises a substantially sterile liquid.
37. The administration device according to claim 35, wherein the liquid comprises a medicinal liquid.
Description
BRIEF DESCRIPTION OF FIGURES
[0087] Further embodiments, features and effects will follow from the appended drawing and corresponding description, in which non-limiting embodiments are disclosed, wherein:
[0088] FIG. 1 depicts a cross sectional view of an assembly of orifice plates and holder according to an aspect of the invention, for use in an aerosol generator or other spraying device;
[0089] FIGS. 2, 3a, 3b, 4, 5a-5c, 6 and 7 depict a cross sectional view of various possible stages of fabrication of the assembly according to FIG. 1;
[0090] FIG. 8a depicts a cross sectional view of orifice plates;
[0091] FIG. 8b depicts a cross sectional view of an assembly of orifice plate and holder, making use of an orifice plate as depicted in FIG. 8a;
[0092] FIG. 9 depicts a cross sectional view of a assembly of orifice plates and holder according to another aspect of the invention, for use in an aerosol generator;
[0093] FIG. 10 depicts a cross sectional view of a assembly of orifice plates and holder according to another aspect of the invention, for use in an aerosol generator;
[0094] FIGS. 11a-11c depicts a cross sectional view of various possible stages of fabrication of a assembly of orifice plates and holder according to another aspect of the invention, for use in an aerosol generator;
[0095] FIGS. 12-14 depict cross sectional views of spray devices in accordance with embodiments of the invention;
[0096] FIG. 15 depicts cross sectional view of a spray device in accordance with embodiments of the invention to illustrate a manufacturing of the spray device using a thermode;
[0097] FIG. 16 shows a graph with microbial test results;
[0098] FIG. 17 explains an effect of a conical (tapering) fit; and
[0099] FIG. 18 depicts a schematic, perspective view of a nozzle plate comprising protrusions.
DETAILED DESCRIPTION OF THE FIGURES
[0100] FIG. 1 shows a part of an aerosol generator according to a potential embodiment of the invention with three orifice plates (1, 10 and 11) and a sintered porous plastic pre filter (12). A spray nozzle orifice plate (1) is mounted in a thermoplastic holder (2). A second orifice plate (10) and a third orifice plate (11) are being mounted with heat and pressure, thus locally thermoplastically deforming the tapered seat wall (5), creating rivet-like flanges (8). These two orifice plates form a last chance filter (orifice plate 10), preferably with orifices which are half the diameter of the spray pore diameter in the spray nozzle orifice plate (1), and a pre filter (orifice plate 11) with larger orifices than the last chance filter. A sintered porous plastic pre filter (depth filter 12) is mounted and is being kept in place by a simple press fit.
[0101] FIG. 2 shows an embodiment of the invention with one orifice plate (1) mounted in a thermoplastic holder (2). The holder (2) is provided with an originally tapered seat (3). The seat tapers from an inlet opening (lower side opening of seat) to a discharging opening (upper side opening of seat). When inserting the orifice plate into the seat, the seat is locally thermoplastically deformed (5), which may tend to perfectly following the contours of the orifice plate (1). At the intended position of the orifice plate in the seat of the holder, i.e. at the position as depicted in FIG. 2, before inserting the orifice plate into the holder, thus before deforming the seat, the outer dimension of the orifice plate (e.g. the outer width, diameter or circumference) exceeds a corresponding inner dimension of the seat (e.g. the inner width, diameter or circumference) of the holder, causing the seat to thermoplastically deform where it contacts the orifice plate when the heated orifice plate is inserted and establishes contact with and because of the orifice plate being over-dimensioned in respect of the seat, exerts a force onto the seat. The dimension of the orifice plate and seat are to be understood as dimensions in a direction substantially perpendicular to the direction of insertion (as indicated by the arrow in FIGS. 3a and 3b as will be described below).
[0102] FIG. 3a shows a partly tapered seat (3) in a thermoplastic holder (2). An orifice plate (1) is provided, and inserted into the seat (a direction of insertion being indicated by the arrow in FIG. 3a), the insertion being performed in a direction of tapering of the seat, i.e. in a direction towards a discharging, outlet opening 4 of the seat which is smaller then the inlet opening. At the outlet opening, the smallest cross section of the tapered seat (3) is smaller than the orifice plate (1).
[0103] FIG. 3b shows that the orifice plate (1) after having been heated or while being heated, has been inserted into the seat followed by pressing the orifice plate (1) into the holder (2) by bringing the orifice plate (1) from the widest side (7) of the tapered seat (3) towards the smallest side (4) of the tapered seat (3), thereby thermoplastically deforming the seat wall (5). The direction of insertion is indicated by the arrow in FIG. 3b. This forms an aerosol generator from the orifice plate with holder, whereas the widest side (6) of the tapered seat is pointing towards the supply side of the liquid (7).
[0104] FIG. 4 shows another potential embodiment of the invention, where an orifice plate (1) is mounted in a thermoplastic holder (2). The orifice plate may have been mounted into the thermoplastic holder making use of the method as described with reference to FIGS. 2 and 3a-3b. As additional step may be performed as follows: By having locally heated and deformed the widest cross section (6) of the tapered seat, a rivet-like flange (8) has been created, which fixates the position of the orifice plate (1). The rivet like flange may be created by temporarily pushing (in the direction of insertion of the orifice plate) an object into the seat, the object having a size (e.g. diameter, circumference, length and/or width) which exceeds that of the orifice plate, causing the seat to deform into the rivet like flange. The object may be heated so as to facilitate the local thermoplastic deformation to form the flange. Alternatively, the object may be inserted after the mounting of the orifice plate while the thermoplastic material of the seat proximate to the orifice plate is still warm, and this still exhibits a degree of thermoplastic plasticity. A manufacturing of the aerosol generator as depicted in FIG. 4 is illustrated with reference to FIG. 5a-5c as described below.
[0105] FIG. 5a shows a tapered seat (3) in a thermoplastic holder (2). An orifice plate (1) is provided, where the smallest cross section of the tapered seat (3) is smaller than the orifice plate (1). The orifice plate is heated before insertion or is inserted into the seat by a heated object, such as a heated bondhead (not shown FIG. 5a-5c.
[0106] FIG. 5b shows the orifice plate (1) placed in the thermoplastic holder (2) in a direction as indicated by the depicted arrow. As the seat tapers toward a dimension that is smaller than the orifice plate, the orfice plate pushes against the tapering seat, thus locally plastically deforming the tapered seat wall (5)
[0107] FIG. 5c shows the creation of the rivet-like flange (8) by using an object, such as in this example a thermode (20) to locally plastically deform the widest end (6) of the tapered seat. Thereto, the thermode is pushed into the seat in the direction of insertion. The thermode may be heated to promote local thermoplastic deformation of the seat.
[0108] FIG. 6 shows a potential embodiment of the invention. An orifice plate (1) is mounted in a thermoplastic holder (2). A second object (9), in this case a metal ring shaped part, is placed just behind the first orifice plate (1), creating a rivet-like flange (8), to keep the orifice plate (1) fixated. The second object 9 may be mounted into the seat in a similar way as the insertion of the thermode as described with reference to FIG. 5c, whereby the second object is left in the seat and the thermoplastic material being allowed to cool down.
[0109] FIG. 7a shows a potential embodiment of the invention with two orifice plates. A first orifice plate (1), which has the function of spray nozzle orifice plate, is mounted in a thermoplastic holder (2). A second orifice plate (10), e.g. with a microsieve function, is being placed just behind the first orifice plate (1), creating a rivet like flange (8). The second orifice plate 10 may be mounted into the seat after having mounted the first orifice plate, whereby the second orifice plate is mounted in a similar way as the mounting of the first orifice plate. In order to again deform the seat while mounting the second orifice plate, the second orifice plate may be larger (in terms of e.g. diameter, circumference, length and/or width) then the first orifice plate. By the assembly method according to the invention a cavity (20) has been formed between the first and second orifice plates. The first and/r second orifice plate may be provided with a recess to form an area in the recess where a thickness of the orifice plate is reduced. The recess may be generated by any suitable technique. For example, in case the orifice plate is manufactured from a semiconductor material such as silicon, the recess may be etched into the orifice plate. In the part of the orifice plate where the thick ness is reduced, on or more openings may be provided to form orifices for generating an aerosol resp. to form a filter,
[0110] FIG. 7b shows a potential embodiment with the same orifice plates, where the second orifice plate (10) has been mounted differently, thus creating a larger cavity (20). In FIG. 7a, the recesses in the first and second orifice plate are provided at a same (upstream) side, while in FIG. 7b, the recesses face each other, to form the larger cavity. FIG. 8a shows two silicon wafers. The first wafer (13) holds several hundreds of spray nozzle orifice plates (4 being depicted in FIG. 8a) and the second wafer (14) holds several hundreds of micro sieve orifice plates (4 being depicted in FIG. 8a). The first wafer is being coated on its top surface with an ultra hydrophobic coating (30). The second wafer is being coated on its top surface with an antimicrobial coating (31)
[0111] FIG. 8b shows an aerosol generator assembly, using orifice plates from the two silicon wafers described in FIG. 8a. The first orifice plate, the nozzle orifice plate (1), has the ultra hydrophobic coating (30) on the outside (i.e. on the downstream side). The second orifice plate, the microsieve plate (10) has an antimicrobial coating which now has ended up on the inside of the cavity (20).
[0112] FIG. 9 shows a potential embodiment of the invention with two orifice plates plus a depot (32) of an anti microbial material, placed in the cavity (20) between the two orifice plates (10 & 11). The depot 32 may be formed by an absorbing structure which absorbs the anti microbial material, or may be formed by the anti microbial material itself.
[0113] FIG. 10 shows a potential embodiment of the invention with three orifice plates. The spray nozzle orifice plate (1) faces the outside world at the downstream side of the aerosol generator. The hole pattern in the second orifice plate, a micro sieve plate (10) is placed asymmetrically in respect of a central axis of the holder extending from the inlet to the discharging opening. The hole pattern in the third orifice plate, also a micro sieve plate (11) is also placed asymmetrically on the other side, i.e. on the other side in respect of the central axis. This way the cavity (20) and the liquid path (21) between the two groups of micro sieve orifices has become very long and narrow, as it extends form the orifices in the third orifice plate which are located at the left side in the drawing of FIG. 10, while the orifices in the second orifice plate are located at the right side in the drawing of FIG. 10. The cavity has further been narrowed in that the recessed in the second and third orifice plates face away from each other casing the thin parts of the orifice plate to be closer together to form a more narrow gad there between. An anti microbial coating (22), applied on both micro sieve chips (10 & 11) prevents bacteria (23) from growing into the container (24) of the device. The container, of which only a part is depicted in FIG. 10, holds the liquid from which the aerosol is to be generated.
[0114] FIG. 11a shows a thermoplastic holder (2). Two orifice plates (1) and 10 are provided, where the smallest cross section of the tapered seat (3) is smaller than the orifice plate (1). In contrast to the seats as depicted in and described with reference to FIGS. 1-10, the seat in the embodiment as depicted in FIG. 11 tapers stepwise instead of continuously. The first and second orifice plates 1 and 10 are placed into the seat by inserting them in the direction of the arrow in FIG. 11a. The first and second orifice plate may or may not be heated and may—but do not necessarily need to cause thermoplastic deformation of the seat.
[0115] FIG. 11b shows the temperature controlled placement of a third orifice plate (11), locally thermoplastically deforming (5) the seat of the holder (2) by introducing the third orifice plate into the seat in the direction of the arrow (FIG. 11b). Part of the thermoplastical material of the holder is being scraped from a wall of the seat (5) in front of the third orifice plate (11) in order to form a flange at 5 between the second orifice plate and the third orifice plate.
[0116] FIG. 11c shows a possible embodiment of an aerosol generator according to the invention as obtained by the placement of the orifice plates as described with reference to FIGS. 11a and 11b, where a first orifice plate (1), functioning as a spray nozzle orifice plate is provided and a second orifice plate (10), functioning as a last chance filter. The temperature controlled placement of a third orifice plate (11), functioning as a pre filter, has created a rivet like flange (8), fixating the first two orifice plates (1 and 10).
[0117] FIG. 12 shows an embodiment of a spray nozzle unit (1) with one nozzle plate (2) with a thickness of 200 um and a size of 1×1 mm. The nozzle plate (2) is made with silicon micromachining. For this a 200 um thick silicon wafer is used as a support and a 1 um thick silicon nitride layer for the provision of the nozzle orifices. The silicon nitride nozzle orifices are here 2 um in diameter. The spray nozzle plate (2) is mounted in a thermoplastic holder or package (3) of medical certified polypropylene that is characterized in having a rim (4) extending over the silicon nozzle plate at the exit or downstream side (5). The rim (4) extends horizontally over the nozzle plate (2) at the downstream side (5) with a length of 200 um and has a thickness of 200 um. The spray nozzle unit (1) further comprises an adapter (6) with a tapering section (7) to counterbalance thermal and pressure expansions of the thermoplastic holder (3). The adapter (6) may further comprise a support rim (8) to support the rim (4) of the holder (3) to strengthen the spray nozzle unit (1) during operation. Here the support rim (8) extends about 150 um and has a thickness of 200 um.
[0118] FIG. 13 shows an embodiment of a spray nozzle unit (1) with a nozzle plate (2), a thermoplastic holder (3) and a microsieve prefilter (9). The microsieve (9) is made with a silicon micromachining method similar as for making the nozzle plate (2) with a thickness of 200 um and has pores with a diameter of 0.45 um. In between the nozzle plate (2) and the prefilter (9) a second polymer rim (10) is present extending over the silicon nozzle plate (2) at the upstream side. Here the second polymer rim has a thickness of 100 um and extends with a length of 200 um. The membrane side of the microsieve (9) is here positioned on the upstream side of the spray nozzle unit (1), but can also be placed inverted.
[0119] FIG. 14 shows an embodiment of a spray nozzle unit (1) with a nozzle plate (2), a thermoplastic holder (3), a microsieve prefilter (9) and a sintered porous plastic prefilter (11), here with a pore size of approximately 10 um. Likewise a third filter (12) can be placed to collect particles from fluid at the upstream side.
[0120] FIG. 15 show a method for manufacturing a spray nozzle unit (1) with use of a thermode (13).
[0121] FIG. 16 shows a graph with microbial test results, comparing a single nozzle unit with a prefilter and a tapering adapter according to the current invention with a single nozzle unit without the use of a tapering adapter. The nozzles are challenged over a period of one week, then the content of the container with a nutrient solution is assessed for bacterial ingrowth.
The earlier nozzles unexpectedly show ingrowth with 0.22 microsieve pores, the new nozzles according to the invention do not, which indicates that the microsieve plates now are assembled in a way that perfectly seals them.
[0122] FIG. 17 shows the importance of a conical fit of the assembled spray nozzle unit in its surroundings. The plastic material used for the plastic holder used to generate this data, is polypropylene, the surrounding adapters A and B are made from a harder plastic (adapter A rapid prototyped polyamid, adapter B milled from polyoxymethylene). The graph shows that at higher pressures the polypropylene holder can be inflated, leading to internal leakages between the nozzle plate and the plastic holder.
[0123] FIG. 18 depicts a schematic, perspective view of a nozzle plate. Local protrusions are provided at each of the edges of the nozzle plate. Various protrusion profiles are depicted. For illustrative purposes, in order to illustrate different possibilities of the protrusion profiles, each edge of the depicted nozzle plate is provided with a different profile.
