Filter, chromatographic bed or chromatographic separator or the like and production method thereof

Abstract

The present disclosure relates to a filter or chromatographic bed or chromatographic separator or the like and an associated production method, where the filter, bed or separator comprises: - a plurality of subsequently printed filter layers defining a porous stationary phase; - a reinforcement configured to maintain the shape and size of the column when pressurized; and - an envelope structure with an input for supply to the stationary phase of a mobile phase and an output for discharge.

Description

[0001] FILTER, CHROMATOGRAPHIC BED OR CHROMATOGRAPHIC SEPARATOR OR THE LIKE AND PRODUCTION METHOD THEREOF

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to column shaped three-dimensional devices, produced using an additive printing technique, more in particular 3D-printing. Such devices may form filters or chromatographic separators to be used in or for chromatography.

[0004] BACKGROUND

[0005] The closest prior art is the article ‘3D-Printed Stationary Phases with Ordered Morphology: State of the Art and Future Development in Liquid Chromatography’ by Salmean and Dimartino in Chromatographia Journal, Vol. 82, pages 443 - 463 published on December 14, 2018, with publication reference XP-036679504.

[0006] Therein, several embodiments of a stationary phase are disclosed for filtering a mobile phase, in particular in the context of chromatography. These embodiments of a 3D printed stationary phase were proposed to replace prior art packed beds, for instance comprising a number of particles, e.g. spherical packed in a tube. In particular, 3D printing allows for production of highly organized micron-sized channels to achieve filtering and / or chromatography. According to this article, there’s a tendency of ‘moving away from stereotypical “packed” beds with spherical particles to bespoke monolithic structures to suit a range of specific applications’. For ease of reference, herein a filter is defined as the instrumental equipment for all such specific applications, even if, such as in the case of chromatography, reference to other equipment or another device, in particular a chromatographic bed or chromatographic separator, would as a matter of fact be technically more correct. Thus, other applications than filters are herein also encompassed within the scope of the appended claims, which also stems from the reference herein below to a stationary phase as forming a component of a filter.

[0007] Furthermore, where the aforementioned article distinguishes 3D printing over the prior art techniques of micromachining and photolithography, cross over technologies may also exist and may fall within the scope of the present disclosure, in particular where for example 3D printing is combined with micromachining and / or photolithography.

[0008] Although the prior art discloses 3D printing to produce a stationary phase, therein a problem is not taken into account, that is for instance associated with 3D printing in a bath of printing material. After the filter or stationary phase is printed, unsolidified material or other material, such as print powder, that is not part of the desired, printed structure, needs to be removed from the channels around which printing material has been solidified to form the channels. Likewise, in application of a filter, filter residue needs to be removed from the same channels. Depending on a length of a printed column, filter or stationary phase, the size of the channels formed therein and the rheology of the substance that needs to be moved through the channels, excessive pressures may be needed to clear the channels therein. The kind of pressure needed for this clearing of the channels will depend on the size and length of the channels, as well as the size of particles or viscosity of material to be cleared from the channels, and may be in excess of 200 bar. At such pressures to remove unsolidified material (such as printing powder) or other manufacturing materials or in use filtered filter residues, structures of 3D printed stationary phases may fail and even collapse, thereby clogging the printed filter channels of the stationary phase, rendering the prior art stationary phase unusable as a filter precisely as a result of an attempt to clear channels thereof.

[0009] Even if only recently developed metal printing techniques were already sufficiently matured to perform filter or stationary phase printing with channel size down to and under micron level, which they are not, then such metal product would fail under such pressures and be compressed, deformed or otherwise destroyed by a clearing process.

[0010] SUMMARY

[0011] To provide an improvement, it’s here proposed to provide a filter or chromatographic bed or chromatographic separator or the like, having a column shape, and comprising:

[0012] - a plurality of subsequently printed filter layers defining a porous stationary phase;

[0013] - a reinforcement configured to maintain the shape and size of the column when pressurized; and

[0014] - an envelope structure with an input for supply to the stationary phase of a mobile phase and an output for discharge.

[0015] In an embodiment, the reinforcement may be printed together with the stationary phase.

[0016] In an alternative or additional embodiment, the reinforcement may be printed from the same material as the stationary phase.

[0017] In an alternative or additional embodiment, the reinforcement may define a sleeve around the stationary phase. Then, the input of the envelope may be connected to the interior of the sleeve.

[0018] In an alternative or additional embodiment, the reinforcement may define at least one strengthening beam extending through the stationary phase. Then, the at least one beam may extend at least one of axially and radially through the stationary phase. A plurality of beams may be provided in different orientations relative to the length or axis of the column shape.

[0019] In an alternative or additional embodiment, the stationary phase may be column shaped having a cross section which is one or more than one of a group of shapes comprising: circular, ellipsoid, rectangular, square, polygonal, and the like.

[0020] In an alternative or additional embodiment, the stationary phase with the reinforcement may be arrested within the envelope. Then, the stationary phase may be arranged within the envelope through an interference fit. More in particular, the stationary phase may be arranged within the envelope through a shrink-fit or an expansion-fit. In an alternative or additional embodiment, the filter may define a three dimensional liquid chromatography separator, more in particular a high performance or high pressure liquid chromatography separator.

[0021] Further, the present disclosure relates to a method of producing a device as set out above, having a 3D column shape, comprising:

[0022] - subsequently printing a plurality of filter layers to define a porous stationary phase;

[0023] - printing in or through at least some of the layers a reinforcement configured to maintain the shape and size of the column when pressurized; and

[0024] - arranging the stationary phase with the reinforcement therein or thereon in an envelope structure having an input for supply to the stationary phase of a mobile phase and an output for discharge.

[0025] In an embodiment, the method may further comprise shrink-fitting or expansion fitting the stationary phase with the reinforcement in the envelope structure.

[0026] Flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of devices, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the blocks may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and / or flowchart illustrations, and combinations of blocks in the block diagrams and / or flowchart illustrations, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Herein below, and with reference to the appended drawing, aspects of the invention will be explained in greater detail by reference to exemplary embodiments shown in the drawings, to which the scope of protection for the invention is by no means limited, and the scope of defined solely in the appended claims, without interpretation of limitations from the following embodiment description into that scope according to the claims, wherein:

[0029] FIG. 1 schematically illustrates a perspective view of an exploded filter or chromatographic separator in a possible embodiment of the present disclosure;

[0030] FIG. 2 schematically illustrates a perspective view of a part of a filter or of a chromatographic separator in another possible embodiment of the present disclosure; FIG. 3 schematically illustrates a perspective view of a part of a filter or of a chromatographic separator in yet a further possible embodiment of the present disclosure;

[0031] FIG. 4 schematically illustrates an assembled filter or chromatographic separator; and

[0032] FIG. 5 schematically illustrates an assembled filter or chromatographic separator in another embodiment than FIG. 4;

[0033] FIG. 6 illustrates steps of a method according to an aspect of the present disclosure; and

[0034] FIG. 7 illustrates an exemplary design of a mesh, web or porous stationary phase according to the prior art.

[0035] DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0036] In the figures, the same or similar reference numbers indicate identical or similar elements, components or functional units. It is noted that, herein, a filter is described, in particular a micro filter, but that the scope of the present disclosure also encompasses chromatographic separators or the like. Reference to a filter is explicitly not a limitation on the scope of the disclosure or of the protection afforded by the appended claims to use as a filter.

[0037] FIG. 1 schematically illustrates a perspective view of a part of an exploded filter 1 or chromatographic separator in a first embodiment of the present disclosure.

[0038] In this embodiment, filter 1 or chromatographic separator has a column shape, as is shown better in FIG 4 and 5, with an elongate axis of the column shape extending in the direction of arrow A, which is also the direction in which fluid or gas to be filtered or mobile phase in chromatography applications passes therethrough. The fluid or gas to be filtered or mobile phase in chromatography applications is not shown in the figures, and may pass through filter or chromatographic separator 1 in a direction opposite to arrow A. Filter or chromatographic separator 1 comprises a plurality of stacked filter layers 2, 3 together defining a mesh, web or porous stationary phase. Each of the layer 2, 3 comprises a number of additively manufactured or 3D printed parallel ribs 4 at a selected distance there between. The ribs may have the shape / form in cross section of polygons, circles, ovals or any other shape, but are here embodied as cross sectionally rectangular ribs 4. The ribs 4 are strategically placed, in correspondence with a function to be achieved, i.e. filtering or chromatography, or another purpose. Namely, not only the shapes of but also distances between ribs 4 may be different for distinct application, i.e. to form a filter 1 or function as a chromatographic separator 1. As a mere example, the intermediate distance between ribs may have any value from 0,5 up to 100 pm. In any one particular form, distances between ribs are preferably constant, but may vary to form a gradient structure, for example with depth of a travel distance of the fluid, gas or mobile phase through the filter 1 or chromatographic separator.

[0039] Ribs 4 in layers 2 extend in one direction, and ribs in layers 3 extend in another direction. The another direction of ribs 4 in layers 3 may be perpendicular to the direction of ribs 4 in layers 2, but any other angle may also be contemplated. In a single layer the ribs 4 may be interrupted so as not to extend over the full width of the layer 2, 3 or may be crosslinked within layers 2, 3, or may be linked, as shown, across adjacent layers 2, 3. More layers with ribs 4 extending in yet other directions may be interposed. Subsequent layers 2 are offset or translated relative to one another in relation to an axial direction. The same holds for subsequent layers 3. This is illustrated by line 8 in FIG. 1, where ribs 4 in subsequent layers 2 have a width or thickness that is at least approximately equal to the distance between ribs 4 in layers 2, and of which a right side in one of the layers 2 and a left side in a subsequent one of the layers 2 is on line 8. The same holds for subsequent layers 3.

[0040] In this manner, a flow of fluid or gas to be filtered or mobile phase in chromatography applications is made to meander through the mesh, web or porous stationary phase comprising the layers 2, 3; there is no intended straight flow line for such fluid or gas to be filtered or mobile phase in chromatography applications to pass through the mesh, web or porous stationary phase comprising the layers 2, 3 of ribs 4.

[0041] It is noted here that the shown and described mesh, web or porous stationary phase comprising the layers 2, 3 of ribs 4 is merely exemplary, and that any of the structures known from the above acknowledged prior art could be used instead of the shown and described mesh, web or porous stationary phase comprising the layers 2, 3 of ribs 4. For example, a more closed or organic design could be realized with organic shapes of resulting channels for the fluid or gas to be filtered or mobile phase in chromatography applications to meander through, like the designs shown in FIG.’s 5, 9, 15 and 16 of the above acknowledged prior art, of which an example is included in FIG. 7. Precisely the freedom of design associated with 3D printing is one of the advantages over micromachining and the like for which the above acknowledged prior art and the present disclosure rely thereon, but with no limitation on the actual design of the mesh, web or porous stationary phase. Consequently, the disclosure of the above acknowledged prior art is herein incorporated in its entirety by reference thereto. Further, in the shown embodiment the filter 1 or chromatographic separator and mesh, web or porous stationary phase comprising the layers 2, 3 of ribs 4 have a rectangular cross sectional circumference, but any other circumferential shape may be applied. In summary: the stationary phase is column shaped having a cross section which is one or more than one of a group of shapes comprising: circular, ellipsoid, rectangular, square, and polygonal, but yet further shaped may be applied.

[0042] An envelope structure 5 is provided around the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4 therein. As shown in FIG.’s 4 and 5, envelope structure 5 may have different embodiments, but most if not all such embodiments will have an input 6 for supply of a mobile phase and an output 7 for discharge. Arrow A extending from the input 6 towards the output 7 is also shown in FIG.’s 4 and 5.

[0043] Layers 2, 3 of ribs 4 are, as noted above, additively manufactured or 3D printed. When ribs 4 of one of the layers 2, 3 are printed, preferably at the same time and preferably from the same material a sleeve 9 is printed to form a first embodiment of a reinforcement. A portion of length of sleeve 9 thus becomes an integral portion of subsequent layers 2, 3, adding to the interconnectivity thereof and reinforcing the resulting structure. Sleeve 9 may alternatively be manufactured separately and even from other material and be adhered, bonded, molten or otherwise mechanically connected to the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4 therein. Then, the sleeve 9 could be integrated into the envelope structure 5. However, when using a machine for additive manufacturing or 3D printer to manufacture the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4 therein, it is preferred to simultaneously print one of the layers 2, 3 and a connecting portion of surrounding sleeve 9.

[0044] Sleeve 9 is inserted into envelope 5 without play, to hold sleeve 9 still in place, even if fluid or gas to be filtered or mobile phase in chromatography applications is pressed through the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4. When pressures may reach a value in excess of 200 bar, it is beneficial if a clamp fit, interference fit or the like is applied, and most preferably a shrink fit or expansion fit is employed. An interference fit may be formed on the basis of friction between sleeve 9 and envelope 5, where sleeve 9 may be pressed with force into envelope 5 to be arrested in the interior thereof. A shrink fit or expansion fit may be formed by heating envelope 5 for expansion thereof, and / or cooling sleeve 9 with the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4 therein for shrinking it. Then sleeve 9 with the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4 is inserted into envelope 5 whereafter the envelope 5 will shrink or sleeve 9 will expand as one or both return to temperature equilibrium. Thus, there’s no free space between sleeve 9 and envelope 5 for the fluid or gas to be filtered or mobile phase in chromatography applications to pass along an outside of sleeve 9.

[0045] In an assembled state, a shoulder 10 may be defined by envelope 5 extending beyond sleeve 9 in axial direction (corresponding with arrow A), where a distributor element 11 may be pressed in shoulder 10 against the mesh, web or porous stationary phase to distribute fluid or gas to be filtered or mobile phase in chromatography applications over the input 6 side end surface of the mesh, web or porous stationary phase, in order to connect input 6 of the envelope 5 to the interior of sleeve 9. A similar distribution element 11 may be is arranged against the opposition output 7 side end of the mesh, web or porous stationary phase, to avoid any misconnection.

[0046] FIG. 2 and FIG. 3 schematically illustrate perspective views of a part of a filter or of a chromatographic separator in another possible embodiment of the present disclosure. The difference with the embodiment of figure 1 resides in the manner of forming a reinforcement. Not shown, but still present in the embodiment of FIG. 2 and FIG. 3 is envelope 5 and optionally also sleeve 9 (as an alternative reinforcement is implemented), but focus is here on the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4, where therein reinforcing beams 12 are printed into the structure of the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4 therein.

[0047] In the embodiment of FIG. 2, at least one (and maybe more than one) reinforcing beam 12 may be printed into the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4 for reinforcement beam 12 to extend axially, i.e. in the direction of arrow A. Reinforcing beams(s) 12 may extend beyond end surfaces of the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4 therein, to be engaged and arrested by connectors or fasteners (not shown) extending into envelope 5 both on the input 6 side and on the output 7 side, to properly engage and arrest the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4 therein, even when fluid, gas or mobile phase is pressed therethrough at pressures potentially in excess of 200 bar. In the embodiment of FIG. 3, at least one (and maybe more than one) reinforcing beam 12 may be printed into the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4 for reinforcement beam 12 to extend radially, i.e. perpendicular to the direction of arrow A. Reinforcing beams(s) 12 may extend radially outward to inner wall of sleeve 9 or inner wall of envelope 5, to be engaged and arrested by connectors or fasteners (not shown) at the interior walls of sleeve 9 or envelope 5, to properly engage and arrest the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4 therein, even when fluid, gas or mobile phase is pressed therethrough at pressures potentially in excess of 200 bar. Sleeve 9 may then be omitted, or beam(s) 12 may be printed to extend beyond the outer boundary of sleeve 9. On the other hand, with respect to prevention of a flow along the outside of the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4 therein, omitting sleeve 9 could result in effectively bypassing the intention of the filter or of a chromatographic separator, especially under excessive pressures, and therefore sleeve 9 is preferably provided for the purpose of flow restriction, even if beam(s) 12 is (are) are provided to embody a strengthening or reinforcing measure and prevent collapse of the structure of the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4 therein.

[0048] It is noted here that FIG. 2 and FIG. 3 show 3D representations of a very small section of a completed structure. At the scale of ribs 4 having a width of for example 50pm, these figures represent each less than a millimetre sized cube in a filter or chromatographic separator that is several centimetres in diameter and even longer in the axial direction of arrow A.

[0049] FIG. 4 schematically illustrates an assembled filter or chromatographic separator and FIG. 5 illustrates another embodiment than FIG. 4. In the embodiment of FIG. 4, envelope 5 comprises a tube 13 with screw thread at the input 6 side and output 7 side and screw caps 14, screwed onto the screw threads at the ends of tube 13. As noted above, the tube be have one of several inner cross sectional shapes, such circular, ellipsoid, rectangular, square, polygonal, and the like. The same is true for the one piece closed tube 15 of FIG. 5, which may be welded shut with end plates to enclose the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4. The reinforcements are then still necessary, in both embodiments of FIG. 4 and FIG. 5, to avoid collapse of the structure of the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4 inside the envelope, regardless of whether thereto one or more beam 12 or sleeve 9 is deployed.

[0050] FIG. 6 illustrates steps of a method according to another aspect of the present disclosure. In a method of producing a fdter or chromatographic separator having a column shape according to the present disclosure, several steps are performed, but not necessarily sequentially. In step 601, subsequently a plurality of filter layers 2, 3 are printed to define a porous stationary phase. Preferably at the same time as printing each of the layers 2, 3, in step 602, a reinforcement 9, 12 is printed in or through at least some of the layers, where this reinforcement 9, 12 is configured to maintain the shape and size of the column (and more in particular of the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4) when pressurized. Then, in step 603, the stationary phase in optionally the form of the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4 is arranged with the reinforcement therein or thereon in envelope structure 5 having an input 6 for supply to the stationary phase of a mobile phase and an output 7 for discharge. This latter step may include step 604 of shrink-fitting the mesh, web or porous stationary phase with the layers 2, 3 of ribs 4 in the envelope 5.

[0051] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0052] The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of embodiments of the present invention has been presented for purposes of illustration, but is not intended to be exhaustive or limited to the implementations in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the present invention. The embodiments were chosen and described in order to best explain the principles and some practical applications of the present invention, and to enable others of ordinary skill in the art to understand the present invention for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

CLAIMS1. A device from a group comprising at least a filter and a chromatographic separator, having a column shape, comprising:- a plurality of subsequently printed filter layers defining a porous stationary phase;- a reinforcement configured to maintain the shape and size of the column when pressurized; and- an envelope structure with an input for supply to the stationary phase of a mobile phase and an output for discharge.

2. The device according to claim 1, wherein the reinforcement is printed together with the stationary phase.

3. The device according to claim 1 or 2, wherein the reinforcement is printed from the same material as the stationary phase.

4. The device according to any of the preceding claims, wherein the reinforcement defines a sleeve around the stationary phase.

5. The device according to claim 4, wherein the input of the envelope is connected to the interior of the sleeve.

6. The device according to any of the preceding claims, wherein the reinforcement defines at least one beam extending through the stationary phase.

7. The device according to claim 6, wherein the at least one beam extends at least one of axially and radially through the stationary phase.

8. The device according to any of the preceding claims, wherein the stationary phase is column shaped having a cross section which is one or more than one of a group of shapes comprising: circular, ellipsoid, rectangular, square, polygonal, and the like.

9. The device according to any of the preceding claims, wherein the stationary phase with the reinforcement is arrested within the envelope.

10. The device according to claim 9, wherein the stationary phase is arranged within the envelope through an interference fit.

11. The device according to claim 10, wherein the stationary phase is arranged within the envelope through a shrink-fit or an expansion fit.

12. The device according to any of the preceding claims, wherein the filter defines a three dimensional liquid chromatography filter, more in particular a high performance or high pressure liquid chromatography filter.

13. A method of producing a device according to any one of the preceding claims, having a column shape, comprising: - subsequently printing a plurality of filter layers to define a porous stationary phase;- printing in or through at least some of the layers at least one reinforcement configured to maintain the shape and size of the column when pressurized; and- arranging the stationary phase with the reinforcement therein or thereon in an envelope structure having an input for supply to the stationary phase of a mobile phase and an output for discharge.

14. The method according to claim 13, further comprising shrink-fitting or expansion fitting the stationary phase with the reinforcement in the envelope structure.

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