1. Field of the Invention
The invention relates to a filter module with a housing formed from a first plastic and with a filter which is arranged in the housing and is made from a second plastic, wherein the housing is adhesively bonded to the filter by means of an adhesive via a first bonding surface of the housing made from the first plastic and via a second bonding surface of the filter made from the second plastic.
The invention further relates to a method for using a filter module and to a method for producing a filter module.
2. Description of the Related Art
DE 10 2007 052 088 A1 discloses a filter module with a tubular housing made of a plastic within which a filter made of a ring-shaped bundle of hollow fiber membranes is arranged. The housing made of a plastic has a first bonding surface at its respective ends that is adhesively bonded using adhesive to a second bonding surface formed by the ends of the membrane filter. The hollow fiber membranes are sealed with a potting resin at their end adjacent to an inlet and are open at their other end facing an outlet.
The adhesive bonds must withstand not only the filtration pressure but also the test pressures required in biotechnology.
In the case of the known filter module it is disadvantageous that tube sleeves overlapping the housing tube ends are arranged at the ends and these are relatively laborious to install. Nevertheless, there is a risk that the adhesive bonding between the bonding surfaces will not withstand the high test pressures required in biotechnology.
The problem that the present invention seeks to solve is to improve the known filter modules and the methods for their manufacture so that they have, on the one hand, a cost-effective design and, on the other, can withstand a test pressure up to 5 bar.
The invention relates to a filter module with a housing formed from a first plastic. A filter is arranged in the housing and is formed from a second plastic the housing is bonded adhesively to the filter by an adhesive via a first bonding surface of the housing made from the first plastic and via a second bonding surface made from the second plastic. Adhesive bonding of the first bonding surface of the housing and of the second bonding surface of the filter is accomplished via an intermediate piece with bonding surfaces made from a plastic that is identical to or different from the first plastic, and at least one of the bonding surfaces is activated by plasma or corona pre-treatment prior to the adhesive bonding.
Plasma or corona pre-treatment uses electrical discharge to change the surface of polymers. This results in the formation of functional groups on the surface of the substrate that enable improved adhesion and wettability. Pre-treatment with atmospheric plasma is especially cost-efficient. Surface treatment using plasma activation enables adhesive bonding of sufficient strength and also sufficient long-term durability. In particular, it also makes it possible to adhesively bond different plastics to one another.
The housing may be designed as a flexible tube and the filter may be a hollow fiber element having a plurality of hollow fiber membranes. The entire filter module thus has a certain flexibility to simplify connection of the filter module. The filter module therefore serves not only for filtration of media passed through it but also as a flexible connection.
The hollow fiber element may be sealed at least to a first end in a radial direction with respect to the adjacent tube end and the first end of the hollow fiber element may be bonded adhesively directly to the tube or to the intermediate piece that is connected firmly to the tube. In particular, the hollow fiber membranes of the hollow fiber element are open at the first end. The hollow fiber membranes can be either open or sealed at the second end of the hollow fiber element facing away from the first end. A ring-shaped channel is arranged between the tube and the hollow fiber element, and is connected to at least one connection. Depending on the configuration, the subject of the application can therefore be operated in “dead-end” as well as “cross-flow” mode.
The tube may be made of a silicone or polypropylene while the hollow fiber membranes are made of a polyethersulfone. In particular, the first end of the hollow fiber element, with its hollow fiber membranes, may be bonded adhesively to or potted with the tube or the intermediate piece using a polyurethane as an adhesive. The intermediate piece can be made of a thermoplastic, preferably polypropylene.
The plasma or corona pre-treatment of the bonding surfaces described above makes it possible to adhesively bond or pot the same or different plastics with the necessary strength.
In another embodiment of the invention, the hollow fiber element is sealed at its second end facing away from the first end in a radial direction vis-à-vis the adjacent tube end, with its hollow fibers being open at the second end. The second end of the hollow fiber element is bonded adhesively directly to the tube or to a second intermediate piece firmly attached to the tube. The one or more intermediate pieces can be designed as a T-shaped connector with a connection to the ring-shaped channel. In this case, both dead-end and cross-flow operation is possible.
The one or more intermediate pieces can however also be designed as a sleeve surrounding the end of the hollow fiber element.
The invention also relates to a method for using a filter module, such as the above-described filter module. The method includes attaching the filter module to a flexible container and together they form a connection-ready unit that can be pre-sterilized. In particular, the flexible container (bag) can be designed as a single-use bioreactor.
In each case, the hollow fiber membranes on the inlet side of the filter module are firmly and tightly attached to the tube or the connector piece, and the individual hollow fibers are open so that internal through-flow is possible. While the hollow fibers are exposed to a relatively high test pressure during performance of a filter integrity test, the ring-shaped channel surrounding the hollow fiber element, and therefore also the housing designed as a tube, are exposed to a significantly lower pressure. This ensures that the permissible working pressure of the tube, for example of the silicone tube, is significantly below the test pressure of the hollow fiber element and that the silicone tube is not exposed to undesirable loads during the test.
The invention further relates to a method for producing a filter module by performing the following steps:
Activation of the bonding surfaces by plasma or corona pre-treatment prior to adhesive bonding results in an adhesive bond which has higher strength, e.g. during performance of a pressure test. In particular, it is possible to adhesively bond silicone or polypropylene to polyethersulfone and to use polyurethane as an adhesive.
According to another preferred embodiment of the invention, the adhesive in Step (b) is mixed from two components in a pre-specified ratio before it is applied or used for potting. It has proved favorable to cure the adhesive in Step (c) in a temperature-controlled centrifuge.
Further features and advantages of the invention may be derived from the following specific description and from the drawings.
A filter module 1 essentially comprises a housing 2 and a filter 3.
In the exemplary embodiments in
According to the exemplary embodiments in
According to the exemplary embodiments from
Between the tube 2 and the hollow fiber element 8 there is arranged a ring-shaped channel 24 that is connected to at least one connector 25.
In the exemplary embodiment from
The inner surface of the second end 17 of the intermediate piece 10 forms a first bonding surface 18 with respect to the first end 16 of the hollow fiber element 8 while the circumference of the first end 16 forms a second bonding surface 19, which can be adhesively bonded to the first bonding surface 18 using the adhesive 15. In this case also, the first bonding surface 18 of the intermediate piece 10 can be activated by plasma pre-treatment to enhance the strength of the adhesive bond.
According to the exemplary embodiment in
According to the exemplary embodiments in
While in the exemplary embodiment in
According to the exemplary embodiment in
To produce the filter module, the following steps are performed, for example:
Of course, the embodiments discussed in the specific description and shown in the figures are merely illustrative exemplary embodiments of the present invention. In light of this disclosure, a person skilled in the art is given a wide range of possible variations.
Number | Date | Country | Kind |
---|---|---|---|
10 2013 112 863 | Nov 2013 | DE | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/EP2014/075077 | 11/20/2014 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2015/075099 | 5/28/2015 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
4283284 | Schnell | Aug 1981 | A |
20030029785 | Dannenmaier | Feb 2003 | A1 |
20030102264 | Pope et al. | Jun 2003 | A1 |
20040195165 | Bernard et al. | Oct 2004 | A1 |
20080237127 | Okafuji | Oct 2008 | A1 |
20100072124 | Morikawa | Mar 2010 | A1 |
20130061748 | Sims et al. | Mar 2013 | A1 |
Number | Date | Country |
---|---|---|
10 2007 052 088 | May 2009 | DE |
0 315 252 | May 1989 | EP |
9845028 | Oct 1998 | WO |
0160502 | Aug 2001 | WO |
0177284 | Oct 2001 | WO |
Entry |
---|
English language machine translation of WO 0177284, 13 pages, No Date. |
English Translation of International Preliminary Report on Patentability dated May 24, 2016. |
International Search Report. |
Number | Date | Country | |
---|---|---|---|
20160296890 A1 | Oct 2016 | US |