Patent Application
20160200038
The field of the invention generally relates to fluid management devices and, in particular, connectors or interfaces used therein. More specifically, the invention pertains to connectors or interfaces used by pharmaceutical and biological applications or other hygienic process industries involving silicone tubing or other conduits.
Many commercial products are produced using chemical as well as biological processes. Pharmaceuticals, for example, are produced in commercial quantities using scaled-up reactors and other equipment. So-called biologics are drugs or other compounds that are produced or isolated from living entities such as cells or tissue. Biologics can be composed of proteins, nucleic acids, or complex combinations of these substances. They may even include living entities such as cells. In order to produce biologics on a commercial scale, sophisticated and expensive equipment is needed. In both pharmaceutical and biologics, for example, various processes need to occur before the final product is obtained. For example, in the case of biologics, cells may be grown in a growth chamber or the like and nutrients may need to be carefully modulated into the growth chamber. Waste products produced by cells may also have to be removed on a controlled basis from the fermentation chamber. As another example, biologic products produced by living cells or other organisms may need to be extracted and concentrated. This process may involve a variety of filtration and separation techniques.
Because there are a number of individual processes required to be produce the final product, various reactants, solutions, and washes are often pumped or otherwise transported to various subsystems using conduits and associated valves. These systems may be quite cumbersome and organizationally complex due to the large numbers of conduits, valves, sensors, and the like that may be needed in such systems. Not only are these systems visually complex (e.g., resembling spaghetti) they also include many components that are required to sterilized between uses to avoid cross-contamination issues. Indeed, the case of drug and biologic preparation, the Federal Food and Drug Administration (FDA) is becoming increasingly strict on cleaning, sterilization or bio-burden reduction procedures that are required for drug and pharmaceutical preparations. This is particularly of a concern because many of these products are produced in batches which would require repeated cleaning, sterilization or bio-burden reduction activities on a variety of components.
Some attempts have been made at incorporating various disposable elements into the system. For example, conduits or lines connecting various systems or elements have been made of silicone. Unfortunately, silicone tubing or conduits often have to be reinforced along their periphery to avoid the possibility of leakage through an aneurysm or the like that develops at the wall of the tubing. Reinforced silicone tubing is, however, rather expensive and is not as flexible as un-reinforced silicone.
In addition, silicone tubing often connects to other connectors or junctions (e.g., Tees, Wyes, unions, elbows) as part of the overall system. Current interfaces between silicone tubing and various connectors are deficient in a number of respects. First, current interfaces are limited in the pressure that they can handle. For example, existing connections between silicone tubing and connectors can operate at pressures at or below about 30 psi. There is a growing need to utilize higher pressures within systems because higher pressures (as well as larger tubing diameters) enables higher throughput. In addition, the interface between the silicone tubing and the connector often requires an external clamping member such as a zip tie which surrounds the junction between the silicone tubing and the inner connector. Unfortunately, the presence of these zip ties or other clamping members on the exterior tubing can lead to tears or breakages in the disposable gloves used by workers which jeopardizes the sterile environment in which these systems are typically used.
Another disadvantage of current junctions and interfaces between silicone tubing and various devices is the fact that they introduce another material that contacts the pharmaceutical or biological component that is carried through the system. While plastics and silicone have known interactions with pharmaceutical and biological components, other materials have unknown or deleterious effects on the final product. This tertiary contact with the product may jeopardize the purity and sterility of the ultimate product. For example, connectors and junctions are sometimes created using an internal mandrel. During the manufacturing process, the use of the mandrel produces flash which may have to be manually removed prior to final assembly and use. Inevitably, however, some flash may remain which can clog or otherwise disrupt the process. It also introduces a variable in the form of the overmolding or joining silicone that is now a product contact material that needs to be monitored and qualified for the manufacturer's validation documentation.
U.S. Pat. No. 5,447,341 illustrates a molded hose branch of rubber that is formed by slipping completely vulcanized rubber hose lengths with ends onto the free ends of a plastic tubing branching piece. The assembly is placed into a mold and a thermoplastic material such as a blended mixture of polyproplylene and EPDM is injected molded around the assembly so as to join the thermoplastic material to the rubber hose lengths. The problem with such a construction in connection with systems that rely on silicone, in conventional silicone molding processes, the temperature at which silicone cures would cause the inner plastic branching piece to melt. Standard platinum cured silicone may require extended temperature of around 180° C. to cross-link silicone. These high temperatures would melt or otherwise destroy the underlying plastic branching piece.
U.S. Pat. No. 6,290,265 discloses a tubing and connector assembly that includes a multi-lumen connector having at least three flexible tubes molded onto the connector. The process of making the connector and tubing assembly includes forming a first part of the connector with two tubes molded therein and then removing an internal mold member prior to molding the final connector portion and third tube in place. As noted above, in this method, an internal mandrel-type structure is used as the method uses an inner mold member and mold insert.
U.S. Pat. No. 6,432,345 illustrates a single-step method of manufacturing a silicone tube manifold. The method forms, in a single step, a silicone manifold interconnecting a plurality of silicone tubes. The method is performed by providing a silicone insert piece having a network of interior channels dimensioned the same as the silicone tube interiors. Solid non-silicone plugs are inserted into the insert piece and the ends of the silicone tubes and the resulting assembly is placed in a mold cavity. Liquid silicone is added to the mold cavity and is then heated and cured to form the desired manifold interconnecting the tubes. The manifold is then removed from the mold and a source of pressurized air is used to blow out the plugs.
U.S. Pat. No. 8,424,923 illustrates a fluid transfer assembly for transporting medicinal substances. The fluid transfer assembly includes flexible tubes and a manifold each comprising silicone. The manifold has an inner protrusion and connector portions having inner walls. Free ends of the tubes are inserted into complementary configured inner walls of the connector portions until each of the free ends abut the inner protrusion, which creates a continuous uninterrupted passageway between the inner bores of the tubes through the manifold. This patent discloses the formation of an outer capsule by using silicone rubber that is introduced into a molding assembly.
According to one aspect of the invention, a fluid management assembly includes a connector having at least one inlet and at least one outlet and a lumen extending there between, wherein the connector comprises a plastic material. The assembly includes a first silicone tubing connected to the at least one inlet at a first interface and a second silicone tubing connected to the at least one outlet at a second interface. A silicone overmolding surrounds the connector, the first interface, and the second interface, wherein the silicone overmolding comprises a UV-curable silicone.
According to another embodiment, a method of forming a fluid management assembly includes a coupling first and second silicone tubing portions to a plastic material connector having at least one inlet and at least one outlet and a lumen extending there between, wherein the at least one inlet is coupled to the first silicone tubing portion at a first interface and wherein the at least one outlet is coupled to the second silicone tubing portion at a second interface; inserting the connector into a cavity of a mold; injecting a liquid silicone rubber into the mold cavity; and applying UV radiation to the liquid silicone rubber to cure the silicone.
In another embodiment, a fluid management assembly includes a connector having at least one inlet and at least one outlet and a lumen extending there between, wherein the connector comprises a plastic material. A first tubing is portion connected to the at least one inlet at a first interface. A second tubing portion connected to the at least one outlet at a second interface. The assembly includes a polymer-based overmolding surrounding the connector, the first interface, and the second interface, wherein the polymer-based overmolding comprises a UV-curable material.
In another embodiment, a method of forming the fluid management assembly discussed above includes coupling first and second tubing portions to the connector, wherein the at least one inlet is coupled to the first tubing portion at a first interface and wherein the at least one outlet is coupled to the second tubing portion at a second interface. The connector is inserted into a cavity of a mold and an un-cured liquid polymer is injected into the mold cavity. UV radiation is applied to the un-cured liquid polymer to cure the polymer into a solid material.
In the embodiment of
The connector 20 may be made from a number of polymer materials. For example, the connector 20 may be made from a plastic material. Plastic materials include standard thermoplastics and polyolefins such as polyethylene (PE) and polypropylene (PP). The connector 20 may also be formed from fluoropolymers such as polyvinylidene fluoride (PVDF) or Perfluoroalkoxy (PFA), Polytetrafluoroethylene (PTFE), Polycarbonate (which may be more thermally resistant) and the like. Typically, the connector 20 is made from a polymer material that would be compromised upon exposure to high thermal temperatures like those experienced in conventional thermal curing processes.
Still referring to
In one aspect of the invention, the polymer-based overmolding 30 is silicone based. For example, SILOPREN available from Momentive Performance Materials Inc. (Albany, N.Y.) is a UV cured Liquid Silicone Rubber (LSR) that may be used as the overmolding 30. SILOPREN is a two-component LSR what uses a mixing ratio of 100:2. Another example of a UV cured silicone is ADDISIL available from Momentive Performance Materials Inc. (Albany, N.Y.) which offers high cure speed at room temperatures. ADDISIL silicone rubber is a two component solution that uses a mixing ratio of 100:0.5 (Rubber Base:Catalyst). The benefits of using a UV curable overmolding 30 are numerous. First, there is no heating of the materials as is required in conventional silicone curing techniques. Thus, the overmolding 30 may be formed at substantially room temperatures. If the polymer based connector 20 described herein were to be overmolded with conventional thermally-cured silicone, the connector 20 itself would melt, deform, or otherwise fail during the curing process. Here, using the UV curing process, the connector 20 remains unaffected by the curing process. Because no heating is required, the process also has low energy consumption. Further, the UV curing process uses less equipment and can increase throughput as heating up and cool-down tend to consume a considerable amount of time. Another example of a UV curable silicone is the SEMICOSIL UV product made by Wacker Chemie AG (Munich, Germany).
Standard liquid silicone rubbers are processed in molds generally at temperatures between 180 and 200° C. UV-cured LSR parts can be made with transparent molds cured by UV light as explained herein. UV curing typically occurs at ambient or slightly above ambient temperatures (e.g., 25-40° C.). For thick parts, UV curing is advantageous because the product may cross-link much more quickly than with thermal curing because the low thermal conductivity of the silicone rubber is not a factor. Another advantage of UV curing is that the curing is initiated when the light is first turned on rather than on first contact with the heated mold. This difference eliminates the problem of silicone rubber scorching. Related to this, the liquid silicone (or other polymer) can be pumped into the mold relatively slowly and at low pressures.
In one aspect of the invention, a method of forming a fluid management assembly 10 includes coupling first and second silicone tubing portions (e.g., 12, 14, 16) to a connector 20 having at least one inlet and at least one outlet and a lumen extending there between, wherein the at least one inlet is coupled to the first silicone tubing portion at a first interface and wherein the at least one outlet is coupled to the second silicone tubing portion at a second interface. The connector 20 is inserted into a cavity of a mold 40. Alternatively, the silicone tubing portions 12, 14, 16 may be connected to the connecter 20 after it has been inserted into the mold 40. A liquid silicone rubber is injected into the mold cavity 46 and surrounds the connector 20 and connected tubing portions 12, 14, 16. UV radiation from the UV light source 48 is applied to the liquid silicone rubber to cure the silicone. While this embodiment is described in the context of a UV-curable silicone, it should be understood that other UV-curable polymers are also contemplated.
It should be understood that the fluid management assembly 10 is designed to be disposable. Systems that are disposable or incorporate disposable elements are advantageous because they avoid the need for cleaning-in-place (CIP) cleaning, sanitization, or re-sterilization. A major advantage of the embodiments described herein is that the product contained within the system only contacts two components—the interior surface of the tubing 12, 14, 16 as well as the interior surface of the connector 20. The product does not contact any third substance such as a mandrel or flashing material left from some other component used during the manufacturing process. The fluid management assembly 10 is also scalable meaning that large diameter tubes can be used. Further, the fluid management assembly 10 is very robust and able to handle large pressures.
In another alternative embodiment of the invention, a fluid management assembly may be made using a mandrel using one or more techniques described above, for example, as noted in U.S. Pat. No. 6,290,265, however the mandrel is used in conjunction with a UV-curable overmolding as described herein. In such an alternative embodiment, there is no need for a separate connector.
While embodiments of the present invention have been shown and described, various modifications may be made without departing from the scope of the present invention. The invention, therefore, should not be limited, except to the following claims, and their equivalents.
This Application claims priority to U.S. Provisional Patent Application No. 61/871,752 filed on Aug. 29, 2013, which is hereby incorporated by reference in its entirety. Priority is claimed pursuant to 35 U.S.C. §119 and any other applicable statute(s).
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US14/52383 | 8/22/2014 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 61871752 | Aug 2013 | US |
