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EP-4739369-A1 - INFUSION ASSEMBLY

EP4739369A1EP 4739369 A1EP4739369 A1EP 4739369A1EP-4739369-A1

Abstract

An Infusion assembly comprises a tube (1), a connector (20a, 20b) comprising a connection portion (200a, 200b) configured to be engageable with the tube (1), and a joining agent (30) adapted for solvent bonding the connection portion (200a, 200b) with the tube (1), wherein the connection portion (200a, 200b) comprises a receiving surface (202a, 202b) for receiving the joining agent (30). The joining agent (30) comprises a polar solvent and a styrene block copolymer.

Inventors

  • BAUMGART, Steffen

Assignees

  • Fresenius Kabi Deutschland GmbH

Dates

Publication Date
20260513
Application Date
20240703

Claims (15)

  1. 1. Infusion assembly, comprising: a tube (1), a connector (20a, 20b) comprising a connection portion (200a, 200b) configured to be engageable with the tube (1), and a joining agent (30) adapted for solvent bonding the connection portion (200a, 200b) with the tube (1), wherein the connection portion (200a, 200b) comprises a receiving surface (202a, 202b) for receiving the joining agent (30), characterized in that the joining agent (30) comprises a polar solvent and a styrene block copolymer.
  2. 2. Infusion assembly according to claim 1 , characterized in that the joining agent (30) comprises at most 30%, preferably 15-20%, of the styrene block copolymer.
  3. 3. Infusion assembly according to claim 1 or 2, characterized in that the polar solvent comprises tetrahydrofurane, dichloromethane, methylethylketone, or acetone, or a combination of at least two thereof.
  4. 4. Infusion assembly according to one of the preceding claims, characterized in that the connection portion (200a, 200b) comprises a taper section (210a, 210b, 210b’, 210b”), in particular a chamfer, configured to control the amount of joining agent (30) to be distributed at the connection portion (200a, 200b) when the tube (1) is engaged with the connector (20a, 20b).
  5. 5. Infusion assembly according to claim 4, characterized in that the taper section (210a, 210b, 210b’, 210b”) is adapted to reduce a diameter (d1 , d2, d1’, d2’) of the connection portion (200a, 200b).
  6. 6. Infusion assembly according to claims 4 or 5, characterized in that the taper section (210b’, 210b”) comprises one or more recesses (211) and/or protrusions (212).
  7. 7. Infusion assembly according to claim 6, characterized in that the recesses (211) and/or protrusions (212) extend in the direction of the longitudinal extension of the connector (20a, 20b).
  8. 8. Infusion assembly according to one of claims 4 to 7, characterized in that the taper section (210a, 210b, 210b’, 210b”) is formed at an angle of 3 to 180°, preferably at an angle of 30 to 60°.
  9. 9. Infusion assembly according to one of the preceding claims, characterized in that the connection portion (200a, 200b) comprises a bushing for receiving an end section (10) of the tube (1) within an inner perimeter (201b) of the bushing, or a plug adapted to be inserted with an outer perimeter (201 b) at least in part into the end section (10) of the tube (1).
  10. 10. Infusion assembly according to claim 9, characterized in that the receiving surface (202a, 202b) extends at least in part along the inner perimeter (201b) of the bushing, or along the outer perimeter (201a) of the plug.
  11. 11 . Infusion assembly according to one of the preceding claims, characterized in that the connector (20a, 20b) comprises at least one out of acrylonitrile butadiene styrene, methyl methacrylate acrylonitrile butadiene styrene, poly(methyl methacrylate), polycarbonate, styrene-ethylene-butadiene-styrene, styrene-butadiene-styrene, polystyrene, styrene acetonitrile and thermoplastic polyester and/or a combination of at least two thereof.
  12. 12. Infusion assembly according to one of the preceding claims, characterized in that the tube (1) comprises a thermoplastic elastomer.
  13. 13. Method for joining a tube (1) to a connector (20a, 20b) comprising the steps (S1-S4) of: providing a tube (1), providing a connector (20a, 20b) comprising a connection portion (200a, 200b) configured to be engageable with the tube (1), applying a joining agent (30) adapted for solvent bonding the connector (20a, 20b) and the tube (1) and comprising a polar solvent and a styrene block copolymer to a receiving surface (202a, 202b) of the connection portion (200a, 200b) and/or at an inner surface (100b) and/or an outer surface (100a) of the tube (1), engaging the tube (1) and the connector (20a, 20b) with one another such that the tube (1) and the connector (20a, 20b) are in fluid connection with each other.
  14. 14. Method according to claim 13, characterized by controlling the amount of joining agent (30) distributed between the tube (1) and the connector (20a, 20b) when the tube (1) is engaged with the connector (20a, 20b), by stripping off excess joining agent (30) at a taper section (210a, 210b, 210b’, 210b”) of the connection portion (20a, 20b).
  15. 15. Method according to claim 14, characterized in that the taper section (210b’, 210b”), in particular the chamfer, comprises recesses (211) and/or protrusions (212) for receiving and/or displacing the joining agent (30) during engagement of the tube (1) and the connector (20a, 20b).

Description

Infusion Assembly Description The invention relates to an infusion assembly, comprising a tube, a connector and a joining agent. The invention also relates to a method for joining a tube to a connector. Infusion sets are often utilized in the medical field for administering fluids or liquids, e.g. liquid drugs, to a patient. Such infusion sets usually comprise one or more tubes for conveying the fluid to and from the patient, and one or more infusion components, such as for example a drip chamber, a pump section, filters, or adapters, each containing at least one connector to be engaged with the tube(s). Typically, such tubes are made from thermoplastic elastomer, especially polyvinylchlorides or polyurethanes, and the respective connectors are made of or comprise a thermoplastic polymer. For the connection of the tube(s) to the connector(s), solvent bonding by means of joining agents is often used in the prior art among other technologies like for example gluing by means of cyanoacrylates since it allows to create bonds with great strength, and durability of the bond(s). Moreover, it turned out to be a relatively economic process in terms of speed and material costs. Typically, joining agents used for solvent bonding comprise solvents such as cyclohexane, cyclohexanone, methylethylketone, or mixtures out of them. US 10,238,854 B2 relates to a method for joining a tube to a connector with a joining agent composition including a liquid hydrocarbon. However, there exists an ongoing demand for improving the retention force between tubing and connector to ensure a secure connection between these components for making the connection particularly durable for medical tube set assemblies. It is an object of the instant invention to provide a reliable and durable connection between a tube and a connector in a simple manner. This object is achieved by an infusion assembly comprising the features of claim 1 . Accordingly, an infusion assembly comprises a tube, a connector comprising a connection portion configured to be engageable with the tube, and a joining agent adapted for solvent bonding the connection portion with the tube. Herein, the connection portion comprises a receiving surface for receiving the joining agent. According to the invention, the joining agent comprises a polar solvent and a styrene block copolymer, in particular a styrene block copolymer based thermoplastic elastomer. Utilizing a polar solvent allows for superficially dissolving, especially for a superficial softening, of the receiving surface of the connection portion. This superficial dissolving of the receiving surface can give the receiving surface itself adhesive properties and, thus, can enable particularly good adhesion properties between tube and connector. The connection portion can be configured as a pocket or fitting. Hence, the receiving surface can be the inner surface of the pocket or the outer surface of the fitting. The joining agent may be applied to an inner diameter or to an outer diameter of the connection portion of the connector or the tube or a combination thereof. As such, by assembling the tube into the pocket or onto the fitting of the connector, the joining agent is distributed, especially spread or smeared, over the receiving surface of the connector and the corresponding surface portion of the tube and solvent bonded by means of the joining agent. The receiving surface can be understood as the surface of the connection portion on which the joining agent is applied and/or distributed. In an example, the joining agent comprises at most 30%, preferably 15-20%, of the styrene block copolymer. These styrene contents turned out to provide particularly strong binding forces of the joining agent. The polar solvent may comprise tetrahydrofurane. The polar solvent optionally comprises dichloromethane, methylethyl ketone and/or acetone. In an example, the connection portion comprises a taper section, in particular a chamfer, which is configured to control the amount of joining agent to be distributed at the connection portion when the tube is engaged with the connector. Due to the taper section, excess joining agent can be wiped off and/or distributed during engaging the tube and the connector with one another. This provides for a defined and evenly distributed layer of joining agent between the receiving surface of the connection portion and the corresponding surface of the tube. As such, a particularly uniform and reliable contact and adhesion between tube and connection portion is achieved. In addition, the taper section may facilitate easy assembly of the tube and the connector. The taper section may be adapted to reduce a diameter of the connection portion. In an example, the diameter at the site of the connection portion, which gets, during assembly, in contact first with the tube, is larger than the inner diameter of the connection portion. As such, the taper section allows for striping off excess joining agent and