Joining technologies The end of the weld?

TROY OSTRENG, SENIOR PRODUCT MANAGER FOR CPC’S BIOPHARMACEUTICAL BUSINESS, ASSESSES THE ADVANTAGES OF ASEPTIC CONNECTORS COMPARED WITH TUBE WELDING IN SMALL VOLUME BIOPHARMA PROCESSING.

Historically, tube welding has been the only option for biopharma system designers and processors to make closed sterile connections in small volumes using small-bore tubing. As the industry continues to evolve, we are seeing unprecedented demand for new therapies, effi ciencies, and improved speedto-market.

The drive to process optimization has led manufacturers to evaluate all steps in their workfl ows to determine whether they can make improvements. One such area is the use of aseptic connections to create closed sterile systems. Today, manufacturers can move away from the cumbersome tube welding process towards singleuse connectors which are quick and easy-to-use, require almost no space in a cleanroom and provide effi cient, seamless, and sterile fl uid transfer.

SPACE AND TIME Cleanroom space is extremely valuable; the ability to remove welding equipment in favor of single-use connectors is, therefore, attractive to those looking to optimize the space they have when compared with the expensive and time-consuming process of validating new space. Single-use connectors are ready to use and have been validated for material biocompatibility, extractables, sterility, and leakage (Figure 1). From a practical perspective, once validated, welders also need to be moved into position and the correct size tubing holder must be obtained and inserted. They must then be initialized, the tubing loaded, welded, and then cured — a process that can take an average of 4–7 minutes in total; multiply the setup time by hundreds of welds each week, operator time stacks up considerably. One hundred welds, for example, would require 6.67 hours of welding time at the lower end of the timescale at four minutes, whereas aseptic

The end of the weld?

connectors are presterilized and ready to go in a tubing/bag assembly and require mere seconds to connect and actuate.

LENGTH AND MATERIAL Aseptic connectors can also be applied to any tubing length with no minimum requirement, and to any type of tubing, including silicone (Figure 2). Diff erent types can also be connected; for example, silicone to C-Flex, and diff erent hose barb sizes can be used at opposite sides of the connector. Genderless options eliminate the need to carry male/female components, and connectors of the same family can be interconnected. For welding, minimum tubing lengths are often required to fi t into the welder, and only the same kinds of tubing materials can be fused together. In addition, welding cannot be used on silicone as the material burns during the process. Welders must also be set up for a specifi c tubing size and material, adding a further stage to the process.

RISK OF CONTAMINATION Using aseptic connectors also reduces the risk of contamination as the margin for error is far narrower. For example, not following manufacturers’ recommendations in tube welding can lead to placing tubing with the incorrect diameter in the tube holder. This can cause small pinholes in the weld, due to pinching or squeezing the tubing out of the holder during the weld process. Welding diff erent tubing types together — whether knowingly or unknowingly — can also lead to weld failure. With aseptic connectors there is little to no contamination risk because validated aseptic connectors maintain a sterile boundary between two adjoining single-use systems.

COST Finally, there is the question of cost. There is a common misconception that tube welding is more aff ordable than single-use aseptic connectors, but when the cost of the welder and its upkeep, blade costs and operator hours are taken into consideration, aseptic connectors are clearly an economical alternative. In tube welding, capital equipment and ancillary equipment costs range from a few thousand dollars to tens of thousands per welder in each cleanroom. Aseptic connectors eliminate capital expenditures associated with primary and backup welding equipment as well as maintenance costs.

CONCLUSION When properly applied, both sterile tube welders and single-use aseptic connectors can create reliable connections. Factors such as ease of use, downtime potential, operator error risk, cost, and supply management, however, are important factors for system designers and processors. Aseptic connectors — particularly genderless models — deliver the fl exibility, ease of use, reliability and cost effi ciencies that are highly sought after in state-of-the-art biopharma manufacturing. They also address the challenges to design and operate processes that are robust, reliable, and repeatable. In this respect, the ‘end of the weld’ may be here, and the benefi ts are clear to see.

As easy as 1-2-3

Single-use connectors are ready to use and have been validated for material biocompatibility, extractables, sterility, and leakage

Image below: Figure 1: Single-use connectors are ready to use and have been validated for material biocompatibility, extractables, sterility, and leakage.

Image top right: Figure 2: Aseptic connectors can be applied to any tubing length with no minimum requirement, and to any type of tubing, including silicone. Testing indicates that making a sterile connection with a MicroCNX connector is up to four times faster than an operator using a tube welder: in the time required to create one weld, up to four MicroCNX connections could be completed. Multiply those numbers over the course of a year, and the operational e ciencies are clear.

The easy, three-step process for using aseptic connectors requires minimal training. Users simply “Pinch-Click-Pull”: 1) pinch to remove the protective cover; 2) click together the connector halves; and 3) pull out the protective membranes so fl ow can start. In comparison, tube welding involves a dozen or more steps, with challenges including maneuvering the tube welder into position, dealing with equipment maintenance, and requiring precise technique to create a successful weld. With aseptic connectors there is no risk of faulty welds, welder breakdowns, or production delays due to weld equipment downtime.