The reliability of a drug delivery system is non-negotiable. For manufacturers producing high-volume, critical components like IV and infusion sets, the bond between flexible tubing and rigid valve or connector assemblies is a defining characteristic of product performance and patient safety. This joint must be robust, leak-proof, and capable of withstanding sterilization and daily use.
When seeking an adhesive solution that delivers both exceptional strength and rapid throughput, medical-grade cyanoacrylate (CA) adhesives, often called “super glue,” are the industry standard.
The Critical Challenge in IV and Infusion Set Assembly
Bonding flexible plastic or rubber tubing (such as PVC, TPE, or silicone) to a rigid plastic valve or hub (like ABS, PC, or acrylic) presents several key engineering challenges:
- Material Dissimilarity: Ensuring a strong, lasting bond between materials with different surface energies and flexibilities.
- Aesthetics and Performance: Avoiding “blooming” (white residue) which can be cosmetically unacceptable and, in rare cases, compromise device function.
- Speed and Efficiency: Achieving cure times measured in seconds to maintain high-volume automated production lines.
- Biocompatibility: The final, cured adhesive must meet ISO 10993-5 standards for cytotoxicity, confirming its suitability for patient contact applications.
Why Medical-Grade Cyanoacrylate is the Preferred Solution
Medical-grade cyanoacrylate adhesives, like the Incure Cyro-Weld™ series, offer a decisive advantage:
- Single-Component Simplicity: No mixing, heating, or complex dispensing equipment is required. The adhesive cures almost instantly upon contact with trace moisture on the substrate surfaces.
- Speed and Throughput: Cure speeds are typically measured in seconds, drastically reducing fixturing time and increasing production output.
- High Bond Strength: CAs provide excellent tensile and shear strength on a wide variety of plastics and elastomers, essential for preventing pull-out failures.
Recommended Solution: Incure Cyro-Weld™ CM-3 Wicking Grade
For the specific application of bonding tubing to valve assemblies—where the tubing is typically inserted into a connector or hub, creating a very tight, narrow joint—we highly recommend the use of a low-viscosity, wicking-grade adhesive.
The optimal choice for this precision work is Incure Cyro-Weld™ CM-3.
| Feature | CM-3 Advantage for Tubing/Valve Bonding |
| Ultra-Low Viscosity (3 cP) | Allows the adhesive to flow effortlessly into the microscopic gap between the assembled tubing and valve via capillary action, ensuring 100% joint encapsulation. |
| Wicking Grade | Designed specifically for pre-assembled, tight-tolerance parts, eliminating the need for complex, simultaneous dispensing and assembly steps. |
| Ultra-Fast Setting | Maximizes production speed by achieving handling strength almost instantaneously upon flow and contact. |
| Meets ISO 10993-5 | Certified to meet cytotoxicity standards, confirming its safe use in critical medical device applications. |
| Substrate Versatility | High-strength bonding to common medical plastics (P), rubber/elastomers (R), and metals (M). |
Technical Deep Dive: The Power of Capillary Action
The “wicking” nature of the Cyro-Weld™ CM-3 is the key to its success in this application. Unlike standard adhesives applied before assembly, CM-3 is dispensed after the tubing has been inserted into the valve.
- Assembly: The tubing is inserted into the valve/hub assembly.
- Dispensing: A small bead of CM-3 is placed around the circumference of the joint opening.
- Penetration: The ultra-low viscosity (3 cP, similar to water) combined with the narrow gap draws the adhesive deep into the joint (capillary action), forming a complete and robust seal along the entire contact area.
This method minimizes material use, reduces waste, and eliminates the risk of incomplete coverage, resulting in superior pull-out and torque strength.
The Next Step for Your Production Line
When transitioning to a new adhesive, full validation is paramount. The Incure Cyro-Weld™ CM-3 provides the technical performance and compliance baseline necessary to streamline the adhesive selection process for your IV/infusion sets or drug delivery systems.
To explore how Cyro-Weld™ CM-3 can optimize your assembly processes, contact an Incure technical specialist today.
Disclaimer: While Incure products are formulated to meet ISO 10993-5 standards and are designed to withstand common sterilization methods, it remains the medical device manufacturer’s responsibility to fully qualify and validate the adhesive within their specific device, production processes, and intended sterilization cycle to ensure final regulatory compliance and product performance.