For disposable medical catheters, medical adhesives are classified as medical device bonding materials. For components in contact with human tissue, medicinal solutions, or blood, the adhesives must meet the following requirements: biocompatibility (ISO 10993), sterilizability (via ethylene oxide [EO], γ-irradiation, or high-temperature steam), low leaching potential, and compatibility with antimicrobial solutions; the appropriate adhesive selection varies significantly depending on the bonding application. For single-use consumables, particular consideration should be given to curing speed, suitability for batch automated production, and the absence of solvents.
I. Breakdown of Application Scenarios
1. Disposable medical catheters (infusion lines, central venous catheters [CVC], PICC catheters, gastric tubes, urinary catheters, interventional microcatheters)
Disposable medical catheters: typical bonding sites:
- Catheter body and Ruhr connector (PP/PC/PE/TPU)
- Catheter, tail seat, extension tube, and three-way fitting seat
- Catheter, metal reinforcement wire, and metal end piece
- Adhesion of the balloon catheter balloon to the catheter body
- Adhesion of identification labels and protective covers
2. Needle-type devices (blood collection needles, injection needles, indwelling needles)
Needle-type devices alongside disposable medical catheters: typical bonding sites:
- Metal needle tube + plastic needle holder (PP/PC) – the core bonding station
- Pin mount, protective cap, and sealing gasket
- Indwelling needle hose and metal needle base
Common Types of Adhesives and Their Applicable Applications
1. UV-curable adhesive (UV adhesive, acrylate-based) ⭐ Recommended choice for large-volume single-use consumables
For disposable medical catheters and related devices, applicable to: needle-to-base joint bonding, catheter connector bonding, and transparent plastic bonding ✅ Advantages:
- Cures extremely rapidly (within seconds), making it ideal for high-speed automated production lines;
- Single-component formula; no mixing required;
- Low shrinkage and high bonding precision;
- Medical-grade option available: low ion leaching, solvent-free, and sterilizable via EO/γ irradiation;
- Transparent version; allows inspection for excess adhesive and bubbles. ❌ Limitations:
- A light-transmitting surface is required; opaque metals combined with dark-colored plastics cannot be fully cured using UV light curing.
- Difficulties in curing the thick adhesive layer;
- Certain grades may swell after prolonged exposure to normal saline or oils.
Standard protocol: Adhesion of indwelling needles, blood collection needles, and metal needles to PC/PP needle holders; use of PC quick-connect couplings with transparent catheters.
PP material is difficult to bond; therefore, a primer-based UV adhesive should be selected, or the PP surface should be pre-treated with a dedicated PP primer.
2. Two-component room-temperature curing epoxy adhesive (medical-grade epoxy)
✅ Advantages: High strength, chemical resistance, excellent sealing properties, and high hardness after curing; biocompatibility is achievable. ❌ Disadvantages: Requires mixing, slow curing time (ranging from minutes to hours), relatively brittle, unable to provide flexible bonding, and some epoxy compounds may exhibit higher levels of leaching. Applications: Suitable for metal bases and rigid plastic structural components; not suitable for flexible sections of conduits.
3. Rapid-curing adhesive (cyanoacrylate CA adhesive, medical rapid-curing adhesive)
✅ Advantages: Rapid curing at room temperature, suitable for bonding in narrow gaps, and low equipment investment. ❌ Disadvantages: The cured material is brittle, not suitable for prolonged immersion in normal saline; curing is moisture-dependent and thus susceptible to variations in ambient humidity; prone to discoloration; many conventional instant-curing adhesives fail to meet biocompatibility requirements. Applications: Non-invasive, short-term fluid-contact auxiliary assembly; for single-use consumables, UV-curable adhesives are now being prioritized as a replacement in primary bonding stations.
Medical CA may be used for partial catheter-assisted fixation; however, it is not recommended as the primary structural adhesive for needles.
4. Silicone rubber (RTV silicone, addition-cured silicone)
✅ Advantages: Excellent elasticity, resistance to high and low temperatures, superior biocompatibility, and resistance to moist heat sterilization; soft texture, making it suitable for flexible components. ❌ Disadvantages: Slow curing rate; relatively low bonding strength; some variants exhibit low-molecular-weight leaching; difficulty in spray painting. Applications: Airbag bonding, sealing gaskets, flexible assemblies, and ventilator tubing sealing; not suitable for bonding in needle-based structural applications under mechanical stress.
5. PU Polyurethane Adhesive (Medical PU)
✅ Advantages: High elasticity, resistance to bending, resistance to bodily fluids, compatibility with TPU and PVC catheters, and flexible bonding capability. ❌ Disadvantages: Two-component system requiring precise mixing; relatively long curing time. Applications: TPU interventional catheters, flexible tubing connections, and areas subject to dynamic bending.
III. Recommended Key Sub-segmentation Strategies
✅Option A: Single-use needle (metal needle barrel + PC needle holder) [Most commonly used in mass production]
Adhesive type for disposable medical catheters: Medical-grade UV-curable acrylic adhesive
- Base material: stainless steel needle tube + PC needle holder
- Process: dispensing → pin insertion → UV lamp curing (2–5 s)
- performance requirement:
- ISO 10993 – Cytotoxicity and skin irritation;
- No cracking occurs, and no intensity decay is observed after sterilization with EO or γ-rays;
- High tensile pull-out strength (the pin cannot be pulled out);
- Low precipitation, ensuring no contamination of the medicinal solution;
- Resistant to alcohol wiping.
If the pin base is made of PP, it requires pre-treatment with a PP primer or the use of modified UV adhesive.
✅Option B: Catheter Tuer connector (TPU/PE catheter + PC/PP connector)
- TPU+PC: Medical-grade UV adhesive (transparent joint);
- TPU+PP (opaque): addition of silicone adhesive / medical-grade PU adhesive;
- Balloon catheter: balloon and catheter body; medical-grade silicone material.
✅Option C: In-vitro medical devices (monitoring equipment, infusion pump housings, sensors)
- Plastic housing snap-fit auxiliary fixation: medical-grade UV adhesive or medical-grade RTV silicone sealant;
- Fixing of metal and plastic structures: medical-grade epoxy resin;
- Waterproof sealing: low-volatility silicone.
IV. Key Selection Evaluation Criteria (Mandatory Testing for Medical Adhesives)
- Biocompatibility: ISO 10993 (cytotoxicity, sensitization, hemolysis; mandatory for invasive medical devices)
- Sterilization tolerance: effects of EO (ethylene oxide) / γ-irradiation / 121 °C steam on mechanical strength, discoloration, and leaching after sterilization
- Substrate compatibility: PC, PP, PE, TPU, PVC, stainless steel; plastic surface energies vary significantly (PP has the highest adhesion difficulty)
- Media compatibility: immersion in normal saline, glucose solution, alcohol, and drug solutions
- Mechanical properties: tensile strength, shear strength, and bending fatigue (for flexible conduits)
- Extraction Testing: Heavy metals, extractables, and ion content (per pharmacopoeial requirements)
- Production compatibility: curing speed, dispensing stability, and excess adhesive control
| Application site | Substrate Combination | Recommended adhesive type | Curing method | remarks |
| Indwelling needle / Blood collection needle: steel needle + PC needle holder | stainless steel+PC | Medical UV adhesive | UVlight-cure | The preferred choice for high-speed production lines |
| Steel pin + PP pin holder | stainless steel+PP | UV adhesive + PP primer | UVlight-cure | The primer application process increases costs. |
| TPU conduit + PC quick connector | TPU+PC | Medical UV adhesive | UVlight-cure | Joint light transmittance |
| TPU catheter + PP connector | TPU+PP | Medical PU / Additive Silicone Gel | Heat / room-temperature curing | Opaque structure |
| Catheter balloon adhesion | Latex/TPU airbag + tube body | Addition of silicone | Curing by heating at room temperature | Flexibility is required |
| Rigid structural components of medical devices | PC/ABS + Metal | Medical epoxy resin | Two-component, room-temperature curing | High strength, but relatively brittle |
| Equipment sealing and vibration damping | Plastic + Metal | Medical-grade silicone | room curing | High elasticity |
Inspecting Hidden Bonds in Disposable Medical Catheters
For disposable medical catheters, define an inspection plan around the actual connector geometry and the fluid path. Check deposit placement before curing, then examine the assembled joint for excess adhesive, visible voids and obstruction of the lumen. With UV curing adhesive systems, include the light access through the assembled parts in the process review; an exposed outer bead does not show what happened inside a concealed overlap. Isn’t the hidden interface the place that needs attention when an apparently clean joint behaves differently during testing?
Reviewing the Joint After Processing
Before disposable medical catheters move from trials to routine assembly, compare the joint condition before and after the intended cleaning, sterilization and handling sequence. It’s helpful to record where separation starts during pull or bend testing, alongside leakage and flow observations. Set acceptance criteria for the device and the actual exposure conditions. A product category alone does not establish suitability for patient contact. To discuss material evaluation, share the substrates and assembly drawing with JOME; keep biological assessment and finished device validation within the device development process.
JOME manufactures the full JOME product catalogue in its own factory for customers in more than 30 countries. Readers continuing from Introduction to Adhesive Solutions for the Aerospace will find the Shanghai JOME Industrial Co. product line covers the full portfolio, and project questions go to the ask JOME for grade selection help.