Adhesives for medical technology: Loctite solutions for medical devices
For decades, Henkel has been offering adhesives for medical technology under its Loctite brand, which are used by developers and manufacturers of medical devices.
Henkel is constantly developing its Loctite adhesives for medical technology in line with developments in medical device technology, including in the area of adhesive equipment for dosing, curing, monitoring and automation.
IN BRIEF:
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Table of contents
- Loctite adhesives for medical technology
- Advice on Loctite adhesives for medical devices
- Frequently asked questions (FAQs) about “Adhesives for medical technology”
Loctite adhesives for medical technology
Loctite offers adhesives for medical technology as well as automation, curing, monitoring and dosing systems to process these adhesives productively.
What adhesives are available for medical applications?
Our company has many years of expertise, high-quality products and expert technical support. We also offer the world’s most comprehensive and diverse range of adhesives, dispensing devices and curing systems. We offer over 40 products for the manufacture of biocompatible medical devices and several hundred other products for applications that do not require a biocompatibility assessment.
In addition, the manufacturer Henkel states that most fully cured Loctite adhesives for medical applications retain their bonding performance even after exposure to standard sterilization procedures and exposure times. However, according to Henkel, designers and users should test the adhesives extensively on real parts and under real application conditions to ensure that they meet or exceed the requirements.
The more than 40 Loctite adhesives for medical applications include cyanoacrylate adhesives for medical technology, light-curing cyanoacrylate adhesives for medical technology, light-curing acrylate adhesives for medical technology and epoxy resin adhesives for medical technology (also known as epoxy medical technology adhesives).
The respective adhesive types are suitable for different medical products and devices, which may include the following:
- Needles
- Catheter
- Withdrawal, storage and management systems for liquids
- Endoscopes
- Surgical instruments
- Knee orthoses
- Crap devices
- Ventilators
- Infusion pumps
- Wheelchairs
- Hospital beds
- Imaging devices
- X-ray machines
Using a special 3D tool, you can see examples of a whole range of products in which adhesives for medical technology are used in the medical sector in a graphically simulated hospital room created by Henkel.
Henkel-Loctite has also published a video on the subject of “Adhesives in medical technology”:
Adhesive properties in comparison
In the following table of the manufacturer Henkel you can compare the adhesive properties of the mentioned adhesives with other types of adhesives:
| Light-curing acrylic adhesives | Light-curing silicone adhesives | Light-curing cyanoacrylate adhesives | Cyanoacrylates | Epoxies | |
| Advantages | Fast curing / adhesion to plastic | Excellent temperature resistance | Wide variety of bonding applications | Wide variety of bonding applications | Large selection of formulations |
| Restrictions | Light curing system required | Low cohesive strength | Low elongation at break | Low elongation at break | Mixing required |
| Temperature resistance (typical for the type of adhesive) | -40 °C to 100 °C | -40 °C to 149 °C | -40 °C to 100 °C | -40 °C to 120 °C | -40 °C to 149 °C |
| Temperature resistance (highest rated product) | 130 °C | 149 °C | 100 °C | 135 °C | 149 °C |
| Resistance to environmental influences (polar solvents) | Good | Good | Medium | Bad [1] | Very good |
| Resistance to environmental influences (non-polar solvents) | Very good | Poor to moderate | Good | Good | Excellent |
| Adhesion to metals | Good | Good | Very good | Very good | Excellent |
| Adhesion to plastics [2] | Excellent | Good | Excellent | Excellent | Sufficient |
| Adhesion to glass | Excellent | Good | Not recommended | Not recommended | Excellent |
| Adhesion to rubber | Sufficient | Sufficient | Very good | Very good | Sufficient |
| Tensile shear strength | High | Low | High | High | High |
| Peel strength | Medium | Medium | Low [3] | Low [3] | Medium |
| Tensile strength | High | Low | High | High | High |
| Extensibility/flexibility | Medium | Very high | Low to medium | Low to medium | Low |
| Hardness | Semi-rigid | Soft | Rigid | Rigid | Rigid |
| Number of components | 1 | 1 | 1 | 1 | 1 and 2 |
| Curing temperature | not applicable | not applicable | not applicable / room temperature | Room temperature | Heat or room temperature |
| Fixing time (average) | 15 seconds | 60 seconds | 5 seconds | 60 seconds | 5 hours |
| Fixing time (fastest) | 5 seconds | 60 seconds | 2 seconds | 5 seconds | 3 hours |
| Fixing time (complete curing) | 2 to 30 seconds | 72 hours | 24 hours | 24 hours | 24 hours |
| Gap filling (ideal (in mm)) | 0.051 to 0.254 | 0.102 to 0.152 | 0.025 to 0.254 | 0.025 to 0.076 | 0.102 to 0.152 |
| Gap filling (maximum (in mm)) | 6,35 | 6,35 | 4,318 | 0,254 | 12,7 |
| Gap filling (dosing/mixing required) | No | No | No | No | Yes (2 parts) |
[1] Cyanoacrylates have very good moisture resistance on plastics.
[2] Uncured liquid adhesives can cause stress cracking in certain thermoplastics, e.g. polycarbonate, acrylate and polysulfone. Special products and processing techniques are available. Refer to the LOCTITE Design Guide to Bonding Plastics (LT-2197) for more information.
[3] Exception: viscoplastic cyanoacrylates have a particularly high peel strength.
Source: Henkel
Adhesives for medical devices
In another table from the manufacturer Henkel you can compare the Loctite adhesives for the assembly of medical products and devices:
| PRODUCT | TYPE OF ADHESIVE | CURATION WITH | VISCOSITY (MPA-S) | FLUORESCENT | TEMPERATURE RANGE (°C) | MOST IMPORTANT FEATURES |
| 402 | Cyanoacrylate adhesive | Moisture | 150 | No | -40 to 135 | Low viscosity, good heat aging and heat resistance |
| 4011 S | Cyanoacrylate adhesive | Moisture | 100 | No | -40 to 120 | Low viscosity, ideal for acidic substrates and in dry environments, good temperature resistance |
| 4031 | Cyanoacrylate adhesive | Moisture | 1300 | No | -40 to 82 | Medium viscosity, minimizes ventilation requirements, reduces white residues |
| 4061 S | Cyanoacrylate adhesive | Moisture | 20 | No | -40 to 120 | Capillary action, fast bonding of plastic and rubber, ideal for acidic substrates and in dry environments, good thermal performance |
| 4601 | Cyanoacrylate adhesive | Moisture | 50 | No | -40 to 71 | Low viscosity, minimizes ventilation requirements, reduces white residues |
| 4902 | Cyanoacrylate adhesive | Moisture | 200 | No | -40 to 82 | Very high flexibility, low module |
| SF 7701 | Cyanoacrylate adhesive | N/A | 1 | Yes | N/A | Cyanoacrylate adhesion promoter for low-energy plastics |
| 4310 | Light-curing acrylate adhesive | UV, visible light, moisture | 175 | Yes | -54 to 100 | Low viscosity, viscoplastic*, fast dry-to-touch surface and shadow curing |
| 4311 | Light-curing acrylate adhesive | UV, visible light, moisture | 1050 | Yes | -54 to 100 | Medium viscosity, viscoplastic*, fast dry-to-the-touch surface and shadow curing |
| AA 3381 | Light-curing acrylate adhesive | UV | 5000 | No | -54 to 130 | Highly flexible adhesive, ideal for flexible bonded joints |
| AA 3921 | Light-curing acrylate adhesive | UV, visible | 150 | Yes | -54 to 149 | Low viscosity, highly fluorescent, excellent sterilization resistance |
| AA 3922 | Light-curing acrylate adhesive | UV, visible | 300 | Yes | -54 to 149 | Excellent resistance to sterilization, excellent adhesion to PC |
| AA 3926 | Light-curing acrylate adhesive | UV, visible | 5500 | Yes | -54 to 149 | High viscosity, highly fluorescent, excellent sterilization resistance |
| AA 3936 | Light-curing acrylate adhesive | UV, visible | 11000 | Yes | -54 to 149 | High viscosity, good for stress-sensitive plastics, excellent through-hardening |
| AA 3951 | Light-curing acrylate adhesive | UV, visible | 200 | Yes | -54 to 149 | Low-viscosity, fast-curing, highly flexible adhesive, ideal for flexible bonding lines |
| AA 3953 | Light-curing acrylate adhesive | UV, visible | 550 | Yes | -54 to 149 | Fast-curing, highly flexible adhesive, ideal for flexible bonding lines |
| AA 3961 | Light-curing acrylate adhesive | UV, visible | 80 | Yes | -54 to 149 | Very low viscosity, fast LED curing, ideal for warp-resistant bonding applications |
| AA 3963 | Light-curing acrylate adhesive | UV, visible | 350 | Yes | -54 to 149 | Low viscosity, fast LED curing, excellent moisture and accelerated ageing resistance |
| AA 3979 | Light-curing acrylate adhesive | UV, visible | 56500 | Yes | -54 to 149 | Gel viscous, good fluorescence, good dry-to-touch curing |
| SI 5056 | Light-curing acrylate adhesive | UV, visible | 2200 | No | -54 to 149 | Medium-viscosity silicone adhesive, heat and moisture resistant |
| EA M-31CL | Epoxy resin adhesive | 2K mix | 6000 (mixed) | No | -54 to 149 | Clear epoxy with excellent impact resistance, 30 minute working time |
| EA M-121HP | Epoxy resin adhesive | 2K mix | 11000 (mixed) | No | -54 to 149 | Epoxy resin with high strength and thermal shock resistance, 120 minutes processing time |
* when cured by UV or visible light
Source: Henkel
Equipment solutions
Loctite has also developed equipment solutions specifically for use with Loctite medical adhesives, namely dispensing, curing and monitoring systems.
Automated robot-controlled dispensing systems are also part of the Loctite range, enabling reproducible and reliable dispensing. This makes processes more efficient, reduces material waste and lowers production costs.
Loctite’s LED light curing systems ensure lower energy consumption, faster curing, less heat generation, longer service life and safer disposable parts.
Please also read our article “ HireaLoctite dispenser and Loctite light curing system“.
Advice on Loctite adhesives for medical devices
When it comes to advice on Loctite adhesives for medical technology – for example in relation to product selection and automation – you are in good hands with the Henkel distributor abovo. We at abovo, based in Selzach, Switzerland, have been an authorized distributor of Henkel Adhesive Technologies products for around 20 years; initially in the Henkel Electronics division and since 2022 also in the Henkel Industry division.
Contact our Henkel experts at abovo today to find out how you can use Loctite adhesives in the design and manufacture of medical devices:
- Telephone : +41 32 552 44 44
- E-mail: info@abovo.ch
If you contact us by e-mail, we will reply as quickly as possible.