Henkel, a manufacturer of adhesives, sealants, and functional coatings, has introduced three new low-pressure molding (LPM) materials designed to seal and protect medical devices from moisture, temperature extremes, chemicals, vibration, impact, and other environmental concerns.
Using a gentle, low-pressure process, Loctite PA 6732, Loctite PA 6682, and Loctite PA 6951 completely encapsulate medical devices including catheters, tube sets, connectors, and surgical tools, as well as sensors and switches used in medical diagnostic and monitoring equipment.
All three LPM products are tested to Henkel’s protocols based upon ISO 10993 biocompatibility standards including skin sensitization, with certificates available on request.
Hot-melt adhesives are thermoplastic polymers or resins that liquefy when heated. However, LPM hot-melts completely replace the thermoplastic housings, allowing manufacturers to produce complex and intricate assemblies by customizing part geometry, surface texture, color, and opacity.
These materials form an adhesive bond with the entire component being encapsulated, becoming part of the component’s three-dimensional form and creating a water-tight, chemically-resistant seal.
The cost-effective LPM process involves three steps:
1. Placing the bare component into a custom mold set
2. Heating the polyamide material and injecting it at low pressure into the mold
3. Letting the material to cool rapidly for 10 to 50 seconds before removing the newly encased and bonded component for immediate use
Formulated to allow greater design freedom than traditional medical encapsulants, Loctite PA 6732, Loctite PA 6682, and Loctite PA 6951 are single component, solvent-free polyamides that are solid at room temperature.
Derived from natural fatty acid feed stocks obtained from renewable resources such as soy, rapeseed and sunflowers, they are green and sustainable. No harmful fumes are released during the molding process, and all products are RoHS and REACH-compliant.
Loctite PA 6732 is an amber material that performs well in temperatures from -40 to 140°C. Clear Loctite PA 6682 is designed for use in temperatures between -25 and 105° C. Loctite PA 6951 is a colorless material that performs well in temperatures from -40 to 100° C.