MagShield™ FIBER – Advanced containment and protection system for permanent magnets

MagShield™ FIBER represents the new generation of glass-fiber reinforced heat-shrink tubes, developed by Politubes for the retention and protection of permanent magnets in brushless (BLDC / SPM) motor rotors.
Born from extensive co-development with the R&D departments of leading international manufacturers, MagShield™ FIBER is designed to meet the highest standards of automation, mechanical strength and thermal performance required by modern e-mobility and industrial applications.

Hybrid technology: heat-shrink polyester + high-strength composite fiber

The MagShield™ FIBER tube combines two advanced materials:

• A heat-shrink polyester layer ensuring perfect adhesion to the rotor and full protection of magnet edges.
• A high-strength composite fiber that provides outstanding mechanical and thermal performance, with dimensional stability up to 170 °C, surpassing conventional thermoplastics.

Secure fixation, adhesive-free and fully automatable

The tube is fitted over the rotor with magnets in place and heat-shrunk at safe temperatures, well below the Curie point.
The result is a robust and durable mechanical bond, stable even at high rotation speeds — without magnetic flux loss and without adhesives or curing times.

Technical and production advantages

• No resins or adhesives: faster assembly and higher production efficiency.
• Lower magnetic flux losses compared to metal rings.
• High thermal resistance and dimensional stability under dynamic stress.
• Easy end-of-life removal for magnet recovery, supporting circular-economy principles.

Applications with bonded magnets (NdFeB / Ferrite)

Particularly effective in motors using bonded magnets produced by compression or injection molding, thanks to its ability to:

• Prevent corrosion of magnetic alloys.
• Preserve the mechanical integrity of the magnet during operation and thermal cycling.

Technical specifications

• Thickness: 0.19 – 0.35 mm
• Operating temperature: –70 °C to +170 °C
• Compatible with fully automated assembly lines

Benefits for BLDC motor manufacturers

• High mechanical and thermal strength
• Elimination of metal retaining rings and two-component adhesives
• Reduced motor weight and noise
• Perfect adhesion to magnets and rotor surface
• Complete magnet protection and extended motor lifetime
• Seamless automation integration
• Removable for recycling and magnet recovery

MagShield™ FIBER is already adopted by global leaders in electric motor technology, perfectly suited for lean manufacturing and high-automation environments.