One of the key elements to reducing heatloss using thermal blinds is to get a good edge seal between the blind and the frame when they are down. This is achieved using high-performance magnets which are sealed within the blind along the outer edges. Each ‘internal’ magnet is then paired with a self-adhesive magnet attached to the window frame, which ‘click’ tightly together when the blind is lowered. They are described by the manufacturer as “Ultra High Performance Neodymium Magnets” – the most powerful permanent magnets known. They are supplied in nickel finish but can be painted on site (we’ve used Humbrol enamels) to match your frame.

We use 10mm diameter N42 Neodymium Magnets. The NORTH pole is on the showing magnetic face and the SOUTH pole is on the face covered in adhesive. These Magnets are plated with 3 layers of protective coatings – Nickel + Copper + Nickel (Ni-Cu-Ni). More technical details are below;

magnets are 10mm diameter & just 1mm thick

Magnetic Face: 10mm dia
Thickness: 1mm
Grade: N42
Plating: Ni-Cu-Ni ( Nickel )
Material: NdFeB ( Neodymium )
Performance (Gauss): 1200
Vertical Pull (Kg): 0.45
Slide Resistance (Kg): 0.09
Max Temp (degrees C): 50
Fixing: 3M Self Adhesive

Component sample showing magnets with 3M backing sheet on left, loose on right with white painted magnet at top

The magnets have approximately 1200 Gauss on each face. Each magnet can support a steel weight of up to 0.45kg vertically from the magnetic face when in flush contact with a mild steel surface of equal thickness to the magnet. Each magnet can also support up to 0.09kgs in a sheer position before beginning to slide down a steel surface under the same conditions. These magnets can be fixed in place using 3M Self Adhesive and have a maximum operating temperature of 50 degrees C.

For a typical blind of four folds there are ten magnets down each side, and 20 supplied for the frame to match these internal magnets, so 40 in total. The blinds would probably work with fewer – the red sample blind can be held horizontally & the blind still holds on to the frame!

The magnets can be painted to match the frame