This linear polarising film allows light waves at only one orientation to pass. It will therefore block almost all light if two sheets are angled at 90 degrees.
Polarising film can be used to view internal stress in some clear plastics (e.g. acrylic). The stress is observed by viewing the plastic interposed between two sheets of film. Polarising film is also used for 3D film projection. Two slightly different images are projected, superimposed onto the same screen, through polarizing filters at a 90-degree angle. The viewer wears 3D eyeglasses, where the glasses are also polarising filters at a 90-degree angle. Each filter passes light that is similarly polarised, also blocking the orthogonally polarized light — each eye therefore see a different image, creating the 3D effect.
The film will typically transmit ~40% of the light, while two layers at a 90-degree angle will transmit less than 0.001%.
Create window blinds where the user can control the inflow of light by adjusting the angle between the filters.
Put the two sheets on top of each other and turn them at a 90-degree angle in order to block almost all light.
We sell the samples in sets of two, so you can experiment with blocking the light. Sample sizes are:
- 45 mm x mm 45
- 22 mm x 45 mm