Idvac Ltd, UK, a specialist in advanced vacuum and thin film technology, has been investigating the properties of some Liquid Crystals (LCs) for packaging and security applications.
In a recent development, Idvac in collaboration with XRD Nano Limited has succeeded in embedding Fresnel lens effect on its colour shifting liquid crystal film. This resulted in a Fresnel lens with an aesthetically appealing colour shifting effect from red to green depending on the angle of viewing.
Fresnel lenses are made of concentric rings. Each ring bends the light slightly more than the one below it, so all the light rays emerge in perfect and parallel beams.
At present, they are used in different fields including decorative packaging and security documents.
XRD Nano Limited recent development in UV casting equipment has made the production of Fresnel lenses on flexible films, including Colour Shifting liquid crystal films, easy and cost-efficient. UV embossing can be done at very high speeds (100 to 250 m / min) and integrated with a gravure press to make the process inline.
Idvac recent work will extend the functionality of Fresnel lenses to add enhanced optical properties and sensing abilities. The new enhanced properties will be an added value for applications such as brand protection, anti-counterfeiting and smart packaging in multiple industries, including pharmaceuticals.
This new development has the following features:
- The colour shifting LC coated PET film is applied as a single layer using standard wet coating application methods such as printing, flexo, gravure etc.
- The LC colour shift film can be transparent or semi-transparent.
- Micro Fresnel lenses can be embedded onto the colour shifting liquid crystal film to produce bright colour change from red to green depending on the angle of viewing.
- The colour shifting Fresnel lens is visible when viewed from top or back side of the LC coated film.
- The colour shifting Fresnel lens is easy to observe from a distance and from a multiple viewing angles under standard lighting conditions.
- The colour shifting Fresnel lens can be combined with other security features such as micro printing, holographic security pattern and a tamper evident layer to make unique products.
- The production of the colour shifting Fresnel lenses is carried out using UV casting R2R machine to make the product easy to manufacture and cost-efficient.
Idvac ltd is based in Manchester Science Park, England and has over 25 years of experience in the holographic and 40 years in advanced vacuum coating technology markets including UK, Europe, USA, Asia and Far East, to improve the image, brand and durability of their products. The company develops new processes and supplies process know-how and retrofits to convert standard vacuum metallisers to produce unique coatings for different applications including security documents.
Company Press Release