Emi, LLC

Thorn Emi Plc

Ashok W Vaidya

Robert A Woolley

James L Wales

Coating apparatus for a thin plastics web comprises a coating deposition station for applying a coating to the web by vapor deposition and a support for supporting the web at the coating deposition station. The apparatus includes a device for urging gas into the region where the thin plastics web converges with the support to improve the thermal coupling between the web and the support and also to reduce the coefficient of friction between the web and support. The gas enables the coating to be applied by vapor deposition at coating speeds of up to 90 meters per minute without deformation of the thin plastics web.

Coating apparatus for thin plastics webs

A magnetic field gradiometer includes a pair of coils, encompassing different regions of space. A SQUID is provided to detect a difference in flux linking the coils thereby to provide a measure of a magnetic field gradient between the coils. A control element of a superconducting material is provided in the vicinity of the coils and a heater is controlled to vary the proportion of the element assuming the superconducting state. By suitably varying this proportion the balance condition of the coils can be altered. The control element may operate in a feed back circuit. A coil subjects both coils to an alternating magnetic field at a preset frequency. A component in the output of the SQUID having this frequency is used to control the heater.

Growing community of inventors

High Wycombe, United Kingdom

Ashok W Vaidya