Composites for Shielding Solutions

Lamiflex produces advanced composite materials for use in a wide range of industrial applications. The company has developed next generation EMI and RFI shielding solutions that combine high surface conductivity across broad range frequencies with the light weight, design flexibility, and cost advantages of composite materials. Lamiflex’s shielding materials include a family of semi-manufactured preimpregnated materials based on nickel, zinc, gold and silver in reinforced polyester, glass Nomex, carbon and epoxy resin. The company also produces customized, finished parts based on these composites that can be adapted to any geometric solution. Lamiflex's composites have industrial and military applications in many sectors, including aerospace, telecommunications, automotive, undersea systems, and electronics.

Technological evolution in all industrial sectors, including civil and military sectors, is accompanied by an ever more increasing use of electronic instruments that handle, automates and simplify technology itself.

Wireless connections and greater power transmission have made clear how delicate and vulnerable electronic technology has become.

Electromagnetic interferences are often the cause of malfunctioning that can lead to accidents, loss of machinery and instruments and in the worst of cases to loss of human lives.

A few years ago, use of metal equipment provided secure protection through the “Faraday cage” effect but the greater use of composite material to lighten structure has caused electronic technology to be lacking in this type of protection and therefore more vulnerable.

Companies specialized in electromagnetic protection, like EMI and RFI have united their skills and joined companies in the composite sector creating a new series of products that can fuse lightness with conductive shielding properties.

Lamiflex has consequently developed a series of semi-manufactured pre-impregnated material starting from metallic textile solutions with different types of metal: nickel, zinc, gold and silver according to the high levels of electrical conductibility or the high resistance to corrosion they provide or the compatibility of human interaction without causing health risks as is the case with zinc.

Also the types of reinforcements developed can provide a wide range of choice according to the specific type of application. As a result pre-impregnated articles in low grain polyester material can be produced in order to create layers of conductive shielding combined with pre existing composite structures with minimum impact on weight but with a low signal measuring between 40 and 70dB for each layer depending on frequency. Thus, pre-impregnated products can be obtained with reinforcements in metallic carbon for the construction of parts that have the necessary requirements for mechanical functioning and shielding.

The Faraday pre-impregnated series developed by Lamiflex technicians, brings together the above characteristics creating a series of pre-impregnated pieces in reinforced polyester, glass, Nomex, carbon and epoxy resin with an ample range of temperatures for polymerization (from 120° to 180°) in order to satisfy a wide range of applications that are compatible with most Aeronautical approved resins (tests carried out on Hexel resins for example – 1454)

The choice of pre-impregnated pieces of this kind combines the drapability of the material and its conductive capacity making more complex forms possible that perform well and offer a high degree of shielding.

However, it is important to know how to handle these fabrics, in fact, incorrect use could cause problems of conduction due to unforeseen and unchecked excess resin that can form an insulating film and impede the electrical contacts necessary to close the circuits.

Lamiflex shielding solution Page 2

Lamiflex technicians have set up a series of user techniques and complementary conductive material that optimize the electrical contacts so that pre-impregnated material can be adapted to any geometric solution.

The main applications for this type of material is certainly cable trunking and protective paneling for containers of electronic equipment..

A practical example that shows the union of textile flexibility with the technology of composite material concerns the creation of ultra-light rigid and flexible tubes for the helicopter sector which continues to have an increasing need to combine the reduction of weight with greater and more complex avionics that, in the absence of protective metallic structures, is more vulnerable.

Apart from producing semi-manufactured articles like pre-impregnated pieces, Lamiflex can also produce finished parts or make products conductively shielding in composite material already in use by means of molding conductive layers with a suitable cycle in an autoclave or oven which permits products to have shielding characteristics without rebuilding the whole piece.

Because of the complexity of systems and precision of requirements of military products and more stringent on electromagnetic compatibility, all military products are mandatory through the EMC standards. Electromagnetic shielding pre-preg are to achieve electromagnetic compatibility of the election will be the composite shielding material, widely used in supporting land, sea and air military communications equipment, electronic module, cabinet shielding, satellite radar, military terminals.

Avionic equipments are easily interfered by electromagnetic waves. EMC shielding pre-preg helps to protect millions dollars of advanced avionic devices.

Due to communications equipment industry’s own high-speed digital signal processing and wide microwave operating band, highly sensitive to electromagnetic interference, communications products have enacted mandatory electromagnetic compatibility standards and procedures for complex networks.

According to the applications and equipment work of the different environment, wave shield to provide communications equipment electromagnetic compatibility composite shielding materials.

Other uses of these materials may find its way into applications where there is need of localized heating by Joule effect (heating, deicing, etc…) and all other designs where the imagination can wander.

Consequently finished products are available for final application that could potentially attract sectors technically more sensitive to costs such as civil and construction sectors.