Electro magnetic interference (EMI) is a common phenomenon that can affect the functioning of numerous electronic devices, which are becoming increasingly prevalent in our everyday lives.
EMI causes the disturbance of a variety of systems including audio / video, telecommunications / telephony, sensitive measuring, monitoring and testing apparatus used in many fields of application, such as public, industrial, medical, aerospace and so on. With the new generation of digital electronic systems, the problem has increased. In their unmodified state, most thermoplastic polymers are completely transparent to EM radiation. With sixty years of experience in engineering thermoplastics (ETPs), LATI has developed a range of injection-mouldable products in which it is possible to create an effective shielding barrier against EMI. This range is collectively known as LATISHIELD.
The technology depends on the right combination of base polymers, special metallic fibres and other additives to satisfy the shielding and other requirements for the application in question. The metallic fibres used, which are characterised by a particular physical
form and composition specinc for the use, are dispersed homogeneously after moulding into the polymer matrix, forming the shielding structure of the moulded part, otherwise known as a Faraday Cage. These fibres have proven to be very efficient as a filler material for electrically-conductive plastics and very low amounts are sufficient to fulfil EMI regulations. With such low filler levels, all the general characteristics of the compound remain more or less unchanged, and the compounds can be transformed into components on standard injection-moulding equipment. However, moulding parameters need to be fine tuned to optimise residual fibre length and ensure homogeneity of dispersion in the part.
In addition to the effective shielding effect, LATISHIELD compounds offer other important benefits where electrostatic discharge (ESD) may disturb or damage critical equipment or devices.
With LATISHIELD, volume-resistivity values of 101 – 103 Ohms can easily be achieved.
The colouring of the LATISHIELD compounds is hardly affected. Most colours can be matched, eliminating the need for a secondary painting operation, as well as metallisation, electroplating and so forth. Finally, some LATISHIELD grades are also suitable for contact with food.
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