Note: This is the second article of a three-part series covering plastics in electrical and electronic (E/E) device (1) trends, (2) material/process advances and (3) applications.


Convergence among computer, consumer electronics and telecom industries continue to blur the lines between information, entertainment and communication. Electrical and electronic (E/E) applications polymer development is pushing plastic resin properties. This is in response to ongoing demand for smaller electronic devices where high heat and high-flow grades permit more intricate, miniaturized parts in electronic applications.

Let's take a look at new E/E material and process advances.

We'll start with a look at a new highly flexible halogen-free FR compound. Cogegum GFR 380, a new polyolefin grade developed by Solvay Specialty Polymers, delivers greater flexibility and superior flame resistance compared to competitive silane-grafted halogen-free flame retardant (HFFR) materials. The new compound, which represents a major breakthrough in the silane-grafted HFFR space, and it addresses the inherent limitations of silane-grafted HFFR materials, which are typically stiff because of the lack of a plasticizer component.

Solvay Specialty Polymers
Cogegum GFR 380 silane-grafted HFFR power cable.

With its 38 Shore D hardness, the new grade is softer and more flexible than competitive silane-grafted HFFRs, which typically exhibit 45-50 Shore D hardness. Cogegum GFR 380 incorporates a master batch that contains special additives to improve cross-linking action and aging. An anti-ultraviolet agent for enhanced weatherability is also part of the formulation.

The material is rated for use up to 90 degrees C (194 F) and can be adapted for certain applications up to 105 C (221 F). Cogegum GFR 380 also provides superior flame retardant properties compared to competitive silane-grafted HFFRs. During burning, the material's char is compact and protects the cable from accelerated burning.

The new grade also offers the same chemical resistance as previous grades to such substances as oil, fuels, alkalines, acids and service fluids. Power, data and signal cables are among the key application areas. Solvay says it plans to expand the technology platform to include other silane-grafted HFFR materials in the near future.

Continuing, a new thermoset transfer molding semiconductor technology has been developed with a complete freedom of shape that brings an extra dimension to sensor and microelectromechanical systems (MEMS) encapsulation. Transfer molding with a thermosetting compound and a proprietary tool is being positioned as an alternative to thermoplastics and standard injection molding in production of some semiconductor devices.

The transfer molding process "nCapsulate," developed by Dutch company Sencio BV, uses a novel thermoset epoxy compound with unique flow properties. During molding, the compound becomes fluid with a low viscosity so that the tiny, 25 µm (micrometer) wires are not bent. This is not possible with injection molding.

The nCapsulate process delivers better isotropy and thermomechanical stability than the thermoplastics of standard injection molding technologies. The technology also allows "freeform encapsulation," that is encapsulation formed into any shape required in contrast to traditional encapsulation technologies that are limited to standard shapes and form factors.

Freeform encapsulation allows functional features to be incorporated for mounting, alignment and support, or to embed sensors directly into the component. This helps manufacturers to streamline or eliminate post-encapsulation assembly.

Sencio BV
Thermoset transfer molding semiconductor technology.


Next, compounded antimicrobial treatment for medical electronic devices is becoming increasingly important. Microorganisms continue to cause infections in the healthcare industry, where countless patients come into contact with drug-resistant bacteria.

For instance, one study found that more than 77 percent of electrocardiogram (ECG) cables are colonized by antibiotic-resistant pathogens. The risk of infection can be substantially reduced through the use of antimicrobial cables, cable systems and equipment casings.

A proprietary, innovative technology from Leoni Kabel GmbH based on the Lewis acid-base theory gives plastic surfaces a germ-killing effect. This process gives treated objects a special property that resembles the human skin's protective shield of acids. It involves acid ions being released on the surface of cables that lower the pH value on the outer surface of the jacket. This restricts the cell functions of the bacteria and their separation, so that they ultimately die.

A special metal oxide is incorporated in the plastic matrix of the cable jacket. It can be added in variable doses, with even a low concentration showing more than 99.99 percent bacteria-killing effectiveness.

The key benefit is that this acid technology maintains the hygienic effect. Another benefit is that the pathogens are destroyed not from the inside, but from the outside across the cell envelope. The formation of biofilm on the cable or the device casing is thereby stemmed, making it more difficult for bacteria to colonize the surface.

The mechanical properties of the cable and its handling are said to remain unchanged. Leoni's antimicrobial cables have also passed initial tests in accordance with DIN EN ISO 10993-5 and DIN EN ISO 10993-10 for medical equipment.

Leoni Kabel
ECG cable — bacteria laden (left) vs. antimicrobial compounded treated (right).


Finally, a recent breakthrough in pultruded/overwrapped thermoplastic composite transmission line is a notable plastics technical marketing advance. Wire and cable producers are making greater use of new and upgraded materials from resin suppliers and compounders to meet evolving market needs. These upgrades can be in areas such as stiffness and shielding, weight reduction, safety and environmental resistance.

The recently introduced C7 Overhead Conductor developed by Southwire Co. LLC and Celanese Corporation offers a new option for utility transmission lines. The C7 Overhead Conductor features a multistranded composite core of Celstran continuous fiber-reinforced thermoplastic rods (CFR-TPR) from Celanese.

The new transmission conductor delivers nearly double the capacity and exhibits less sag than the same diameter aluminum conductor steel-reinforced (ACSR) product. The design allows for minimum sag at higher power transfer, and the stranded Celstran CFR-TPR core means there is no single point of failure for the overhead conductor.

The C7 Overhead Conductor is comprised of seven 3.2-mm (millimeter) diameter strands of carbon fiber, or more depending on cable diameter, pultruded with polyphenylene sulfide (PPS) and then overwrapped with a polyether ether ketone (PEEK) material to provide protection from galvanic corrosion and to provide abrasion resistance from other strands.

The bundled strands, overwrapped by Southwire with an aluminum conductor, provide a redundancy of structural support in high-load conditions, which means that the failure of one or two or three strands will not result in failure of the entire line. In addition, the carbon fiber core operates at a generally lower temperature, which maximizes energy throughput and minimizes capacity loss. The carbon fiber can also operate hotter without damaging the line.

This combination of materials provides distinct advantages compared to alternative "high temperature low sag" technology and conventional conductors:

  • The only all-thermoplastic composite core with high-temperature performance (180 to 225 degrees C)
  • Minimal thermal expansion — lowest level available in a composite core for minimal sag increase at high power transfer
  • Light weight — high strength-to-weight ratio
  • Multielement core — no single point of failure, unlike monolithic constructs
  • Flexible and robust — installs like traditional conductor without the need for special training and equipment
  • Use of conventional connectors — traditional, crew-friendly, two-piece compression fittings

Southwire/Celanese
C7 overhead transmission conductor.