TECHNOLOGY | ELECTRICALLY CONDUCTIVE
Witcom Engineering Plastics has seen demand for electrically conductive compounds grow steadily since the company was founded in 2004. “This is related to the increasing need for safety and technological developments - often requiring EMI shielding - and mainly driven by ATEX require- ments and continuous metal replacement,” according to Christine Van Bellingen, Business Development Manager. “We have gained significant experience with the development and realisation of conductive compounds, incorporating various types of conductive additives, to be able to cover the whole conductivity range – from 10-1
to 1011
Figure 1: EMI Shielding performance of PolyOne Surround long fibre electrically conductive compounds versus aluminium Source: PolyOne
Surround long-fibre materials are well suited to housings for advanced driver assistance systems (ADAS). As automakers continue to add ADAS functionality to automobiles, more electronic control units (ECUs), cameras, and sensors are needed and it is becoming increasingly critical to minimise risk of “cross talk” between components. Surround material is lighter in weight and easier to process than traditional materials such as alumini- um or copper — the company claims Surround solutions weigh up to 60% less. Injection moulding also permits more complex shapes and imposes fewer design constraints than metallic alternatives.
Right: Lati has developed a number of electrically conductive compounds for the HVAC industry
34
HVAC applications Italian technical compounder Lati has developed several new electrically conductive compounds for the HVAC industry. Key objectives in this field require constant improvement in performance, such as reduced energy consumption, without compromising safety. Germany-based Wolf is using an electrically conductive Latiohm compound to manufacture the couplings that handle the air-gas blend in condensing boilers. The company says the application required uniform electrical conductivity sufficient to prevent electrostatic charge accumulation. It selected Latiohm 66-07 PD08 G/30, which uses carbon fibres and specially selected electrically conductive additives. The compound is said to have provided the mechanical strength (100 MPa at 90°C), dimensional stability and long lifetime required to withstand the temperatures found inside the boiler.
Speciality compounder COMPOUNDING WORLD | February 2019 Ohm/sq – in-
cluding the manufacture of coloured conductive compounds,” she says. The company works with all commodity and engineering plastics, except PVC, and is not limited to the use of carbon black to impart electrical conductivity, Van Bellingen says. “Although carbon blacks offer lots of advantages, they also have some limitations, which can be fulfilled by other conduc- tive additives such as carbon fibres or stainless steel fibres. We select the most appropriate conductive additive to provide the best overall properties needed, as each individual conductive additive will bring its specific added properties,” she explains. “One of our key strengths is to be able to
produce conductive compounds that have many other additional functionalities on top of electrical conductivity,” she says.
Sensor shielding Witcom views its most important market segments in electrically conductive compounds as automo- tive, industrial, HVAC, safety equipment, measuring equipment and dust extraction. “We see an increasing demand for radar absorbing EMI shielded material for autonomous driving and ADAS sensors,” Van Bellingen says. “The HVAC industry is rather conservative and can still use a lot of metal, but European players understand the huge benefit of conductive plastics to make axial fan blades and fans for central heating systems. Last year we also responded to a special customer request to develop a coloured conductive polyamide compound that offered toy compliance. We are now seeing more requests for electrically conductive com-
pounds that also involve food contact compliance.”
Witcom has delivered a number of
www.compoundingworld.com
PHOTO: LATI
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70
