• Advanced Search
(800) 965-9872
You are here: | |
BLOB enclosure with partial aluminum coating
Vapour-plating plant: enclosure placed in bracket; all parts that are not to be vapour-plated must be maskedVapour-plating plant for EMC ALVACOAT(R) processSOFT-CASE with aluminum coatingTOPTEC enclosure with aluminum coatingDATEC-CONTROL with aluminum coatingSNAPTEC enclosure with aluminum coating and machiningShell-Type-Case with aluminum coating and contact strips (acc.)Conductive seals on requestCovers with aluminum coatingBLOB enclosure with partial aluminum coating
Vapour-plating plant: enclosure placed in bracket; all parts that are not to be vapour-plated must be masked
Vapour-plating plant for EMC ALVACOAT(R) process
SOFT-CASE with aluminum coating
TOPTEC enclosure with aluminum coating
DATEC-CONTROL with aluminum coating
SNAPTEC enclosure with aluminum coating and machining
Shell-Type-Case with aluminum coating and contact strips (acc.)
Conductive seals on request
Covers with aluminum coating
BLOB enclosure with partial aluminum coating

RFI-EMI Shielding - Aluminum coating

Aluminum coating

The aluminum coating is applied in a high vacuum. The 99.99 % pure aluminum is vaporized within a short period of time and is deposited on the plastic surface. The thickness of the coating is approx. 2.5 µm. This makes a shielding effect of 30-40 dB possible in the frequency range of 30 to 1000 MHz. The special aluminum coating is also characterized by good adhesion. To achieve an even better shielding effect, other coating thicknesses are available on request.

Certification in accordance with UL 746C / ALVACOAT®*

We have certification in accordance with UL 746C for the following materials in the standard OKW colors:
  • Cycolac S157
  • Rotec ABS 1001 FR/E
  • Rotec ABS 3001
  • Terluran GP-22
  • Novodur P2H-AT
  • Lexan 141R(f2)
  • Durethan BKV15H2.0+
  • Luran KR2867 CWU
  • Romiloy ASA/PC 8170
For current information, please refer to www.ul.com online certifications directory under UL File Number E257055.
To download a certificate, see the bottom of this page.

*ALVACOAT® is a registered trademark of OKW Gehäusesysteme GmbH and identifies the process used by OKW to coat plastic parts made of standard materials that are certified in accordance with UL 746C.

RFI/EMI and plastic enclosures

The non-conducting material used for plastic cases, for example ABS and PC, has advantages in voltage and contact protection compared with metal materials. It behaves like an insulator.

For devices that cause electromagnetic interference (see also attachment below) or whose operation is impaired by such interference, plastic cases without special measures offer only moderate protection.

The main reasons for EMC-interference are:

  • within low range of frequency < 100 MHz
    conductive interference
  • within medium range of frequency 30-300 MHz
    radiation from cables (cable serves as antenna)
  • within high range of frequency > 300 MHz
    interference radiation penetrating through material and openings
To meet current EC directives and standards, a variety of measures is required. For reasons of cost-effectiveness we recommend the following procedure:
  • The complete electric/electronic equipment, including board layout, should be designed in such a way that RFI/EMI requirements are met. This also includes a reduction in conducted interference and the elimination of cable interference radiation.
  • Partial screening of the sensitive components or interference radiators.
  • Reduction of interfering radiation entering through openings.
  • Increase in the screening effect of the case.

Additional RFI/EMI measurements

As almost every case is provided with openings and cable connections which reduce the shielding effect, it is important to observe the following recommendations:
  • Cable glands
    In order to maintain the protection class of the case and to improve the cable radiation, a suitable screw fitting of cables becomes necessary.
  • Improvement of contact
    As contact for our coated plastic cases we offer gaskets consisting of a foam core with silicone material. The silicone sheath contains copper particles that are silver-plated.
Please keep in mind that the use of external accessories may influence e.g. the protection class and can cause corrosion. For this reason, we recommend consulting the supplier prior to the use of these external accessories.

Coating of other materials on request.

  • Video