PAINTED ENCLOSURES
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For plastic enclosures, in smaller volumes, a customer-specific colour is best achieved by painting. Moulding with a customer specified colour of the plastic material is possible at a 500-piece level, but becomes more cost effective for single runs that exceed 1000 pieces (for more information see special colour moulding). For aluminium enclosures, painting is the only option for custom colours. The preferred method uses polyester powder paint, in standard RAL colours. Thorough surface preparation and cleaning is the key in achieving a high-quality and long-lasting finish. Other surface treatments are available for aluminium enclosures. Please contact the factory for more details. |
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EMC A variety of shielding methods are available for plastic enclosures. The characteristics of these methods are shown in the following table. As the table indicates, Ni-Painting is the most cost-effective option, while Ag-painting is the most costly. In addition to the interior conductive coating, attaining a high degree of shielding requires a special conductive gasket material be installed. Excellent results in sealing the base-cover joint have been achieved using a silver filled elastomeric gasket, such as CHO-SEAL 1350. In combination with Ni-painting, a relatively effective level of shielding can be achieved. |
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EMC Shielding Data Sheet of Plastic enclosures
30 MHz 1030 MHz |
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Aluminium Enclosures Aluminium enclosures are inherently conductive, making them ideal for EMI/RFI protection. Only the addition of a conductive gasket is required. However, the specific enclosure must be prepared in order for it to receive the conductive gasket: the gasket groove channel needs to be either unpainted or stripped of paint. The former method is preferable and is available by special order from the factory. Standard CHO-SEAL 1350 gasket characteristics. This gasket is used by FIBOX for both plastic and aluminium enclosures. |
| Characteristic | |
Test procedure |
| Elastomer binder | Silicone | |
| Conductive filler | Ag/Glass | |
| Volume resistivity Ohm-cm, max. as supplied without pressure-sensitive adhesive |
0.01 | CEPS-0002 |
| Hardness | 65 +/- 5 | Shore A |
| Elongation, min. | 75 % | ASTM-D412 |
| Compression set, 70 hrs. at 100 ° C, max. |
30 % | ASTM-D395 Method B |
| Low temperature flex TR10, min. |
- 55 ° C | ASTM-D1329 |
| Shielding effectiveness dB 100 Mhz E-field 500 MHz E-field 2 GHz Plane Wave 10 GHz Plane Wave |
100 100 90 8 |
Modified MIL-STD-285 Reference measured through 610x610 mm opening |
| Volume resistivity after heat aging Ohm-cm, max. |
0.01 | CEPS-0002 |
| Post tensile set volume resistivity Ohm-cm, max |
0.01 | CEPS-0002 |
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Shielding effect of aluminium enclosures |
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| dB 100 80 60 |
 30 MHz 1030 MHz |
Diagram: |
RFI shielding effect of FIBOX Euronord II AL 121208 aluminium enclosure; unpainted interior and Cho-Seal 1350 conductive gasket.
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NOMENCLATURE SCREEN-PRINTED ENCLOSURES Plastic and aluminium enclosures • Silk screen-printing is available and recommended for enclosure batches of less than 1000 pieces. It is ideal for flat surfaces and large areas and is available in multiple colours.
Tampo (Pad) printing is the best solution for batches of over 1000 pieces. It is suitable for printing on both flat and curved surfaces and compact areas such as inside surfaces. The total size is more limited than in silk screening. Both methods offer printing with 1 to 3 colours for RAL or PMS specifications. B/W paper or film original suitable for printing will ensure a good printing result. Please consult the factory for specific details and requirements of reproducible artwork. |
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