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PAINTED ENCLOSURES

Special

Painting is recommended for plastic enclosure batches of less than 500pcs (see also colouring of plastic enclosures).

Aluminium enclosures are painted with polyester powder paint in standard RAL colours, according to the following process.

Standard pre-treatment (passivation) method is Fe-phosphatizing. Yellow chromatizing and other special pre-treatments on request.

Unpainted enclosures are also pre-treated; they are ready for the customer´s own powder or wet painting process.

EMC

Plastic Enclosures

Various shielding methods of plastic enclosures and their characteristics are shown in the table below. As the table demonstrates, Ni-Painting is clearly the most cost-effective option.

The best results in sealing the base-cover joint have been achieved with the special conductive gasket CHO-SEAL 1350. In combination with Ni-painting of the inside of the enclosure a relatively effective level of shielding is achieved

EMC

EMC Shielding Data Sheet of Plastic enclosures

Shielding
method
Coating
thickness
microns
EMI-shielding
attenuation dB
ASTM ES 7-83
Sheet
resistance
Ohm/square
Relative
coating
costs


  Ni-painting


50

35-60 dB

0,5

1

  Ag-painting
  (fast drying silver)

  Ag-painting

  Ag/Cu-painting

  Cu-painting

  Graphite-Painting

  Al Vacuum coating

  Zn-Arc



25

25

50

50

50


1

50



55-65 dB
(100 MHz)
60 - 65 dB

60 - 65 dB

60 - 65 dB

40 dB (100 MHz)


40 dB (100 MHz)

60 - 65 dB


0.01

0.1

0.2

0.25

10 (25 micr.)


0.1

0.25 - 0.8


55

50

3

2

2


10

5

Shielding effect of Ni-painting


dB          

60

40

20

Ni-painting

Diagram:
Telecom Finland Ltd,
Testing laboratory.
Test report
TL 940015

                  30 MHz                                                      1030 MHz 


Aluminium Enclosures

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

 Shielding effect of aluminium enclosures

dB
100

80

60


Aluminium shielding
30 MHz                                                   1030 MHz

Diagram:
Telecom Finland Ltd, Testing laboratory.
Test report
TL 940015

RFI shielding effect of FIBOX Euronord II AL 121208 aluminium enclosure; unpainted interior and Cho-Seal 1350 conductive gasket.


PRINTED ENCLOSURES

Plastic and aluminium enclosures

  • Silk screen printing is recommended for enclosure batches of less than 1000pcs. It is suitable for flat surfaces, also large areas.
  • Tampo printing

Tampo printing is the best solution for batches over 1000pcs. It is suitable for printing on both flat and curved surfaces of limited size; and tight spots like inside surfaces.

Both methods offer printing with 1 to 3 colours to RAL or PMS specifications.

B/W paper or film original suitable for printing will ensure a good printing result.   

 

Printed2

Printed

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