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SRBOX enclosure gaskets offer the best protection
 
Gasketing plays an essential role in enclosure protection.  In the long run, the IP rating and its reliability depend mainly on the properties
of the gasket used in the enclosure. Key performance factors of a gasket are its compression set and proper fit in the gasket groove. The
best general purpose gasket material is polyurethane which has an exceptionally low compression set. When accurately injection foamed,
the polyurethane gaskets stay tightly in the right place. And EPDM material provides the best protection against the most popular industrial
chemicals. However, it is wise to check the effect of a chemical on each gasket material since the chemical resistance of gasket material
varies greatly.
 
In some cases the perfomance of an enclosure can be modifed by changing its gasket. The degree of protection depends on the material
and the cross-section profile of the gasket. When choosing gasket material, compare the elasticity properties of different materials and how
these properties are affected by cold and heat, or by contact with various chemicals. An important factor is that both the enclosure and gasket
must withstand the same chemicals in order to reach a safe resistivity.
 
SRBOX enclosures are well designed
 
The degree of ingress protection (IP) of an enclosure is mainly dependent on the properties of its gasket. Nevertheless, the gasket must
also properly fit the enclosure. In addition to the cross-section profile of the enclosure. In addition to the cross-section profile of the gasket,
there is the cross section of the gasket's contact with the surfaces of the enclosure bases and covers. If the cross-section structures
and manufacturing accuracy of an enclosure are not top quality, the IP rating will remain low even when equipped with a good gasket.
Naturally, all SRBOX enclosures arecarefully designed and precision made. Using SRBOX enclosures, you only need to focus on the
variances in gasket materials.
 
SRBOX enclosure gaskets are made of PUR, EPDM, neoprene and silicon materials. Let's take a closer look at the characteristics of
these materials: Table 1 includes some commonly-used physical properties of the gaskets. Note that the chemical resistances in the
box and in Table 2 are only rough generalizations to give you some clues to gasket material behavior. The resistance of each chemical
should be checked separately. For additional information, please contact SRBOX.
 
Reliable SRBOX PUR gaskets(polyurethane)
 
PUR differs from other gasket materials as it is shaped by special foam injection in the enclosure's gasket groove(usually in the cover).
In this way, the gasket sticks permanently and securely to the enclosure. This ensures a reliable IP rating. PUR gaskets have an extremely
low permanent compression set(the amount of residual displacement after the compressing load has been removed). In addition, the
mechanical properties remain stable in -50 to + 130℃ temperature range. The material can easily withstand various weather conditions.
 
PUR gaskets are resistant to fats, oils, and acids, but they do not withstand strong alkalis.
 
Sturdy SRBOX EPDM gaskets(ethylene-prophene-diene-monomer)
 
These gaskets have a very low permanent compression set and are resistant to cold and heat in a wide -50 to +120℃ temperature range.
Ozone, oxygen and UV radiation have little effect on EPDM gaskets which makes them suitable to outdoor conditions as well.
 
Due to their chemical structures, SRBOX EPDM gaskets resist polar solvents well. The gasket material is suitable for application
environments where tolerance is required against water, salt fluids, steam, alcohols, glycols, phosphate based esters or weak acids,
and weak alkalis. EPDM gaskets are not resistant to many oils and hydrocarbon based solvents.
 
Weather-resistant SRBOX NEOPRENE gaskets(chloroprene rubber)
 
Mechanical properties of neoprene material are good and its permanent compression set is fairly low. Temperature resistance is from
-40 to +100℃. Neoprene is selfextinguishing with excellent weather resistance properties such as sunlight, oxygen and ozone which do
not affect the material.
 
Neoprene gaskets are resistant to oils, fats, hydrocarbons and alcohols, although some of these may cause limited material swelling.
 
Temperature-resistant SRBOX SILICON gaskets
 
Silicon gaskets have an exceptionally wide -60 to + 170℃temperature resistance range. They are primarily used in extremely cold or
hot environments. Silicon is resistant to alcohols and ketones, but strong acids and strong alkalis have dissolving effects on the material.
 
Table 1 SRBOX gasket materials: physical properties comparison
 
 Property  Unit  PUR  EPDM  Neoprene  Silicon
           
 Temperature range  ℃  -50 to +130  -50 to +120  -40 to +100  -60 to +170
 Tensile strength  Mpa  0,4  13,0  8,0  9,4
 Elongation at break  %  110  300  250  540
 Hardness  Shore A  12  65  66  52
 Density  g/cm^3  0,33  1,12  1,6  1,15
 Compression set  %  5  20  35  14
 
Table 2 SRBOX gasket materials: chemical resistance comparison
 
 Property  PUR  EPDM  Neoprene  Silicon
         
 Chemical  
 Neutral salts  Good  Good  Good  Good
 Acids, low concentrations  Moderate  Good  Moderate  Moderate
 Acids, high concentrations  Poor  Moderate  Poor  Poor
 Alkalis, low concentrations  Moderate  Good  Good  Moderate
 Alkalis, high concentrations  Poor  Good  Moderate  Poor
 Petroleums  Poor  Poor  Moderate  Poor
 Hydraulic oils  Good  Poor  Moderate  Poor
 Alcohols  Moderate  Good  Good  Good
 Cooling fluids  Moderate  Good  Moderate  Good
 
 
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