Page 118 - SICCO catalog

SICCO Technical Information
SICCO Materials & Glossary
EPDM Cellular rubber # (Ethylene-Propylene-Diene-Rubber) This smooth product is used for example for the sealing tape of desiccator doors. It is produced in a so-called expansion manufacture and shows cells in the inside of the product which are not connected. That is why components or sealings made of a primary product through cut out do not lose their capability of sealing. EPDM Cellular rubber is extremely light-weight with a density of approx. 0,13g/cm3 and an excellent thermal insulator through its low thermal conductivity of approx. 0,04 Wm*K. The service temperature is limited from -40 °C to +100 °C (temporary 120 °C). It is resistant to many acids and ba- ses in common concentrations, potassium and sodium combinations (such as saline solution), aqueous alum, detergents, photographic chemicals, cold ammonia, acetylene, alcohols, glycolbased antifree- ze fluids and ozone respectively silicone oil. It is not resistant to hydrocarbons (oils, greases, petrol), chlorinated hydrocarbons such as methylene chloride or carbon tetrachloride as well as nitro compounds and concentrated nitric or hydrochloric acids.
Natural Silicone
This elastomer with very good perma- nently elastic properties is characterized by a wide range of applications. It is
used as a neutral netting alkoxy-based 1K-Silicone grease and sealing compound for sealing plastic and glass panels, cable lead-ins and the Iris Port openings. The compatibility with strainless acrylic glass can be confirmed. During curing process small quantities of alcohol can be re- leased. Therefore, a good ventilation has to be provided during treatment. Through interaction of the cured natural silicone with liquid or gaseous chemicals such as iodine, bromine or aldehyde containing substances, the sealing compound can change color. If necessary, experiments have to be made beforehand.
Dischargeable silicone
It is used for the sealing of discs, for sealing of cable lead-ins or the Iris Port openings and more applications where electrostatic discharging is required. The discharge capability is achieved through addition of sooty particles. The specific contact resistance ρ as per DIN EN ISO 3915 (1999) is approx. 0,25 Ω x cm. During curing process small quantities of oxime connections can be released. Therefore,
a good ventilation has to be provided during treatment. If the applicator uses materials which will be afterwards treated with dischargeable silicone, he should clarify beforehand that its contents do not change the product (color for example).
NR Natural Rubber (Polyisoprene)“ “Natural Rubber” (NR) is used for gloves and other products with high-elastic properties. NR is the basic product of rubbers and is supplemented by silicone elastomers which are characterized by good elasticity at low temperatures, or by fluorine elastomers (FKM) or perfluore- lastomers (FFKM) which are especially used at high temperatures or in direct contact with aggressive chemicals. NR is resistant to high-energy radiation. That is why the products made of this material can be gamma-sterilized and are suitable for food, pharma and nuclear industries. Alternatively, it can be sterilized in an autoclave at 120°C for preparation of sterile products. NR loses its elasticity at temperatures < -40 °C. The maximum operating temperature should not exceed +80 °C. Thanks to its resistance to alcohols, acids and bases, NR is widely applicable.
Dischargeable EPDM (Etyhlene-Propylene-Diene-Rubber) This synthetic rubber is used in dischar- geable versions of products which contain sooty particles such as gloves. They are used if an electrostatic charging should be avoided in case of contact. Therefore
it is especially suitable for the use in ex- protected applications (contact resistance 4,8 *104 Ω * cm, DIN EN 1149-2, fulfils ATEX requirements) respectively in elect- ronic industries. The contents are conform to current FDA positive list. They are valid as per the criteria of the pharmaceutical, medical and food markets. Dischargeable EPDM is suitable for repeated steam ste- rilization without sticking. However, the maximum possible operating temperature must not be exceeded. EPDM loses its elasticity at temperatures < -20 °C. The maximum operating temperature should not exceed +130 °C. The material is free of halogen and resistant to many oxidizing media.
Black glass fibre reinforced PA
This glass fibre reinforced thermoplast is mainly used for corner connections, hin- ges or rails. Due to its high rigidity glass fibre reinforced PA is preferably used for all kinds of structural parts. Because of the additional stabilisation the material has a very high hydrolysis resistance at a continuous service temperature of 130°C and also has a good resistance against most acids. Nonetheless the material should not get in contact with hydroflu- oric acid or moderate respectively strong leaches. Furthermore glass fibre rein- forced PA stands out due to its excellent insulation properties. A direct contact with open flames should be avoided due to the given combustibility.
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