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14 Nov 2022
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Silicone Rubber ( MQ, VMQ, PVMQ )

VMQ

Silicone Rubber ( MQ, VMQ, PVMQ )

Physically, silicones are based on silicon, an element derived from quartz. To create this class of synthetic elastomers, pendant organic groups such as methyl, phenyl and vinyl are attached to silicon atoms. The different addition of side chains can achieve significant variations in properties. Silicones have excellent heat, ozone and corona resistance, very well dielectric stability, and resistance to many oils, chemicals, and solvents. And for all elastomers, silicones possess the best flexible property at low temperature. But it also has some weakness like low tensile strength, poor tear and wear resistance.

Cure system – Peroxide-Cured vs. Platinum cured

Standard silicone compounds are usually peroxide – cured. Platinum- cured compounds offer better flexible properties and very low volatile matter. Platinum – cured silicones usually are applied in medical system or other required low volatile matter, but they need to be produced in clean room and higher cost of platinum catalyzer so they are more expensive than peroxide-cured ones.

Other Common Variations:

►Silicones can be formulated with only “white list” ingredients as specified in 21.CFR 177.2600 for use in applications Where the elastomer will be in contact with food or beverages.

►Silicones can be submitted for approval approval by the National Sanitation Foundation (NSF) for use in drinking water applications.

►Silicones are usually used in automotive system like boots, oil filter valve, gasket in light….etc.

►Silicone parts can be used in medical system which especially require compliance to USP CLASS VI.

Performs Well In…

►Engine and transmission oil ( mineral oils )

►Diluted salt solution

►Moderate water

►Dry heat

►Ozone, weather resistance

Doesn’t Perform Well In…

►Concentrated acids and alkalis

►Steam over 120°C

►Petroleum oils and fuel

►Ketones

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admin_ilkhani
14 Nov 2022
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Carboxylated Nitrile ( XNBR )

XNBR Carboxylated Nitrile ( XNBR ) Cabboxylated Nitrile is similar to Nitrile rubber, but the polymer backbone has been chemically modified with Carboxylic Acid containing group. This result is XNBR with more excellent abrasion and tear resistance than traditional NBR. For this reason, XNBR based parts are usually applied in dynamic assembly such as seals and rod wipers. Cure system - Sulfur - Cured Standard XNBR compounds are sulfur-cured Performs Well In… ►Aliphatic hydrocarbon ►Vegetable and mineral oils and greases ►Diesel ►Water Dilute acids, alkali and salt solutions Doesn't Perform Well ...

admin_ilkhani
14 Nov 2022
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Thermoplastic Polyurethane ( TPU )

TPU Thermoplastic Polyurethane ( TPU ) Thermoplastic polyurethane (TPU) is an elastomer that is fully thermoplastic. Like all thermoplastic elastomers, TPU is elastic and melt-processable. Further, it can be processed on extrusion as well as injection, blow and compression molding equipment. Thermopalstic polyurethane ( TPU ) is a unique category of plastic created when a polyaddition reaction occurs between a diisocyanate and one or more diols that results in high resilience, good compression set, plus resistance to impacts, abrasions, tears, weather, and ...