ZEMSIL® در فرآیندهای شیمیایی

Silicone Materials in Chemical Processing

Chemical processing plants operate under conditions that destroy most organic materials: concentrated acids and bases, chlorinated solvents, steam, high-pressure reaction vessels, and continuous duty cycles measured in years rather than months. Silicone materials — including coupling agents, defoamers, corrosion-resistant sealants, and high-temperature coatings — have become standard inputs across refining, specialty chemicals, agrochemicals, and fine chemical manufacturing.

Unlike general industrial rubber, silicone offers thermal stability from -60 °C to +230 °C continuous (short-term excursions to 300 °C), resistance to steam and many oxidizing media, and dielectric properties that matter increasingly as chemical plants add instrumentation and control equipment. The penalty is cost and, in some chemistries, attack by concentrated aromatics or ketones — applications engineers must match the silicone grade to the actual media exposure.

Key Application Areas

Reactor and heat exchanger seals: HTV silicone gaskets and O-rings for flanged connections on reactors, autoclaves, and heat exchangers operating above the capability of EPDM or NBR. For exposure to hydrocarbon streams, fluorosilicone (FVMQ) grades provide additional chemical resistance. ZEMSIL SB-HTV compounds are available in 40–80 Shore A for compression-molded gaskets; SB-RTV2 two-part systems suit in-situ formed gaskets on large flanges.

Pipe and vessel penetration seals: where pipes carrying process streams penetrate walls or equipment enclosures, silicone sealants maintain the fire and chemical barrier. SS-N neutral-cure sealant and SS-WS waterborne-system sealant handle temperatures to +200 °C.

Foam control in reaction vessels: exothermic reactions, distillation columns, and effluent treatment all generate foam that reduces throughput and risks vessel overflow. ZEMSIL defoamers — DF-A (silicone oil/silica compound), DF-B (self-emulsifying), and DF-C (aqueous emulsion) — are used at 10–200 ppm to break foam in fermentation, reaction, and wastewater applications. DF-F is specified for food-contact and potable water applications where FDA compliance is required.

Surface treatment of fillers and pigments: chemical plants that compound pigments, specialty fillers, or functional powders rely on silane coupling agents to compatibilize inorganic surfaces with organic matrices. CS-550 (KH-550), CS-560 (KH-560), and CS-570 (KH-570) cover the primary amino, epoxy, and methacryloxy functionalities. Surface treatment improves dispersion, reduces viscosity, and dramatically increases composite strength.

High-temperature coatings on process equipment: silicone resins — SR-AC (acrylic-modified) and SR-EP (epoxy-modified) — are binders for heat-resistant coatings on boilers, reactors, stacks, and exhaust headers to +600 °C. These coatings prevent corrosion under insulation (CUI) and reduce maintenance intervals.

Product Selection by Chemical Media

Regulatory and Certification Considerations

Chemical plants selling into regulated markets impose traceability and compliance requirements on silicone components:

• FDA 21 CFR 177.2600: food-contact silicone rubber compositions — relevant for food or pharma API plants.
• ATEX / IECEx: equipment in explosive atmospheres; silicone itself is not a hazard but compound additives must be declared.
• REACH SVHC: silane coupling agents are registered substances under REACH; SDS and registration numbers available on request.
• ISO 9001 / ISO 14001: ZEMSIL operates under a quality management system with full batch traceability.

Sourcing Considerations

Procurement teams in chemical processing specify silicone by hardness, temperature rating, and compression set (the key seal-performance indicator). Request data for:

• Compression set at 150 °C / 70 h (ASTM D395 / ISO 815)
• Elongation at break and tensile strength (ASTM D412)
• Volume swell in relevant media (ASTM D471)

ZEMSIL supplies HTV compounds in standard 10 kg slabs or custom mixed-and-pre-formed sheet. Sealants ship in 300 ml cartridges or 600 ml sausages. Coupling agents and defoamers ship in 25–200 kg drums. Lead time for standard grades is 7–14 days ex-works; custom HTV formulations require 3–5 weeks.

Related Reading

Silane coupling agents overview, Defoamers application guide, HTV silicone rubber, Silicone sealants, High-temperature resistance, Chemical processing industry context.