Rubber

Rubber, more accurately referred to as an elastomer, is a stretchy and elastic material widely used for sealing components and for damping shocks and vibrations in engineering and construction.

Sealing Components

Common rubber sealing elements include O-rings, seals for hydraulic and pneumatic cylinders, shaft seals (known as "gufero"), flat gaskets for pipe flanges and plumbing, pressure cooker lid seals, conical plugs, and window/door sealing profiles to fill gaps between frame and sash.

Vibration and Shock Absorption

Rubber is used in silent blocks, stoppers, machine base pads, building foundations, and automotive tires. Protective rubber edging (e.g. between glass and railings) helps absorb structural pressure but does not provide a sealing function.

Types of Rubber and Their Properties

• SBR – General-purpose mechanical rubber: Inexpensive, abrasion-resistant, operates up to 80°C.
• NBR – Oil-resistant rubber: Resists oils and fats; “NBR Super” also resists gasoline.
• EPDM – Weather-resistant rubber: Withstands up to 120°C, UV- and weather-resistant, not suitable for oils or gasoline.
• NR – Natural rubber: High elasticity and abrasion resistance, ideal for slingshots, model-making, and food-grade applications.
• Food-grade rubber: Includes red NR/SBR blends and white oil-resistant NBR used in food industry settings.

In former Czechoslovakia, rubber types were classified using ČSN standards, similar to steel. Today, rubber is usually categorized by its intended application.