Sheet Rubber for Sealing, Cushioning & Protecting
Garlock Rubber Technologies manufactures an extensive line of sheet rubber products including unsupported sheet, diaphram sheet, cloth-inserted sheet, bridge bearing pads, Viblon™ vibration pad, conveyor skirt rubber, and chute lining rubber.
GRT inventories many common thickness and widths of sheet rubber products but can also custom build elastomers from 1/32" to 1 1/2" thick and up to 72" wide.
The following chart is a useful tool to provide a general education of the common names of elastomers, their chemical name and their positive as well as negative properties.
Elastomers and Their Performance Characteristics
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Butyl IIR (isobutylene-isoprene)
+ Excellent resistance to acids and alkalis.
Excellent weathering properties and heat resistance.
Excellent electrical resistance. Low permeability to air.
Cold weather properties are fair.
- Poor resistance to fuels, solvents, oils and hydrocarbons.
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CPE (Chlorinated Polyethylene)
+ Excellent oxidation resistance.
Good oil resistance, heat resistance, ozone resistance and weather resistance.
Fair resistance to ketones and ethers.
- Poor cold weather properties.
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EPDM (ethylene-propylene diene)
+ Excellent resistance to ozone, sunlight and oxygen.
Excellent resistance to acids, alkalis and ketones.
Excellent heat resistance and aging.
- Poor resistance to fuels and oils.
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Fluoroelastomer (VITON fluroelastomer, a registered trademark of DuPont Dow Elastomers)
+ Excellent resistance to heat and oil combinations: hot greases found in engines and compressors.
Excellent resistance to a wide range of concentrated acids.
Impact resistance is fair.
- High cost of fluoroelastomer may limit usage to extreme applications.
Resilience is low and tear strength is limited unless certain compounding steps are taken to improve it.
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SBR (Styrene butadiene)
+ Good abrasion resistance and excellent impact and cut-and-gouge resistance. Can be compounded for use as skirtboard rubber, lining rubber, conveyor belt covers, tires and other extremely demanding applications. Used as gasket material and as an economical general purpose sheet.
- Not suited for use with oils, fuels, solvents, or hydraulic fluids.
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Silicone
+ Excellent properties for both hot and cold temperature extremes; excellent weathering properties; resists ozone and oxygen attack. Long service life can be expected at 200°F to 400°F (93°C to 204°C).
- Poor resistance to oils, fuels, and hydrocarbons. Fair performance when exposed to acids, alkalis and solvents. Physical properties (tensile, abrasion, tear and cut growth) are fair.
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Natural Rubber NR (Gum)
+ Good gasket material due to excellent physical properties such as resilience, tear strength and wear resistance. Natural rubber is used effectively as sand and shot blast curtain material because of its high abrasion resistance and resilience.
- Deteriorates when exposed to oils, fuels, solvents, and hydraulic fluids. Poor resistance to sunlight, ozone and oxygen.
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Neoprene CR (chloroprene)
+ Good oil- and petroleum-based solvent resistance. Good weather and ozone resistance. Neoprene may be blended with SBR rubberto achieve an economically priced sheet for moderately oil resistant applications.
- Poor resistance to degreaser solvents. Content levels of neoprene can vary widely. Application problems may occur when using blended or commercial grades of neoprene sheet of unknown quality levels in contact with oil, solvents and fuels.
Where good oil or fuel resistance is required, the fabricator and user need to specify one of the following:
• A known manufacturer's product
• An ASTM call-out
• A military specification
• An ASTM specified oil resistance level based on an ASTM test (e.g. oil swell)
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Nitrile (butadiene-acrylonitrile)
+ Excellent resistance to oils, solvents and fuels.
Resistant to a broader range of aromatic hydrocarbons than neoprene. Nitrile may be blended with SBR rubber to achieve an economically priced sheet for moderately oil resistant applications.
- Application problems may occur when using nitrile of unknown quality levels in extreme oil resistance applications or in contact with fuels and solvents. Content levels of nitrile can vary widely.
Where oil or fuel resistance is required, the fabricator and user need to specify one of the following:
• A known manufacturer's product
• An ASTM call-out
• A military specification
• An ASTM specified oil resistance level based on an ASTM test (e.g. oil swell)
Contact C&R Resources for elastomer selection assistance and where to buy rolls or fabricated parts.