Custom Rubber Compounding: 1,000 Unique Formulations and Counting

Flexan specializes in custom rubber compounding. We mix our materials in house, giving us complete control of the formula and the flexibility to make materials to meet very specific customer requirements. Many other molding companies outsource that function. With our own in-house laboratory for material R&D and mixing capabilities, Flexan has developed a library of more than 1,000 proprietary elastomer formulas, each prepared for a specific application.

Our chemists draw on that experience when helping you select the best material for your part and its operating environment. We have experience with natural, synthetic and high-performance compounds, encompassing more than 350 raw materials and 80 organic elastomers. We can quickly develop a custom formulation, with material sampling for testing purposes to ensure that the compound and the part will perform as specified.

Unlike plastic materials, which computers can model to predict performance, rubber is difficult to model, yet it is essential for certain applications that require flexibility and durability. Flexan concentrates on custom rubber compounding, so we can take the guesswork out of rubber for our clients by providing expert advice from the early design stages to the end product.

Understanding Thermoset Elastomers

An elastomer is a polymer with viscoelasticity, which simultaneously exhibits the properties of a very thick fluid and a flexible solid.Thermoset elastomers are a class of polymers that are cured by cross linking molecular chains during the molding process, which requires the right amount of pressure and temperature to set the part into its permanent shape. Unlike plastics, which can break under pressure or melt in intense heat, rubber and elastomers hold up well to dynamic operating conditions, temperature variations, and harsh environments.

Rubber is the common name used for a variety of elastomers, but natural rubber is one of the least commonly used materials in industrial applications. When selecting the right elastomer for the application, our chemists and engineers consider such factors as the part’s operating conditions and the material’s ability to resist such environmental hazards as contact with oil and other fluids, abrasion, and temperature fluctuations, as well as the material’s cost.

In preparing a rubber compound for a specific application, we develop a recipe of the proper elastomer plus a mix of specialized additives to address such issues as resistance to UV, ozone or oil, bonding, and electrical conductivity.

Elastomer Families

General Purpose Elastomers
Lower cost materials for standard applications

  • EPDM
  • Natural rubber
  • Poly-isoprene
  • SBR
  • Silicone

High Performance Elastomers
Engineered materials that hold up best under extreme conditions

  • FKM
  • FSI
  • HNBR

Oil/Hydrocarbon-Resistant Elastomers
Wide range of solutions based on the specific oil or chemical

  • FKM
  • FSI
  • HNBR
  • NBR
  • Neoprene
  • Urethane

High Temperature Elastomers
275°F/135°C and above

  • EPDM
  • FKM
  • FSI
  • HNBR
  • Silicone

Low Temperature Elastomers
– 20°F/-29°C and below

  • Butyl rubber
  • EPDM
  • FKM
  • FSI
  • HNBR
  • NBR
  • Neoprene
  • Silicone

Compounding Capabilities in the U.S. and China

  • In-house R&D
  • Material selection and sourcing
  • Mixing facilities
  • Mills and preforming equipment
  • Material quality control
  • 100% traceability of materials