Materials

Elastomers Processed by Presray Pawling


Common Name-
Base Polymer
Natural
Rubber
Butyl
EPDM or
EP Rubber
Neoprene
Nitrile or
NBR or Buna-N
Silicone
Fluorocarbon
Fluorosilicone
Chemical Name
Polyisoprene
Isobutylene
Isoprene
Ethylene
Propylene
Chloroprene
Acylonitrile
Butadiene
Polysiloxane
Fluoronated
Hydrocarbon
Fluorovinyl Silicone
ASTM Designation NR IIR EPDM CR NBR VMQ FKM FVMQ
Tensile Strength (psi) Over 3000 Over 2000 Over 2000 Over 2000 Over 2000 Over 1200 Over 1000 Over 1200
Hardness Range (Durameter A) 30-90 40-75 50-90 25-80 40-95 40-80 60-80 40-70
Adhesion to Metals Excellent Good Good Excellent Excellent Excellent Good Excellent
Adhesion to Fabrics Excellent Good Good Excellent Good Excellent Good Excellent
Tear Resistance Very Good Good Fair Good Fair Poor to Good Fair Poor to Good
Abrasion Resistance Excellent Good Good to Excellent Very Good Good Poor Good Poor
Compression Set Excellent Fair Good Good Good Very Good Good to Excellent Fair
Resilience                
          Cold Excellent Poor Good Good Good Excellent Fair Excellent
          Hot Excellent Very Good Very Good Very Good Good Excellent Good Excellent
Impermeability to Gases Good Outstanding Good Good Good Poor Excellent Poor
Acid Resistance                
          Mild Dilute Fair to Good Excellent Excellent Excellent Fair to Good Excellent Excellent Excellent
          Strong Concentrated Fair to Good Good Good Good Good Fair Good Good
Solvent Resistance                
      Aliphatic Hydrocarbons Poor Poor Poor Fair to Good Excellent Poor Excellent Excellent
      Aromatic Hydrocarbons Poor Poor Poor Poor Poor Poor Excellent Good
      Oxygenated (Ketones, etc) Poor Good Good Poor Poor Poor Poor Poor
      Lacquer Solvents Poor Poor Poor Poor Poor Poor Poor Poor
Resistance To:                
    Swelling in Lubricating Oil Poor Poor Poor Good Very Good Poor Excellent Good
    Gasoline Poor Poor Poor Good Excellent Fair Excellent Excellent
    Animal Oils Poor Fair Fair Fair Excellent Good Excellent Excellent
    Water Absorption Very Good Very Good Very Good Good Very Good Excellent Good Good
    Oxidation Good Excellent Excellent Very Good Good Excellent Excellent Excellent
    Ozone Poor Fair to Good Outstanding Very Good Fair Excellent Excellent Excellent
    Sunlight Aging Poor Very Good Outstanding Very Good Poor Excellent Good Excellent
    Heat Aging Fair Good Very Good Good Good Outstanding Outstanding Outstanding
    Low Temperature Very Good Good Very Good Good Fair to Good Outstanding Fair Outstanding
    Flame Poor Poor Poor Good Poor Fair Good Excellent
    Vegetable Oils Poor Fair Fair Good Good Fair Good Fair
    Chlorinated Hydrocarbons Poor Poor Poor Poor Fair Poor to Fair Excellent Good

Reinforcing Fabrics

For critical applications involving high mechanical stresses, Presray Pawling silicone rubber seals and other products are reinforced with durable industrial fabrics to gain:

  • Increased Tensile Strength
  • Improved Resistance To Tear
  • Added Resistance to Compression for Better Sealing Force
  • Resistance to Rupture
    (Inflatable Seals)
  • Increased Stiffness of the Seal Mounting Flanges

Open Mesh

Tightweave
Open Mesh Tight Weave

Cover materials
For rugged sealing applications and other uses where the product is subjected to excessive friction and abrasion, Presray Pawling parts can be covered with a tough layer of PTFE, tightweave polyester or fiberglass fabric.