Materials

Thermoplastics used in fabrication are those that are “melt processable.” Their shape can be changed through thermoforming and they can be welded. Those frequently considered for corrosion applications include:

  • PVC (Polyvinyl Chloride)  This amorphous thermoplastic is the most common. It is low in cost and is easy to fabricate. PVC is excellent in handling many strong acid and alkali solutions and has a temperature capability of about 140 degrees F.
  • CPVC (Post Chlorinated PVC)  Similar to PVC but higher in temperature capability (about 190 degrees F.). Welding and fabrication are more difficult than PVC.
  • PP (Polypropylene) This crystalline polymer has a temperature capability of about 212 degrees F. It is excellent in handling organic acids and alkalis, alcohols, aldehydes and phenols. It is unsuitable for halogens, aromatic and chlorinated hydrocarbons.
  • HDPE (High Density Polyethylene)  This a non-fluorinated thermoplastic with chemical resistance properties similar to Polypropylene. It is available as a sheet lining with a maximum service temperature of 185° F

Fluoroplastics  These plastics all contain fluorine which is highly electro negative making them inert and chemical resistant They also tend to handle high temperatures and are very pure.

  • PVDF (Polyvinylidene Fluoride)  The most commonly used fluoropolymer. It has a high level of purity, excellent chemical resistance and a temperature capability of up to about 250 degrees F. It is frequently used for strong acids, solvents and in the handling of DI water. It is not recommended for caustics.
  • ECTFE (Ethylene Chlorotrifluoroethylene)  ECTFE is similar to PVDF in its chemical resistance and has somewhat improved resistance to caustic and chloride environments. It exhibits excellent melt processing properties and has the lowest coefficient of expansion of any of the fluorinated materials, making it a good selection for high thermal cycling environments.
  • ETFE (Ethylene Tetrafluoroethylene) - is a partially fluorinated thermoplastic. It is resistant to most chemicals except concentrated oxidizing acids at elevated temperatures, alkali amines, certain organic solvents, alkali metals at ambient temperature, fluorine at elevated temperatures, and certain halogenated compounds.
  • FEP (Fluorinated ethylene propylene)  A fully fluorinated thermoplastic which is chemically inert. FEP is subject to attack at ambient temperature by alkali metals, alkali metal organics and fluorine.
  • PFA (perfluoroalkoxy) The most chemically inert of all the fluorinated materials. PFA is very similar in composition to PTFE and FEP (fluorinated ethylene-propylene). PFA and FEP both share PTFE’s useful properties of low coefficient of friction and non-reactivity but are more easily formable.

Elastomers any of various elastic materials that resemble rubber (resumes its original shape when a deforming force is removed)

  • Chlorobutyl is a synthetic based elastomer with resistance to ozone and sunlight, strong alkalis and other harsh chemicals.
  • Neoprene (Polychloroprene) is a synthetic based elastomer and has excellent resistance to alkalis, sulfuric acid, and water. It is not suitable for solvents, halogens or phenols.
  • Hypalon® ( Chlorosulfonated Polyethylene) is a synthetic based elastomer with excellent resistance to ozone and sunlight, chromic, sulfuric and nitric acids.

Please contact us for any of your corrosion protection material questions or issues.