Compression Molding


Compression Molding

Thermech Engineering manufactures compression-molded stock shapes and finished components from plastic and composite polymers, primarily PTFE, melt-processible Fluoropolymers and other Engineered Plastics.  Compression molding involves subjecting powder or pellet resins to substantial pressures inside of a closed die set to create rods, tubes, sheets, plates, near-net shapes or complex finished parts.  Using our decades of compression molding experience, we combine premium resins and sophisticated process technologies to create superior compression-molded shapes and machined parts that meet or exceed your specifications.

We do not mold general-purpose engineering plastics (ABS, nylon, PVC) or commodity industrial plastics (polypropylene, polyethylene, polystyrene).  We will, however, research and manufacture all high-performance plastic materials which are compatible with our compression-molding equipment.  This includes custom blends that are tailored for specific customer requirements.  Just ask.  We’ll be glad to help.

Early in its decades-long history, Thermech concentrated on molding high-volume production items such as Teflon® backup rings but gradually began producing more sophisticated items such as cryogenic seals for the aerospace industry, including seals for the Space Shuttle Main Engine (SSME).  Today, critical high-tech compression-molded components that require advanced testing and top-notch quality control make up the bulk of Thermech’s production.  Our AS9100D with ISO 9001:2015 registered quality management system ensures that our compression-molded parts consistently meet or exceed the specifications of our customers in industries such as:

  1. Aerospace and Defense

  2. Chemical Processing Industry (CPI)

  3. Electrical Engineering

  4. Electronics

  5. Machine Shops Medical

  6. Oil & Gas

  7. Seal Manufacturers

  8. Semiconductor

  9. Water & Wastewater Treatment

Benefits of Compression Molding

Compression molding enhances the properties of Fluoropolymers and other Engineered Plastics, delivering the performance required for the most demanding applications.  Thermech produces compression-molded forms that have low internal stresses and superior dimensional stability, which enables us to hold tight tolerances in the parts that we machine.  Our highly efficient processing techniques yield maximum performance semi-finished shapes and machined parts with minimum waste, which translates into maximum value for our customers.

  1. Enhanced properties compared to other manufacturing methods

  2. 1.Higher tensile strength

  3. 2.Greater elongation

  4. 3.Increased hardness

  5. 4.Improved toughness

  6. 5.Greater dimensional stability

  7. 6.Lower coefficient of friction

  8. 7.Enhanced dielectric properties

  9. Minimized internal stress and warping

  10. Excellent dimensional stability and machining accuracy

  11. Near-net molding limits scrap, which saves money, especially when molding expensive plastic compounds

  12. Large, bulky parts can be molded

  13. Ability to manufacture large basic shapes that cannot be made using extrusion techniques

  14. Ability to mold polymers that are inherently not well suited for other processing methods

  15. Ability to produce custom blends

  16. Reduced mold costs—we have hundreds of mold sizes in stock

  17. Low minimum quantities allow you to order just what you need without having to pay for expensive tooling or small-run setup charges

  18. For prototypes or small quantities, machining compression-molded plastics is a cost-effective alternative to building expensive molds

Compression Molding Resins

In addition to standard Fluoropolymers and other Engineered Plastics, Thermech compression molds two families of custom-compounded resins: TECfluorfil fluoropolymers and TECthermalon engineered plastics.

Compression-molded Shapes and Sizes


  1. Diameters up to 27”

  2. Lengths up to 24”


  1. OD up to 39”

  2. ID as narrow as ½”

  3. Lengths up to 24”


  1. Thicknesses from 0.003” to 4”

  2. Widths x Lengths from 12” x 12” to 36” x 36”

Sheet rods:

  1. Diameters from 0.25” to 3”

Near-net shapes:

  1. To your custom specifications

Working with Thermech on Compression Molding Projects

Since 1949, we have built our reputation as the source for custom materials and technology solutions for difficult polymer problems.  Engineers and buyers routinely collaborate with us because of our deep expertise, great customer service and phenomenal quality control.

If you would like to inquire about working with us to manufacture exceptional compression-molded parts that solve your challenges, please call us at (714) 533-3183 or email us at

Perfecting Surfaces Since 1949   •

(714) 533-3183

Compression Molding


Compression Molding of Teflon® PTFE, PFA, FEP, ETFE / Tefzel®,

PCTFE / Kel-F® / NEOFLON™, PEEK / VICTREX®, PI / Vespel®, PEI / ULTEM™, PPS / Ryton®


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Compression Molding

Plastics Machining

Teflon® Coating / Spray Coating

Powder Coating

Quality Management System

AS9100 Registered

ISO9001 Registered

Chemours Teflon Industrial Licensed Applicator

Whitford Licensed Applicator

Aerospace Coatings

Medical Coatings

Non-stick Pan Coatings

Mold Release Coatings

Compression Molding Resins


  PTFE / Teflon®





  ETFE / Tefzel®

  PVDF / Kynar®

  ECTFE / Halar®




  PI / Vespel®


  PPS / Ryton®

  PBI / Celazole®




Spray Coating Materials





  Teflon® PTFE

  Teflon® FEP

  Teflon® PFA

  Teflon® One Coats

  Teflon® PTFE/PFA Blends



  Xylan® XLR




Powder Coating Materials

  Halar® ECTFE

  Teflon® ETFE

  Teflon® FEP

  Teflon® PFA

  Ryton® PPS


PTFE Etching and Bonding