How to Choose a Seal Material

Residential window and door manufacturers commonly use either EDPM or PVC for their seals. These materials offers varying benefits and are suitable in many applications. Manufacturers of commercial door systems, luxury residential window systems, and windows and doors for medical facilities often use a higher quality material, like TPV, for performance and aesthetic advantages.

Ethylene Propylene Diene Monomer (EPDM) is a synthetic rubber, frequently chosen for its performance in cold temperatures and elasticity (its ability to recover its original shape after being compressed or stretched). EPDM gaskets also boast high resistance to aging. However, its poor resistance to chemicals can lead to premature corrosion and blemishing. As a thermoset, EPDM cannot be recycled and reused for future seals.

Unlike EPDM, which is primarily extruded in black, PVC is colorable and can be extruded to fit with a window or door system’s style. While PVC has greater resistance to chemicals than EPDM, exposure to warmer temperatures will cause rapid aging in PVC components. Over time, PVC seals will shrink and warp, making a door vulnerable to leaks. PVC also doesn’t perform well in cold temperatures and will become brittle and inflexible.

Thermoplastic Vulcanizates (TPVs) are a newer offering in the market. Developed in the 1980s, TPVs are advanced, high-performance elastomers that combine the best attributes of rubber and thermoplastics, making them a popular choice in applications where durability and aesthetics are equally important.

TPVs consist mostly of fully cured EPDM rubber molecules encapsulated in a polypropylene matrix.  EPDM particles give TPV excellent compression recovery, elasticity, long-term weatherability, and other benefits. The polypropylene matrix gives TPV its recyclability, tight tolerances, light weight, and color-ability. It is also non-marking and has a pleasant surface texture, making it an ideal choice for commercial and luxury residential applications. TPV is not a good choice when there is exposure to temperatures continuously above 250°F (or 275°F intermittently).

A graph comparing weathering resistance across a variety of gasket materials
A graph comparing compression set data between a variety of gasket materials
A graph comparing hardness change across a variety of gasket materials

Learn more about material performance by clicking here for an independent lab’s aging study on TPV vs PVC seals.

The selection between EPDM, PVC, and TPV deserves a thoughtful examination of the particular application. Reed Rubber Products offers a thorough design review process and has addressed the specific needs for a variety of window and door systems.