Push-In Back Side Seals

Push-in back side seals are weak compression deflection-style gaskets for commercial windows. Like push-in bulb seals, they can take up a large amount of space in the mullion, the part of the window frame that divides or separates it into different sections. However, with a push-in back side seal, the outside lip runs and along the side of the window, producing a sightline where the lip ends.

Glazing Seals for Storefront and Commercial Windows

Vip Rubber and Plastic of La Habra, California (USA) makes push-in back side seals for the storefront and commercial window market. We do not keep these items in stock for small consumer orders, and minimum order quantities apply. Lead times may vary. If you are a manufacturer, we invite you to contact us to discuss your sealing application.

Push-In Back Side Seal Materials

Most push-in back side seals are made of 70-durometer EPDM or Santoprene, a thermoplastic vulcanizate (TPV) that is a high-performance thermoplastic elastomer (TPE).

  • EPDM is an extremely durable, flexible, and weather-resistant synthetic rubber.
  • Santoprene is flexible and has the properties of rubber, but with enhanced performance.

Push-in back side seals are also made of neoprene rubber that meets ASTM C864 requirements. This industry specification is for dense preformed elastomeric compression gaskets used in window glazing and sealing applications. On the Vip website, push-in back side seals are grouped with other types of plastic extrusion profiles.

Compression Deflection and Window Seal Installation

The push-in back seal shown on this web page lacks lateral compression deflection. It has a significant amount of give, however, and provides an alternative to double-sided sponge glazing tapes that use a pressure-sensitive adhesive (PSA) for installation.

Push-in back seals are also relatively easy to install. They are a good choice for sealing the area between the glass panel and the window sash or door frame. These glazing seals prevent air and water leaks and can provide longer-lasting performance than some other door and window gasket options.