Materials: Foamable TPVs for Door & Window Profile Seals

Teknor’s new Sarlink TPV series is said to avoid complications associated with polyurethane seals.

A new series of foamable TPV compounds reportedly exhibit the high resilience needed for effective sealing of door and window profiles. The Sarlink 8100 Series from Teknor Apex Co., Pawtucket, R.I., is being positioned as an alternative to widely used polyurethane (PUR) foams.

Available in a range of 40 to 70 Shore A hardness, these TPV compounds can be foamed to a density of 0.29 g/cm(3) range which is comparable to those of PUR foam used in door seals but is difficult to achieve with standard TPEs. As TPV’s these compounds are said to exhibit lower compressive set than standard TPEs, providing more of the resilience needed to withstand the repeated opening and closing of doors. The Series 8100 compounds can be foamed using both chemical and physical blowing agents, and unlike PUR foams, are processed in standard equipment for thermoplastics. Moreover, unlike PUR, TPVs do not require a curing step, are recyclable, and do not present concerns about isocyanate monomer.

Door and window profiles are typically three-layer structures, with a skin layer providing protection and good appearance, the foam layer, and a rigid component such as PP. The Sarlink 8100 compounds are said to adhere well to, and can be coextruded with, other TPVs, TPOs, and PP.  In addition, the company supplies harder TPVs that serve as skin materials and can also custom-formulate foamable grades of TPVs or styrenic TPEs.