Abstract: A simplified plastic window framing system for single or multiple glazing comprising combinations of complementary extrusions wherein the outward appearance of the finished mullions and peripheral framing appears to be that of single extrusions. In outward appearance the glazing is retained within recesses formed in the mullions or frame members and separable retaining members. The combination creates a substantially rectangular external appearance to the individual mullions and framing members.The framing members are roughly L-shaped and the mullions are roughly T-shaped in cross section. The retaining members are substantially rectangular or trapezoidal in cross section. As finished units however, the mullions and framing members are both substantially rectangular in cross section with only the co-extruded glass seals slightly protruding from the mullions or framing members.

Abstract: A plastic window framing for single or double glazing and single or multiple panes. The frames comprise mullions, glass stops, nailing fins and expansion strips extruded from modified polyolefins that are weather and ultraviolet degradation resistant. The glass stops and expansion strips are co-extruded integral combinations of a hard rigid plastic support and a very flexible sealing portion. Since both the hard rigid portion and the flexible sealing portion of the extrusions are of the same weather and ultraviolet resistant plastic, the plasticizer being the addition for flexibility, the entire framing including the seals can be exposed to the external environment and the mullions can be of relatively simple configuration.The mullions are symmetrical about perpendicular planes longitudinal with the extrusion. The mullions of identical cross-section can be used for vertical and horizontal members of the frame including intermediate mullions between panes.