Abstract: An extruded product having a foam core is formed by blending powdered cellulose with a base resin and an oxidizer to yield a first mixture. The first mixture is compressed, heated and extruded to form a pelletized compound which is compressed and heated into a homogeneous extrudable mixture. Moisture is extracted from the powdered cellulose at one or more points during the process to achieve a moisture content of less than about two percent. A protective cladding is coaxially extruded around a core of the extrudable mixture to form an elongated product having a foam core at least partially enclosed by the protective cladding.

Abstract: A horizontal window blind for virtually total blocking the passage of light has a plurality of slats formed from first and second portions parallel to each other. The portions are interconnected by a transition portion, and a flange portion is provided projecting at an obtuse angle from the second portion. At least one opening is made in the flange portion to pass a lifting cord therethrough. The slats are supported by horizontal cords which are attached to a set of vertical cords. A spacing between the horizontal cords is fixed to a distance which permits an outer edge of the first portion to cover the flange portion with the cord passage opening and at least a part of the second portion when the slats are tilted into the vertical position. Because of the shape of the slats and the relative positioning of the slats when tilted into the vertical position, the lifting cord does not find its way between the slats and light is fully blocked by the blind.

Abstract: A window covering comprises spaced collapsible cells secured to a pair of control cords which may be actuated to cause the cells to expand or contract their cross-sectional shape. In their collapsed and partially expanded conditions, the cells are spaced from each other to permit a variable amount of light to pass therebetween, while in their fully expanded condition the cells preferably contact and overlap each other to completely block passage of light therebetween. The cells can be arrayed in either vertical or horizontal orientations. Another embodiment employs flexible vanes in place of collapsible cells.