Abstract: A thermal insulating curtain, especially for use in greenhouses, which comprises a plurality of superimposed uni-directionally arranged tubular members with a common slat-like partition between each two adjacent ones of said tubular members. Each of these tubular members along its two opposite sides has a folding crease to allow collapsing said tubular members to thereby permit collapsing the entire curtain in a manner of a blind or to roll the curtain up in the manner of a shade.

Abstract: A method of and apparatus for producing continuous surface elements, e.g. for so-called air supported shelters, according to which a tubular foil, preferably of plastic material, is wound in several layers between two drums spaced from each other by a distance substantially equaling half the width of the surface element or integral multiples thereof. Immediately prior to winding the tubular foil between the drums, adhesive is applied to the foil so that the outward side of the tubular foil on a preceding winding adheres along a greater or less path to the inward side of the tubular foil in the following winding.